Bibcode
DOI
Graham, Alister W.; Erwin, Peter; Trujillo, I.; Asensio Ramos, A.
Referencia bibliográfica
The Astronomical Journal, Volume 125, Issue 6, pp. 2951-2963.
Fecha de publicación:
6
2003
Número de citas
230
Número de citas referidas
210
Descripción
The Nuker law was designed to match the inner few (~3-10) arcseconds of
predominantly nearby (<~30 Mpc) early-type galaxy light profiles; it
was never intended to describe an entire profile. The Sérsic
model, on the other hand, was developed to fit the entire profile;
however, because of the presence of partially depleted galaxy cores, the
Sérsic model cannot always describe the very inner region. We
have therefore developed a new empirical model consisting of an inner
power law, a transition region, and an outer Sérsic model to
connect the inner and outer structure of elliptical galaxies. We have
additionally explored the stability of the Nuker model parameters.
Surprisingly, none are found to be stable quantities; all are shown to
vary systematically with a profile's fitted radial extent, and often by
more than 100%. Considering elliptical galaxies spanning a range of 7.5
mag, we reveal that the central stellar densities of the underlying host
galaxies increase with galaxy luminosity until the onset of core
formation, detected only in the brightest elliptical galaxies. We
suggest that the so-called power-law galaxies may actually be described
by the Sérsic model over their entire radial range.
Based on observations made with the NASA/ESA Hubble Space Telescope,
obtained at the Space Telescope Science Institute, which is operated by
the Association of Universities for Research in Astronomy, Inc., under
NASA contract NAS 5-26555.