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The Herschel Orion Protostar Survey: Far-infrared Photometry and Colors of Protostars and Their Variations across Orion A and B

Fischer, William J. and Megeath, S. Thomas and Furlan, E. and Stutz, Amelia M. and Stanke, Thomas and Tobin, John J. and Osorio, Mayra and Manoj, P. and Di Francesco, James and Allen, Lori E. and Watson, Dan M. and Wilson, T. L. and Henning, Thomas (2020) The Herschel Orion Protostar Survey: Far-infrared Photometry and Colors of Protostars and Their Variations across Orion A and B. Astrophysical Journal, 905 (2). Art. No. 119. ISSN 1538-4357.

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The degree to which the properties of protostars are affected by environment remains an open question. To investigate this, we look at the Orion A and B molecular clouds, home to most of the protostars within 500 pc. At ~400 pc, Orion is close enough to distinguish individual protostars across a range of environments in terms of both the stellar and gas projected densities. As part of the Herschel Orion Protostar Survey (HOPS), we used the Photodetector Array Camera and Spectrometer to map 108 partially overlapping square fields with edge lengths of 5' or 8' and measure the 70 and 160 μm flux densities of 338 protostars within them. In this paper we examine how these flux densities and their ratio depend on evolutionary state and environment within the Orion complex. We show that Class 0 protostars occupy a region of the 70 μm flux density versus 160 μm/70 μm flux density ratio diagram that is distinct from their more evolved counterparts. We then present evidence that the Integral-Shaped Filament (ISF) and Orion B contain protostars with more massive inner envelopes than those in the more sparsely populated LDN 1641 region. This can be interpreted as evidence for increasing star formation rates in the ISF and Orion B or as a tendency for more massive inner envelopes to be inherited from denser birth environments. We also provide technical details about the mapmaking and photometric procedures used in the HOPS program.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Fischer, William J.0000-0002-3747-2496
Megeath, S. Thomas0000-0001-7629-3573
Furlan, E.0000-0001-9800-6248
Stutz, Amelia M.0000-0003-2300-8200
Stanke, Thomas0000-0002-5812-9232
Tobin, John J.0000-0002-6195-0152
Osorio, Mayra0000-0002-6737-5267
Manoj, P.0000-0002-3530-304X
Di Francesco, James0000-0002-9289-2450
Allen, Lori E.0000-0002-7789-5119
Watson, Dan M.0000-0001-8302-0530
Wilson, T. L.0000-0003-1755-8759
Henning, Thomas0000-0002-1493-300X
Additional Information:© 2020. The American Astronomical Society. Received 2020 August 14; revised 2020 October 28; accepted 2020 November 3; published 2020 December 21. We thank Babar Ali for his substantial contributions in designing the PACS survey, carrying out the data processing and the photometry, and writing the initial version of this paper while he was a staff scientist at the NASA Herschel Science Center. Support of W.J.F. and S.T.M. for this work was provided by NASA through awards issued by the Jet Propulsion Laboratory, California Institute of Technology. A.M.S. acknowledges funding through Fondecyt regular (project code 1180350) and Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA) BASAL grant AFB-170002. M.O. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the AYA2017-84390-C2-1-R grant (cofunded by FEDER) and through the Center of Excellence Severo Ochoa award for the Instituto de Astrofísica de Andalucía (SEV/2017/0709). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The Herschel spacecraft was designed, built, tested, and launched under a contract to the European Space Agency (ESA) managed by the Herschel/Planck project team by an industrial consortium under the overall responsibility of the prime contractor Thales Alenia Space (Cannes), and including Astrium (Friedrichshafen), responsible for the payload module and for system testing at spacecraft level, Thales Alenia Space (Turin), responsible for the service module, and Astrium (Toulouse), responsible for the telescope, with in excess of 100 subcontractors. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF-IFSI/OAA/OAP/OAT, LENS, SISSA (Italy); and IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy), and CICYT/MCYT (Spain). HIPE is a joint development by the Herschel Science Ground Segment Consortium, consisting of ESA, the NASA Herschel Science Center, and the HIFI, PACS, and SPIRE consortia. Facility: Herschel (PACS). - Software: ATV (Barth 2001), IDL Astronomy User's Library (Landsman 1993), StarFinder (Diolaiti et al. 2000), HIPE (Ott 2010).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1180350
Agencia Estatal de InvestigaciónAYA2017-84390-C2-1-R
Fondo Europeo de Desarrollo Regional (FEDER)UNSPECIFIED
Severo OchoaSEV/2017/0709
Subject Keywords:Protostars ; Star formation ; Infrared sources
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Protostars (1302); Star formation (1569); Infrared sources (793)
Record Number:CaltechAUTHORS:20201221-120012517
Persistent URL:
Official Citation:William J. Fischer et al 2020 ApJ 905 119
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107238
Deposited By: George Porter
Deposited On:21 Dec 2020 20:32
Last Modified:21 Dec 2020 20:32

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