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arXiv · 1308.1310

Probing the Upper Scorpius mass function in the planetary-mass regime

N. Lodieu·P. D. Dobbie·N. J. G. Cross·N. C. Hambly·M. A. Read·R. P. Blake·D. J. E. Floyd
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Abstract

We present the results of a deep ZYJ near-infrared survey of 13.5 square degrees in the Upper Scorpius (USco) OB association. We photometrically selected ~100 cluster member candidates with masses in the range 30-5 Jupiters, according to state-of-the-art evolutionary models. We identified 67 ZYJ candidates as bona-fide members, based on complementary photometry and astrometry. We also extracted five candidates detected with VISTA at YJ-only. One is excluded using deep optical z-band imaging, while two are likely non-members, and three remain as potential members. We conclude that the USco mass function is more likely decreasing in the planetary-mass regime (although a flat mass function cannot yet be discarded), consistent with surveys in other regions.

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N. Lodieu, P. D. Dobbie, N. J. G. Cross, N. C. Hambly, M. A. Read, R. P. Blake, D. J. E. Floyd. 2013-08-06. Probing the Upper Scorpius mass function in the planetary-mass regime. https://doi.org/10.1093/mnras%2Fstt1460

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