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SOFIA/FORCAST Observations of the Sgr A-H H ii Regions: Using Dust Emission to Elucidate the Heating Sources

Hankins, M. J. and Lau, R. M. and Mills, E. A. C. and Morris, M. R. and Herter, T. L. (2019) SOFIA/FORCAST Observations of the Sgr A-H H ii Regions: Using Dust Emission to Elucidate the Heating Sources. Astrophysical Journal, 877 (1). Art. No. 22. ISSN 1538-4357.

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The Sgr A-H H II regions are a collection of sources that may represent one of the most recent sites of star formation in the Galactic center (GC). Examining these H II regions provides important information on the prevalence and distribution of massive stars in the region and may provide clues on the origin of other massive field stars throughout the GC. In this work, we present infrared imaging observations of the Sgr A-H H II regions taken with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) at 19.7, 25.2, 31.5, and 37.1 μm. These data provide high angular resolution maps (~4'') of the sources, which allow us to study the morphology of spatially extended H II regions in detail. The wavelength coverage of FORCAST also supplies important constraints on the dust mass, temperature, and luminosity of the sources. We produce spectral energy distribution models using DustEM to measure the luminosity and dust mass, which range from ~3 × 10^3 to 6 × 10^5 L ⊙ and from ~6 × 10^(−4) to 3 × 10^(−1) M⊙, respectively. Analysis of dust temperatures in the four spatially extended H II regions (H1, H2, H3, and H5) shows that three of these objects require multiple heating sources, and we identify potential stellar candidates. We also compare the size and morphology of the H II regions and demonstrate that the properties of H_2 are consistent with in situ star formation. Lastly, we identify nine additional sources that may be part of the H complex and provide initial characterizations of their infrared emission.

Item Type:Article
Related URLs:
URLURL TypeDescription
Hankins, M. J.0000-0001-9315-8437
Mills, E. A. C.0000-0001-8782-1992
Morris, M. R.0000-0002-6753-2066
Herter, T. L.0000-0002-3856-8385
Additional Information:© 2019 The American Astronomical Society. Received 2018 July 9; revised 2019 February 10; accepted 2019 March 15; published 2019 May 20. We thank the rest of the FORCAST team, including George Gull, Justin Schoenwald, Chuck Henderson, and Joe Adams; the USRA Science and Mission Ops teams; and the entire SOFIA staff. We also thank the reviewer for their insightful comments, which helped improve this manuscript. This work is based on observations made with the NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA science mission operations are conducted jointly by the Universities Space Research Association, Inc. (USRA), under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901. Financial support for FORCAST was provided by NASA through award 8500-98-014 issued by USRA. This research has made use of the VizieR catalog access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23. This publication also makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This material is based on work supported by the National Science Foundation Graduate Research Fellowship under grant No. DGE-1144153.
Funding AgencyGrant Number
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50 OK 0901
NSF Graduate Research FellowshipDGE-1144153
Subject Keywords:Galaxy: center – H II regions
Issue or Number:1
Record Number:CaltechAUTHORS:20190520-125615362
Persistent URL:
Official Citation:M. J. Hankins et al 2019 ApJ 877 22
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:95600
Deposited By: Tony Diaz
Deposited On:20 May 2019 20:39
Last Modified:03 Oct 2019 21:15

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