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BAroxMysox
2004-Aug-28, 10:34 PM
...the very cool image of the "Sombero" galaxy (http://imgsrc.hubblesite.org/hu/db/2003/28/images/a/formats/1280_wallpaper.jpg) at hubblesite.org, when I noticed something down near the caption, right above it's name. It appears to me like two spiral galaxies, but I've been unable to find anything like it on hubblesite.org or after looking on Google (although I don't really know where to begin. :oops:)

Does anyone have any info on this object? I'd really like to see it close-up.

ngc3314
2004-Aug-28, 11:02 PM
...the very cool image of the "Sombero" galaxy (http://imgsrc.hubblesite.org/hu/db/2003/28/images/a/formats/1280_wallpaper.jpg) at hubblesite.org, when I noticed something down near the caption, right above it's name. It appears to me like two spiral galaxies, but I've been unable to find anything like it on hubblesite.org or after looking on Google (although I don't really know where to begin. :oops:)

Does anyone have any info on this object? I'd really like to see it close-up.

An amateur I hear from occasionally pointed it out right after the inital release. It looks like some of the interacting pairs in the Arp atlas, with tidal tails connecting to the spiral arms and all.

There's a pretty deep set of HST ACS exposures, and you want a closer look? There's no pleasing some people! However, if your ocnection is fast, you can grab the full-resolution verion. Their new organization (grumble, in no slightest way "improved") means you have to back all the way up to hubblesite.org and start over to find it, but the 11400x6500 image can be found at http://hubblesite.org/newscenter/newsdesk/archive/releases/2003/28/image/a+warn which shows about as much as you can get. Such oddities get more and more common with deeper looks - I don't know of anyone who's worked with the various deep Hubble images of galaxy fields without remarking about how the galaxy population just gets weird as we look faint (and far back). The two main reasons for this are (1) galaxies really were less settled in the early Universe, and (2) at those redshifts, what we see in the optical range now is what started off in the ultraviolet, which is very sensitive to both the most recent star formation and the distribution of dust, so even nearby galaxies look less symmetric viewed in this light. There were some major projects (involving both Hubble and the Astro-1/2 Shuttle payloads) to survey local galaxies in the UV, so we could tell the difference.

jt-3d
2004-Aug-29, 05:32 AM
NGC 2207 (http://antwrp.gsfc.nasa.gov/apod/ap991109.html) is along the same lines but I don't think that's the same thing.

beskeptical
2004-Aug-29, 06:55 AM
It is a fascinating formation. I can't believe no one has investigated it yet.

BAroxMysox
2004-Aug-29, 05:43 PM
It is a fascinating formation. I can't believe no one has investigated it yet.

That's what I was thinking. NGC 2207 looks similar, but I'm not sure that it's the same one. From what I saw in the hi-res version, it looks pretty neat and worth taking a much closer look at.

Kullat Nunu
2004-Aug-29, 06:21 PM
It is a fascinating formation. I can't believe no one has investigated it yet.

That's what I was thinking. NGC 2207 looks similar, but I'm not sure that it's the same one. From what I saw in the hi-res version, it looks pretty neat and worth taking a much closer look at.

It is definitely not NGC 2207, which is located in compelety different part of the sky and is much closer to us. I checked it with Simbad (http://simbad.u-strasbg.fr/sim-fid.pl), but it is not listed there. So it must be very faint, uncataloged object.

Cougar
2004-Aug-29, 08:45 PM
Such oddities get more and more common with deeper looks - I don't know of anyone who's worked with the various deep Hubble images of galaxy fields without remarking about how the galaxy population just gets weird as we look faint (and far back). The two main reasons for this are (1) galaxies really were less settled in the early Universe, and (2) at those redshifts, what we see in the optical range now is what started off in the ultraviolet, which is very sensitive to both the most recent star formation and the distribution of dust, so even nearby galaxies look less symmetric viewed in this light. There were some major projects (involving both Hubble and the Astro-1/2 Shuttle payloads) to survey local galaxies in the UV, so we could tell the difference.
Of course, there was also the HST NICMOS IR camera, which is explained well in The Morphological Evolution of Galaxies by Roberto G. Abraham and Sidney van den Bergh, a piece of which is quoted below. Apparently your point (1) is indeed the main reason.


Beyond z ~ 1, one must observe galaxies in the IR in order to study them at familiar optical wavelengths in their rest frames. The NICMOS camera on HST had this capability, although its small field of view and limited lifetime meant that relatively few z ~ 1 field galaxies were observed in the near-IR before the instrument ceased functioning. However, over the short lifetime of this camera, it was possible to demonstrate that most galaxies with peculiar optical morphologies remain peculiar when viewed in the near-IR, at least out to z ~ 3. It follows that the strange appearance of these objects is not merely the consequence of “morphological K-corrections” (i.e., of observing only irregularly distributed sites of star formation at rest UV wavelengths while missing the bulk of the galaxy). The peculiar appearance of these objects reflects a genuinely irregular structural state in these galaxies.
This also makes it pretty clear that galaxies and their shapes evolve, putting another nail in the coffin of the steady-state theory, as if that coffin needed any more nails.

ngc3314
2004-Aug-31, 02:10 AM
It is a fascinating formation. I can't believe no one has investigated it yet.

That's what I was thinking. NGC 2207 looks similar, but I'm not sure that it's the same one. From what I saw in the hi-res version, it looks pretty neat and worth taking a much closer look at.

A fascination with the pathology of interacting galaxies is something to be encouraged! In that vein, let me direct this thread's readers to a few collections of such oddities:

http://www.nrao.edu/astrores/HIrogues/webGallery/RoguesGallery00.html

http://www.astr.ua.edu/pairs2.html

and the original, the Arp Atlas in a scanned version:
http://nedwww.ipac.caltech.edu/level5/Arp/frames.html

and its southern followup by Arp and Madore: http://nedwww.ipac.caltech.edu/level5/SPGA_Atlas/frames.html

They're not all symmetric and majestically undisturbed out there. Some of these are hynotically cool.

BAroxMysox
2004-Sep-01, 05:04 PM
Very nifty sites there, ngc3314. Thanks :D I've been digging through those the past couple days here at work, and there are some very interesting formations. And like you said, some are hypnotically cool. Arp 198 (http://nedwww.ipac.caltech.edu/level5/Arp/Figures/big_arp198.gif) for example. 8)

ngc3314
2004-Sep-01, 06:19 PM
Very nifty sites there, ngc3314. Thanks :D I've been digging through those the past couple days here at work, and there are some very interesting formations. And like you said, some are hypnotically cool. Arp 198 (http://nedwww.ipac.caltech.edu/level5/Arp/Figures/big_arp198.gif) for example. 8)

Oh, indeed! And if you root around, you may even notice a familiar-sounding catalog designation. Other than that pair, NGC 5752/4 is my laptop wallpaper - I keep having to move new icons to keep the galaxies in view.