Quantized Redshift revisited

[parejkoj]

First off, thanks for the reply. I'll try and provide a brief (or maybe not so brief... sorry) lesson in eyeball spectroscopy as part of my reply. To really understand these sources, you have to do a deeper analysis of the spectrum, fitting the various lines and the continuum. But you can make some obvious comparisons between sources much more simply.

Also, a technical question about the board itself: when I click the "quote" button, it only quotes your reply, not my comments that you are replying to. Is there a way to get it to quote the entire conversation, so I don't have to go back and fill it in?

Thanks for the info. I guess I included high redshift to my definition just to distinguish quasars from low redshift galaxies they are claimed to be associated with, and which generally have much lower redshift than 0.1 (there are exceptions too, such as 3C 343 where the "galaxy" has z = 0.34 and the "QSO" has z = 0.75).

Hmm... Unfortunately, the STSci archive is down, so I can't access the archival HST data for that region, and it's out of the SDSS coverage area. But glancing at their radio map, the radio source that they are assigning to the galaxy *could* just be a jet from the quasar. I can't say much without knowing more about the objects. According to the data from Lehnert et al. 1999, the redshift of 3c343 is actually 0.998, and they call it a Seyfert 2 galaxy. Though, that's a fine splitting of hairs, if you ask me.

Possibly. I mean an object that generally looks like point source in our images, such as DSS-images, but might deviate from point source in our better images, such as HST-images. If you mean that by "photometrically", then yes. But I guess you can do some fancy tricks with photometrics, so might it even be possible to detect them as non-point sources even from DSS-images (for example)? Does luminosity profiling belong to "photometrics"?

If you know the point-spread function of your imaging system (telescope+camera), you can do PSF subtraction and masking to recover things that would be otherwise hidden due to the brightness of the point source. Here's an example with 3c273 (the brightest quasar, visible by eye in some amateur telescopes!) from Hubble's now dead ACS:

http://www.spacetelescope.org/images/html/opo0303b.html

By luminosity profiling, do you mean determining the light profile of the source? If so, then yes: the light profile tells you whether a source is a point source, or an extended source. But I don't think the DSS PSF is well enough determined to do PSF subtraction

My definition is about visible appearance, but then again, you can't really discriminate QSOs from all objects with my definition.

That's ok, we needed a common place to start from. It's apparent that you've put some thought into this, but there's a *lot* of data out there. Your definition is pretty close to that of Arp et al., from what I can tell.

What about the spectrum?

Well, it's probably here where most of the real definition lies. I really should learn about spectroscopy...

Absolutely! You can't determine the redshift to something without a spectrum (well, photometric redshifts are getting pretty accurate these days, but they are based off of an understanding of the spectral properties of the sources), and the spectrum of a source provides an immense amount of information, besides just redshift. The spectrum of a star and the spectrum of a quasar look drastically different, because they are produced by wildly different systems. I'll give examples below.

It should probably look non-stellar, but how?

Beats me. For example SDSS have had some trouble with stars masquerading as quasars.

The problem that SDSS has had with "stars masquerading as quasars" is that at certain redshifts, quasars have very similar colors to certain stars. What exact redshifts this happens at depends on what the exact filters are that are used in the initial photometric measurement. In the case of SDSS, "quasars" (point sources with certain colors) are selected for follow up spectroscopy based on their u,g,r,i,z colors, and a variety of interesting and rare types of stars were actually discovered this way! For example, spectra that were similar to white dwarf stars, but different from any white dwarfs previously known.

For example, which of these would you consider a quasar? (remember, the automatic computer-based classification in SDSS isn't always correct).

Yes, I know that. I have spent enough time at SkyServer to have noticed that myself. For example, apparent HII regions in galaxies are quite frequently mentioned as quasars, faint quasars, or stars.

Just making sure. The SDSS spectral classification algorithms are quite good, but there are always the edge cases that cause trouble. Heck, the photometric classification is hard itself, which is why galaxyzoo.org was created. But remember, if the spectral classification is wrong, the redshift could be as well!

I'm going to reorder things a bit in my reply.

http://cas.sdss.org/dr6/en/tools/exp...24241235017792

Quasar candidate. Quasars look exactly like this in SDSS images.

Well, we agree on one thing, anyway! Take a good look at the spectrum (click the spectrum image below SpecObjId=... to get a better view of the spectrum), and keep it open for comparison. Broad emission lines, very blue continuum which does not appear to be black-body emission. This is a pretty classic quasar, by any definition. I'll refer to it as (1) below.

http://cas.sdss.org/dr6/en/tools/exp...98663046938695

Not a quasar. I would say this is quite ordinary galaxy.

Good guess; this confused the heck out of me when I first saw it. It is an example of a class of very rare objects, called BL Lacs. The choice of name is unfortunate (as with so much of astronomical nomenclature), because the first one discovered, BL Lacertae, was initially classified as a variable star, so now they're all named like after it . Like most BL Lacs, this particular source is a whoppingly-powerful X-ray and radio source---notice the FIRST and ROSAT cross-ids at the bottom of the explore page. The optical spectrum is nearly featureless, but highly variable on short time scales. Because there are almost no spectral lines (absorption *or* emission), the redshift is somewhat questionable.

BL Lacs are currently thought to be systems where we are looking directly into the "mouth of the beast," if you will. Direct line of sight into the central black hole with the relativistic jet pointed at us. There are less than a thousand known BL Lacs: a hundred or so with SDSS spectroscopy. So, according to the standard view, this is very similar to a quasar, but viewed at a particular angle. It has many of the same properties of other quasars: bright in X-ray and radio, high variability, and a bright point source in the core of a galaxy.

There are three blue objects that I would consider quasar candidates, they are at 6, 9, and 11 o'clock from your object.

Oh, good... I was just chiding myself for not including one of the quasar-like stars on my list, but you found one for me! In the Finding Chart and Navigation pages (I prefer the Navigation, as you can go directly from it to the Explore page for a selected object), you can click the "objects with spectra" box on the left to get red boxes around sources with SDSS spectroscopy. One of your three quasar candidates is actually a blue star. Possibly a white dwarf, though I'm no star expert (if any are reading this, please clarify!):

http://cas.sdss.org/dr6/en/tools/exp...98663046938710

Blue, pure-blackbody continuum, some absorption, no emission? Star. Compare it with (1).

http://cas.sdss.org/dr6/en/tools/exp...97863112294442

Perhaps could be a quasar, but quasar wouldn't first come to my mind when looking at this object.

http://cas.sdss.org/dr6/en/tools/exp...97863112294443

This is slightly worse quasar candidate than the last one in my opinion. I think it has to do with the brightness of the nucleus.

I'll deal with these two together, as they are interacting companions (check the finding chart if you don't believe me; the redshifts are the same). The first is a galaxy hosting a quasar (notice the broad emission lines and spectrum that gets stronger towards blue?), while the second is a star-forming galaxy (notice the strong narrow emission in H-alpha and [SII], and black-body continuum that increases towards ~450 nm, and then falls off?). Compare the two spectra with (1): notice how similar the first is, while the second looks very different.

Also, the first is more than an order of magnitude brighter than the second, in this pair. Something is definitely going on in the nucleus of the first one (which is also a radio and X-ray source).

Keep these spectra in mind as we move on. I'm going to flip the order of the next two...

http://cas.sdss.org/dr6/en/tools/exp...24232638464033

Also a spiral galaxy.

There is a spiral galaxy there, but compare the spectrum with the two above; which does it look more like, the star-forming galaxy, or the quasar? Also, compare it with (1). If you use Firefox, Opera, Safari, or another browser with tabs, open each spectrum in a separate tab and flip between them quickly: (1) looks like a redshifted version of this one.

http://cas.sdss.org/dr6/en/tools/exp...35348562624561

A spiral galaxy, not a quasar.

I'd just call it pretty.

It is a spiral galaxy, but the nuclear spectrum is quite odd: notice how broad the H-alpha emission line is? That's a line-broadening of several thousand kilometers per second! The continuum is kinda funny as well. Definitely a disturbed system, and the galaxy that probably caused the mess is visible just north-west in the finding chart image. There aren't many ways to get an emission line that broad; the standard view is the accretion disk of the central black hole.

http://cas.sdss.org/dr6/en/tools/exp...25550136786984

I don't know what I would say to this if I wouldn't know these are SDSS images (I think I would accept this as a quasar candidate). So far the quasars I have looked at in SDSS images have been blue (to my recollection). I think this is a star in our galaxy. (And the redshift reveals that it most likely isn't a quasar.)

This one is neat, one of my favorite objects in SDSS, and I don't even study stars! It is a double star system, but the resolution of SDSS is not quite good enough to separate them. The spectrum looks odd, but that's because we are seeing the spectra of both stars (one cool and red, the other hot and blue) overlaid on top of each other. What might appear to be emission lines are actually broad absorption in the red star. I think it is a red giant and a white dwarf, though I don't remember what the experts' discussion of it decided.

http://cas.sdss.org/dr6/en/tools/exp...34691424895079

Could be a quasar, but to me it is more likely to be a HII region.

Good call! I'd actually say this is more likely to be a planetary nebula in the blue, star-forming galaxy, rather like the owl nebula (M27) in our own galaxy. Compare it with this spectrum that was taken of a knot in the owl. Strong [OII], very weak H-alpha and H-beta, generally flat continuum. Also compare it to the not-quasar star-forming galaxy in interacting pair above.

http://cas.sdss.org/dr6/en/tools/exp...22983903985955

Not a quasar, a galaxy.

The redshift is high: greater than 2, and it has a strange, very blue spectrum. None of the lines of the other objects above would even be in the SDSS spectral band anymore, due to the high redshift! The strange spectral shape may be due to iron emission (not fit by the SDSS spectroscopic pipeline), or very hot gas (at that redshift, the "peak" around 500 nm corresponds to ~150 nm, which is far-UV!). I might call it a quasar, but that's because the spectrum doesn't look anything like a typical star or galaxy.

I can't do that currently, but I'm quite sure that Arp for example can (as well as anyone else). But here we approach a question I have though about many times; is there a difference between the objects Arp says are quasars associated with quasars and the objects generally classified as quasars. In other words, is there two classes of quasars in this sense? Are Arp's "quasars" special class of objects?

Don't assume that anyone else can identify a quasar just by looking at it! Some of them are pretty odd, as we saw above. And whether something is a Seyfert 1, Seyfert 1.5, Seyfert 1.8, Seyfert 2, quasar, blazar, BL Lac, LoBAL or LINER depends on exactly where you make the dividing lines for a given set of definitions. The standard model has them all as more-or-less different views of similar objects, but that doesn't mean that astronomers won't happily make a dozen observational classifcations.

Personally? I don't really know if Arp has an actual working definition of the term quasar, beyond what you said above about looking like a star but having high redshift. From what I've seen of Arp's work, his quasars are simply those objects that he has selected from other catalogs (SDSS, 2df, or even NED) for his own analysis, thus they are whatever the given catalog classified as a quasar.

[Nereid]

Just to add one tiny thing to this excellent post!

[snip]

But I don't think the DSS PSF is well enough determined to do PSF subtraction

[snip]

IIRC, you can, in fact, determine the PSF quite well ... on an individual plate (or region of a plate), but there is considerable variation between plates (certainly epochs!), and (possibly, I just don't remember) poorly constrained variation between different parts of the same plate.

The digitisation of the original plates was done quite well (the plate machines are - were? I don't know if they're still in use - good examples of precision engineering), but the project's objectives did not include producing a product from which consistent, accurate, well-defined PSFs could be extracted*.

If anyone's interested, since the DSS data is in the public domain, you could have a go at determining the PSFs for yourself ... there are certainly plenty of 'unresolved, point sources' (i.e. stars) all over most plates ... which you can find from one or more of the many online databases.

*At least I don't think the objectives included this; I could well be wrong though.

[Ari Jokimaki]

First off, thanks for the reply. I'll try and provide a brief (or maybe not so brief... sorry) lesson in eyeball spectroscopy as part of my reply. To really understand these sources, you have to do a deeper analysis of the spectrum, fitting the various lines and the continuum. But you can make some obvious comparisons between sources much more simply.

Thanks for the lesson. I ensure you that it's appreciated.

Also, a technical question about the board itself: when I click the "quote" button, it only quotes your reply, not my comments that you are replying to. Is there a way to get it to quote the entire conversation, so I don't have to go back and fill it in?

I don't think there's a way around that, other than constructing the quotes yourself.

Hmm... Unfortunately, the STSci archive is down, so I can't access the archival HST data for that region, and it's out of the SDSS coverage area. But glancing at their radio map, the radio source that they are assigning to the galaxy *could* just be a jet from the quasar. I can't say much without knowing more about the objects. According to the data from Lehnert et al. 1999, the redshift of 3c343 is actually 0.998, and they call it a Seyfert 2 galaxy. Though, that's a fine splitting of hairs, if you ask me.

Sorry, I was little sloppy there. I looked at NED and noticed they give same redshift you are citing, but they refer to a paper from 1985. So then I got to thinking that perhaps there's a mistake in the abstract of the paper I cited, because that's where I copied the numbers. I opened the abstract page of that paper again and then it hit me, they are talking about 3C 343.1 not 3C 343. A small but significant difference, sorry about that. (NED only gives one redshift, the 0.75, for 3C 343.1.)

By luminosity profiling, do you mean determining the light profile of the source?

Yes.

But I don't think the DSS PSF is well enough determined to do PSF subtraction

Just so that it is clear: without PSF subtraction, the luminosity profile of the point-like source is useless?

well, photometric redshifts are getting pretty accurate these days, but they are based off of an understanding of the spectral properties of the sources

From what I've seen in SkyServer, they are still quite far from truth. I think currently I wouldn't trust studies using photometric redshifts to be more than preliminary results, I think they should be confirmed with real redshifts. (Incidentally, the Scranton et al. study mentioned in this thread uses photometric redshifts...)

But remember, if the spectral classification is wrong, the redshift could be as well!

This feels little strange to me. If there's many spectral lines in object's spectrum, isn't the redshift determination then quite solid (excluding some anomalous cases)? I mean it would be quite a coincidence to have all lines showing the same wrong redshift, wouldn't it?

Good guess; this confused the heck out of me when I first saw it.

You're not the only one, NED has two entries for it, one as a galaxy, and one as a QSO (with BLLAC as description). (BL LACs are something Arp considers to be a later stage to quasars in quasar to galaxy evolution cycle.)

BL Lacs are currently thought to be systems where we are looking directly into the "mouth of the beast," if you will. Direct line of sight into the central black hole with the relativistic jet pointed at us. There are less than a thousand known BL Lacs: a hundred or so with SDSS spectroscopy. So, according to the standard view, this is very similar to a quasar, but viewed at a particular angle. It has many of the same properties of other quasars: bright in X-ray and radio, high variability, and a bright point source in the core of a galaxy.

So the redshift of BL LACs don't tell the distance to the objects, because there is quite substantial blueshift due to the velocity of the material in the jet towards us? (I tried to peek at the redshift distribution of BL LACs but apparently you can't query just for BL LACs in NED.)

Oh, good... I was just chiding myself for not including one of the quasar-like stars on my list, but you found one for me! In the Finding Chart and Navigation pages (I prefer the Navigation, as you can go directly from it to the Explore page for a selected object), you can click the "objects with spectra" box on the left to get red boxes around sources with SDSS spectroscopy. One of your three quasar candidates is actually a blue star. Possibly a white dwarf, though I'm no star expert (if any are reading this, please clarify!):

And in "PrimTarget" it says "TARGET_QSO_CAP"...

I'll deal with these two together, as they are interacting companions (check the finding chart if you don't believe me; the redshifts are the same).

As I'm willing to give Arp a benefit of doubt, I don't even need the redshifts to be the same to believe that two objects are interacting. However, due to that same reason, I also don't believe that two objects are interacting just because their redshift are the same.

The first is a galaxy hosting a quasar (notice the broad emission lines and spectrum that gets stronger towards blue?)

Well, so far all objects seem to have spectrum that gets stronger towards blue, especially the one you called possibly a white dwarf. So, I guess that feature doesn't distinguish between quasars and stars then?

Compare the two spectra with (1): notice how similar the first is, while the second looks very different.

That probably requires some experience, because besides the fall off I don't notice much difference in lines, sure there's some difference like the couple very narrow lines in galaxy's spectrum, but the galaxy has also a quite broad line at 7000 Å. I don't think I could distinguish these two from each other (in the sense that are they a quasar or a galaxy) without the fall off.

There is a spiral galaxy there, but compare the spectrum with the two above; which does it look more like, the star-forming galaxy, or the quasar? Also, compare it with (1). If you use Firefox, Opera, Safari, or another browser with tabs, open each spectrum in a separate tab and flip between them quickly: (1) looks like a redshifted version of this one.

Yes, but this one doesn't have stronger spectrum towards blue.

It is a double star system, but the resolution of SDSS is not quite good enough to separate them. The spectrum looks odd, but that's because we are seeing the spectra of both stars (one cool and red, the other hot and blue) overlaid on top of each other.

I can see that. Is this kind of spectrum happening only in double objects, or are there objects that produce similar spectrum by themselves?

Good call! I'd actually say this is more likely to be a planetary nebula in the blue, star-forming galaxy, rather like the owl nebula (M27) in our own galaxy. Compare it with this spectrum that was taken of a knot in the owl. Strong [OII], very weak H-alpha and H-beta, generally flat continuum. Also compare it to the not-quasar star-forming galaxy in interacting pair above.

Curiously, it says "z = 0.0052 +/- 0.0012 (0.40), QSO" in the image of the spectrum. I wonder if that's an automatically created text, or did someone write it there?

The redshift is high: greater than 2, and it has a strange, very blue spectrum. None of the lines of the other objects above would even be in the SDSS spectral band anymore, due to the high redshift! The strange spectral shape may be due to iron emission (not fit by the SDSS spectroscopic pipeline), or very hot gas (at that redshift, the "peak" around 500 nm corresponds to ~150 nm, which is far-UV!). I might call it a quasar, but that's because the spectrum doesn't look anything like a typical star or galaxy.

I'm not sure I understand why. This object has couple of quite narrow looking emission lines, and a fall off toward blue.

Don't assume that anyone else can identify a quasar just by looking at it!

I don't, I just meant that Arp probably can do it as well as anyone else, I didn't mean I think he (or anyone else) can do it perfectly.

Personally? I don't really know if Arp has an actual working definition of the term quasar, beyond what you said above about looking like a star but having high redshift. From what I've seen of Arp's work, his quasars are simply those objects that he has selected from other catalogs (SDSS, 2df, or even NED) for his own analysis, thus they are whatever the given catalog classified as a quasar.

I don't remember seeing Arp address specifically his definition of quasar, but I think that browse through some of his papers would reveal at least some details more. I might check for some later if I have time.

For other parts of your post I didn't respond: thanks for the info!

[Ari Jokimaki]

I don't remember seeing Arp address specifically his definition of quasar, but I think that browse through some of his papers would reveal at least some details more. I might check for some later if I have time.

Well, it seems that Arp was prepared to this discussion, in his latest paper he suggests a new definition for quasar:

A quasar is a compact (high surface brightness) object which shows appreciable non thermal radiation.

So there.

[Nereid]

How many of the ~600 "obscured AGN" in the Chandra Bootes field* are quasars (or QSOs), in the rtomes classification scheme?

*The arXiv preprint: A rich bounty of AGN in the 9 square degree Bootes survey: high-z obscured AGN and large-scale structure

Bumping this question ... it's now a week old.

rtomes, do you require clarification of the question? If so, please just ask.

If the answer is "I don't know" (or similar), please say so.

If you need more time to answer the question, please say so, and give an indication of when you expect to be answering it.

[parejkoj]

First things first: I just noticed that you are in Finland. That would explain why you are always posting so "late at night."

Thanks for the lesson. I ensure you that it's appreciated.

Just trying to be useful. It helps my understanding to try and explain it.

But before we go any further, I should ask how much you know about spectroscopy to begin with? Do you know what a thermal (blackbody) spectrum is, vs., say, a synchrotron (power law) spectrum? What causes absorption vs. emission lines? Things that can broaden emission lines?

Understanding those is necessary for really understanding what is going on with the spectra that I listed, and why they are different.

Just so that it is clear: without PSF subtraction, the luminosity profile of the point-like source is useless?

No, I think I wasn't clear. The light-profile of a source can tell you whether it is strictly a point source (that is, smaller than the resolution of the camera), and determining the light profile of a known point-source (say, a star) is the first step toward subtracting the PSF; the PSF of the camera is what an ideal point source with infinite signal to noise should look like.

If you have a well determined PSF, you can use the light profile to determine the size of things that are just beyond the PSF, as Mike Brown et al. did to determine the size of Eris (middle of the How Big is it? section, about HST). They got a very good constraint on Hubble's PSF, and used that knowledge to determine the angular size of Eris. They didn't subtract the PSF, just determined what it was for comparison.

I think currently I wouldn't trust studies using photometric redshifts to be more than preliminary results, I think they should be confirmed with real redshifts.

They are actually probably better than you think: one of the two photo-z methods (the PhotoZ2 table in Sky Server) is described at this website. The absolute error plots (done on the validation set, which have spectra) are given for a few different brightness bins. Basically, for galaxies with r-band magnitude brighter than 20, the photo-z estimator has quite small errors.

I don't think Sky Server has photo-z's for quasar candidates listed yet (at least, computed based on knowledge of quasar spectra), but they are also quite accurate. I can't find a good paper about it online (the only ones are based on the SDSS early data release, which was years ago, and the methods are much better now), but there are some Bayesian statistical techniques that work quite well, with small scatter.

But remember, if the spectral classification is wrong, the redshift could be as well!

If there's many spectral lines in object's spectrum, isn't the redshift determination then quite solid (excluding some anomalous cases)? I mean it would be quite a coincidence to have all lines showing the same wrong redshift, wouldn't it?

That depends. There are certain combinations of spectral lines that could potentially confuse an automatic classification system. Again, we're talking about the corner cases here, most of the time everything is fine. As you say, if there are many spectral lines, then there's generally nothing to worry about. But an invalid redshift can result from having few and/or weak lines. If they are weak (low signal-to-noise), or if the spectrum is otherwise odd, the spectral classifier can get it wrong (mis-interpreting lines, thinking that noise features are lines), and thus the redshift can be wrong.

You're not the only one, NED has two entries for it, one as a galaxy, and one as a QSO (with BLLAC as description). (BL LACs are something Arp considers to be a later stage to quasars in quasar to galaxy evolution cycle.)

Well, as you can see, there is definitely a galaxy there. There is also a very odd nuclear source. The spectrum of the nucleus in this case might include some of the galaxy's spectrum shining through, but I'm not really sure. Remember, NED just contains a list of objects that were described in a paper somewhere, it is not a telescopic survey itself. This object was probably first discovered as a galaxy (in DSS plates, I'd bet), and, from the NED reference list, the BL Lac was discovered in 1989 by Remillard et al. after follow-up from X-ray observations.

I'm rather curious what Arp et al. have to say about the immense X-ray and radio emission from these sources. We're talking outrageous fluxes here (note I said fluxes, not luminosities!). The standard model, where we are looking down the jet from the black hole, explains the features of these systems quite well. Some of the details are still a bit tricky...

So the redshift of BL LACs don't tell the distance to the objects, because there is quite substantial blueshift due to the velocity of the material in the jet towards us?

That depends. Jet-induced blueshift could be one reason why the redshift might be wrong. Another reason is that there are very few lines in the spectrum, so it is hard to get a redshift in the first place (see my discussion above). In think the redshift of this particular system is ok, because there are enough absorption lines (possibly from the host galaxy) to get a good redshift determination. But for many BL Lacs, this is not the case, because the nuclear source is so much brighter than the host galaxy itself, and the optical spectrum of a BL Lac is nearly featureless.

http://cas.sdss.org/dr6/en/tools/exp...98663046938710
Blue, pure-blackbody continuum, some absorption, no emission? Star.

And in "PrimTarget" it says "TARGET_QSO_CAP"...

Yup! That means it was targeted for spectroscopy because the pipeline thought it might be a quasar (though you may have already figured that out). The spectroscopy targeting flags are listed in this table and details on the spectroscopic target selection algorithm are available, if you'd like to peruse them. They aren't easy to digest, though.

As I'm willing to give Arp a benefit of doubt, I don't even need the redshifts to be the same to believe that two objects are interacting. However, due to that same reason, I also don't believe that two objects are interacting just because their redshift are the same.

Ok, here's a few questions for you (being the present potential supporter of Arp and company), though I'm sure they've all been asked before: how do you propose determining whether two objects are at the same distance, if you don't think their redshifts are relevant quantities for distance determination? I understand that Arp et al. claim that the redshifts of quasars are actually due to some, unknown, undetermined and undescribed physical process, but then how do you determine the distances to things? Remember, there are over a million objects in SDSS DR6 with spectroscopy, including more than a hundred thousand quasars, ~800,000 galaxies and ~300,000 stars... And if the redshifts to galaxies are trustworthy, why not quasars?

And what about galaxies where some other measure is used to determine the distance, and it agrees with the redshift (to a fairly good degree, if not exactly)? What about other measures of distance, say estimates based on normalized galaxy sizes, or rough luminosity distances? Those aren't precise, but they qualitatively match the theory that redshift is a measure of distance: further things are smaller and dimmer.

The first is a galaxy hosting a quasar (notice the broad emission lines and spectrum that gets stronger towards blue?)

Well, so far all objects seem to have spectrum that gets stronger towards blue, especially the one you called possibly a white dwarf. So, I guess that feature doesn't distinguish between quasars and stars then?

It does distinguish, but you have to understand the actual spectral shape. That's why I asked about Blackbody vs. power-law spectra above. Stars are generally nearly perfect blackbodies, with some absorption lines due to the photosphere. Quasars generally have a power-law spectrum (flux proportional to frequency^alpha), which you can see in the rate at which the flux increases toward blue wavelengths.

A good place to start about stellar spectra might be the Stellar Spectral Types Project from the Advanced Projects page (the one from Basic Projects is a simpler subset of that one, but the Advanced one has a lot more description).

Compare the two spectra with (1): notice how similar the first is, while the second looks very different.

That probably requires some experience, because besides the fall off I don't notice much difference in lines, sure there's some difference like the couple very narrow lines in galaxy's spectrum, but the galaxy has also a quite broad line at 7000 Å. I don't think I could distinguish these two from each other (in the sense that are they a quasar or a galaxy) without the fall off.

And now we've run into the problem with using the quick-look spectra in SDSS! They are not designed to do science from, just for a quick glance.

In the star-forming galaxy's spectrum, the "quite broad line at ~7000Å" is, infact, the Hα, [NII] blended doublet. You can kind of make out the doublet in the image, but it is much more obvious in the complete FITS spectrum. The quasar spectrum, on the other hand, has little sign of the [NII] line, and very broad wings (look at the base of that line, as well as Hβ, in particular). This particular quasar has relatively narrow lines, compared to some!

If you want to examine the FITS spectra in detail, you can use specview a free Java application from the Space Telescope Science Institute.

http://cas.sdss.org/dr6/en/tools/exp...24232638464033

Yes, but this one doesn't have stronger spectrum towards blue.

Perhaps, but the broad lines are a give-away. Again, just how broad the lines are compared with the star-forming galaxy above is more apparent in the full FITS spectrum. Also, the continuum does not fall off towards short wavelengths, as happens with galaxy spectra. Again, flip back and forth between it and the one we both agree is a quasar (1): the similarities are striking.

I can see that. Is this kind of spectrum happening only in double objects, or are there objects that produce similar spectrum by themselves?

I'm not sure I understand the question, but I'll try and answer what I think you were asking. A spectrum like this is the sum (linear combination, to be exact) of two very different blackbody spectra. It is hard to have two wildly different blackbodies together on the same object: they will thermodynamically equilibrate rather quickly (what's the temperature of things on the surface of the Earth? All roughly the same, and Earth isn't even a blackbody!)

However, what is a galaxy? Lots and lots of stars (and gas and dust, as well). So a galaxy's spectrum (ignoring the gas and dust, for now) should be the sum of a lot of blackbodies of different temperatures. The exact shape of a galaxy's spectrum depends on the stars in it: if they are old stars, it will be redder (cooler), if young stars, bluer (hotter). The gas and dust complicate things because dust preferentially absorbs blue light, and gas can produce absorption or emission lines, depending on how dense it is. So a starforming spiral galaxy might have a blue spectrum like the star earlier, with emission lines from hot gas and some dust absorption, while an old elliptical galaxy in a cluster might show just old, red stars and no signs of gas or dust, because it has all either turned into stars or been kicked out due to interactions.

Curiously, it says "z = 0.0052 +/- 0.0012 (0.40), QSO" in the image of the spectrum. I wonder if that's an automatically created text, or did someone write it there?

You'll find that note on all the SDSS quick-look spectra (including stars). Almost everything data-related in SDSS is automatically generated. There are just too many sources for any kind of manual intervention, in general. The few cases where a person was in the loop are usually mentioned (e.g. the MANUAL_MAPPED specZWarning flag).

In this particular case, the spectroscopic pipeline found that the spectrum was best fit by a quasar template--hence the QSO identifier. But it doesn't have PNe templates to draw on when fitting, so this type of object would cause confusion. The redshift looks to be correct, though, since there are plenty of lines and it identified them correctly (again, compare with the owl nebula).

http://cas.sdss.org/dr6/en/tools/exp...22983903985955
I might call it a quasar, but that's because the spectrum doesn't look anything like a typical star or galaxy.

I'm not sure I understand why. This object has couple of quite narrow looking emission lines, and a fall off toward blue.

I may have to rescind that statement! Looks like this one has a supernova in the spectrum, as described in Madgwick et al. 2003! It may well be a galaxy spectrum (though at very high redshift) with the supernova providing some of the stranger features. Looks like I got caught out on that one... And the SN probably isn't visible in the image at all, because the spectroscopy happened a year or more later.

As I said, I'm still learning!

[parejkoj]

And while I was preparing the previous reply, which just barely made the maximum character cut (sorry it took a while: I've been busy with a paper), you posted this:

Well, it seems that Arp was prepared to this discussion, in his latest paper he suggests a new definition for quasar:

A quasar is a compact (high surface brightness) object which shows appreciable non thermal radiation.

So there.

That definition is pretty close to the standard definition, depending on what exactly is meant by "appreciable." After all, star-forming galaxies and planetary nebulae can have "appreciable" narrow emission lines (which are non thermal) due to hot gas, as I discussed above. And a supernova is an "appreciable" non-thermal point source, like the one that confused me (though it's only around for a short while)...

[rtomes]

Bumping this question ... it's now a week old.

rtomes, do you require clarification of the question? If so, please just ask.

If the answer is "I don't know" (or similar), please say so.

If you need more time to answer the question, please say so, and give an indication of when you expect to be answering it.

I have not been following the thread because it has not been about quantized redshifts but about quasar interpretation. I am not en expert on quasar classification and do not intend to be so, so I don't know why anyone would ask about "my quasar classification scheme".

I do have views about periodicity in redshifts. I can easily show that redshift periodicity does not mean we are at a special place in the Universe. I think that I can also show that the analysis that finds no periodicity is flawed in terms of what Arp and Narlikar claim. If anyone wants to discuss those topics then I would be happy to.

[Thanatos]

I thought those topics had already been discussed. Please clarify your objections.

[parejkoj]

I have not been following the thread because it has not been about quantized redshifts but about quasar interpretation. I am not en expert on quasar classification and do not intend to be so, so I don't know why anyone would ask about "my quasar classification scheme".

I do have views about periodicity in redshifts. I can easily show that redshift periodicity does not mean we are at a special place in the Universe. I think that I can also show that the analysis that finds no periodicity is flawed in terms of what Arp and Narlikar claim. If anyone wants to discuss those topics then I would be happy to.

And therein lies the rub. If you don't have a consistent classification scheme for quasars, how can you make any claims about redshift quantization? Depending on what objects you allow into your definition, you may begin to find a "quantization" simply due to the way you've defined the sample.

That is the whole reason the folks behind SDSS have worked so hard to generate uniform samples of objects. But I can tell you right now, just selecting everything marked "QSO" from SDSS will not provide a uniform sample (see my discussion above with Ari). Look again at my comments earlier in this thread about this, and make sure you understand the Richards et al. 2007 paper...

[Ari Jokimaki]

First things first: I just noticed that you are in Finland. That would explain why you are always posting so "late at night."

Or, early in the morning as I see it (although for this post it's evening here).

...how much you know about spectroscopy to begin with?

Not much more than you have told me in this thread.

Do you know what a thermal (blackbody) spectrum is, vs., say, a synchrotron (power law) spectrum?

I have a some kind of idea of thermal spectrum, but I have no idea of synchrotron spectrum.

What causes absorption vs. emission lines?

Emission lines represent the characteristic spectrum of the source emitting the light. Emission lines are places in spectrum where the amplitude gets (noticeably) stronger, i.e. they are shown as peaks in the diagram of the spectrum.

Absorption lines appear when some of the light is absorbed during it's journey by some intervening matter. Absorption lines are places in spectrum where the amplitude gets (noticeably) weaker, i.e. they are shown as valleys in the diagram of the spectrum.

Things that can broaden emission lines?

At least scattering. I'm not sure if very strong gravitational field, or time dilation effects near black holes could cause broadening, or do they cause only shifting?

I'm rather curious what Arp et al. have to say about the immense X-ray and radio emission from these sources. We're talking outrageous fluxes here (note I said fluxes, not luminosities!).

A browse through Arp's papers might help here. I know I have seen him mentioning/talking about BL LACs in quite many papers, but right now I don't know which one would be the best for your question.

how do you propose determining whether two objects are at the same distance, if you don't think their redshifts are relevant quantities for distance determination?

You just have to use other methods than redshifts. It is very difficult, though.

I understand that Arp et al. claim that the redshifts of quasars are actually due to some, unknown, undetermined and undescribed physical process,

Well, no, the process has been proposed. Redshift of all objects are due to their age, or rather due to their mass which increases when object ages. This is called Variable mass hypothesis, and it is described in Narlikar & Arp (1993).

...but then how do you determine the distances to things?

You use other distance indicators. (If Arp is correct, then redshift as such cannot be trusted as a distance indicator, but Arp (and I) does think that redshift distance relation holds for low redshift galaxies.)

Remember, there are over a million objects in SDSS DR6 with spectroscopy, including more than a hundred thousand quasars, ~800,000 galaxies and ~300,000 stars...

I don't think I understand your point here.

And if the redshifts to galaxies are trustworthy, why not quasars?

Redshifts of galaxies (as distance indicators) are not trustworthy. While there generally is a redshift distance relation for low redshift galaxies, you can't look at redshift of a galaxy and conclude the distance to that galaxy based on redshift alone. But you can't do that very well in the standard view either, there's always peculiar velocities introducing errors to galaxy's redshift distance. With Arp's model, there's just one more redshift component (the intrinsic) more to think about. We also have to remember that the discordant redshift evidence is not only about quasars, most convincing evidence is about galaxies, the NGC 7603 being a good example of that.

In Arp's model redshift is always related to the age of objects. Newly created matter has high redshift which then decreases while the object ages. Quasars are considered very new objects so they have very high redshifts. When time passes they are expected to evolve to galaxies, and their redshift to decrease rapidly towards the low redshifts of their parent galaxies.

And what about galaxies where some other measure is used to determine the distance, and it agrees with the redshift (to a fairly good degree, if not exactly)? What about other measures of distance, say estimates based on normalized galaxy sizes, or rough luminosity distances? Those aren't precise, but they qualitatively match the theory that redshift is a measure of distance: further things are smaller and dimmer.

To my knowledge, Arp generally agrees with distance determination methods except redshift.

I'm not sure I understand the question, but I'll try and answer what I think you were asking.

Your answer answers my question. I tried to ask if that kind of spectrum, that grows stronger in both ends, is always a sign for two objects contributing to the spectrum.

Thank you once again for the good information you have given me!

[rtomes]

I thought those topics had already been discussed. Please clarify your objections.

Hi Thanatos, I repeat some of this below.

And therein lies the rub. If you don't have a consistent classification scheme for quasars, how can you make any claims about redshift quantization? Depending on what objects you allow into your definition, you may begin to find a "quantization" simply due to the way you've defined the sample.

Parejkoj I have made it clear that I am not in the defining what is a quasar business. I understand that consistency is needed and rely on others to do that. However I dispute that quantization will appear based on a definition - it might based on "careful selection".

Well forget quasars for a while. Galaxies have been found to have redshift periodicity at many scales from local to the largest scales.

I posted a graph of a published survey of a pencil beam in two opposite directions that shows a very clear series of peaks in redshift at intervals of delta z of 0.043 (stated as 128 Mpc). That paper received a published reply that said that the statistics did not allow for the fact that galaxies are clustered. The correct statistics were determined and it was found to still be significant. However the paper is treated as if it has been discredited.

Furthermore, I have shown that the periodicity of these structures was 588,000,000 light years (based on the latest Hubble constant at the time that I did the calculation) which is consistent with a reported 586,000,000 year geological cycle (that figure by S Afanasiev, western geologists simply stated in "Megacycles" edited by G Williams in a conference report ~600,000,000 years, but they list a series of period halvings that would indicate about 590,000,000 years). It makes a lot of sense if, as has been suggested by astronomers, these wavelike structures are in fact waves. If they are then we would expect to possibly find evidence of these periods in the geological record.

This match not only confirms the periodicity but allows a more accurate determination of the Hubble constant. It also allows the hypothesis to be tested in greater depth because a number of other shorter geological cycles are reported and some of these can also be seen. Others could be tested for with the data available. I have tried to get the data without success. Help in doing this would be appreciated. I thought that all published papers data was supposed to be publicly available, is that not so?

In 1994 when I first put my Harmonics theory predicted redshift periodicities in the usenet groups, I received an email reply from an astronomer giving me references to Tifft's papers from the 1970s. He had reported finding a series of periodicities, and his list was almost identical to the part of my list at the smaller scale end (<100 km/s). When I did a statistical test on this it was about p<10^-18. You cannot reasonably get such a result if Tifft's results are caused by any sort of errors or if the Harmonics theory figures are not meaningful predictions.

Regards
Ray

[Nereid]

Hi Thanatos, I repeat some of this below.


Parejkoj I have made it clear that I am not in the defining what is a quasar business. I understand that consistency is needed and rely on others to do that.

rtomes, may I ask for an unambiguous clarification then?

In (your) post#2 in this thread, you seem to make a number of quite strong, ATM, claims concerning quasars.

Which, if any, of these do you intend to defend?

For avoidance of doubt, if you do not intend to answer direct, pertinent questions about the ATM claims you have presented, concerning quasars, in this thread, please say so (and consideration will be made to closing this thread forthwith).

However I dispute that quantization will appear based on a definition - it might based on "careful selection".

Are you prepared to answer direct, pertinent questions concerning this assertion?

Well forget quasars for a while. Galaxies have been found to have redshift periodicity at many scales from local to the largest scales.

Are you prepared to answer direct, pertinent questions concerning this assertion?

I posted a graph of a published survey of a pencil beam in two opposite directions that shows a very clear series of peaks in redshift at intervals of delta z of 0.043 (stated as 128 Mpc).

Are you prepared to answer direct, pertinent questions concerning these claims?

That paper received a published reply that said that the statistics did not allow for the fact that galaxies are clustered. The correct statistics were determined and it was found to still be significant. However the paper is treated as if it has been discredited.

Please provide references to the relevant published papers.

Furthermore, I have shown that the periodicity of these structures was 588,000,000 light years (based on the latest Hubble constant at the time that I did the calculation) which is consistent with a reported 586,000,000 year geological cycle (that figure by S Afanasiev, western geologists simply stated in "Megacycles" edited by G Williams in a conference report ~600,000,000 years, but they list a series of period halvings that would indicate about 590,000,000 years).

What are the estimated random and systematic uncertainties in all these values?

What methods were used to produce these estimated uncertainties?

In what sense are two of these numbers "consistent"?

It makes a lot of sense if, as has been suggested by astronomers, these wavelike structures are in fact waves. If they are then we would expect to possibly find evidence of these periods in the geological record.

Which astronomers so suggested (references please)?

What tests have you performed to test the extent to which these structures are "wavelike"?

How consistent are the reported 1990 results with those from 2dF and SDSS?

This match not only confirms the periodicity but allows a more accurate determination of the Hubble constant.

How can "the Hubble constant" be more accurately determined?

It also allows the hypothesis to be tested in greater depth because a number of other shorter geological cycles are reported and some of these can also be seen. Others could be tested for with the data available. I have tried to get the data without success. Help in doing this would be appreciated. I thought that all published papers data was supposed to be publicly available, is that not so?

In 1994 when I first put my Harmonics theory predicted redshift periodicities in the usenet groups, I received an email reply from an astronomer giving me references to Tifft's papers from the 1970s. He had reported finding a series of periodicities, and his list was almost identical to the part of my list at the smaller scale end (<100 km/s). When I did a statistical test on this it was about p<10^-18. You cannot reasonably get such a result if Tifft's results are caused by any sort of errors or if the Harmonics theory figures are not meaningful predictions.

Which "Tifft[] papers from the 1970s"?

What "statistical test" did you do? How did these tests incorporate the stated random and systematic errors in the galaxy redshift data?

Where did you publish the results of your work?

[rtomes]

rtomes, may I ask for an unambiguous clarification then? ...

I am happy to answer questions.

The values for the redshift periodicities predicted by the harmonics theory for galaxies are exact. There are no uncertainties. They derive from the formula (1+z)^h=2 where h is a strong harmonic number as shown in the various graphics that I have presented. I agree with Arp that the periodicities are uniform in delta log(1+z), or equivalently, from the above derived z values you have a tendency to (1+z)^n with any integer n for the observed 1+z. An example to make this clear. The strong harmonic of h=2880 gives (1+z)^2880=2 so z=.0002407 which gives zc of 72.15 km/s. The observed values for 1+z should be powers of 1.0002407 namely z of .0002407, .0004815, .0007223, .0009632 etc.

The predicted periodicities are shown in this graphic:


The Tifft periodicities are reported in several papers in the late 1970s, a main one being Astrophysical Journal Vol 221 Pg 756-775
1978 May 1. I am sorry I do not have that information to hand for the others. In the first of these papers he reports a 72.135 km/s periodicity with a stated uncertainty of the order of .01-.02, but in subsequent papers he comes up with 72.45 with an unstated uncertainty. In one paper he shows how good the fit is to the data, and the biggest peak is indeed at 72.45 km/s with many additional peaks gradually getting smaller at intervals of +/-0.30 multiples from the main peak.

It should be understood what this type of distribution means (Tifft does not say this, I do). When you have clusters at regular spacings and galaxies at regular spacings (in red shift) then you will get such a pattern because the space between the clusters is so great that if you count one more or one less or even several more or less steps between the clusters you can still get a good fit. If this is not clear I can try and draw you a graphic.

Anyway, the pattern of 72.45 km/s with 0.30 km/s spacings means that there is an extra periodicity that is 72.45/0.30 times as big as the observed one and this is the cluster spacing. That is, the clusters are 240 times as far apart as the galaxies. Note that in the Harmonics theory, 72 km/s is the 2880 harmonic and so the clusters accurately correspond to the 12 harmonic or the .05776 in the graphic). These are two of the biggest five peaks in the graph.

I explain all this to show that Tifft's 72.45 is consistent with the 72.153 prediction even though he is measuring to an accuracy of .01 about. However for the purpose of statistics I take the discrepancy as 0.30 different which is 0.4%.

Tifft also reports other periodicities in several papers and the full list that I found before he got a theory of his own contains 72.45, 36.2, 24.15, 18.1, 12.0, 9.0(?), 8.0, 6.0, 3.0, 2.67 km/s. Many of the values are reported with slight variations, e.g. 7.997 and 8.05 km/s in different papers. Before I knew of these papers I posted a list of my predictions to usenet and an astronomer referred me to Tiffts papers. In my lsit were the larger periodicities as well as the smaller. Of course Tifft's are all in the range of the smaller ones. Of those ones Tifft mentioned all but one or two of my values and had one extra one, the 2.67 km/s. That is in fact the next strongest one after the ones that I listed. Every one of his values is within 0.5% of my values. The statistical test is coming up.


The entire range of the values being considered is say 2 to 100 km/s and the calculations are done on a log basis to allow equal percentage variations as equivalent throughout the range. So the range of logs is log(2) to log(50) with the maximum error being log(1.005). Allowing for the errors being two sided means that Tiffts reported values fell in intervals that amount to only 1/320 of the entire interval in 8/9 or 9/10 values.
If you do a chi-square test on 8/9 values falling within a region where on 1/320 of values are expected to be found by chance alone then you will have difficulty finding a table that goes that far. It is roughly 10*(1/320)^8 or about 10^-19.

This test does not depend on the stated uncertainties. It depends only on the coincidence of the two sets.

The published papers on the 128 Mpc periodicity are listed on the graphic that I posted.

The 586.24 million year geological cycle is, according to S Afanasiev, vastly more accurate than anything else we will be considering. The 128 Mpc figure has no stated accuracy. However looking at the graphic I think that it would certainly be accurate to 1%. The conversion to million light years depends on the Hubble constant and I used the value at the time which is +/- a few percent I think. The result is consistent because the number is the same within 1% for one in years and the other in light years and the Hubble constant is not that accurate. The significance of light years for one and years for the other is that a wave of e/m or gravity that has period 586 million years will have wavelength 586 million light year.

If it is assumed that the geological period is directly related to the galactic waves then the 586.24 million year geological cycle and 128 Mpc figure can be used to calculate a more accurate value for the Hubble constant and the answer I gave was 71.2 km/s/Mpc which would be accurate to 1% if the 128 km/s/Mpc is that accurate. However the data could certainly be used to get an estimate that was more accurate if the analysis were done with this in mind. It might be made much more accurate by including the shorter geological cycles which are evidently also present in the redshift graphic.

That answers at least most of your questions. I expect a few more. :-)

[rtomes]

How many of the ~600 "obscured AGN" in the Chandra Bootes field* are quasars (or QSOs), in the rtomes classification scheme?

I made it very clear several times that I do not have a quasar classification scheme not do I ever intend to have one. Why do you persist in this silliness?

I only ever intend to use data collected by astronomers who have already classified objects. What part of that is not clear to you?

[rtomes]

And therein lies the rub. If you don't have a consistent classification scheme for quasars, how can you make any claims about redshift quantization? Depending on what objects you allow into your definition, you may begin to find a "quantization" simply due to the way you've defined the sample.

That is the whole reason the folks behind SDSS have worked so hard to generate uniform samples of objects. But I can tell you right now, just selecting everything marked "QSO" from SDSS will not provide a uniform sample (see my discussion above with Ari). Look again at my comments earlier in this thread about this, and make sure you understand the Richards et al. 2007 paper...

As I have stated a number of times I do not make definitions for quasars. That is the job of astronomers. I accept the astronomers agreement on what are quasars.

[Nereid]

As I have stated a number of times I do not make definitions for quasars. That is the job of astronomers. I accept the astronomers agreement on what are quasars.

If you take papers published in ApJ (say), over a period of 40 years (say), you will find the astronomers who authored the papers have a wide range of definitions of 'quasar' (or 'QSO', or ...).

You will also find that the same astronomer is very likely to have changed the definition of 'quasar' across time - a Sandage definition in the 1960s (say) is quite different from a Sandage definition in the 1990s (say).

In light of this, how did you go about establishing "the astronomers agreement on what are quasars"?

To take a specific example, in post #2 in this thread you wrote (my bold): "I have just been doing some back of the envelop calculations to see how often the quasar frequencies would change." What did you do to determine "the astronomers agreement on what are quasars", wrt these calculations?

[Nereid]

I made it very clear several times that I do not have a quasar classification scheme not do I ever intend to have one. Why do you persist in this silliness?

I only ever intend to use data collected by astronomers who have already classified objects. What part of that is not clear to you?

The part that is not clear - and which I will continue to ask questions on - is how you determined that the 'quasars' in one source (one paper in ApJ, say) are the same (from a consistent classification point of view) as the 'quasars' in another source (a different paper, from a different decade, by different astronomers, say)?

Or even if 'quasars', however defined, is being used consistently within the same paper.

If you cannot answer these questions, please say so.

If you did not do any consistency checking, please say so.

If you do not understand why this is important, or why definitions of 'quasar', by astronomers, have varied so much over the past 40 years or so (and between astronomers), then please start a thread in the Q&A section. FWIW, it seems that you may have brushed the edges of one of central challenges all astronomers face, in almost all extra-galactic studies.

[Nereid]

I am happy to answer questions.

The values for the redshift periodicities predicted by the harmonics theory for galaxies are exact. There are no uncertainties.

[snip]

Let's start with some basics, shall we?

In "the harmonics theory for galaxies", what is the redshift of a galaxy?

If the "values for the redshift periodicities [...] are exact", does that mean that if a set of observations of galaxy redshifts is analysed and the "redshift periodicities" are >3 sigma (or some other threshhold criterion for hypothesis testing) from the (exact) predicted values, then the theory is inconsistent with observational results?

If not, what does "exact" mean, wrt testing "the harmonics theory for galaxies" for consistency with astronomical observations?

(to be continued)

[Nereid]

[snip]

The Tifft periodicities are reported in several papers in the late 1970s, a main one being Astrophysical Journal Vol 221 Pg 756-775
1978 May 1. I am sorry I do not have that information to hand for the others.

Is this "a main one" (the link is to the abstract in ADS)?

If so, are "Tifft 1976, 1977a, b, hereafter DSR1, DSR2, and DSR3" (from the first line in the Introduction section of the paper whose abstract can be found by clicking on the link above) "the others"?

In the first of these papers he reports a 72.135 km/s periodicity with a stated uncertainty of the order of .01-.02, but in subsequent papers he comes up with 72.45 with an unstated uncertainty. In one paper he shows how good the fit is to the data, and the biggest peak is indeed at 72.45 km/s with many additional peaks gradually getting smaller at intervals of +/-0.30 multiples from the main peak.

[snip]

If I am reading the main Tifft paper correctly, the values of these so-called periodicities depends - to a significant extent - on the validity of a number of assumptions Tifft used to calculate them.

Specifically, and not in any order, nor necessarily a complete list:
* the existence of a "static universal frame"
* determination of the motion of an observatory making redshift observations wrt this "static universal frame", at the time the observations were taken
* suitability of "the galactic coordinate system" to determine "the solar motion"
* absolute accuracy (however defined) of "the galactic coordinate system" Tifft used
* existence of "monostates", "bistates", "blends", etc of redshift systems in galaxies
* techniques for uniquely 'deblending' "the redshift states", either of individual galaxies, or sets of galaxies
* techniques for uniquely removing the "[internal] rotational or radial motion components" of the galaxies
* the local part of the Milky Way (our solar system and nearby stars - Tifft is not clear on how large this locale is) is involved in (radial) "galactic expansion" of ~17.6 or ~18.8 km/s.

Can you please confirm that the existence of the redshift periodicities in the main Tifft paper do, in fact, depend significantly upon the validity of these assumptions?

In your analysis of Tifft's data, what other key assumptions did you find?

[rtomes]

If you did not do any consistency checking, please say so.

I thought that was obvious by now!

[rtomes]

Let's start with some basics, shall we?

In "the harmonics theory for galaxies", what is the redshift of a galaxy?

If the "values for the redshift periodicities [...] are exact", does that mean that if a set of observations of galaxy redshifts is analysed and the "redshift periodicities" are >3 sigma (or some other threshhold criterion for hypothesis testing) from the (exact) predicted values, then the theory is inconsistent with observational results?

If not, what does "exact" mean, wrt testing "the harmonics theory for galaxies" for consistency with astronomical observations?

(to be continued)

Yes, the periodicities should match the predicted values. However one does need to look at the data, because as I showed Tifft found 72.135 which is right and later 72.45 which seems wrong. However closer examination showed that this had multiple peaks at 0.30 intervals with one at 72.15 which is exactly the correct place.

I can take the question "what is the redshift of a galaxy?" in a number of ways.

1. It is the apparent wavelengths relative to the earth based wavelengths for the same elements. But you know that.

2. The cause of cosmological redshifts I think (as Arp worked out before me, but I arrived at independently) is an increase in the mass of particles over time. Of course there will be velocity components also and I think for galaxies these are quite small, and there may be what Arp calls "internal redshifts" for very new galaxies, but these mainly apply to quasars. Very old galaxies may have a small internal blueshift due to being at the centre of clusters. In general most galaxies have the same frequencies at the same universal time (as it were) and as all particle masses increase with time we see distant ones as they were long ago when they were redshifted to what we are now. This is the explanation for why we are not at a unique place at the centre of the universe.

3. If Arp is right then for quasars there is the additional component "internal redshift" which depends on the fact that it is new matter and has not yet come into wave contact with much other matter. As it does so it will move in steps to the normal frequency of galaxies. Arp reports that some galaxies do show this component, but to a much less extent. I am less sure about quasars than galaxies, but do note that in the strong non-linear basis of new matter the normal (1+z)^h=2 can be changed to (1+z)^h=12 and that for quasars this gives a repeated ratio for (1+z) of 1.230 when h=12. This value does fit the quasar jumps that Arp lists. But I do not think it productive to go into this at this time as it is more speculative that the other stuff.

[rtomes]

Is this "a main one" (the link is to the abstract in ADS)?

If so, are "Tifft 1976, 1977a, b, hereafter DSR1, DSR2, and DSR3" (from the first line in the Introduction section of the paper whose abstract can be found by clicking on the link above) "the others"?If I am reading the main Tifft paper correctly, the values of these so-called periodicities depends - to a significant extent - on the validity of a number of assumptions Tifft used to calculate them.

Specifically, and not in any order, nor necessarily a complete list:
* the existence of a "static universal frame"
* determination of the motion of an observatory making redshift observations wrt this "static universal frame", at the time the observations were taken
* suitability of "the galactic coordinate system" to determine "the solar motion"
* absolute accuracy (however defined) of "the galactic coordinate system" Tifft used
* existence of "monostates", "bistates", "blends", etc of redshift systems in galaxies
* techniques for uniquely 'deblending' "the redshift states", either of individual galaxies, or sets of galaxies
* techniques for uniquely removing the "[internal] rotational or radial motion components" of the galaxies
* the local part of the Milky Way (our solar system and nearby stars - Tifft is not clear on how large this locale is) is involved in (radial) "galactic expansion" of ~17.6 or ~18.8 km/s.

Can you please confirm that the existence of the redshift periodicities in the main Tifft paper do, in fact, depend significantly upon the validity of these assumptions?

In your analysis of Tifft's data, what other key assumptions did you find?

That paper is one that shows 72.135 km/s but also mentions 72.46 km/s. It seems to also mention 36 km/s and 12 km/s. I am not sure if this is one that I saw before, sorry.

Yes, a static universal frame. Originally Tifft calculated this himself, but there are multiple solutions that fir reasonably well. Once the CMBR frame was determined he adopted that and still got his results.

Yes, we must adjust all our observed redshifts to that frame taking account of solar motion variations through the year and our drift relative to CMBR.

I do not see why a galactic co-ordinate system is needed.

The accuracy is very important, and Tifft claims that his values were accurate to +/-0.8 km/s back in the late 1970s. Certainly some of his histograms showed very sharp peaks and secondary peaks at 3 and 6 km/s away from them. These are expected smaller quanta, so they do show that teh accuracy are as he claimed.

I am not familiar with the term "blends". Arp has reported galaxies that show discontinuities in their redshift profiles of 72 km/s. IMO this would happen when a galaxy is in the process of shifting from one state to the next and would be a bit like water freezing or something like that. It would begin somewhere and spread out as a wave, though there might be a few leaders and laggards. This data of Arp's is hard to explain any other way. Sorry, I do not have a reference for that.

Yes, the galaxies rotation must be removed. Normally the curve should be symmetrical about the centre, but I can see that care would be needed in this.

The galactic expansion of ~18 km/s is not something that I have heard of before. I cannot see a need for anything different to our CMBR motion.

Of interest is something else that just came to mind. Have a look at the average rotational velocity of the inner planets relative to the Sun. They show clear 12 and 6 km/s multiples. Most are very close with only Venus off by 1 km/s. Also an analysis of nearby star radial velocities shows a slight tendency to more being at multiples of 12 km/s.


I cannot think of any other assumptions in Tifft's work. Later on, he developed with someone else a theory to explain the quanta. After that I find his data accord a bit less well with Harmonics theory.

[Nereid]

Is this "a main one" (the link is to the abstract in ADS)?

If so, are "Tifft 1976, 1977a, b, hereafter DSR1, DSR2, and DSR3" (from the first line in the Introduction section of the paper whose abstract can be found by clicking on the link above) "the others"?If I am reading the main Tifft paper correctly, the values of these so-called periodicities depends - to a significant extent - on the validity of a number of assumptions Tifft used to calculate them.

Specifically, and not in any order, nor necessarily a complete list:
* the existence of a "static universal frame"
* determination of the motion of an observatory making redshift observations wrt this "static universal frame", at the time the observations were taken
* suitability of "the galactic coordinate system" to determine "the solar motion"
* absolute accuracy (however defined) of "the galactic coordinate system" Tifft used
* existence of "monostates", "bistates", "blends", etc of redshift systems in galaxies
* techniques for uniquely 'deblending' "the redshift states", either of individual galaxies, or sets of galaxies
* techniques for uniquely removing the "[internal] rotational or radial motion components" of the galaxies
* the local part of the Milky Way (our solar system and nearby stars - Tifft is not clear on how large this locale is) is involved in (radial) "galactic expansion" of ~17.6 or ~18.8 km/s.

Can you please confirm that the existence of the redshift periodicities in the main Tifft paper do, in fact, depend significantly upon the validity of these assumptions?

In your analysis of Tifft's data, what other key assumptions did you find?

That paper is one that shows 72.135 km/s but also mentions 72.46 km/s. It seems to also mention 36 km/s and 12 km/s. I am not sure if this is one that I saw before, sorry.

Yes, a static universal frame. Originally Tifft calculated this himself, but there are multiple solutions that fir reasonably well. Once the CMBR frame was determined he adopted that and still got his results.

He did? Where did he publish this revision?

Did you check his calculations?

Yes, we must adjust all our observed redshifts to that frame taking account of solar motion variations through the year and our drift relative to CMBR.

I do not see why a galactic co-ordinate system is needed.

What analyses did you do to check the dependence (or lack of it) of the Tifft redshift periodicities on the assumptions used re a galactic co-ordinate system?

The accuracy is very important, and Tifft claims that his values were accurate to +/-0.8 km/s back in the late 1970s. Certainly some of his histograms showed very sharp peaks and secondary peaks at 3 and 6 km/s away from them. These are expected smaller quanta, so they do show that teh accuracy are as he claimed.

How extensively did you check his calculations?

The number of high quality galaxy spectra - available online - has increased enormously since the 1970s. What analyses have you done, using at least a well-defined sample of these newer spectra, to check Tifft's conclusions?

I am not familiar with the term "blends".

What about "monostates" and "bistates"?

Perhaps a simpler question might be: given a perfectly accurate redshift of a galaxy (we'll look at definitions later), which Tifft declares to be not a "monostate", how is a specific redshift period/quantum determined?

Arp has reported galaxies that show discontinuities in their redshift profiles of 72 km/s. IMO this would happen when a galaxy is in the process of shifting from one state to the next and would be a bit like water freezing or something like that. It would begin somewhere and spread out as a wave, though there might be a few leaders and laggards. This data of Arp's is hard to explain any other way. Sorry, I do not have a reference for that.

If you don't have a reference for it, what merit should this have, in any scientific investigation?

For example, I could claim that "[t]his data of Arp's" was all made up, late one evening after a too many pints at the local pub. Without a reference, how can anyone reading this decide, objectively, whose story is right?

Yes, the galaxies rotation must be removed. Normally the curve should be symmetrical about the centre, but I can see that care would be needed in this.

The galactic expansion of ~18 km/s is not something that I have heard of before.

How does the existence of this, as an assumption by Tifft, affect the conclusions concerning redshift periodicities?

After all, you cited the Tifft paper as the source of these (presumably you have used the conclusions in your own analyses on your own ideas); if there is no basis for such an assumption, shouldn't the whole chain leading to Tifft's conclusions be re-done (at a minimum)?

I cannot see a need for anything different to our CMBR motion.

Please show that Tifft's conclusions are unchanged if this assumption of a galactic expansion of ~18 km/s is removed.

Of interest is something else that just came to mind. Have a look at the average rotational velocity of the inner planets relative to the Sun. They show clear 12 and 6 km/s multiples. Most are very close with only Venus off by 1 km/s. Also an analysis of nearby star radial velocities shows a slight tendency to more being at multiples of 12 km/s.

What sources are you using, as inputs to your analysis?

I cannot think of any other assumptions in Tifft's work. Later on, he developed with someone else a theory to explain the quanta. After that I find his data accord a bit less well with Harmonics theory.

Clarification: does "his data" refer to the (derived) conclusions, in published papers by Tifft? Or the input redshifts (etc) he used to do his calculations? Both? Something else?

If "Harmonics theory" predictions are "exact", what - quantitatively - does "accord a bit less well" mean?

[Nereid]

Yes, the periodicities should match the predicted values. However one does need to look at the data, because as I showed Tifft found 72.135 which is right and later 72.45 which seems wrong. However closer examination showed that this had multiple peaks at 0.30 intervals with one at 72.15 which is exactly the correct place.

How many peaks did Tifft find?

What is the status of all the peaks other than 72.15?

I can take the question "what is the redshift of a galaxy?" in a number of ways.

1. It is the apparent wavelengths relative to the earth based wavelengths for the same elements. But you know that.

Indeed. If we use this definition, or understanding, then every galaxy has a 'redshift range' rather than a single redshift. Further, this range is far greater than what we might call the 'instrument factor' (i.e. how accurately and precisely the telescope/spectrograph can measure a wavelength). To the extent that the spectrum of different parts of a galaxy can be obtained, at least part of the galaxy's 'redshift range' can be seen to be due to integration over different regions, each with its own (much smaller) 'redshift range'.

What, for the purposes of inputs to "Harmonics theory" analyses, galaxy redshifts did/do you use?

2. The cause of cosmological redshifts I think (as Arp worked out before me, but I arrived at independently) is an increase in the mass of particles over time.

Has the rtomes version of this idea been published? If so, where?

If not, would you please state how, in the rtomes idea, "the mass of particles" varies with time ... quantitatively?

Of course there will be velocity components also and I think for galaxies these are quite small, and there may be what Arp calls "internal redshifts" for very new galaxies, but these mainly apply to quasars. Very old galaxies may have a small internal blueshift due to being at the centre of clusters. In general most galaxies have the same frequencies at the same universal time (as it were) and as all particle masses increase with time we see distant ones as they were long ago when they were redshifted to what we are now. This is the explanation for why we are not at a unique place at the centre of the universe.

3. If Arp is right then for quasars there is the additional component "internal redshift" which depends on the fact that it is new matter and has not yet come into wave contact with much other matter. As it does so it will move in steps to the normal frequency of galaxies. Arp reports that some galaxies do show this component, but to a much less extent. I am less sure about quasars than galaxies, but do note that in the strong non-linear basis of new matter the normal (1+z)^h=2 can be changed to (1+z)^h=12 and that for quasars this gives a repeated ratio for (1+z) of 1.230 when h=12. This value does fit the quasar jumps that Arp lists. But I do not think it productive to go into this at this time as it is more speculative that the other stuff.

Indeed. It seems clear, to me at least, that we aren't even at first base ... common understanding of key terms used at the input stage (the redshift of a galaxy, for example).

[Nereid]

If you did not do any consistency checking, please say so.

I thought that was obvious by now!

If you have done no, or very little, consistency checking, what status does anything you have posted, re quasars have (in a scientific sense)?

And I would like a straight answer please ... how much (cross-paper/source, quasar definition) consistency checking did you do?

[Bancor]

A number of posts ago I closed my intervention in this thread by writing:

Now it's better for me to retire, so I'll not interfere with this interesting discussion.

Now I dare to contradict myself and my decision because, about thirty posts later, I seem that this is not a discussion any more, but a sort of inquisitory tomographic scrutiny.

Obviously, I don't intend any criticism to Nereid here, I simply express my perception of the mood in the thread.

Maybe this depends on the fact that many explanations are needed to correctly understand rtomes's hypothesis/theory (interesting anyway!), maybe that it depends on something else.
For instance, I don't know if rtomes is or considers himself an Arpian, but he does seem to be, as he confirmed to be willing to defend, together with its own, Arp's ideas too.
And this, according the rules ruled by the rulers of the forum, is a mortal sin, as Arp's thread was closed long ago (by the way, without any tangible conclusion), so the argument has to be forgotten (a kind of what ancient Romans called "damnatio memoriæ").

But let me say, in the most friendly spirit of collaboration, that isn't by sweeping the rubbish under the carpet that science (in general) and cosmology (in particular) may solve its problems.

I apologise to anyone might feel hurted by those rermarks, and I ask you all to take them as a fair contribution.

[Nereid]

A number of posts ago I closed my intervention in this thread by writing:


Now I dare to contradict myself and my decision because, about thirty posts later, I seem that this is not a discussion any more, but a sort of inquisitory tomographic scrutiny.

Obviously, I don't intend any criticism to Nereid here, I simply express my perception of the mood in the thread.

If I may be permitted to remind all readers of the clearly stated BAUT rule concerning this ATM section, in particular this part (my bold):

"Direct questions must be answered in a timely manner.

People will attack your arguments with glee and fervor here; that's what science and scientists do."

Gleeful and fervid attacks on arguments ("some idea which goes against commonly-held astronomical theory") do, I'm sure, contribute to the 'mood' of all threads in the ATM section.

Personally, I think that is as it should be. In any case, my personal opinion is pretty much irrelevant ... the BAUT rules are what they are.

Maybe this depends on the fact that many explanations are needed to correctly understand rtomes's hypothesis/theory (interesting anyway!), maybe that it depends on something else.
For instance, I don't know if rtomes is or considers himself an Arpian, but he does seem to be, as he confirmed to be willing to defend, together with its own, Arp's ideas too.
And this, according the rules ruled by the rulers of the forum, is a mortal sin, as Arp's thread was closed long ago (by the way, without any tangible conclusion),

That may, or may not be so (the bit about a tangible conclusion). In any case, surely it's irrelevant?

I mean, the BAUT rules, and the (now not so new) ATM policies, are what they are. As I pointed out to another BAUT member who posted here recently, the About BAUT section is the place for such discussions; perhaps the (still open) The Future of ATM thread?

Switching to mod mode ... if rtomes had indicated that the ATM ideas he would be presenting were solely Arpian, then this thread would have been closed some time ago. However, as rtomes has made clear, several times, the ATM ideas being presented (and defended) are his own (albeit derived to some extent from, and similar in some ways to, some of those published by Arp).

Also, let's not forget that there are many papers published by Arp which contain good observational data ... the data are thus in the public realm and available to anyone who chooses to use them (as rtomes has stated, though not so clearly, he did).

so the argument has to be forgotten (a kind of what ancient Romans called "damnatio memoriæ").

But let me say, in the most friendly spirit of collaboration, that isn't by sweeping the rubbish under the carpet that science (in general) and cosmology (in particular) may solve its problems.

I apologise to anyone might feel hurted by those rermarks, and I ask you all to take them as a fair contribution.

May I respectfully suggest that these comments do not belong in this thread? That they should really be part of the on-going discussion on the nature of this ATM section, or the oft stated scope of (the science-based parts) of BAUT? in the About BAUT section?

[Bancor]

Nereid,
I expressed my perception of the mood only, no other.
And my personal opinion is pretty much irrelevant too... and I implicitly admitted that the rules are the rules, isn'it?

As to your recall of The future of ATM thread, you're quite right: it was my fault not having read it. However, as I see that's a very long thread, I promise I'll do my best to know the various questions debated there, and if I'll be able I'll post my opinions.

Nevertheless, I hope that my aim was correctly perceived: personally, I dislike any discussion about non-standard views in science where its proponent has to be prepared to combat an ordeal.
But its only my opinion, of course.

Thanks for your kind attention.

[rtomes]

A number of posts ago I closed my intervention in this thread by writing:

Now I dare to contradict myself and my decision because, about thirty posts later, I seem that this is not a discussion any more, but a sort of inquisitory tomographic scrutiny.

Obviously, I don't intend any criticism to Nereid here, I simply express my perception of the mood in the thread.

Maybe this depends on the fact that many explanations are needed to correctly understand rtomes's hypothesis/theory (interesting anyway!), maybe that it depends on something else.
For instance, I don't know if rtomes is or considers himself an Arpian, but he does seem to be, as he confirmed to be willing to defend, together with its own, Arp's ideas too.
And this, according the rules ruled by the rulers of the forum, is a mortal sin, as Arp's thread was closed long ago (by the way, without any tangible conclusion), so the argument has to be forgotten (a kind of what ancient Romans called "damnatio memoriæ").

But let me say, in the most friendly spirit of collaboration, that isn't by sweeping the rubbish under the carpet that science (in general) and cosmology (in particular) may solve its problems.

I apologise to anyone might feel hurted by those rermarks, and I ask you all to take them as a fair contribution.

My main purpose in this thread is to show that quantization or periodicity of redshifts are consistent with data and that various reasons given against this are mistaken and that some analysis might be mistaken. Of necessity I must quote Arp and Tifft and a few others that did much of the original research. It is clear that it is best to start with galaxies rather than quasars as there are less contentious issues. If I cannot convince anyone about galaxy redshift periodicities then I don't hold out much hope for doing it for quasars. So it would be best to leave the quasar stuff aside an concentrate on galaxies.

I do think all the classification of quasar stuff is largely a red herring. The definition may have wandered a bit, but that does not invalidate earlier work or mean that similar results will not happen with the new basis. However I can see no point in the continued inquisition on this when I have made myself perfectly clear that I do not do quasar classification, but use only the results of others classification. I depend on them being consistent within any one survey or sample.

To some extent this thread is mixing a bit with my harmonics theory. That is OK to some extent, because knowing only of the 72 km/s periodicity I was able to determine an explanation for that and predict other periodicities and their relative strengths. After I posted this prediction to usenet in 1994, that prediction was verified by me receiving an email from an astronomer telling me about Tifft's papers from the late 1970s which had essentially the same periodicities in them. Therefore Tifft's work is very important to me because it confirms my work and my work confirms his.

Unfortunately Tifft developed his own theory with someone else in the mean time and so he was less interested in my work than he might have been.

I would not call myself an Arpian, but I do think that some of Arp's ideas have been dismissed through wrong understanding. I arrived independently at the idea of particle mass increase over time that Arp and Narlikar advocate. He arrived at it by consideration of quasar internal redshifts, believing that they are nearby. I arrived at from redshift periodicity and and harmonics energy moving to smaller scales.

I am happy to concentrate on Tifft related periodicities because the significance of the fit between Harmoniocs theory and Tiffts periodicities is so high that it makes no sense to say that either is false. How could a false theory and misconstrued data turn out to agree at p<10^-18?


One final comment though is that Harmonics theory should not be seen as just an explanation of redshift periodicities. It is primarily based in cycles periods and spacial regularity and applies at all scales in the universe.