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Title: THE FIRST Hi-GAL OBSERVATIONS OF THE OUTER GALAXY: A LOOK AT STAR FORMATION IN THE THIRD GALACTIC QUADRANT IN THE LONGITUDE RANGE 216. Degree-Sign 5 {approx}< l {approx}< 225. Degree-Sign 5

We present the first Herschel PACS and SPIRE photometric observations in a portion of the outer Galaxy (216. Degree-Sign 5 {approx}< l {approx}< 225. Degree-Sign 5 and -2 Degree-Sign {approx}< b {approx}< 0 Degree-Sign ) as a part of the Hi-GAL survey. The maps between 70 and 500 {mu}m, the derived column density and temperature maps, and the compact source catalog are presented. NANTEN CO(1-0) line observations are used to derive cloud kinematics and distances so that we can estimate distance-dependent physical parameters of the compact sources (cores and clumps) having a reliable spectral energy distribution that we separate into 255 proto-stellar and 688 starless sources. Both typologies are found in association with all the distance components observed in the field, up to {approx}5.8 kpc, testifying to the presence of star formation beyond the Perseus arm at these longitudes. Selecting the starless gravitationally bound sources, we identify 590 pre-stellar candidates. Several sources of both proto- and pre-stellar nature are found to exceed the minimum requirement for being compatible with massive star formation based on the mass-radius relation. For the pre-stellar sources belonging to the Local arm (d {approx}< 1.5 kpc) we study the mass function whose high-mass end shows amore » power law N(log M){proportional_to}M {sup -1.0{+-}0.2}. Finally, we use a luminosity versus mass diagram to infer the evolutionary status of the sources, finding that most of the proto-stellar sources are in the early accretion phase (with some cases compatible with a Class I stage), while for pre-stellar sources, in general, accretion has not yet started.« less
Authors:
; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [3] ;  [4] ; ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. Istituto di Astrofisica e Planetologia Spaziali-INAF, Via Fosso del Cavaliere 100, I-00133 Roma (Italy)
  2. Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
  3. Osservatorio Astrofisico di Arcetri-INAF, Largo E. Fermi 5, I-50125 Firenze (Italy)
  4. Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
  5. IRFU/SAp CEA/DSM, Laboratoire AIM CNRS, Universit Paris Diderot, F-91191 Gif-sur-Yvette (France)
  6. DIET-Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni, Universita di Roma La Sapienza, via Eudossina 18, I-00184 Roma (Italy)
  7. Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)
  8. Department of Physical Science, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan)
  9. Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, Panepistimiopolis, 15784 Zografos, Athens (Greece)
  10. Dipartimento di Matematica e Fisica, Universita del Salento, CP 193, I-73100 Lecce (Italy)
Publication Date:
OSTI Identifier:
22121848
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 772; 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; CATALOGS; DENSITY; DISTANCE; ENERGY SPECTRA; GALAXIES; LUMINOSITY; MASS; PHOTOMETRY; STARS; TEMPERATURE DISTRIBUTION