A Thermal Infrared Imaging Study of Very Low-Mass, Wide Separation Brown Dwarf Companions to Upper Scorpius Stars: Constraining Circumstellar Environments

Abstract

We present a 3-5um LBT/MMT adaptive optics imaging study of three Upper Scorpius stars with brown dwarf (BD) companions with very low-masses/mass ratios (M_BD < 25M_Jup; M_BD / M_star ~ 1-2%), and wide separations (300-700 AU): GSC 06214, 1RXS 1609, and HIP 78530. We combine these new thermal IR data with existing 1-4um and 24um photometry to constrain the properties of the BDs and identify evidence for circumprimary/secondary disks in these unusual systems. We confirm that GSC 06214B is surrounded by a disk, further showing this disk produces a broadband IR excess due to small dust near the dust sublimation radius. An unresolved 24um excess in the system may be explained by the contribution from this disk. 1RXS 1609B exhibits no 3-4um excess, nor does its primary; however, the system as a whole has a modest 24um excess, which may come from warm dust around the primary and/or BD. Neither object in the HIP 78530 system exhibits near- to mid-IR excesses. We additionally find that the 1-4um colors of HIP 78530B match a spectral type of M3+-2, inconsistent with the M8 spectral type assigned based on its near-IR spectrum, indicating it may be a low-mass star rather than a BD. We present new upper limits on additional low-mass companions in the system (<5M_Jup beyond 175AU). Finally, we examine the utility of circumsecondary disks as probes of the formation histories of wide BD companions, finding that the presence of a disk may disfavor BD formation near the primary with subsequent outward scattering.

Accepted for publication in ApJ (14 pages, 9 figures)

References in corpus (20)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Optical Images of an Exosolar Planet 25 Light Years from Earth
• Protoplanetary Disk Structures in Ophiuchus
• The Disk Population of the Upper Scorpius Association
• Direct Imaging and Spectroscopy of a Planetary Mass Candidate Companion to a Young Solar Analog
• Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
• Direct Imaging Discovery of a `Super-Jupiter' Around the late B-Type Star Kappa And
• The Planetary Mass Companion 2MASS1207-3932 B: Temperature, Mass and Evidence for an Edge-On Disk
• JHK Observations of Faint Standard Stars in the Mauna Kea Near-Infrared Photometric System
• HD 203030B: an Unusually Cool Young Sub-Stellar Companion near the L/T Transition
• Direct Imaging Confirmation and Characterization of a Dust-Enshrouded Candidate Exoplanet Orbiting Fomalhaut
• Discovery of a Young Substellar Companion in Chamaeleon
• Confidence Level and Sensitivity Limits in High Contrast Imaging
• Disks around Brown Dwarfs in the Sigma Orionis Cluster
• Medium-separation binaries do not affect the first steps of planet formation
• Large Binocular Telescope Adaptive Optics System: New achievements and perspectives in adaptive optics
• Binary frequency of very young brown dwarfs at separations smaller than 3 AU
• The Incidence of Debris Disks at 24 μm and 670 Myr
• New Brown Dwarf Companions to Young Stars in Scorpius-Centaurus
• Clio: a 3-5 micron AO planet-finding camera

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