RT Journal Article
T1 Radial variation of attenuation and star formation in the largest late-type disks observed with GALEX
A1 Gil De Paz, Armando
AB For a sample of 43 nearby, late-type galaxies, we have investigated the radial variation of both the current star formation rate and the dust-induced UV light attenuation. To do this we have cross-correlated IRAS images and GALEX observations for each of these galaxies and compiled observations of the gas (CO and H I) and metal-abundance gradients found in the literature. We find that attenuation correlates with metallicity. We then use the UV profiles, corrected for attenuation, to study several variants of the Schmidt law and conclude that our results are compatible with a simple law similar to the one of Kennicutt extending smoothly to lower surface densities, but with considerable scatter. We do not detect an abrupt break in the UV light at the threshold radius derived from Hα data (at which the Hα profile shows a break and beyond which only a few H II regions are usually found). We interpret the Hα sudden break not as a change in the star formation regime (as often suggested), but as the vanishingly small number of ionizing stars corresponding to low levels of star formation.
PB University Chicago Press
SN 0067-0049
YR 2007
FD 2007-12
LK https://hdl.handle.net/20.500.14352/51746
UL https://hdl.handle.net/20.500.14352/51746
LA eng
NO © 2007. The American Astronomical Society. All rights reserved. Artículo firmado por 27 autores. GALEX (Galaxy Evolution Explorer) is a NASA Small Explorer, launched in 2003 April. We gratefully acknowledge NASA’s support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d’Etudes Spatiales of France and the Korean Ministry of Science and Technology. A. G. d. P. is partially financed by the Spanish Programa Nacional de Astronomía y Astrofísica under grant AYA2003-01676. We also thank the MAGPOP network for its support, and the referee for very constructive comments.
NO Programa Nacional de Astronomía y Astrofísica (PNAyA), España
NO Marie Curie Research Training Actions (UE)
NO Unión Europea. FP6
NO Sexto Programa Marco de la UE FP6
DS Docta Complutense
RD 6 sept 2025