Astronomy and Astrophysics – Astronomy
Scientific paper
Jul 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994aj....108...76a&link_type=abstract
The Astronomical Journal, vol. 108, no. 1, p. 76-83
Astronomy and Astrophysics
Astronomy
23
Infrared Astronomy, Markarian Galaxies, Seyfert Galaxies, Spectral Energy Distribution, Star Formation, Galactic Nuclei, Near Infrared Radiation
Scientific paper
Near-infrared (1.2-2.4 micrometers) images are presented for the central 10 arcsec of the Seyfert 1 galaxy Markarian 231. We find a faint, but intrinsically luminous (Mk approximately -20.7) secondary peak in the near-infrared light distribution approximately 3.5 arcsec (2.7 kpc) south of the primary Seyfert 1 nucleus. Since there is no optical or infrared evidence for ongoing star formation at the location of this secondary peak, and its near-infrared luminosity and color are comparable to slightly reddened spiral bulges or elliptical nuclei, we identify this peak with the stripped nucleus of the companion galaxy involved in the Mrk 231 merger event. Depending upon the exact ratio of the masses of the primary and secondary nucleus in the Mrk 231 system we estimate a merger time scale of less than or equal to 109 yr. The morphology of the southern nucleus suggests that it may have recently survived a close passage (r less than 200 pc) with the Seyfert 1 nucleus on a highly elliptical orbit, in which case the merger time scale may be significantly shorter (approximately 107 yr. We re-calculate the average merger time scale for the seven ultraluminous infrared galaxies with double nuclei in the Bright Galaxy Sample (the BGS) of Soifer et al. (AJ, 98, 766 (1989)) and derive a value of approximately 108 yr. Since seven of ten of the ultraluminous infrared galaxies in the BGS are now known to be double, we estimate the ultraluminous 'phase' may be close to this value. Along with Arp 220 and Mrk 273, Mrk 231 is the third member of the class to possess a high brightness temperature non-thermal radio core and a double nucleus, suggesting the time scale for the generation or fueling of the active nucleus can be much less than the dynamical time scale for the merger of the progenitor nuclei.
Armus Lee
Graham James R.
Larkin James E.
Matthews Keith
Soifer Thomas B.
No associations
LandOfFree
Near-infrared imaging of Markarian 231: Evidence for a double nucleus does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Near-infrared imaging of Markarian 231: Evidence for a double nucleus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Near-infrared imaging of Markarian 231: Evidence for a double nucleus will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1252604