THE FMOS-COSMOS SURVEY OF STAR-FORMING GALAXIES AT z ∼ 1.6. I. Hα-BASED STAR FORMATION RATES AND DUST EXTINCTION

Journal Article · Fri Nov 01 00:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/777/1/L8· OSTI ID:22215393

Kashino, D.; Sugiyama, N. ^[1]; Silverman, J. D. ^[2]; Rodighiero, G. ^[3]; Renzini, A. ^[4]; Arimoto, N. ^[5]; Daddi, E. ^[6]; Lilly, S. J.; Carollo, C. M. ^[7]; Sanders, D. B.; Zahid, H. J.; Chu, J.; Hasinger, G.; Kewley, L. J. ^[8]; Kartaltepe, J. ^[9]; Nagao, T. ^[10]; Capak, P. ^[11]; Ilbert, O. ^[12]; Kajisawa, M. ^[13]; others, and

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1. Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya 464-8602 (Japan)
2. Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, Kashiwanoha, Kashiwa 277-8583 (Japan)
3. Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 3, I-35122 Padova (Italy)
4. INAF Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, I-35122 Padova (Italy)
5. National Astronomical Observatory of Japan, Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States)
6. CEA-Saclay, Service d'Astrophysique, F-91191 Gif-sur-Yvette (France)
7. Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-strasse 27, 8093 Zürich (Switzerland)
8. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
9. National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ 85719 (United States)
10. The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8302 (Japan)
11. California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)
12. Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France)
13. Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan)

We present the first results from a near-IR spectroscopic survey of the COSMOS field, using the Fiber Multi-Object Spectrograph on the Subaru telescope, designed to characterize the star-forming galaxy population at 1.4 < z < 1.7. The high-resolution mode is implemented to detect Hα in emission between 1.6-1.8 μm with f {sub Hα} ∼> 4 × 10{sup –17} erg cm{sup –2} s{sup –1}. Here, we specifically focus on 271 sBzK-selected galaxies that yield a Hα detection thus providing a redshift and emission line luminosity to establish the relation between star formation rate and stellar mass. With further J-band spectroscopy for 89 of these, the level of dust extinction is assessed by measuring the Balmer decrement using co-added spectra. We find that the extinction (0.6 ∼< A {sub Hα} ∼< 2.5) rises with stellar mass and is elevated at high masses compared to low-redshift galaxies. Using this subset of the spectroscopic sample, we further find that the differential extinction between stellar and nebular emission E {sub star}(B – V)/E {sub neb}(B – V) is 0.7-0.8, dissimilar to that typically seen at low redshift. After correcting for extinction, we derive an Hα-based main sequence with a slope (0.81 ± 0.04) and normalization similar to previous studies at these redshifts.

• OSTI ID: 22215393
• Journal Information: Astrophysical Journal Letters, Vol. 777, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMIC DUST
DETECTION
EMISSION
GALAXIES
LUMINOSITY
MASS
RED SHIFT
RESOLUTION
SPECTRA
STARS
UNIVERSE