We present a mid-infrared investigation of the scaling relations between supermassive black hole masses (MBH) and the structural parameters of the host spheroids in local galaxies. This work is based on 2D bulge-disc decompositions of Spitzer/IRAC 3.6 μm images of 57 galaxies with MBH estimates. We first verify the accuracy of our decomposition by examining the Fundamental Plane (FP) of spheroi...

Young galactic X-ray point sources (XPs) closely trace the ongoing star formation in galaxies. From measured XP number counts we extract the collective 2-10 keV luminosity of young XPs, L x , which we use to gauge the current star-formation rate (SFR) in galaxies. We find that, for a sample of local star-forming galaxies (i.e., normal spirals and mild starbursts), L x correlates linearly with t...

Dwarf, irregular and infrared-luminous starburst galaxies are all known to have “steep” luminosity functions with faint-end behavior roughly φ(L) ∝ L−1.8. This form is exactly what is expected if the luminosities of these objects fade with time as L ∝ t−1.3, because the objects spend more time at low luminosities than high, even if they form with a wide range of initial masses. Models of young ...

Courteau et al. (2007a) reported on the dependence of the ratio of a galaxy’s maximum circular velocity, Vc, to its central velocity dispersion, σ0, on morphology, or equivalently total light concentration. This Vc − σ0−concentration relation, which involves details about the local and global galaxy physics, poses a fundamental challenge for galaxy structure models. Furthermore, not only must t...

The presence of dilute hot cavities in the intracluster medium (ICM) at the cores of clusters of galaxies changes the relation between gas temperature and its X-ray emission properties. Using the hydrostatic equations of a porous medium we solve for the ICM density for a given temperature as a function of the filling factor of dilute bubbles. We find that at a given temperature, the core X-ray ...

After recalling a general non-perturbative expression for the luminosity-redshift relation holding in a recently proposed “geodesic light-cone” gauge, we show how it can be transformed to phenomenologically more convenient gauges in which cosmological perturbation theory is better understood. We present, in particular, the complete result on the luminosity-redshift relation in the Poisson gauge...

Recent work suggests that rich clusters of galaxies commonly have large populations of dwarf (ie. low luminosity) members, that is their luminosity function (LF) turns up to a steep slope at the faint end. This population, or more particularly the relative numbers of dwarfs to giants, appears to be very similar for clusters of similar morphology, but may vary between cluster types. We have prev...

Since molecular gas is distributed in the inner disk of galaxies while HI in the outer disk, CO emission can trace the inner rotation curves more accurately than HI. We have derived most-completely sampled rotation curves by combining HI and CO position-velocity diagrams. We show that inner rotation curves have a steep increase within the central few hundred-pc region. The inner behavior of rot...

This is the fifth paper in a series studying the stellar components, star formation histories, star formation rates and metallicities of a blue compact galaxy (BCG) sample. Based on our high-quality groundbased spectroscopic observations, we have determined the electron temperatures, electron densities, nitrogen abundances and oxygen abundances for 72 star-forming BCGs in our sample, using diff...

We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the formation of cluster galaxies. We calculate the evolution of clusters by combining the semi-analytic model of galaxy formation of Cole et al. with a simple model for the thermodynamic properties of the intracluster medium. We focus on the clust...