Gems in the outer galaxy: Near-infrared imaging of three young clusters at large galactic radii

Journal Article · Sat Feb 01 04:00:00 EST 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/781/2/95· OSTI ID:22348121

Davidge, T. J. ^[1]

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1. Dominion Astrophysical Observatory, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

Images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric seeing by the Gemini Multi-conjugate Adaptive Optics System are used to investigate the stellar contents of the young outer Galactic disk clusters Haffner 17, NGC 2401, and NGC 3105. Ages estimated from the faint end of the main sequence (MS) and the ridgeline of the pre-main sequence on the (K, J – K) color-magnitude diagrams are consistent with published values that are based on the MS turnoff, with the GSAOI data favoring the younger end of the age range for NGC 2401 in the literature. The mass function (MF) of NGC 2401 is similar to that in the solar neighborhood, and stars spanning a wide range of masses in this cluster have similar clustering properties on the sky. It is concluded that NGC 2401 is not evolved dynamically. In contrast, the MF of Haffner 17 differs significantly from that in the solar neighborhood over all masses covered by these data, while the MF of NGC 3105 is deficient in objects with sub-solar masses when compared with the solar neighborhood. Low-mass objects in Haffner 17 and NGC 3105 are also more uniformly distributed on the sky than brighter, more massive, MS stars. This is consistent with both clusters having experienced significant dynamical evolution.

• OSTI ID: 22348121
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 781; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COLOR
COMPARATIVE EVALUATIONS
EVOLUTION
GALAXIES
IMAGES
LUMINOSITY
MASS
NEAR INFRARED RADIATION
OPTICS
SKY
STARS