STAR FORMATION HISTORY IN THE SMALL MAGELLANIC CLOUD: THE CASE OF NGC 602

Journal Article · Sun Mar 15 04:00:00 EDT 2009 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/137/3/3668; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21269273

Cignoni, M ^[1]; Sabbi, E; Nota, A; Meixner, M; Sirianni, M; Smith, L J ^[2]; Tosi, M; Angeretti, L ^[3]; Degl'Innocenti, S; Moroni, P G. Prada ^[4]; Carlson, Lynn Redding ^[5]

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1. Dipartimento di Astronomia, Universita degli Studi di Bologna, via Ranzani 1, I-40127 Bologna (Italy)
2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD (United States)
3. Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy)
4. Dipartimento di Fisica 'Enrico Fermi', Universita di Pisa, largo Pontecorvo 3, Pisa I-56127 (Italy)
5. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States)

Deep Hubble Space Telescope/Advanced Camera for Surveys photometry of the young cluster NGC 602, located in the remote low-density 'wing' of the Small Magellanic Cloud (SMC), reveals numerous pre-main-sequence (PMS) stars as well as young stars on the main sequence. The resolved stellar content thus provides a basis for studying the star formation history (SFH) into recent times and constraining several stellar population properties, such as the present-day mass function (PDMF), the initial mass function, and the binary fraction. To better characterize the PMS population, we present a new set of model stellar evolutionary tracks for this evolutionary phase with metallicity appropriate for the SMC (Z = 0.004). We use a stellar population synthesis code, which takes into account a full range of stellar evolution phases to derive our best estimate for the SFH in the region by comparing observed and synthetic color-magnitude diagrams. The derived PDMF for NGC 602 is consistent with that resulting from the synthetic diagrams. The star formation rate in the region has increased with time on a scale of tens of Myr, reaching (0.3-0.7) x 10{sup -3} M {sub sun} yr{sup -1} in the last 2.5 Myr, comparable to what is found in Galactic OB associations. Star formation is most complete in the main cluster but continues at moderate levels in the gas-rich periphery of the nebula.

• OSTI ID: 21269273
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 3 Vol. 137; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
INTERGALACTIC SPACE
MAGELLANIC CLOUDS
NEBULAE
PARTICLE TRACKS
PHOTOMETRY
STAR CLUSTERS
STAR EVOLUTION
STARS
TELESCOPES