We analyze the activity of 89 comets observed with the Spitzer Space Telescope.We conclude that at least 24% of Jupiter-family comets are active at 3–7 AU.Comets are more likely to be active post perihelion.We find that all survey targets comets with perihelion inside of 1.8 AU are inactive.

Using a compilation of 379 massive (stellar mass M ≳ 1011 M⊙) spheroid-like galaxies from the near-infrared Palomar/DEEP-2 survey, we investigated, up to z ˜ 1, whether the presence of companions depends on the size of the host galaxy. We explored the presence of companions for mass ratios with respect to the central massive galaxy down to 1 : 10

Not Available

Studying the properties of the few compact massive galaxies that exist in the local Universe (Trujillo et al. 2009) might provide a closer look to the nature of their high redshift (z >= 1.0) massive counterparts. By this means we have characterized their main kinematics, structural properties, stellar populations and star formation histories with

We study the galaxy stellar mass function in different environments in the local Universe, considering both the total mass function and that of individual galaxy morphological types. We compare the mass functions of galaxies with log10M*/M⊙ ≥ 10.25 in the general field and in galaxy groups, binary and single galaxy systems from the Padova

We have analyzed the radial distribution of old stars in a sample of 218 nearby face-on disks, using deep 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. In particular, we have studied the structural properties of those disks with a broken or down-bending profile. We find that, on average, disks with a genuine single