Optical and Near-Infrared Integral Field Spectroscopy of the SCUBA Galaxy N2-850.4
Abstract
We present optical and near-infrared integral field spectroscopy of the SCUBA galaxy SMMJ163650.43+405734.5 (ELAIS N2 850.4) at z = 2.385. We combine Lyα and Hα emission line maps and velocity structure with high-resolution HST ACS and NICMOS imaging to probe the complex dynamics of this vigorous starburst galaxy. The imaging data show a complex morphology, consisting of at least three components separated by ∼1 arcsec (8 kpc) in projection. When combined with the Hα velocity field from UKIRT UIST IFU observations we identify two components whose redshifts are coincident with the systemic redshift, measured from previous CO observations, one of which shows signs of AGN activity. A third component is offset by 220 ± 50 km s^(−1) from the systemic velocity. The total star-formation rate of the whole system (estimated from the narrow-line Hα and uncorrected for reddening) is 340 ± 50 M_⊙ yr^(−1). The Lyα emission mapped by the GMOS IFU covers the complete galaxy and is offset by +270 ± 40 km s−1 from the systemic velocity. This velocity offset is comparable to that seen in rest-frame UV-selected galaxies at similar redshifts and usually interpreted as a starburst-driven wind. The extended structure of the Lyα emission suggests that this wind is not a nuclear phenomenon, but is instead a galactic-scale outflow. Our observations suggest that the vigorous activity in N2 850.4 is arising as a result of an interaction between at least two dynamically-distinct components, resulting in a strong starburst, a starburst-driven wind and actively-fuelled AGN activity. Whilst these observations are based on a single object, our results clearly show the power of combining optical and near-infrared integral field spectroscopy to probe the power sources, masses and metallicities of far-infrared luminous galaxies, as well as understanding the role of AGN- and starburst-driven feedback processes in these high-redshift systems.
Additional Information
© 2005 RAS. Accepted 2005 February 3. Received 2005 February 3; in original form 2004 December 6. We are very greatful to the referee, Seb Oliver, for his constructive report which significantly improved the content and layout of this paper. We would like to thank Brad Cavanagh, Peter Draper and Stephen Todd for useful discussions and help regarding the UIST IFU data reduction pipeline and Watson Varicatt and Sandy Leggett for observing the target with UIST IFU in UKIRT queue mode in 2003A. We would also like to thank Matt Mountain and Jean-Rene Roy for accepting the GMOS IFU programme for Science Demonstration, Inger Jørgensen and Kathy Roth for vital assistance in observing the target with GMOS, and Bryan Miller for useful discussion regarding the GMOS data reduction pipeline. We acknowledge Roger Davies and Gerry Gilmore, who were the joint PIs of the GMOS-DDT proposal. We also acknowledge useful discussions with Alastair Edge, Jim Geach, David Gilbank, Thomas Greve, Chris Simpson, Martin Ward and Richard Wilman. AMS acknowledges support from PPARC, IRS acknowledges support from the Royal Society, RGB acknowledges a PPARC Senior Fellowship and he Euro 3D Research Training Network. AWB acknowledges support from NSF AST-0205937 and the Alfred Sloan Foundation. The United Kingdom Infrared Telescope (UKIRT) is operated by the Joint Astronomy Centre on behalf on the UK Particle Physics and Astronomy Research Council. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for the Space Telescope Science Institute (MAST) for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts. The Infrared Telescope Facility (IRTF) is operated by the University of Hawaii under Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration, Office of Space Science, Planetary Astronomy Program.Attached Files
Published - 401.full.pdf
Accepted Version - 0502096
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Additional details
- Eprint ID
- 76422
- Resolver ID
- CaltechAUTHORS:20170409-065332465
- Particle Physics and Astronomy Research Council (PPARC)
- Royal Society
- Euro 3D Research Training Network
- AST-0205937
- NSF
- Alfred P. Sloan Foundation
- NAS5-26555
- NASA
- NAG5-7584
- NASA
- NCC 5-538
- NASA
- Created
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2018-04-02Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field