Detection of a High Brightness Temperature Radio Core in the Active-galactic-nucleus-driven Molecular Outflow Candidate NGC 1266
Abstract
We present new high spatial resolution Karl G. Jansky Very Large Array (VLA) H I absorption and Very Long Baseline Array (VLBA) continuum observations of the active-galactic-nucleus-(AGN-)driven molecular outflow candidate NGC 1266. Although other well-known systems with molecular outflows may be driven by star formation (SF) in a central molecular disk, the molecular mass outflow rate of 13 M_☉ yr^(–1) in NGC 1266 reported by Alatalo et al. exceeds SF rate estimates from a variety of tracers. This suggests that an additional energy source, such as an AGN, may play a significant role in powering the outflow. Our high spatial resolution H I absorption data reveal compact absorption against the radio continuum core co-located with the putative AGN, and the presence of a blueshifted spectral component re-affirms that gas is indeed flowing out of the system. Our VLBA observations at 1.65 GHz reveal one continuum source within the densest portion of the molecular gas, with a diameter d < 8 mas (1.2 pc), a radio power P_(rad) = 1.48 × 10^(20) W Hz^(–1), and a brightness temperature T_b > 1.5 × 10^7 K that is most consistent with an AGN origin. The radio continuum energetics implied by the compact VLBA source, as well as archival VLA continuum observations at lower spatial resolution, further support the possibility that the AGN in NGC 1266 could be driving the molecular outflow. These findings suggest that even low-level AGNs may be able to launch massive outflows in their host galaxies.
Additional Information
© 2013 American Astronomical Society. Received 2013 April 29; accepted 2013 October 23; published 2013 December 4. We thank the anonymous referee for thoughtful comments that have improved the strength of this work. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for CARMA construction was derived from the Gordon and Betty Moore Foundation, the Kenneth T. and Eileen L. Norris Foundation, the James S. McDonnell Foundation, the Associates of the California Institute of Technology, the University of Chicago, the states of California, Illinois, and Maryland, and the National Science Foundation. Ongoing CARMA development and operations are supported by the National Science Foundation under a cooperative agreement, and by the CARMA partner universities. This research was funded in part by NSF grant 1109803. Facilities: VLA, VLBA, HSTAttached Files
Published - 0004-637X_779_2_173.pdf
Submitted - 1310.7588v1.pdf
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Additional details
- Alternative title
- Detection of a High Brightness Temperature Radio Core in the AGN-Driven Molecular Outflow Candidate NGC 1266
- Eprint ID
- 43457
- Resolver ID
- CaltechAUTHORS:20140121-144652520
- NAS5-26555
- NASA
- Gordon and Betty Moore Foundation
- Kenneth T. and Eileen L. Norris Foundation
- James S. McDonnell Foundation
- Caltech Associates
- University of Chicago
- State of California
- State of Illinois
- State of Maryland
- CARMA partner universities
- AST-1109803
- NSF
- Created
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2014-01-22Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field