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Title: Hydrogen fluoride toward luminous nearby galaxies: NGC 253 and NGC 4945

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 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{sub 2}){sub out} ∼ 1 × 10{sup 7} M {sub ☉} and an outflow rate as large as M-dot ∼6.4 M {sub ☉} yr{sup –1}. In the case of NGC 4945, the axisymmetric velocity components in the HF line profile are 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 {sub ☉} yr{sup –1}, inside an inner radius of ≤200 pc. The gas accretion rate to the central active galactic nucleus is much smaller, suggesting that the inflow may 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 nearbymore » galaxies with bright dust continuum and a promising new tracer of molecular gas in high-redshift galaxies.« less
Authors:
; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125-4700 (United States)
  2. Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States)
  3. LERMA/LRA, Ecole Normale Supérieure and Observatoire de Paris, 24 rue Lhomond, F-75005 Paris (France)
  4. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
  5. Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
Publication Date:
OSTI Identifier:
22357191
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ABUNDANCE; ASYMMETRY; AXIAL SYMMETRY; DETECTION; DUSTS; GALAXIES; GALAXY NUCLEI; HYDROGEN; HYDROGEN FLUORIDES; MASS; MOLECULES; RED SHIFT; SPACE; VELOCITY