title: VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITHHERSCHEL.
abstract: We present the first ~7.5'×11.5' velocity-resolved (~0.2 km s-1) map of the [C ii] 158μm line toward the Orion molecular cloud 1 (OMC 1) taken with theHerschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41αhydrogen recombination and COJ=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud (G0>500,nH>5×103cm-3) and from dense PDRs (G≳104,nH≳105cm-3) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [13C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of theL[C ii]/LFIRandLFIR/MGasratios and show thatL[C ii]/LFIRdecreases from the extended cloud component (~10-2-10-3) to the more opaque star-forming cores (~10-3-10-4). The lowest values are reminiscent of the "[C ii] deficit" seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasingL[C ii]/LFIRratio correlates better with the column density of dust through the molecular cloud than withLFIR/MGas. We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observedL[C ii]/LFIRvariations through the cloud.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain.
authors.forename: Javier R
authors.initials: JR
authors.lastname: Goicoechea
authors.affiliation: Herschel Science Centre, ESA/ESAC, P.O. Box 78, Villanueva de la Cañada, E-28691 Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Teyssier
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain ; RAL Space, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK.
authors.forename: M
authors.initials: M
authors.lastname: Etxaluze
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099, USA.
authors.forename: P F
authors.initials: PF
authors.lastname: Goldsmith
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Ossenkopf
authors.affiliation: LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris, France ; École Normale Supérieure, 24 rue Lhomond, F-75005, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Gerin
authors.affiliation: Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Bergin
authors.affiliation: Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden.
authors.forename: J H
authors.initials: JH
authors.lastname: Black
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Cernicharo
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC). Calle Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Cuadrado
authors.affiliation: LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Encrenaz
authors.affiliation: LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris, France ; École Normale Supérieure, 24 rue Lhomond, F-75005, Paris, France.
authors.forename: E
authors.initials: E
authors.lastname: Falgarone
authors.affiliation: Observatorio Astronómico Nacional (OAN IGN), Apdo. 112, 28803, Alcalá de Henares, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Fuente
authors.affiliation: Institute for Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Hacar
authors.affiliation: LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris, France.
authors.forename: D C
authors.initials: DC
authors.lastname: Lis
authors.affiliation: INAF, Istituto di Radioastronomia, via P. Gobetti 101, 40129, Bologna, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Marcelino
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 66, Cambridge, MA 02138, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Melnick
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: H S P
authors.initials: HS
authors.lastname: Müller
authors.affiliation: Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Persson
authors.affiliation: Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint-Martin d'Héeres, France.
authors.forename: J
authors.initials: J
authors.lastname: Pety
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Röllig
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schilke
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Simon
authors.affiliation: Department of Astronomy, University of Massachusetts, LGRT-B 619E, 710 North Pleasant Street, Amherst, MA 01003, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Snell
authors.affiliation: I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Stutzki
keywords: H ii regions; ISM: clouds; galaxies: ISM; infrared: galaxies