2010/04/02 by Masato Onodera, Nobuo Arimoto, N. Arimoto +10 · 27 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Extinction (optical mineralogy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminous infrared galaxy #Metallicity #Photometry (optics) #Physics #Redshift #Star formation #Stars #Stellar mass #Stellar population #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/715/1/385
published in The Astrophysical Journal 715(1), 385-405 (IOP Publishing) · Accepted for publication in Astrophysical Journal; 33 pages; 17 figures; emulateapj.cls
arxiv created 2010/04/02 · openalex publication_date 2010/04/28 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Results are presented from near-infrared spectroscopic observations of a sample of BzK -selected, massive star-forming galaxies ( sBzK s) at 1.5 < z < 2.3 that were obtained with OHS/CISCO at the Subaru telescope and with SINFONI at the Very Large Telescope. Among the 28 sBzK s observed, Hα emission was detected in 14 objects, and for 11 of them the [N ii ] λ6583 flux was also measured. Multiwavelength photometry was also used to derive stellar masses and extinction parameters, whereas Hα and [N ii ] emissions have allowed us to estimate star formation rates (SFRs), metallicities, ionization mechanisms, and dynamical masses. In order to enforce agreement between SFRs from Hα with those derived from rest-frame UV and mid-infrared, additional obscuration for the emission lines (that originate in H ii regions) was required compared to the extinction derived from the slope of the UV continuum. We have also derived the stellar mass–metallicity relation, as well as the relation between stellar mass and specific SFR (SSFR), and compared them to the results in other studies. At a given stellar mass, the sBzK s appear to have been already enriched to metallicities close to those of local star-forming galaxies of similar mass. The sBzK s presented here tend to have higher metallicities compared to those of UV-selected galaxies, indicating that near-infrared selected galaxies tend to be a chemically more evolved population. The sBzK s show SSFRs that are systematically higher, by up to ∼2 orders of magnitude, compared to those of local galaxies of the same mass. The empirical correlations between stellar mass and metallicity, and stellar mass and SSFR are then compared with those of evolutionary population synthesis models constructed either with the simple closed-box assumption, or within an infall scenario. Within the assumptions that are built-in such models, it appears that a short timescale for the star formation (≃100 Myr) and large initial gas mass appear to be required if one wants to reproduce both relations simultaneously.