The WBL 687 Galaxy Group

The WBL 687 galaxy group is a small group of 3 galaxies in Pegasus just west of the northeastern star of the Great Square, Beta Pegasi. Red shift puts the group about 420 million light-years distant. The group consists of NGC 12191, UGC 12193 and CGCG 474-032. Redshift also shows UGC 12198 to be of about the same redshift. Out of my frame to the north, UGC 12194 is a similar galaxy with a very slightly greater redshift that puts it 430 million light-years distant. These 5 likely constitute the PPS2 007 group. Though it is centered just above NPM1G +27.0631 which has no redshift but appears to be more distant so likely this is just coincidence. Still I'd like to know more about this galaxy as it appears to have a plume to the southwest yet no interacting companion is to be found. Is it the result of a merger?

UGC 12191 is a SB spiral at 420 million light-years by redshift but about 100 million light-years closer by other measurements. Since the other galaxies all have the same redshift as it has I'm going to go with the redshift distances here though this results in a very large galaxy. It is a nearly face on Sb spiral that's some 165,000 light-years across if the 420 million light-year distance is correct. Going with the nearer distance makes it 130,000 light-years in diameter, still very large as spiral go.

UGC 12193 is listed at NED as a SB(s)bc spiral and is seen fully face on. It is slightly larger in angular size though looks much larger since it is seen almost fully face on. It's size works out to be 175,000 light-years in diameter. There was no non redshift distance estimates for it.

The third, much smaller, member is CGCG 474-032. It is a rather normal sized spiral at 65,000 light-years in diameter. It appears to be an old, dying spiral by its mostly red color. It stands in rather stark contrast to the vibrant star formation in the larger spirals evidenced by their strong blue color.

The two UGC galaxies are separated by only 110 seconds of arc. If they are at the same distance that would mean they could be as close as a quarter of a million light-years. I'd expect some tidal distortion though if this is their first time close that might not show as yet. Still I think it likely there's more separation than this between them. Of course the might be unrelated though I find this unlikely.

The probable 4th member of the group UGC 12198 is seen rather edge on, still it is rather large at 110,000 light-years across. It too seems to still have active star formation unlike CGCG 474-032.

There's not a lot on this field at NED. As such I broke my usual rule and annotated all galaxies at NED in the field, not just those with redshift distance. I didn't include those that are listed as UvS sources as most are stars and separating the two nearly impossible with more than 400 listed in this image to sort through.

14" LX200R at f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick

Originally Posted by John[_2_]

On Tue, 10 Mar 2015 06:46:10 +0000, WA0CKY
wrote:
,snipped

Thank you for all the nice images.

I was wondering whether you'd seen this:
http://www.bbc.co.uk/guides/zymwq6f
and whether you were thinking of taking part?
J.

I can't fathom what this outfit is trying to do. There are already far better images of Orion with detail and depth far beyond anything possible with even a million cameras of the type they want to use. Seems more an effort to get people to realize their simple cameras can take astro pictures than to do real science. https://farm8.staticflickr.com/7633/...6e5da3ea_o.jpg
Keep in mind this is made of a mosaic of 49 individual images each several millions of pixels in size so the full image in raw from is many gigabytes in size with resolution far beyond any digital camera and lens. Also since each of the 49 is made up of many sub frames taken at different wavelengths it used a total of 1860 frames taking 220 hours to collect. And this is just the work of one amateur, Rogelio Bernal Andreo.

Also software to combine hundreds of images taken by various cameras at various angles and image scale already exists on the commercial market. Why they invented their own I don't know. RegiStar has been doing this for many years. Newcomers such as PixInsight and a combination of three programs by CCDWare have joined the market. Though for this project the older RegiStar would be my choice as it doesn't have memory issues the others do when dealing with so many images.

As to UGC 8621 it is what Arp called a spiral galaxy with one heavy arm and that back in the 60's. Again nothing new or cutting edge about it. As I like to image galaxies that fit his peculiar galaxy categories it is on my to-do list. But if they really wanted high resolution images of it the Sloan image is again already far better than most amateurs can take as they have seeing many times better than most do and apertures to take advantage of this. Gemini North could improve on that several fold in only 2 minutes of time. Galaxy zoo astronomers could be able to convince some one to use their time to spend 2 minutes on it if there really was a need. It is a Seyfert 1.8 (some say Seyfert 2) galaxy about 280,000 light-years distant so closer than these in my post but also much smaller in physical size so more difficult to pull detail from an image unless seeing is excellent which mine rarely is. Thus it's been on the list now for 7 years and never a sufficient night to give it a go. Under perfect conditions I could do it at 0.5" per pixel (0.8 for the cropped version the the galaxy group above). I've attached the SDSS9 image at 0.1". No amateur could hope to improve on that. Also for real data using a spectroscope to get measurements of its rotation curve and if odd a detailed curve at many points would be necessary and no amateur can collect the light needed nor afford a spectroscope with sufficient dispersion to make such measurements. So again I don't know what they plan to accomplish other than pointing out amateurs can image galaxies at this distance, something we've been doing for years.

Rick

Rick,

lots of detail in these tiny galaxies.

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


The WBL 687 galaxy group is a small group of 3 galaxies in Pegasus just
west of the northeastern star of the Great Square, Beta Pegasi. Red
shift puts the group about 420 million light-years distant. The group
consists of NGC 12191, UGC 12193 and CGCG 474-032. Redshift also shows
UGC 12198 to be of about the same redshift. Out of my frame to the
north, UGC 12194 is a similar galaxy with a very slightly greater
redshift that puts it 430 million light-years distant. These 5 likely
constitute the PPS2 007 group. Though it is centered just above NPM1G
+27.0631 which has no redshift but appears to be more distant so likely
this is just coincidence. Still I'd like to know more about this galaxy
as it appears to have a plume to the southwest yet no interacting
companion is to be found. Is it the result of a merger?

UGC 12191 is a SB spiral at 420 million light-years by redshift but
about 100 million light-years closer by other measurements. Since the
other galaxies all have the same redshift as it has I'm going to go with
the redshift distances here though this results in a very large galaxy.
It is a nearly face on Sb spiral that's some 165,000 light-years across
if the 420 million light-year distance is correct. Going with the
nearer distance makes it 130,000 light-years in diameter, still very
large as spiral go.

UGC 12193 is listed at NED as a SB(s)bc spiral and is seen fully face
on. It is slightly larger in angular size though looks much larger
since it is seen almost fully face on. It's size works out to be
175,000 light-years in diameter. There was no non redshift distance
estimates for it.

The third, much smaller, member is CGCG 474-032. It is a rather normal
sized spiral at 65,000 light-years in diameter. It appears to be an
old, dying spiral by its mostly red color. It stands in rather stark
contrast to the vibrant star formation in the larger spirals evidenced
by their strong blue color.

The two UGC galaxies are separated by only 110 seconds of arc. If they
are at the same distance that would mean they could be as close as a
quarter of a million light-years. I'd expect some tidal distortion
though if this is their first time close that might not show as yet.
Still I think it likely there's more separation than this between them.
Of course the might be unrelated though I find this unlikely.

The probable 4th member of the group UGC 12198 is seen rather edge on,
still it is rather large at 110,000 light-years across. It too seems to
still have active star formation unlike CGCG 474-032.

There's not a lot on this field at NED. As such I broke my usual rule
and annotated all galaxies at NED in the field, not just those with
redshift distance. I didn't include those that are listed as UvS
sources as most are stars and separating the two nearly impossible with
more than 400 listed in this image to sort through.

14" LX200R at f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick


--
WA0CKY