Discovery of X-Ray Emission from Young Suns in the Small Magellanic Cloud

Type Journal Article
Names L. M. Oskinova, W. Sun, C. J. Evans, V. Hénault-Brunet, Y.-H. Chu, J. S. Gallagher, M. A. Guerrero, R. A. Gruendl, M. Güdel, S. Silich, Y. Chen, Y. Nazé, R. Hainich, J. Reyes-Iturbide
Publication The Astrophysical Journal
Volume 765
Pages 73
Journal Abbreviation The Astrophysical Journal
Date March 1, 2013
DOI 10.1088/0004-637X/765/1/73;
ISSN 0004-637X
URL http://adsabs.harvard.edu/abs/2013ApJ...765...73O
Library Catalog NASA ADS
Abstract 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.
Tags H II REGIONS, ISM: bubbles, MAGELLANIC CLOUDS, X-rays: stars, outflows, stars: pre-main sequence, stars: winds
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