THE REST-FRAME SUBMILLIMETER SPECTRUM OF HIGH-REDSHIFT, DUSTY, STAR-FORMING GALAXIES

Spilker, J. S.; Marrone, D; Aguirre, J.; Aravena, M; Ashby, M.; Béthermin M.; Bradford C.M.; Bothwell, M.; Brodwin M.; Carlstrom, J. E.; Chapman, S; Crawford, T. M.; De Breuck, C; Fassnacht C.D.; Gonzalez, A. H.; et. al.

Abstract

We present the average rest-frame spectrum of high-redshift dusty, star-forming galaxies from 250 to 770 GHz. This spectrum was constructed by stacking Atacama Large Millimeter/submillimeter Array (ALMA) 3 mm spectra of 22 such sources discovered by the South Pole Telescope and spanning z = 2.0-5.7. In addition to multiple bright spectral features of (CO)-C-12, [C I], and H2O, we also detect several faint transitions of (CO)-C-13, HCN, HNC, HCO+, and CN, and use the observed line strengths to characterize the typical properties of the interstellar medium of these high-redshift starburst galaxies. We find that the (CO)-C-13 brightness in these objects is comparable to that of the only otherz > 2 star-forming galaxy in which (CO)-C-13 has been observed. We show that the emission from the high-critical density molecules HCN, HNC, HCO+, and CN is consistent with a warm, dense medium with T-kin similar to 55K and n(H2) >= 10(5.5) cm(-3). High molecular hydrogen densities are required to reproduce the observed line ratios, and we demonstrate that alternatives to purely collisional excitation are unlikely to be significant for the bulk of these systems. We quantify the average emission from several species with no individually detected transitions, and find emission from the hydride CH and the linear molecule CCH for the first time at high redshift, indicating that these molecules may be powerful probes of interstellar chemistry in high-redshift systems. These observations represent the first constraints on many molecular species with rest-frame transitions from 0.4 to 1.2 mm in star-forming systems at high redshift, and will be invaluable in making effective use of ALMA in full science operations.

Más información

Título según WOS: THE REST-FRAME SUBMILLIMETER SPECTRUM OF HIGH-REDSHIFT, DUSTY, STAR-FORMING GALAXIES
Título según SCOPUS: The rest-frame submillimeter spectrum of high-redshift, dusty, star-forming galaxies
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 785
Número: 2
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2014
Idioma: English
URL: http://stacks.iop.org/0004-637X/785/i=2/a=149?key=crossref.ae88e4521bb2e482a58f954b0aab4962
DOI:

10.1088/0004-637X/785/2/149

Notas: ISI, SCOPUS