Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 2010 | Published
Journal Article Open

Herschel and SCUBA-2 imaging and spectroscopy of a bright, lensed submillimetre galaxy at z = 2.3


We present a detailed analysis of the far-infrared (-IR) properties of the bright, lensed, z = 2.3, submillimetre-selected galaxy (SMG), SMM J2135-0102 (hereafter SMM J2135), using new observations with Herschel, SCUBA-2 and the Very Large Array (VLA). These data allow us to constrain the galaxy's spectral energy distribution (SED) and show that it has an intrinsic rest-frame 8-1000-μm luminosity, L_(bol), of (2.3±0.2) × 10^(12) L_☉ and a likely star-formation rate (SFR) of ~400 yr-1. The galaxy sits on the far-IR/radio correlation for far-IR-selected galaxies. At ≳70 μm, the SED can be described adequately by dust components with dust temperatures, T_d ~ 30 and 60 k. Using SPIRE's Fourier- transform spectrometer (FTS) we report a detection of the [C ii] 158 μm cooling line. If the [C ii], CO and far-IR continuum arise in photo-dissociation regions (PDRs), we derive a characteristic gas density, n ~ 10^3 cm^(-3), and a far-ultraviolet (-UV) radiation field, G_0, 10^(3)× stronger than the Milky Way. L_[CII]/L_(bol) is significantly higher than in local ultra-luminous IR galaxies (ULIRGs) but similar to the values found in local star-forming galaxies and starburst nuclei. This is consistent with SMM J2135 being powered by starburst clumps distributed across ~2 kpc, evidence that SMGs are not simply scaled-up ULIRGs. Our results show that SPIRE's FTS has the ability to measure the redshifts of distant, obscured galaxies via the blind detection of atomic cooling lines, but it will not be competitive with ground-based CO-line searches. It will, however, allow detailed study of the integrated properties of high-redshift galaxies, as well as the chemistry of their interstellar medium (ISM), once more suitably bright candidates have been found.

Additional Information

© 2010 ESO. Received 30 March 2010; Accepted 20 April 2010; Published online 16 July 2010. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. We thank Steve Hailey-Dunsheath for useful discussion. We thank Fred Lo for granting DDT observations, and Wayne Holland for observing SMMJ2135 during SCUBA-2 commissioning. SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK); and NASA (USA). SCUBA-2 is funded by STFC, the JCMT Development Fund and the Canadian Foundation for Innovation.

Attached Files

Published - Ivison2010p11859Astron_Astrophys.pdf


Files (385.5 kB)
Name Size Download all
385.5 kB Preview Download

Additional details

August 22, 2023
October 20, 2023