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Thread: Quasar galaxies

  1. #1
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    Quasar galaxies

    Hi everyone,

    A while ago, after observing Markarian 231, I took a look at some literature to learn more about quasars and to try to find out whether or not there are quasars, whose host galaxies can be observed visually. There is a "Catalogue of quasars and active nuclei: 13th ed.", published by M.-P. Véron-Cetty and P. Véron in 2010, which contains an impressive database of quasars, blazars and active galactic nuclei objects:

    https://www.aanda.org/articles…a1418...a14188-10.html

    http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/518/A10

    They define a quasar as follows:
    -starlike object or object with starlike nucleus
    -with broad emission lines
    -that is brighter than absolute magnitude Mblue = -22.25 mag

    Please also refer to this discussion:
    https://www.deepskyforum.com/showthr...-Markarian-231



    Earlier this week I was able to observe three objects from this list:


    PGC 54701 = MCG+11-19-006 (UMi, 15.4 bmag, 0.9' x 0.6', type E, 620 million Ly)
    According to data from Simbad its absolute blue magnitude would be -21.2 Mag. But even if it is fainter than the criterion above, physically it still is a very interesting object.
    In my 20" Dobsonian at 419x magnification I saw an elongated galaxy without structure, but with a stellar nucleus.


    NGC 6166 (Her, 11.8 mag, 2.1' x 1.5', type E, 410 million Ly)
    Absolute blue magnitude -22.7 Mag according to Simbad. Wow this is an NGC galaxy categorized as a quasar according to this paper. It is also called 3C 338.
    In my 20" Dobsonian at 419x magnification I saw a large and elongated galaxy with a diffuse outer area. The center area was mottled, sometimes I thought I saw something stellar in the center. But it doesn't look like a nucleus way brighter than the remainder of the galaxy.
    It is a lot of fun to observe so many of these members of Abell 2199 galaxy cluster around NGC 6166.


    PGC 100408 = NPM1G+27.0587 (Lyr, 14.9 bmag, 0.6' x 0.4', type Sb, 850 milllion Ly)
    According to data from Simbad its absolute blue magnitude would be -22.4 Mag, bright enough to be called a quasar according to the definition above.
    In my 20" Dobsonian at 419x magnification I observed a homogeneous and elongated smudge with a stellar center. Its appearance is rather similar to Markarian 231, but its absolute magnitude is more luminous.

    Please find attached my sketches of these objects.


    Clear skies

    Robin
    Attached Images Attached Images

  2. #2
    Member Howard B's Avatar
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    Great stuff Robin, and I'm glad you found such a straightforward definition of a quasar during your research.
    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

  3. #3
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    Helpful information and nice compilation together with practical results. Thanks for your work Robin.

    I found two entries concerning NGC 6166 in Abell 2199.

    The first sketch shows a 12'x9' field around NGC 6166. At that time I only could see the first companion of NGC 6166 at 16:28:39 / +39:33:10. The second companion was not visible.
    Abell2199.jpg
    home

    Four years later and under somewhat better seeing I could barely see the second companion at 16:28:39 / 39:33:03. It was the limit for the 27-inch and a 60/40 pop which was repeatedly visible for seconds each.
    Clear Skies, uwe
    http://www.deepsky-visuell.de
    Germany

    27" f/4,2

  4. #4
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    Hi Howard and Uwe,

    Thanks for your comments!
    Yes, the second companion was at the very limit for me for 20", visible for definitely less than 60% of the time.
    Luckily, street lights were switched off at the nearest village in the middle of the night.

    Clear skies

    Robin

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