The Star-Forming Region NGC 346 in the Small Magellanic Cloud with Hubble Space Telescope ACS Observations I. Photometry

Abstract

We present a photometric study of the star-forming region NGC 346 and its surrounding field in the Small Magellanic Cloud, using data taken with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). The data set contains both short and long exposures for increased dynamic range, and photometry was performed using the ACS module of the stellar photometry package DOLPHOT. We detected almost 100,000 stars over a magnitude range of V ~ 11 to V ~ 28 mag, including all stellar types from the most massive young stars to faint lower main sequence and pre-main sequence stars. We find that this region, which is characterized by a plethora of stellar systems and interesting objects, is an outstanding example of mixed stellar populations. We take into account different features of the color-magnitude diagram of all the detected stars to distinguish the two dominant stellar systems: The stellar association NGC 346 and the old spherical star cluster BS 90. These observations provide a complete stellar sample of a field about 5 arcmin x 5 arcmin around the most active star-forming region in this galaxy. Considering the importance of these data for various investigations in the area, we provide the full stellar catalog from our photometry. This paper is the first part of an ongoing study to investigate in detail the two dominant stellar systems in the area and their surrounding field.

8 pages, 5 figures, Accepted for publication in The Astrophysical Journal Supplement Series, A high-resolution version can be found at: http://www.astro.uni-bonn.de/~dgoulier/Science/Gouliermis+_NGC346_I.pdf

References in corpus (2)

• The Discovery of a Population of Pre-Main Sequence Stars in N66/NGC346 from Deep HST/ACS Image
• Far-Ultraviolet & Halpha Spectroscopy of SNR0057-7226 in the SMC HII Region N66

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• Star-formation rates from young-star counts and the structure of the ISM across the NGC346/N66 complex in the SMC
• NGC 346 in The Small Magellanic Cloud. IV. Triggered Star Formation in the HII Region N66
• Discovery of the Pre-Main Sequence Population of the Stellar Association LH 95 in the Large Magellanic Cloud with Hubble Space Telescope ACS Observations
• The Star-forming Region NGC 346 in the Small Magellanic Cloud with Hubble Space Telescope ACS Observations. II. Photometric Study of the Intermediate-Age Star Cluster BS 90
• Low-mass pre--main-sequence stars in the Magellanic Clouds
• Ionization and Star Formation in the Giant HII Region SMC-N66
• The sub-solar Initial Mass Function in the Large Magellanic Cloud