Star formation properties of Universidad Complutense de Madrid survey galaxies

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 cons...

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Detalles Bibliográficos
Autores: Gil De Paz, Armando, Aragón Salamanca, A., Gallego Maestro, Jesús, Alonso Herrero, A., Zamorano Calvo, Jaime, Kauffmann, G.
Tipo de recurso: artículo
Fecha de publicación:2000
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/59806
Acceso en línea:https://hdl.handle.net/20.500.14352/59806
Access Level:acceso abierto
Palabra clave:52
Hubble deep field
Emission-line galaxies
Spectral energy-distributions
Formation history
Morphological analysis
Starburst galaxies
Redshift galaxies
Disk galaxies
UCM galaxies
Ultraviolet
Astrofísica
Astronomía (Física)
Descripción
Sumario: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.