1. MOLECULAR GAS IN THE X-RAY BRIGHT GROUP NGC 5044 AS REVEALED BY ALMA
- Author
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Youichi Ohyama, Christine Jones, Philippe Salomé, Jeremy Lim, Simona Giacintucci, Fabrizio Brighenti, Francoise Combes, Ming Sun, Ewan O'Sullivan, Fabio Gastaldello, Stephen Hamer, Jan M. Vrtilek, Laurence P. David, Henrique R. Schmitt, William R. Forman, Alastair C. Edge, Pasquale Temi, Dinh-V Trung, William G. Mathews, S. Bardelli, Littoral, Environnement, Télédétection, Géomatique (LETG - Brest), Littoral, Environnement, Télédétection, Géomatique UMR 6554 (LETG), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Caen Normandie (UNICAEN), Université de Nantes (UN)-Université de Nantes (UN), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), University of California [San Diego] (UC San Diego), University of California, Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), École normale supérieure - Paris (ENS-PSL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California (UC), Laurence P. David, Jeremy Lim, William Forman, Jan Vrtilek, Francoise Combe, Philippe Salome, Alastair Edge, Stephen Hamer, Christine Jone, Ming Sun, Ewan O'Sullivan, Fabio Gastaldello, Sandro Bardelli, Pasquale Temi, Henrique Schmitt, Youichi Ohyama, William Mathew, Fabrizio Brighenti, Simona Giacintucci, and Dinh-V Trung
- Subjects
active [Galaxies] ,astro-ph.GA ,galaxies: active ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,clusters: general [Galaxies] ,Cooling flow ,Laser linewidth ,galaxies: groups: individual: NGC 5044 ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,Physics ,[PHYS]Physics [physics] ,Supermassive black hole ,Molecular cloud ,Spatially resolved ,groups: individual (NGC 5044) [Galaxies] ,X-ray ,Velocity dispersion ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,ISM. [Galaxies] ,galaxies: clusters: general ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,galaxies: ISM - Abstract
A short 30 minute ALMA observation of the early-type galaxy NGC 5044, which resides at the center of an X-ray bright group with a moderate cooling flow, has detected 24 molecular structures within the central 2.5 kpc. The masses of the molecular structures vary from 3e5 to 1e7 Mo3 and the CO(2-1) linewidths vary from 15 to 65 km/s. Given the large CO(2-1) linewidths, the observed structures are likely giant molecular associations (GMAs) and not individual molecular clouds (GMCs). Only a few of the GMAs are spatially resolved with the cycle 0 ALMA beam and the average density of these GMAs yields a GMC volume filling factor of about 15%. The observed masses of the resolved GMAs are insufficient for them to be gravitationally bound, however, the most massive GMA does contain a less massive component with a linewidth of 5.5 km/s (typical of an individual virialized GMC). We also show that the GMAs cannot be pressure confined by the hot gas. Given the observed CO(2-1) linewidths of the GMAs (i.e., the velocity dispersion of the embedded GMCs) they will likely disperse on a timescale of about 12 Myr, which is less than the central cooling time of the hot gas, so the embedded GMCs within a GMA must condense out of the hot gas at the same time and arise from local concentrations of thermally unstable parcels of hot gas. There are no indications of any disk-like molecular structures and all indications suggest that the molecular gas follows ballistic trajectories after condensing out of the thermally unstable hot gas. The 230 GHz luminosity of the central continuum source is 500 times greater than its low frequency radio luminosity and probably reflects a recent accretion event by the central supermassive black hole. The spectrum of the central continuum source also exhibits an absorption feature.
- Published
- 2014
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