Results 1 to 3 of 3

Thread: Object of the Week January 19, 2014 Discordant Redshifts A few Examples from Dr Arp

  1. #1
    Co-Founder DSF.com Jimi Lowrey's Avatar
    Join Date
    Feb 2012
    Location
    Fort Davis Texas
    Posts
    570

    Object of the Week January 19, 2014 Discordant Redshifts A few Examples from Dr Arp

    I have had Dr Halton "Chip" Arp on my mind a lot the last few weeks since his passing. It seems to me after the many many hours reading his papers over the years that I have lost a old friend. I thought for this OOTW I would show a few examples of his many discordant redshift galaxies. I know most of you know of the poster child of discordant redshift NGC 4319 and Mrk 205 here are a few others.

    NGC 7603 AKA Arp 92

    Pisces

    RA
    23 18 56
    DEC
    +00 14 38

    Redshift

    NGC 7603 Z .029524

    NGC 7603B Z .055742

    NGC 7603.jpg

    It sure looks like the galaxies are interacting? What do you think?

    This object is from the 1971 paper if you would like to read more http://adsabs.harvard.edu/abs/1971ApL.....7..221A

    ------------------------------

    NGC 1199 AKA Hickson 22A and 2Masxi j0303366-153740

    Eridanus

    RA
    03 03 38
    DEC
    -15 36 50

    Redshift

    NGC 1199 Z.008573

    2MASXi j0303366-153740 Z.044400

    ARP 1978 NGC 1199.jpgsdss ngc1199.jpg

    Arp thought that the 2 Masxi galaxy was foreground of NGC 1199? I am not so sure? What do you think?

    This is from the 1978 paper http://adsabs.harvard.edu/abs/1978ApJ...220..401A

    -----------------------------

    NGC 1232 AKA Arp 41 and NGC 1232A

    Eridanus

    RA
    03 39 45
    Dec
    -20 34 52

    Redshift

    NGC 1232 Z.005347

    NGC 1232A Z.022012

    NGC1232.jpg

    NGC 1232 sure looks like it is merging with NGC 1232A to me this one is a real head scratcher. What do you think??

    This Object is from the 1982 paper.http://adsabs.harvard.edu/abs/1982ApJ...263...54A

    These are just a few of Arps examples of galaxies with discordant redshifts, I have enjoyed viewing many of them over the years and will continue to read and seek out others to observe. Halton "Chip" Arp might be gone but I am sure he will not soon be forgotten. I know that I will think of him every time I observe one of his "Peculiar Galaxies"! Thanks for the Memories!

    "GIVE IT A GO AND LET US KNOW"

    GOOD LUCK AND GREAT VIEWING!
    Last edited by Jimi Lowrey; January 19th, 2014 at 08:38 PM.
    Clear Skies,

    Jimi Lowrey
    Fort Davis Texas

    48"F4 OMI/TEC
    28'F4 ATM

  2. #2
    Member
    Join Date
    Feb 2012
    Location
    Germany
    Posts
    813
    Good choice to dedicate the OOTW to Arp's objects Jimi. And the objects are also well chosen, I love to look at those discordant redshift galaxies.

    The two 2MASXi galaxies were to tough for my old 16", I found no entry in my observing list.

    But NGC 1232 is really a very good example to scratch heads. It really looks like an original merger. The color and these structures deceive us. I had the chance to observe and sketch both "distant" related objects from the top of the ORM at La Palma with my 14,5".



    My discordant redshift galaxy favorite is HCG 55 - VV 172. Other cool pair I remember is NGC 4496A,B - VV 76
    Clear Skies, uwe
    http://www.deepsky-visuell.de
    Germany

    27" f/4,2

  3. #3
    Member Howard B's Avatar
    Join Date
    Feb 2012
    Location
    Scappoose, Oregon USA
    Posts
    571
    Hi Jimi, I really enjoy these discordant redshift pairs too, but of the three objects above I only have one observation of NGC 7603 from December 2009. It really isn't much but here are my notes and sketch:

    "This was considerably fainter than I expected but star hopping got me to the same galaxy twice and the photo in the Arp book confirms I got the right faint galaxy - and companion! At mag 16.8 that's pretty good in these less than perfect viewing conditions. 7603 needs a darker, steadier sky but both objects are there, with "B" needing only casual averted vision to pop out. 253x and 408x, SQM 21.07."

    Arp92_N7603_crop.jpg Arp92_N7603_crop_invert.jpg
    Howard
    30-inch f/2.7 alt-az Newtonian
    https://sites.google.com/site/howardbanichhomepage/
    https://sites.google.com/site/sprays...pemirrors/home
    Contributing Editor, Sky & Telescope magazine

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •