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rodin
2009-Jul-12, 11:00 PM
What have you got :)

Spaceman Spiff
2009-Jul-12, 11:29 PM
Have you tried Google?

But to get you started, one of the regulars here maintains a website on quasars with this set of images (http://www.astr.ua.edu/keel/agn/qsohosts.html) of host galaxies.

ngc3314
2009-Jul-13, 12:41 AM
But to get you started, one of the regulars here maintains a website on quasars with this set of images (http://www.astr.ua.edu/keel/agn/qsohosts.html) of host galaxies.

Oh, yeah, what he said. (Just moved to a new server - good thing all the nameserver links seem to be properly updated.)

You could also type quasar names into the Hubble Legacy Archive (http://hla.stsci.edu/hlaview.html) and pull up images (some color-composite) in great abundance. Many of them live up to the designation and still look like stars even in typical Hubble images, though.

RussT
2009-Jul-13, 11:03 AM
Oh, yeah, what he said. (Just moved to a new server - good thing all the nameserver links seem to be properly updated.)

You could also type quasar names into the Hubble Legacy Archive (http://hla.stsci.edu/hlaview.html) and pull up images (some color-composite) in great abundance. Many of them live up to the designation and still look like stars even in typical Hubble images, though.



At one point there was a popular scheme, based on observations of nearby radio galaxies and Seyfert galaxies, suggesting that radio-loud quasars would live in elliptical galaxies and radio-quiet ones would be found in spirals. Only one part of this really works - radio-loud objects don't seem to be found in spiral galaxies. However, radio-loud and radio-quiet objects can be found in elliptical galaxies or merging systems, so the distinction isn't as clear-cut as we might have liked.

So, here is a question for you ngc3314

To the best of your knowledge, which I know is considerable, do you think...

1. That Joe Silks "Contracting huge HI/HII cloud" for the creation of a SMBH, is even a reasonable possibility for Quasars to be considered as "New Galaxies"?
2. that a Quasar could be considered a New Galaxy as a white hole in any way?

The main reason I ask that, is that I agree with mainstream that the masses of SMBH's in Quasars are in the billions of Sol masses, which makes them just like M87, as an Elliptical Galaxy, so how could a "New Galaxy" start off with a billion+ mass SMBH?

ngc3314
2009-Jul-15, 01:26 PM
So, here is a question for you ngc3314

To the best of your knowledge, which I know is considerable, do you think...

1. That Joe Silks "Contracting huge HI/HII cloud" for the creation of a SMBH, is even a reasonable possibility for Quasars to be considered as "New Galaxies"?
2. that a Quasar could be considered a New Galaxy as a white hole in any way?

The main reason I ask that, is that I agree with mainstream that the masses of SMBH's in Quasars are in the billions of Sol masses, which makes them just like M87, as an Elliptical Galaxy, so how could a "New Galaxy" start off with a billion+ mass SMBH?

Both of these are Good Questions. The striking similarity of the highest-redshift quasars to those in the more recent Universe suggests that, at least in rare cases in the most favorable environments, supermassive black holes in the billion-solar-mass range could form quickly (within something like 800 million years for the WMAP cosmology). That's really tight unless there was a seeding process jump-starting the mass somewhere above the mass of a single collapsed star. In a gas-rich environment, the mass could grow almost exponentially until local material is exhausted, after which the main growth mechanism would be tidal shredding of stars (at the least). 5 or 6 orders of magnitude is just plausible in this was, but 8 seems right out. Population III stars are attractive, perhaps leaving black holes of 100 solar masses or more, but it's not blindingly obvious whether they would end up in galactic nuclei (since their superdupernova explosions can disrupt their entire parental subgalactic cloud. Can, could, would have - we need new verb tenses to be unambiguous in these cases...). Ideas have also been floated of the rapid collapse of star clusters which become so dense as to have a significant gravitational redshift (and therefore need relativistic calculations to follow their evolution); direct collapse of protogalactic clouds which become too dense to be stopped by quantum forces; dark matter in the form of "sterile neutrinos", which would form kiloparsec-scale degenerate configurations which would be ripe accretion fodder for the first stelar black hole that wandered in; and "dark stars", hypothetical entities which would exist if dark matter consists of Majorana particles (their own antiparticles) and could therefore annihilate in the particularly dense environment of a normal stars sitting in the center of a dark-matter mass peak. All these have reasonably detailed studies and their own defenders.

Both galaxies and GRBs have been found at larger redshifts than quasars, so we do not really have a problem of the black hole coming first. We may have an interesting issue of the black hole growing more rapidly than the galaxy (baryonic) mass in some cases, which is odd considering what a nice statistical connection these properties have today.

I'l pass up commenting on white holes, the reason being that what I think I know about the concept is that they are allowed by GR, but sustaining them requires forms of matter of which no trace has been observed. Black holes have pretty solid evidence[1], but I'm not sure anyone knows of a distinctive signature of white holes.

[1] At least astronomers' idea of black holes - too compact for neutron-degenerate matter, well above the mass limit for neutron stars, invisible throughout the accessible EM spectrum. The more exotic properties don't matter much for most astrophysical connections, though I do know some X-ray types who cite timing evidence for frame-dragging in the accretion disk.

chornedsnorkack
2009-Jul-16, 06:45 AM
Most galaxies do not have cores.

Look at Large Magellanic Cloud. Supposedly irregular, but it looks suspiciously like a barred spiral galaxy viewed from edge. In the middle of the bar, there is modestly dense star field - but no core. Then look at Triangulum. A pretty spiral galaxy - but again, in the middle there is a modestly dense star field with no core.

How do galaxies form cores?

rodin
2009-Jul-17, 03:39 PM
Using Google to search Quasar images was my first port of call. Thing is - the only photos I could pull up showed jets emerging from only one pole.

Is there an example of a quasar whose photograph shows a jet emerging from both poles, as per all 'artist impressions'?

rodin
2009-Jul-17, 05:35 PM
Quasar photograph showing single ejection

http://images.astronet.ru/pubd/2002/02/11/0001174687/pks1127_xray_opt.jpg

http://images.google.com/imgres?imgurl=http://images.astronet.ru/pubd/2002/02/11/0001174687/pks1127_xray_opt.jpg&imgrefurl=http://www.astronet.ru/db/xware/msg/1174687&usg=__wzHfiCrI-VfuRepbB02SHkKQeFQ=&h=361&w=714&sz=24&hl=en&start=88&sig2=RV17rnWKUIuHQgAjxHRy-A&um=1&tbnid=-d1yYSmj6xJIDM:&tbnh=71&tbnw=140&prev=/images%3Fq%3Dquasar%26ndsp%3D18%26hl%3Den%26rlz%3D 1B2RNFA_enGB284%26sa%3DN%26start%3D72%26um%3D1&ei=7bNgSrvcJKaSmwPy2ojdDA

http://apod.nasa.gov/apod/image/0109/3c175_vla.jpg

http://images.google.com/imgres?imgurl=http://apod.nasa.gov/apod/image/0109/3c175_vla.jpg&imgrefurl=http://apod.nasa.gov/apod/ap010905.html&usg=__PhomCvPTYTKSfFRX3Ts2q7KR044=&h=414&w=625&sz=58&hl=en&start=59&sig2=Z5Y5jFKXrbro_u0jpWDVfg&um=1&tbnid=cVGcdosrDABrDM:&tbnh=90&tbnw=136&prev=/images%3Fq%3Dquasar%26ndsp%3D18%26hl%3Den%26rlz%3D 1B2RNFA_enGB284%26sa%3DN%26start%3D54%26um%3D1&ei=yrNgStHXKKaGmwPay43KDA

Quasar artist's impression (typical of many such)

http://www.fas.org/irp/imint/docs/rst/Sect20/h_accretion_disk_02.jpg

Are there any actual photographs that support the idea Quasars eject material from both poles?

also

Is it possible to measure independently red shifts for both parent quasar and ejecta?

rodin
2009-Jul-20, 02:23 PM
Is the lack of double-beam quasar photographs here indicative they don't exist :confused:

parejkoj
2009-Jul-21, 07:57 PM
Any jet launched both toward and away from us, the part heading toward us is amplified through "Doppler beaming," while the part heading away from us is correspondingly deamplified. So the jet traveling toward us will always be brighter, so often only one jet will be readily visible (as is the case with 3c273).

With that in mind, there are plenty of pictures of double-lobed jets: NGC 4261 (http://www.iop.org/EJ/article/1538-3881/122/6/2954/201312.text.html), and again on larger scales (http://csep10.phys.utk.edu/astr162/lect/active/ngc4261.html), NGC 326 and other X-shaped jets (http://en.wikipedia.org/wiki/X-shaped_radio_galaxy), 3c219 (http://www.astro.phy.ulaval.ca/staff/paramita/AllPages/gsu/gsu_research.html). Do a google image search for "double lobed radio jet" without the quotes, and you'll get plenty of others.

chornedsnorkack
2009-Jul-21, 08:56 PM
Any jet launched both toward and away from us, the part heading toward us is amplified through "Doppler beaming," while the part heading away from us is correspondingly deamplified. So the jet traveling toward us will always be brighter, so often only one jet will be readily visible (as is the case with 3c273).

With that in mind, there are plenty of pictures of double-lobed jets: NGC 4261 (http://www.iop.org/EJ/article/1538-3881/122/6/2954/201312.text.html), and again on larger scales (http://csep10.phys.utk.edu/astr162/lect/active/ngc4261.html), NGC 326 and other X-shaped jets (http://en.wikipedia.org/wiki/X-shaped_radio_galaxy), 3c219 (http://www.astro.phy.ulaval.ca/staff/paramita/AllPages/gsu/gsu_research.html). Do a google image search for "double lobed radio jet" without the quotes, and you'll get plenty of others.

Not only does Doppler beaming mean that the jet travelling towards us is brighter than the other - it means that if you compare two equally bright double jets, one with jets at right angles to us and another with one jet pointed at us, the jet pointed at us is much brighter. Which means that the double lobed jets are much harder to see than the single lobed ones!

RussT
2009-Jul-22, 09:20 AM
Both of these are Good Questions. The striking similarity of the highest-redshift quasars to those in the more recent Universe suggests that, at least in rare cases in the most favorable environments, supermassive black holes in the billion-solar-mass range could form quickly (within something like 800 million years for the WMAP cosmology).

BUT, those are Elliptical Galaxies, like M87, with their "Jets", and no gas left for star formation......So do those galaxies evolve "backwards"?

In addition, the farthest of those, started in the same basic amount of space as the Milky Way (Considered the oldest galaxy, due to having the oldest stars (Clusters)), and M87, so how could our galaxy only have a SMBH with ~ 4 million Sol masses?
We haven't evolved 'backwards', have we? I mean our SMBH is supposed to continue to gain mass, right?

rodin
2009-Jul-22, 09:26 AM
Any jet launched both toward and away from us, the part heading toward us is amplified through "Doppler beaming," while the part heading away from us is correspondingly deamplified. So the jet traveling toward us will always be brighter, so often only one jet will be readily visible (as is the case with 3c273).

With that in mind, there are plenty of pictures of double-lobed jets: NGC 4261 (http://www.iop.org/EJ/article/1538-3881/122/6/2954/201312.text.html), and again on larger scales (http://csep10.phys.utk.edu/astr162/lect/active/ngc4261.html), NGC 326 and other X-shaped jets (http://en.wikipedia.org/wiki/X-shaped_radio_galaxy), 3c219 (http://www.astro.phy.ulaval.ca/staff/paramita/AllPages/gsu/gsu_research.html). Do a google image search for "double lobed radio jet" without the quotes, and you'll get plenty of others.
Thanks. I have seen some double lobed radio galaxies, but not jet anything you could call a two-way jet. I will search further though and check out your links.

rodin
2009-Jul-22, 09:29 AM
Not only does Doppler beaming mean that the jet travelling towards us is brighter than the other - it means that if you compare two equally bright double jets, one with jets at right angles to us and another with one jet pointed at us, the jet pointed at us is much brighter. Which means that the double lobed jets are much harder to see than the single lobed ones!

How do we know if a jet is pointing towards us? Is there a way of measuring this, other than just assuming it is because it is brighter?

RussT
2009-Jul-22, 09:44 AM
Most galaxies do not have cores.

Look at Large Magellanic Cloud. Supposedly irregular, but it looks suspiciously like a barred spiral galaxy viewed from edge. In the middle of the bar, there is modestly dense star field - but no core. Then look at Triangulum. A pretty spiral galaxy - but again, in the middle there is a modestly dense star field with no core.

How do galaxies form cores?

This is a good question also...

At least for the Late Galaxies, it would appear that they start very slowly and evolve very slowly over vast periods of time...



http://www.narrabri.atnf.csiro.au/public/images/ngc2915/
BTW, it would appear that this is NOT a "Dwarf Galaxy", even though it is listed as a BCD (Bright Compact Dwarf)

Also look up LSB's Low Surface Bright Galaxies.

And to add to the mystery of when and how...

http://www.physorg.com/news3154.html
First Dark galaxy

And, this part of your post that is lower down than the one I quoted...

if you compare two equally bright double jets, one with jets at right angles to us and another with one jet pointed at us, the jet pointed at us is much brighter. Which means that the double lobed jets are much harder to see than the single lobed ones!

I think is a little confusing...

The double Jets means that those two jets are coming out of the accretion disc on each end of the SMBH, perpendicular to the accretion disc.

When one is pointed directly at us, those are Blasars, when they are at angles where they are not pointed at us then they are Quasars.

chornedsnorkack
2009-Jul-22, 01:25 PM
BUT, those are Elliptical Galaxies, like M87, with their "Jets", and no gas left for star formation......So do those galaxies evolve "backwards"?

In addition, the farthest of those, started in the same basic amount of space as the Milky Way (Considered the oldest galaxy, due to having the oldest stars (Clusters)), and M87, so how could our galaxy only have a SMBH with ~ 4 million Sol masses?
We haven't evolved 'backwards', have we? I mean our SMBH is supposed to continue to gain mass, right?

Well, it cannot lose any.

Look around our nearby galaxies. Large Magellanic Cloud is less than 200 000 years younger than Milky Way. There is no way that Milky Way could have been like Large Magellanic Cloud a mere two hundred thousand years ago!

Amber Robot
2009-Jul-22, 03:19 PM
http://apod.nasa.gov/apod/image/0109/3c175_vla.jpg

Are there any actual photographs that support the idea Quasars eject material from both poles?


Did you not just answer your own question? :confused:

rodin
2009-Jul-25, 12:08 PM
Did you not just answer your own question? :confused:

Some of the more recent pics that I have seen thanks to this thread do show dual-lobes.

This particular image is very interesting.

First of I was thinking that the jet was coming from the lower right. However, it makes more sense that the two similar clouds are accumulated ejecta from the cental core. In the current picture only one jet is visible.

I am interested in this galaxy. It looks to be viewed from Earth side-on as both lobes are of similar intensity.

Can the lobes and core quasar have redshift determined independently and if so has this been done?

ngc3314
2009-Jul-25, 01:44 PM
Can the lobes and core quasar have redshift determined independently and if so has this been done?

Not for the radio-emitting jets and lobes - they have very broad-band smooth spectra (essentially power-law, flux scaling as a power of the frequency). The closest we can come is seeing cooler gas (with emission lines) interacting with the jets, which gives modest velocities relative to the central galaxies if it had been directly shocked by the relativistic outflows, this gas would be too hot to give optical emission lines. The closest we can come is for microquasars, which are neutron stars or black holes from stellar remnants which have twin-jet outflows. In these cases we can often measure the apparent motions of the two sides, which indicate relativistic flows with the oncoming side Doppler boosted and sped up in our reference frame. The case of SS433 remains unique - for reasons I don't know, its inner jets are internally col enough to hae emission lines, so we know that they are ejected at 0.26c (and in opposite directions at once).

It is also relevant for quasars and double-lobed radio galaxies that the lobes with the brighter jets (which relativistic boosting suggests are on the near side and approaching) show less depolarization from foreground material, also making sense if they are in front and Doppler boosted (the Laing effect).