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Ever curious,PHD
The space telescope Hubble has taken a deep space photograph! This was taken in one direction. Has there been photos deep space photos taken in the opposite direction as well as left,right,up, and down of this first photo? And the scientist have us (Earth) situated in particular region of the universe. Would that mean these other (direction) have been taken? Thank you.
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The deep space photo and the ultra deep space photo are the only two that have been taken. The choice of direction was simply to find a blank area near the poles such that Hubble could look at it continuously. There is no need to do them in a variety of directions.
The Earth is situated at the exact center of the universe, as is every other object in the universe.
Order of Kilopi
Established Member
Plus the Extended Groth Strip, the 53W002 high-redshift group, and a large number of ACS fields all over the sky which are almost as deep as the HDFs - the M31 halo field, the NGC 3314 lensing experiment, which have very rich deep backgrounds. The COSMOS survey covered a full 2 square degrees in one filter.Originally Posted by 01101001
Order of Kilopi
(bold added)
Now you wouldn't happen to have been involved in that by any chance would you?
Order of Kilopi
This sounds interesting! I'd like to know more about the NGC 3314 lensing
experiment because I have an ATM hypothesis that a particular type of very
faint gravitational lensing might occur in particular situations. Because of
the extreme faintness, I expect longer exposures such as the Hubble deep
field images to be required. Where can I get more info?
-- Jeff, in Minneapolis
http://www.FreeMars.org/jeff/
"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"
"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves
Established Member
Ahh, the NGC 3314 microlensing experiment. I'm a little embarrassed that results haven't yet seen the light of day. This is in part because the PI moved on to other lensing applications, other team members scattered around the planet, and my attempts to get going were really slowed down by certain, umm, features of the drizzle software as originally distributed by STScI. I, at least, haven't given up - there are new software tools that are working a lot better for putting the various images on common coordinate systems for detailed comparison and making a superresolved master frame in each filter.
This started when the eventual PI convinced me that my back-of-the-envelope estimate of the microlensing rate between stars in the foreground and background galaxies was too pessimistic by about an order of magnitude, and noted that being able to sample relative velocities modulated by the different senses of relative galaxy rotations made such a survey sensitive to a different mass/velocity combination than the Milky Way lensing surveys. The project got an amazing allocation - 30 visits of 2 orbits each, with an orbit of each visit devoted to V and I dithered-image sets. Each of these images goes strikingly deeper than the well-known (look up) WFPC2 data - I hoped for a while we might even get two Cepheid distances from the data. To this point, suboptimal image comparison does show strong microlensing candidates, the brightest detected about 5 times and peaking near V magnitude 27. he visits were spaced to sample amplification timescales from 2 weeks to a year. All the images have been public in the archives for some time now - program IDs are 9445 and 9977. The data span the range from May 2002 to May 2004.
Aside from our various goals (microlensing, and of course dust) the stacked mean images go very deep, looking through the edge of the Hydra galaxy cluster (Abell 1060). Because the images have various rotation angles and centers, only lately have I seen a good combination version to start appreciating the background riches.
Last edited by ngc3314; 2008-Jul-17 at 03:30 PM. Reason: typo
Order of Kilopi
Cool! too bad you couldn't just've cashed in one of those orbits and maybe bought yourself some observing tools, like Maseratis
Established Member
Eeeek not Maserati!
Order of Kilopi
I thinkCharles is asking about the observational support for universal isotropy. The ultimate support for this is the uniformity of the cosmic microwave background, which has indeed been measured in "the opposite direction" as well as left, right, up, down, and everything in between. It turns out to be uniform to 1 part in 100,000. Highly isotropic! Since that time, gravity has resulted in localized anisotropies, but it has done so similarly throughout the universe.
Here is a somewhat-related paper by Collins and Hawking -- Why Is the Universe Isotropic?
Everyone is entitled to his own opinion, but not his own facts.
Order of Kilopi
Hmmm. Microlensing is not what I'm mainly interested in, but it is
still interesting to me. The fact that you have (at least potentially)
a very deep image obviously is interesting to me. I am interested in
gravitational lensing of light from distant galaxy clusters by nearer
objects not in the same cluster. So NGC 3314 itself isn't a good
distant source for my purpose, but it might be a lensor of more
distant objects.
I know nothing at all about software for predicting / simulating
gravitational lensing. Can you tell me where to start finding out
about it? What I would really like is for someone who is already
adept at using such software to run a few simulations for me.
-- Jeff, in Minneapolis
http://www.FreeMars.org/jeff/
"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"
"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves
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