Sigma-drop galaxies are characterized by a drop in the stellar velocity dispersion in their centers. One of the most likely theories to explain this phenomenon is that there is a young stellar population that has recently formed, and that has inherited the kinematics of the gas. We compare the morphology of the dust and the Hα emission in 20 σ-drop

After our tentative detection of an optical counterpart to CXOU J010043.1-721134 from archival Hubble Space Telescope (HST) imaging, we have followed up with further images in four bands. Unfortunately, the source originally identified is not confirmed. We provide deep photometric limits in four bands and accurate photometry of field stars around

Here, we present briefly the methodology we have implemented to study the spatial distribution of massive star formation in galaxies. To do this, we analyze a sample of 759 galaxies in a range of redshifts extending up to z˜ 1. We use data from different surveys, which span in wavelength from FUV to NIR (GALEX, COMBO17, and GOODS-HST). The aim is

The unconditional mass function (UMF) of dark matter haloes has been determined accurately in the literature, showing excellent agreement with high-resolution numerical simulations. However, this is not the case for the conditional mass function (CMF). Here, we propose a simple analytical procedure to derive the CMF by rescaling the UMF to the

Using HST/ACS broad- and narrow-band (Hα) images of M51 we have examined the ionizing radiation budget in a set of luminous H II regions in a spiral arm between 5 kpc and 11 kpc from the center. The extinctions within the regions were estimated, and a mean value for the differential extinction coefficient, RV, of 3.3, similar to the Galactic value

We present two-dimensional Hα velocity fields for ten well-defined nuclear rings observed with the DensePak fiber-optic array on the KPNO WIYN telescope. In this paper, we present detailed results for two of those rings, in NGC 1530 and NGC 4314. We conclude that in general regions of enhanced Hα, thus massive star formation, in the nuclear rings