J/MNRAS/338/508 Photometry+spectroscopy of UCM galaxies (Perez-Gonzalez+, 2003)
Stellar populations in local star-forming galaxies.
I. Data and modelling procedure.
Perez-Gonzalez P.G., Gil de Paz A., Zamorano J., Gallego J.,
Alonso-Herrero A., Aragon-Salamanca A.
<Mon. Not. R. Astron. Soc. 338, 508 (2003)>
=2003MNRAS.338..508P 2003MNRAS.338..508P
ADC_Keywords: Galaxies, IR ; Galaxies, photometry ; Galaxies, spectra
Keywords: methods: data analysis - galaxies: evolution - galaxies: photometry -
galaxies: stellar content - infrared: galaxies
Abstract:
We present an analysis of the integrated properties of the stellar
populations in the Universidad Complutense de Madrid (UCM) Survey of
Hα-selected galaxies. In this paper, the first of a series, we
describe in detail the techniques developed to model star-forming
galaxies using a mixture of stellar populations, and taking into
account the observational uncertainties. We assume a recent burst of
star formation superimposed on a more evolved population. The effects
of the nebular continuum, line emission and dust attenuation are taken
into account. We also test different model assumptions, including the
choice of specific evolutionary synthesis model, initial mass
function, star formation scenario and the treatment of dust
extinction. Quantitative tests are applied to determine how well these
models fit our multiwavelength observations for the UCM sample. Our
observations span the optical and near-infrared, including both
photometric and spectroscopic data. Our results indicate that
extinction plays a key role in this kind of study, revealing that low-
and high-obscured objects may require very different extinction laws
and must be treated differently. We also demonstrate that the UCM
Survey galaxies are best described by a short burst of star formation
occurring within a quiescent galaxy, rather than by continuous star
formation. A detailed discussion on the inferred parameters, such as
the age, burst strength, metallicity, star formation rate, extinction
and total stellar mass for individual objects, is presented in Paper
II of this series.
Description:
Photometric and spectroscopic parameters for 191 galaxies in the UCM
Survey of emission-line galaxies Lists I and II (Cats. J/ApJS/95/387
and J/ApJS/105/343). For each galaxy, the table gives: redshift,
BrJKs magnitudes and errors inside 3 disk-scale circular apertures
(measured in r), Hα equivalent widths and errors, aperture sizes
in kpc, Hα/Hβ ratio (corrected for stellar absorption),
Galactic extinction, morphological type, spectroscopic type, and
absolute Ks-band magnitude.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 110 191 Photometric and spectroscopic parameters for
191 galaxies in the UCM Survey
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See also:
J/ApJS/95/387 : Universidad Complutense de Madrid list 1 (Zamorano+ 1994)
J/ApJS/105/343 : Universidad Complutense de Madrid list 2 (Zamorano+ 1996)
J/ApJS/122/415 : Universidad Complutense de Madrid list 3 (Alonso+, 1999)
J/A+AS/120/323 : Long-slit spectroscopy of UCM galaxies (Gallego+ 1996)
J/A+A/365/370 : Photometry of UCM galaxies. II. (Perez-Gonzalez+, 2001)
J/MNRAS/338/525 : Recent star formation in UCM gal. II. (Perez-Gonzalez+, 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- UCM UCM galaxy name
12- 17 F6.4 --- z Redshift
19- 23 F5.2 mag Bmag Johnson B magnitude (1)
25- 28 F4.2 mag e_Bmag rms uncertainty on Bmag
30- 34 F5.2 mag rmag ?=99.99 Gunn r magnitude (1)
36- 39 F4.2 mag e_rmag ?=9.99 rms uncertainty on rmag
41- 45 F5.2 mag Jmag ?=99.99 J magnitude (1)
47- 50 F4.2 mag e_Jmag ?=9.99 rms uncertainty on Jmag
52- 56 F5.2 mag Ksmag ?=99.99 Ks magnitude (1)
58- 61 F4.2 mag e_Ksmag ?=9.99 rms uncertainty on Ksmag
63- 67 F5.1 0.1nm EW Hα equivalent width (emission)
69- 73 F5.1 0.1nm e_EW rms uncertainty on EW
75- 79 F5.2 kpc 3dL 3 times the disk scale (2)
81- 85 F5.2 --- Ha/Hb Intensity ratio Hα to Hβ (3)
87- 91 F5.3 mag ext Galactic extinction in B (4)
93- 97 A5 --- MType Morphological type (5)
99-103 A5 --- SpType Spectroscopic type (6)
105-110 F6.2 mag KsMAG ?=999.99 Absolute Ks-band magnitude (7)
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Note (1): All magnitudes are measured inside a circular aperture of
radius 3*scale-disks measured in the r-band.
Note (2): The cosmology used is H0=70km/s/Mpc, Lambda=0.3, OmegaM=0.7.
Note (3): Hα to Hβ ratio corrected for a stellar absorption of 3Å.
Note (4): Galactic extinction from Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S)
Note (5): Morphological type based on B data, Perez-Gonzalez et al., 2001,
Cat. J/A+A/365/370).
Note (6): Spectroscopic type extracted from Gallego et al., 1996,
Cat. J/A+AS/120/323
Note (7): Absolute Ks-band magnitude corrected for Galactic extinction.
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Acknowledgements: Pablo G. Perez Gonzalez
References:
Perez-Gonzalez et al., Paper II 2003MNRAS.338..525P 2003MNRAS.338..525P, Cat. J/MNRAS/338/525
(End) Pablo G. Perez-Gonzalez [UCM, Spain] 10-Jan-2003