In a previous study, Virtual Observatory tools were used to cross-match the IPHAS catalogue with the 2MASS catalogue for searching young very low-mass objects. We defined photometric criteria to identify Halpha emission sources with near-infrared colors similar to known young very low-mass stars and brown dwarfs. Spectral types have been derived

We present the analysis of the photometric and spectroscopic properties of a pilot sample of spectroscopically-confirmed intermediate-redshift blue compact dwarf galaxies (BCDs) located in the Hubble Ultra Deep Field. We found that applying the classic BCD definition, we recover a mix of galaxies with a wide range of star-forming activity

According to theory, high energy emission from the coronae of cool stars can severely erode the atmosphere of orbiting planets. To test the long term effects of the erosion we study a large sample of planet-hosting stars observed in X-rays. The results reveal that massive planets (M_p sin i > 1.5 Mjup) may survive only if exposed to low accumulated

We present a detailed study of PKS 1814-637, a rare case of powerful radio source (P5 GHz = 4.1 × 1025 W Hz-1) hosted by a disk galaxy. Optical images have been used to model the host galaxy morphology confirming it to be dominated by a strong (and warped) disk component that is observed close to edge-on to the line of sight. This is the first

In this work we analyze the star formation rates and stellar masses of a sample of 157 star forming galaxies at z ˜ 0.84 (Villar et al. 2008), selected by their Hα flux with a narrow band filter. We compare star formation rates (SFR) measured with different tracers (Hα, UV and IR) finding that they are in good agreement after extinction correction

The aim of this study is to determine the physical parameters of the binary V1430 Aql from the study of light curves obtained in different filters V, R, I, J and K using the code BINAROCHE, radial velocity curves published by Popper (2000) and analysis of spectra covering the range 3000 A to 9000 A. The results indicate that the spectral types of