The Stellar Content of Active Galaxies

Stellar Populations in the Central Galaxies of Fossil Groups

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

The stellar content of brightest cluster galaxies

We present near-infrared K-band spectroscopy of 21 elliptical or cD Brightest Cluster Galaxies (BCGs), for which we have measured the strength of the 2.293 µm CO stellar absorption feature. We find that the strength of this feature is remarkably uniform among these galaxies, with a smaller scatter in equivalent width than for the normal elliptical population in the field or clusters. The scatte...

Stellar Populations in Active Galaxies

The role of stars and starbursts in AGN has been a recurring issue for nearly as long as AGN have been recognized as hosts of interesting phenomena. The heated “starburst versus monster” controversy of the 80’s and 90’s was gradually replaced by “starburst plus monster” studies, as observational work in the past decade has firmly established that accretion onto a super-massive black-hole and st...

Classification & Stellar Content of Galaxies - A. Sandage

Measuring Stellar Velocity Dispersions in Active Galaxies

We present stellar velocity dispersion (σ∗) measurements for a significant sample of 40 broad-line (Type 1) active galaxies for use in testing the well-known relation between black hole mass and stellar velocity dispersion. The objects are selected to contain Ca II triplet, Mg Ib triplet, and Ca H+K stellar absorption features in their optical spectra so that we may use them to perform extensiv...