Skip to main content

Research Repository

Advanced Search

The interstellar medium in high-redshift submillimeter galaxies as probed by infrared spectroscopy

Wardlow, Julie L.; Cooray, Asantha; Osage, Willow; Bourne, Nathan; Clements, David; Dannerbauer, Helmut; Dunne, Loretta; Dye, Simon; Eales, Steve; Farrah, Duncan; Furlanetto, Cristina; Ibar, Edo; Ivison, Rob J.; Maddox, Steve; Micha?owski, Micha? M.; Riechers, Dominik; Rigopoulou, Dimitra; Scott, Douglas; Smith, Matthew W. L.; Wang, Lingyu; van der Werf, Paul; Valiante, Elisabetta; Valtchanov, Ivan; Verma, Aprajita


Julie L. Wardlow

Asantha Cooray

Willow Osage

Nathan Bourne

David Clements

Helmut Dannerbauer

Loretta Dunne

Associate Professor

Steve Eales

Duncan Farrah

Cristina Furlanetto

Edo Ibar

Rob J. Ivison

Steve Maddox

Micha? M. Micha?owski

Dominik Riechers

Dimitra Rigopoulou

Douglas Scott

Matthew W. L. Smith

Lingyu Wang

Paul van der Werf

Elisabetta Valiante

Ivan Valtchanov

Aprajita Verma


Submillimeter galaxies (SMGs) at are luminous in the far-infrared, and have star formation rates, SFR, of hundreds to thousands of solar masses per year. However, it is unclear whether they are true analogs of local ULIRGs or whether the mode of their star formation is more similar to that in local disk galaxies. We target these questions by using Herschel-PACS to examine the conditions in the interstellar medium (ISM) in far-infrared luminous SMGs at –4. We present 70–160 μm photometry and spectroscopy of the [O IV]26 μm, [Fe II]26 μm, [S III]33 μm, [Si II]34 μm, [O III]52 μm, [N III]57 μm, and [O I]63 μm fine-structure lines and the S(0) and S(1) hydrogen rotational lines in 13 lensed SMGs identified by their brightness in early Herschel data. Most of the 13 targets are not individually spectroscopically detected; we instead focus on stacking these spectra with observations of an additional 32 SMGs from the Herschel archive—representing a complete compilation of PACS spectroscopy of SMGs. We detect [O I]63 μm, [Si II]34 μm, and [N III]57 μm at in the stacked spectra, determining that the average strengths of these lines relative to the far-IR continuum are , , and , respectively. Using the [O III]52 μm/[N III]57 μm emission line ratio, we show that SMGs have average gas-phase metallicities . By using PDR modeling and combining the new spectral measurements with integrated far-infrared fluxes and existing [C II]158 μm data, we show that SMGs have average gas densities, n, of and FUV field strengths, (in Habing units: ), consistent with both local ULIRGs and lower luminosity star-forming galaxies.


Wardlow, J. L., Cooray, A., Osage, W., Bourne, N., Clements, D., Dannerbauer, H., …Verma, A. (2017). The interstellar medium in high-redshift submillimeter galaxies as probed by infrared spectroscopy. Astrophysical Journal, 837(1), Article 12.

Journal Article Type Article
Acceptance Date Jan 9, 2017
Publication Date Feb 27, 2017
Deposit Date Apr 27, 2017
Publicly Available Date Apr 27, 2017
Journal Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 837
Issue 1
Article Number 12
Keywords Galaxies: high-redshift, Galaxies: ISM , Galaxies: star formation, Gravitational lensing: strong submillimeter
Public URL
Publisher URL
Additional Information © 2017 The American Astronomical Society. All rights reserved.


Interstellar medium pdf.pdf (1.4 Mb)

Copyright Statement
Copyright information regarding this work can be found at the following address:

You might also like

Downloadable Citations