Depleted cores, multicomponent fits, and structural parameter relations for luminous early-type galaxies

作者：Dullo Bililign T^*; Graham Alister W

来源：Monthly Notices of the Royal Astronomical Society, 2014, 444(3): 2700-2722.

DOI：10.1093/mnras/stu1590

• galaxies: elliptical and lenticular, cD
• galaxies: fundamental parameters
• galaxies: nuclei
• galaxies: photometry
• galaxies: structure

New surface brightness profiles from 26 early-type galaxies with suspected partially depleted cores have been extracted from the full radial extent of Hubble Space Telescope images. We have carefully quantified the radial stellar distributions of the elliptical galaxies using the core-Sersic model whereas for the lenticular galaxies a core-Sersic bulge plus an exponential disc model gives the best representation. We additionally caution about the use of excessive multiple Sersic functions for decomposing galaxies and compare with past fits in the literature. The structural parameters obtained from our fitted models are, in general, in good agreement with our initial study using radially limited (R less than or similar to 10 arcsec) profiles, and are used here to update several %26apos;central%26apos; as well as %26apos;global%26apos; galaxy scaling relations. We find near-linear relations between the break radius R-b and the spheroid luminosity L such that R-b proportional to L-1.13 +/- 0.13, and with the supermassive black hole mass M-BH such that R-b proportional to M-BH(0.83 +/- 0.21). This is internally consistent with the notion that major, dry mergers add the stellar and black hole mass in equal proportion, i.e. M-BH proportional to L. In addition, we observe a linear relation R-b proportional to R-e(0.98 +/- 0.15) for the core-Sersic elliptical galaxies - where R-e is the galaxies%26apos; effective half-light radii - which is collectively consistent with the approximately linear, bright-end of the curved L-R-e relation. Finally, we measure accurate stellar mass deficits M-def that are in general 0.5-4 M-BH, and we identify two galaxies (NGC 1399, NGC 5061) that, due to their high M-def/M-BH ratio, may have experienced oscillatory core-passage by a (gravitational radiation)-kicked black hole. The galaxy scaling relations and stellar mass deficits favour core-Sersic galaxy formation through a few %26apos;dry%26apos; major merger events involving supermassive black holes such that M-def proportional to M-BH(3.70 +/- 0.76), for M-BH greater than or similar to 2 x 10(8) M-circle dot.

• 出版日期2014-11-1