We present mid-IR observations of a sample of very low-mass stars and brown dwarfs in the Upper Scorpius association. The main goal of these observations is to derive the disk frequency and the disk properties of the sample in order to shed light on brown dwarf formation theories. The observations have been performed with VISIR at the Very Large

The Virgo Intra-Cluster Stars (VICS) project is a 37 orbit HST program to study the stellar constituents of Virgo's intracluster space. The survey is centered on a region of space 180 kpc (projected) from the nearest major galaxy (M 86), at a location where the underlying cluster surface brightness is μ V ˜ 27.5 ± 0.5. The data include extremely

We report the discovery of a very low-luminosity (MV -10) dwarf galaxy in the Virgo Cluster within the ACS field of the VICS Project (Ciardullo et al.). The galaxy, which is ˜ 1 kpc in extent, is clearly resolved into stars, and provides us with the first direct look at the stellar population of a low-luminosity system in a galaxy cluster. A F606W

Deep HST ACS images of Virgo from the VICS project (Ciardullo et al.) contain 4 resolved objects that appear to be intergalactic globular clusters (IGCs). Evidence for this interpretation comes from the objects' integrated colors and magnitudes, which are consistent with those of Virgo globulars, their radial surface brightness profiles, which are

We continue the development of our Voronoi Galaxy Cluster Finder (VGCF) technique by applying it to galaxy catalogs obtained with B and R band observations of four high galactic latitude fields of 0.5 × 0.5 square degrees each. These fields are deep (Rlim ˜ 23, Blim ˜ 26) and partially overlap the Palomar Distant Cluster {Survey} (PDCS) fields at

We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodeled gravitational-wave bursts in 473 hr of coincident data collected during early 2003. No candidate signals were found. We set an upper limit of 0.12 events per day on the rate of detectable gravitational-wave