Star formation properties of Universidad Complutense de Madrid survey galaxies
Loading...
Official URL
Full text at PDC
Publication date
2000
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Citations
Exportar
Citation
Abstract
We present new near-infrared J and K imaging data for 67 galaxies from the Universidad Complutense de Madrid (UCM) survey used in the determination of the SFR density of the local Universe by Gallego et al. This is a sample of local star-forming galaxies with redshift lower than 0.045, and they constitute a representative subsample of the galaxies in the complete UCM survey. From the new data, complemented with our own Gunn−r images and long-slit optical spectroscopy, we have measured integrated K-band luminosities, r−J and J−K colours, and Hα luminosities and equivalent widths. Using a maximum likelihood estimator and a complete set of evolutionary synthesis models, these observations allow us to estimate the strength of the current (or most recent) burst of star formation, its age, the star formation rate and the total stellar mass of the galaxies. An average galaxy in the sample has a stellar mass of 5×10^10 M_⊙ and is undergoing (or has recently completed) a burst of star formation involving about 2 per cent of its total stellar mass. We identify two separate classes of star-forming galaxies in the UCM sample: low-luminosity, high-excitation galaxies (HII-like) and relatively luminous spiral galaxies (starburst disk−like). The former show higher specific star formation rates (SFRs per unit mass) and burst strengths, and lower stellar masses than the latter. With regard to their specific star formation rates, the UCM galaxies are intermediate objects between normal quiescent spirals and the most extreme H II galaxies.
Description
© 2000 RAS.
This work is based on observations obtained at the Lick Observatory, operated by the University of California and on observations collected at the German-Spanish Astronomical Centre, Calar Alto, Spain, operated by the Max-Planck Institute fur Astronomie (MPIE), Heidelberg, jointly with the Spanish Commission for Astronomy. It is also partly based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Royal Greenwich Observatory in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. A. Gil de Paz thanks the Institute of Astronomy of the University of Cambridge for all the facilities and support during his stay there. J. Gallego and A. Gil de Paz acknowledge the invitation, hospitality and facilities provided during the 3rd Guillermo Haro Workshop, included in the Guillermo Haro Programme at the INAOE (Mexico). We also thank C.E. García Dabó, C. Sánchez Contreras and R. Guzmán for stimulating conversations and the referee Dr. M. Edmunds for his useful comments and suggestions. A. Gil de Paz acknowledges the receipt of a Formación del Profesorado Universitario fellowship from the Spanish Ministry of Education. A. Aragón Salamanca acknowledges generous financial support from the Royal Society. A. Alonso Herrero was supported by NASA on grant NAG 5-3042. This research was also supported by the Spanish Programa Sectorial de Promoción General del Conocimiento under grants PB96-0610 and PB96-0645. This work was partially carried out under the auspices of EARA, a European Association for Research in Astronomy, and the TMR Network on Galaxy Formation and Evolution funded by the European Commission.