A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Others » Astro Pictures
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

ASTRO: NGC 2793 Another Arp didn't include but could have



 
 
Thread Tools Display Modes
  #1  
Old July 10th 14, 06:37 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2793 Another Arp didn't include but could have

NGC 2793 is another galaxy I'm surprised Arp didn't find a place for in
his Atlas of Peculiar Galaxies. It certainly is peculiar and quite
similar to Arp 6/NGC 2537 but with "wind effects". He has a category
for interacting galaxies he calls "Wind Effects". NGC 2793 certainly
appears to have a strong east wind blowing across it creating wispy blue
streaks across it. It also is a ring galaxy which he included but again
these were interacting galaxies. In fact ring galaxies like 2793 are
usually thought to be the result of a near direct hit on the core of a
spiral by a dense "bullet" galaxy. Yet there's no candidate for a
"bullet" in this case. I found only a couple papers discussing this.
They mention LEDA 082356 as a possible "bullet" saying it's redshift is
unknown. Turns out it is now known and at nearly 4 times the distance
can't be the cause. Neither paper considers the bright core might hide
a dense superimposed bullet nor has their apparently been any followup
studies of this galaxy. I find the rectangular core shape another
oddity. Usually the pushed to the ring the core takes on an arc that
matches the ring's arc. It may be this galaxy just naturally looks this
way but I find that hard to believe. The ring of star clusters along
the edge is hard to explain without some outside force being involved.

The long diameter of NGC 2793 measures about 29,000 light-years assuming
the 89 million light-year distance. It is located in southeastern Lynx
on the northwestern edge of the Abell 779 galaxy cluster. It isn't
related to that cluster which is about 320 million light-years distant.
It is likely the distant "companion" is an outlying member of the cluster.

The annotated image notes all galaxies in the field for which NED had
redshift data. If the galaxy had a name listed in NED other than just
one that was its coordinates it is noted. Otherwise a G denotes a
galaxy and Q a quasar. One stellar object was listed as a candidate
BLAGN (Broad Line Active Galactic Nucleus) which is likely a underfed
quasar or one hidden behind the galaxy's stars and dust. As light travel
time distances are rather questionable at such high redshifts the
redshift z value is also given for distant quasars when Z is greater than 1.

One asteroid was sneaking out of the frame in the lower right corner
when I started the luminance data and is noted in the annotated image.
One red frame was totally lost to clouds and the remaining frame very
noisy so red data is a questionable. I didn't realize this until I went
to process it months later and too late to reshoot.

14" LX200R @ f/10, L=4x10, R (poor)=1x10' GB=2x10', STL-11000XM,
Paramount ME

Rick

--
Prefix is correct. Domain is arvig dot net

Attached Thumbnails
Click image for larger version

Name:	NGC2793L4X10R1X10GB2X10R.JPG
Views:	376
Size:	309.6 KB
ID:	5197  Click image for larger version

Name:	NGC2793L4X10R1X10GB2X10-ID.JPG
Views:	244
Size:	179.2 KB
ID:	5198  Click image for larger version

Name:	NGC2793L4X10R1X10GB2X10R-CROP125.JPG
Views:	132
Size:	112.5 KB
ID:	5199  
  #2  
Old July 10th 14, 08:56 AM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 2793 Another Arp didn't include but could have

Since I mentioned Arp 6, the Bear Paw Galaxy, here's a link to it at
0.5" per pixel. It dates back to 2008 when my image processing software
and skills were both rather limited. I need to reprocess it.
http://www.spacebanter.com/attachmen...0&d=1205525843

Rick
  #3  
Old July 12th 14, 04:30 PM posted to alt.binaries.pictures.astro
Stefan Lilge
external usenet poster
 
Posts: 2,269
Default ASTRO: NGC 2793 Another Arp didn't include but could have

Rick,

this galaxy indeed looks like NGC 2537. Good find.

Stefan


"Rick Johnson" schrieb im Newsbeitrag
. com...

NGC 2793 is another galaxy I'm surprised Arp didn't find a place for in
his Atlas of Peculiar Galaxies. It certainly is peculiar and quite
similar to Arp 6/NGC 2537 but with "wind effects". He has a category
for interacting galaxies he calls "Wind Effects". NGC 2793 certainly
appears to have a strong east wind blowing across it creating wispy blue
streaks across it. It also is a ring galaxy which he included but again
these were interacting galaxies. In fact ring galaxies like 2793 are
usually thought to be the result of a near direct hit on the core of a
spiral by a dense "bullet" galaxy. Yet there's no candidate for a
"bullet" in this case. I found only a couple papers discussing this.
They mention LEDA 082356 as a possible "bullet" saying it's redshift is
unknown. Turns out it is now known and at nearly 4 times the distance
can't be the cause. Neither paper considers the bright core might hide
a dense superimposed bullet nor has their apparently been any followup
studies of this galaxy. I find the rectangular core shape another
oddity. Usually the pushed to the ring the core takes on an arc that
matches the ring's arc. It may be this galaxy just naturally looks this
way but I find that hard to believe. The ring of star clusters along
the edge is hard to explain without some outside force being involved.

The long diameter of NGC 2793 measures about 29,000 light-years assuming
the 89 million light-year distance. It is located in southeastern Lynx
on the northwestern edge of the Abell 779 galaxy cluster. It isn't
related to that cluster which is about 320 million light-years distant.
It is likely the distant "companion" is an outlying member of the cluster.

The annotated image notes all galaxies in the field for which NED had
redshift data. If the galaxy had a name listed in NED other than just
one that was its coordinates it is noted. Otherwise a G denotes a
galaxy and Q a quasar. One stellar object was listed as a candidate
BLAGN (Broad Line Active Galactic Nucleus) which is likely a underfed
quasar or one hidden behind the galaxy's stars and dust. As light travel
time distances are rather questionable at such high redshifts the
redshift z value is also given for distant quasars when Z is greater than 1.

One asteroid was sneaking out of the frame in the lower right corner
when I started the luminance data and is noted in the annotated image.
One red frame was totally lost to clouds and the remaining frame very
noisy so red data is a questionable. I didn't realize this until I went
to process it months later and too late to reshoot.

14" LX200R @ f/10, L=4x10, R (poor)=1x10' GB=2x10', STL-11000XM,
Paramount ME

Rick

--
Prefix is correct. Domain is arvig dot net

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ASTRO: UGC 240 Another one Arp didn't include Rick Johnson[_2_] Astro Pictures 1 April 8th 14 08:11 PM
ASTRO: Super peculiar galaxies Arp didn't include UGC 9560 and 9562 Rick Johnson[_2_] Astro Pictures 1 November 19th 13 10:16 PM
ASTRO: NGC 2715 One Arp didn't include Rick Johnson[_2_] Astro Pictures 1 October 8th 13 07:44 PM
ASTRO: NGC 7822 - Herschel didn't make a mistake. glen youman Astro Pictures 9 July 24th 10 01:39 PM
sidewalk astro - I didn't mean to start a flame war [email protected] Amateur Astronomy 8 February 14th 06 10:16 PM


All times are GMT +1. The time now is 12:12 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.