DISCOVERY OF X-RAY EMISSION FROM YOUNG SUNS IN THE SMALL MAGELLANIC CLOUD

Journal Article · Fri Mar 01 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/765/1/73· OSTI ID:22167622

Oskinova, L. M.; Hainich, R. ^[1]; Sun, W.; Chen, Y. ^[2]; Evans, C. J. ^[3]; Henault-Brunet, V. ^[4]; Chu, Y. -H.; Gruendl, R. A. ^[5]; Gallagher, III, J. S. ^[6]; Guerrero, M. A. ^[7]; Guedel, M. ^[8]; Silich, S. ^[9]; Naze, Y. ^[10]; Reyes-Iturbide, J. ^[11]

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1. Institute for Physics and Astronomy, University Potsdam, D-14476 Potsdam (Germany)
2. Department of Astronomy, Nanjing University, Nanjing, 210093 Jiangsu (China)
3. UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
4. Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
5. Department of Astronomy, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States)
6. Department of Astronomy, University of Wisconsin-Madison, 5534 Sterling, 475 North Charter Street, Madison, WI 53706 (United States)
7. Instituto de Astrofisica de Andalucia, IAA-CSIC, Glorieta de la Astronomia s/n, E-18008 Granada (Spain)
8. Department of Astrophysics, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria)
9. Instituto Nacional de Astrofisica Optica y Electronica, AP 51, 72000 Puebla (Mexico)
10. GAPHE, Departement AGO, Universite de Liege, Allee du 6 Aout 17, Bat. B5C, B-4000 Liege (Belgium)
11. LATO-DCET/Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, km 16, 45662-000 Ilheus, BA (Brazil)

We report the discovery of extended X-ray emission within the young star cluster NGC 602a in the Wing of the Small Magellanic Cloud (SMC) based on observations obtained with the Chandra X-Ray Observatory. X-ray emission is detected from the cluster core area with the highest stellar density and from a dusty ridge surrounding the H II region. We use a census of massive stars in the cluster to demonstrate that a cluster wind or wind-blown bubble is unlikely to provide a significant contribution to the X-ray emission detected from the central area of the cluster. We therefore suggest that X-ray emission at the cluster core originates from an ensemble of low- and solar-mass pre-main-sequence (PMS) stars, each of which would be too weak in X-rays to be detected individually. We attribute the X-ray emission from the dusty ridge to the embedded tight cluster of the newborn stars known in this area from infrared studies. Assuming that the levels of X-ray activity in young stars in the low-metallicity environment of NGC 602a are comparable to their Galactic counterparts, then the detected spatial distribution, spectral properties, and level of X-ray emission are largely consistent with those expected from low- and solar-mass PMS stars and young stellar objects (YSOs). This is the first discovery of X-ray emission attributable to PMS stars and YSOs in the SMC, which suggests that the accretion and dynamo processes in young, low-mass objects in the SMC resemble those in the Galaxy.

• OSTI ID: 22167622
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 765; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
COMPARATIVE EVALUATIONS
H2 REGIONS
MAGELLANIC CLOUDS
MAIN SEQUENCE STARS
MASS
MILKY WAY
PHOTON EMISSION
PROTOSTARS
SPATIAL DISTRIBUTION
STAR CLUSTERS
STELLAR WINDS
X RADIATION