We use optical integral field spectroscopy (IFS) of nearby supernova (SN) host galaxies (0.005 2.4 Gyr, respectively) than the massive SN Ia hosts (0.04%, 2.01%, and 97.95% in these intervals). We estimate that the low-mass galaxies produce ten times fewer SNe Ia and three times fewer CC SNe than the high-mass group. Therefore the ratio between the

We have characterized the physical properties (electron temperature, density and metallicity) of the ionized gas and the ionizing population (age, metallicity and presence of Wolf-Rayet stars) in the Lynx arc, an HII galaxy at z= 3.36. The ultraviolet doublets (i.e. CIII], SiIII] and NIV) imply the existence of a density gradient in this object

With the NEOWISE portion of the Wide-field Infrared Survey Explorer (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 μm, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether

We report on the discovery and analysis of a striking neutral sodium gas tail associated with comet C/1995 O1 Hale-Bopp. Sodium D line emission has been observed at heliocentric distance r

The X17.0 solar flare of September 07, 2005 released high-energy neutrons, that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In two separate and independent studies of this solar neutron event, the energy spectra as a power law was calculated ( Sako, T., et al., 2006, ApJ, 651, 69. Watanabe, K., et al., 2006. ApJ, 636

We present intermediate- and low-resolution optical spectroscopy (650-915 nm) of seven faint, very red objects ( 20>I>=17.8 , I-Z>= 0.5) discovered in a CCD-based IZ survey covering an area of 1 deg2 in the central region of the Pleiades open cluster. The observed spectra show that these objects are very cool dwarfs having spectral types in the