Bibcode
Graham, A. W.; Trujillo, I.; Erwin, P.
Bibliographical reference
American Astronomical Society Meeting 203, #116.20; Bulletin of the American Astronomical Society, Vol. 35, p.1399
Advertised on:
12
2003
Citations
0
Refereed citations
0
Description
We investigate the nuclear and global structure of early-type galaxies,
and the apparent disparity between the Nuker and Sersic models for
radial light profiles. We show that the so-called "power-law" galaxies
in fact have Sersic r1/n profiles over their entire observed
radial range. Consequently, only three (Sersic-profile) parameters are
required to simultaneously describe both the inner (HST-resolved) and
outer profiles of low-luminosity (M > -20.5 B-mag) elliptical
galaxies. We also find that "core galaxies" have Sersic profiles with a
(partially evacuated) single power-law core. We have developed a
modified (5-parameter) Sersic profile with a power-law core to model the
complete radial extent of luminous galaxies with cores. In addition to
quantifying the global stellar distribution in these systems, we have
derived new estimates of their core radii (and central mass deficits)
and compare these with values obtained using the (5-parameter) Nuker
model.
Support for proposal number HST-AR-09927.01-A was provided by NASA
through a grant from the Space Telescope Science Institute, which is
operated by the Association of Universities for Research in Astronomy,
Inc., under NASA contract NAS5-26555.