Hydrogen Fluoride toward Luminous Nearby Galaxies: NGC 253 and NGC 4945
Abstract
We present the detection of hydrogen fluoride, HF, in two luminous nearby galaxies NGC 253 and NGC 4945 using the Heterodyne Instrument for the Far-Infrared (HIFI) on board the Herschel Space Observatory. The HF line toward NGC 253 has a P-Cygni profile, while an asymmetric absorption profile is seen toward NGC 4945. The P-Cygni profile in NGC 253 suggests an outflow of molecular gas with a mass of M(H_2)_(out) ~ 1 × 10^7 M_⊙ and an outflow rate as large as Ṁ ~ 6.4 M_⊙ yr^(−1). In the case of NGC 4945, the axisymmetric velocity components in the HF line profile is compatible with the interpretation of a fast rotating nuclear ring surrounding the nucleus and the presence of inflowing gas. The gas falls into the nucleus with an inflow rate of ≤ 1.2 M_⊙ yr^(−1), inside a inner radius of ≤ 200 pc. The gas accretion rate to the central AGN is much smaller, suggesting that the inflow can be triggering a nuclear starburst. From these results, the HF J = 1 − 0 line is seen to provide an important probe of the kinematics of absorbing material along the sight-line to nearby galaxies with bright dust continuum and a promising new tracer of molecular gas in high redshift galaxies.
Additional Information
© 2014 The American Astronomical Society. Received 2013 October 1; accepted 2014 February 11; published 2014 March 21. R. M. would like to thank Nick Scoville for reading through the manuscript and providing very helpful comments. HIFI has been designed and built by a consortium of institutes and university departments from across Europe, Canada and the United States under the leadership of SRON Netherlands Institute for Space Research, Groningen, The Netherlands and with major contributions from Germany, France and the US. Consortium members are: Canada: CSA, U. Waterloo; France: CESR, LAB, LERMA, IRAM; Germany: KOSMA, MPIfR, MPS; Ireland, NUI Maynooth; Italy: ASI, IFSI-INAF, Osservatorio Astrofisico di Arcetri-INAF; Netherlands: SRON, TUD; Poland: CAMK, CBK; Spain: Observatorio Astronomico Nacional (IGN), Centro de Astrobiologa (CSIC-INTA). Sweden: Chalmers University of Technology-MC2, RSS & GARD; Onsala Space Observatory; Swedish National Space Board, Stockholm University - Stockholm Observatory; Switzerland: ETH Zurich, FHNW; USA: Caltech, JPL, NHSC. Support for this work was provided by NASA through an award issued by JPL/Caltech. Facilities: Herschel/HIFI.Attached Files
Published - 0004-637X_785_1_22.pdf
Submitted - 1402.6619v1.pdf
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Additional details
- Eprint ID
- 44211
- Resolver ID
- CaltechAUTHORS:20140310-094617449
- NASA/JPL/Caltech
- Created
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2014-03-10Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field