Stellar population and dust extinction in an ultraluminous infrared galaxy at z=1.135
arXiv:0910.2792 · doi:10.1111/j.1365-2966.2009.15873.x
Abstract
We present the detailed optical to far-infrared observations of SST J1604+4304, an ULIRG at z = 1.135. Analyzing the stellar absorption lines, namely, the CaII H & K and Balmer H lines in the optical spectrum, we derive the upper limits of an age for the stellar population. Given this constraint, the minimum {chi}^2 method is used to fit the stellar population models to the observed SED from 0.44 to 5.8um. We find the following properties. The stellar population has an age 40 - 200 Myr with a metallicity 2.5 Z_{sun}. The starlight is reddened by E(B-V) = 0.8. The reddening is caused by the foreground dust screen, indicating that dust is depleted in the starburst site and the starburst site is surrounded by a dust shell. The infrared (8-1000um) luminosity is L_{ir} = 1.78 +/- 0.63 * 10^{12} L_{sun}. This is two times greater than that expected from the observed starlight, suggesting either that 1/2 of the starburst site is completely obscured at UV-optical wavelengths, or that 1/2 of L_{ir} comes from AGN emission. The inferred dust mass is 2.0 +/- 1.0 * 10^8 M_{sun}. This is sufficient to form a shell surrounding the galaxy with an optical depth E(B-V) = 0.8. From our best stellar population model - an instantaneous starburst with an age 40 Myr, we infer the rate of 19 supernovae(SNe) per year. Simply analytical models imply that 2.5 Z_{sun} in stars was reached when the gas mass reduced to 30% of the galaxy mass. The gas metallcity is 4.8 Z_{sun} at this point. The gas-to-dust mass ratio is then 120 +/- 73. The inferred dust production rate is 0.24 +/- 0.12 M_{sun} per SN. If 1/2 of L_{ir} comes from AGN emission, the rate is 0.48 +/- 0.24 M_{sun} per SN. We discuss the evolutionary link of SST J1604+4304 to other galaxy populations in terms of the stellar masses and the galactic winds.
11 pages, 9 figures, accepted for publication in MNRAS
References in corpus (13)
- Mid-Infrared Spectral Diagnosis of Submillimeter Galaxies
- An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies
- A Significant Population of Very Luminous Dust-Obscured Galaxies at Redshift z ~ 2
- Evolution of Dust in Primordial Supernova Remnants: Can Dust Grains Formed in the Ejecta Survive and be Injected into the Early Interstellar Medium?
- Spitzer Mid-Infrared Spectroscopy of Infrared Luminous Galaxies at z~2 I: the Spectra
- Optical to mid-IR observations of Lyman-alpha galaxies at redshift 5 in the HUDF: a young and low mass population
- Obscuration in extremely luminous quasars
- The nature of faint Spitzer-selected dust-obscured galaxies
- AEGIS: Radio and Mid-Infrared Selection of Obscured AGN Candidates
- Extinction curves flattened by reverse shocks in supernovae
- Submillimeter Continuum Properties of Cold Dust in the Inner Disk and Outflows of M82
- AKARI near- and mid-infrared spectroscopy of APM 08279+5255 at z=3.91
- Optical to Near-IR Spectrum of a Massive Evolved Galaxy at z = 1.26
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