The relatively recent insight that energy input from supermassive black holes (BHs) can have a substantial effect on the star formation rates (SFRs) of galaxies motivates us to examine the effects of BH feedback on the scale of galaxy groups. At present, groups contain most of the galaxies and a significant fraction of the overall baryon content of

We report the detection and analysis of the red giant branch (RGB) luminosity function bump in a sample of isolated dwarf galaxies in the Local Group. We have designed a new analysis approach comparing the observed color-magnitude diagrams (CMDs) with theoretical best-fit CMDs derived from precise estimates of the star formation histories of each

Following the report of the newly detected outburst of the transient XTE J1728-295 (possibly IGR J17285-2922 detected by INTEGRAL) in the RXTE PCA bulge scans (ATel #2823), we requested a Swift ToO observation to follow up the source based on the position given by the RXTE PCA best fit results (ATel #2823). The observation was performed on 2010-08

A study of two dE/dSph members of the nearby M81 group of galaxies, KDG61 and UGC5442 = KDG64, has been made. Direct Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images and integrated-light spectra of 6-m telescope of Special Astrophysical Observatory of Russian Academy of Sciences have been used for quantitative star formation

We explore whether medium-resolution stellar spectra can be reconstructed from photometric observations, taking advantage of the highly compressible nature of the spectra. We formulate the spectral reconstruction as a least-squares problem with a sparsity constraint. In our test case using data from the Sloan Digital Sky Survey, only three

The study of hot Jupiter planet atmospheres is giving rise to a surprising and intriguing diversity. Large differences in night/day contrast, chemical abundances, and physical properties are just a few examples of the variety found. A further recent addition to this complex picture is the discovery of a very strong emission feature (a factor of 4