A new transient X-ray source was discovered in the 2011 August 26 Chandra ACIS observation of M31 (OBSID 12973), at RA = 00:42:11.37 DEC = +41:04:25.51. This system is likely to be a low mass X-ray binary with a black hole primary. The emission spectrum contained ~250 net source counts, and was well described by a power law with photon index 1.4 ±

We explore the possibility of discriminating dark energy models from the study of the growth of matter perturbations. For the sake of simplicity, instead of dealing with a great number of models, we have chosen a simple model of dark energy (px=ω0ρxγ, with ω0 0; px, and ρx being pressure and energy density), which is able to reproduce a great

So as to meet the requirements of high spatial resolution techniques, two data acquisition interfaces for ITV and IPD detectors have been developed. These permit a synchronized and simultaneous observation between both of them. The synchronized temporal resolution is 20ms, as well as the data of the ITV, while the reading interface from the IPD

The black hole binary V404 Cyg has provided a primary test bed for models of accretion in quiescent black hole binaries because it is by far the brightest in the X-ray band. Most published work, however, has been based on non-simultaneous data spanning many years since its major outburst in 1989. We present the most complete spectral energy

Using data from the Near-Infrared S0 Survey of nearby, early-type galaxies, we examine the distribution of bar strengths in S0 galaxies as compared to S0/a and Sa galaxies, and as compared to previously published bar strength data for Ohio State University Bright Spiral Galaxy Survey spiral galaxies. Bar strengths based on the gravitational torque

CCD photometry of faint stars in the globular cluster M3 is presented. The observations reach down to V equal to about 23 mag, with a sample of approximately 5000 stars. The resulting color magnitude diagram has a turn-off significantly redder than those obtained in previous studies. Age and distance are derived by fitting the observed mean line to