NGC 3628  (Arp 317)



NGC 3628  is a member of the Leo Triplet of galaxies with M65 and M66. It is also listed as Arp 317 in Halton Arp's "Atlas of Peculiar Galaxies".

It is an edge on spiral that is undergoing a major internal disturbance similar to the state of Messier 82 - 'The Starburst Galaxy'.

Halton Arp together with Margaret and Geoffrey Burbidge believe that this galaxy is the source of  an inordinate number of X-ray sources in its immediate vicinity. ROSAT observations have shown that these x-ray sources are either quasars or compact active galaxies.

There are also two main plumes of  neutral hydrogen that have been radio-mapped across the minor axis of the galaxy. 10 of these quasars are aligned with the galaxies hydrogen plume, the ones to the south are particularly well aligned. One arcminute to the south is a visible filament that links directly  to a quasar of  discordant redshift of 2.15.










I attempted to take a long exposure (6x300s) CCD image of this area with a C9.25 @ f/5.6
to try and reveal some of these features. The image to the right is just beginning to show the faint plume to the south of the galaxy.
Here is another image I took in January 2004 with 50cm f/4 (10 x 20sec)
from Worth Hill Observatory.









This reversed contrast stretch image reveals the plume and in addition quasar like sources F1-F6. F1 is a comet shaped knot.
F2 and F5 are are quasars with a redshift of 0.99 and  2.15.
F3 is a double irregular blue galaxy of unknown redshift. To the north of the plume is F6 a blue compact object of unknown redshift

(Ref: "The Arp Atlas of Peculiar Galaxies - A Chronicle and Observers Guide" - Jeff Kanipe and Dennis Webb. pp 90 showing a deep image of this object taken by the European Southern Observatory).

Click on image to enlarge.
Arp believes this is further evidence to show that quasars may be ejected  from galaxies, and show an intrinsic redshift.
For more on my observations of Arp Galaxies and discordant redshifts look here.


"For some, astronomy faces new and unusual phenomena that call for new ideas. For others, these phenomena are best swept under the rug."
--Geoffrey Burbidge (UC, San Diego)
Prof. Geoffrey Burbidge and Jayant Narlikar have just written a new book titled "Facts and Speculations in Cosmology" which is due to be published in July 2008 (ISBN: 0521865042). Anomalous observations are discussed and an alternative  theory of the origin of the universe is put forward. The front cover is an image of NGC 4319 linked by a bridge to quasar Mrk 205, which was  taken by the 50cm Newtonian at Worth Hill Observatory. Halton Arp also used this image in his recent book "Catalogue of Discordant Redshift Associations.