Two extremely compact Hα-emitting sources have been discovered in our deep images of the Abell 539 and Abell 634 clusters of galaxies. Follow-up spectroscopy of these two unresolved sources have revealed that they are active starburst members of their respective clusters. The Hα luminosities and extreme Hα equivalent widths (of ≃ 430 Å and 1010 Å

We express in linearized form the five classical coupled equations representing the rotating gas disk of a standard disk galaxy. We solve them in three limiting cases for the gas disk: 1) infinite thickness and uniform rotation, 2) finite thickness and uniform rotation, and 3) infinite thickness and shearing box approximating differential rotation

In this proceedings paper we make use of the two-dimensional stellar kinematics of a representative sample of E and S0 galaxies obtained with the SAURON integral-field spectrograph to reveal that early-type galaxies appear in two broad flavors, depending on whether they exhibit clear large-scale rotation or not. We measure the level of rotation via

We present our new scheme for the classification of radial stellar surface brightness profiles for disk galaxies. We summarize the current theoretical attempts to understand their origin and give an example of an application by comparing local galaxies with their counterparts at high redshift (z≈ 1).[-0.8cm]

The volatile abundances in comet 17P/Holmes were measured on three dates (UT 2007 October 27.6 and 31.3 and November 2.3) using high-dispersion (λ/Δλ~2.5×104) infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory and CSHELL at the NASA Infrared Telescope Facility. Compared to other comets, the relative gas production rates in the coma

We study the structural properties of the low surface brightness stellar hosts in blue compact galaxies by fitting a two-dimensional Sérsic law to their optical images. The accurate isolation of the starburst emission is an important strength of the method. It allows us to obtain more reliable structural parameters, especially when a Sérsic law is