Santamaría-Miranda, A., Cáceres, C., Schreiber, M.R. et al. (5 more authors) (2018) Accretion signatures in the X-shooter spectrum of the substellar companion to SR12. Monthly Notices of the Royal Astronomical Society, 475 (3). pp. 2994-3003. ISSN 0035-8711
Abstract
About a dozen substellar companions orbiting young stellar objects or pre-main sequence stars at several hundred au have been identified in the last decade. These objects are interesting both due to the uncertainties surrounding their formation, and because their large separation from the host star offers the potential to study the atmospheres of young giant planets and brown dwarfs. Here, we present X-shooter spectroscopy of SR 12 C, a ∼2 Myr young brown dwarf orbiting SR 12 at an orbital separation of 1083 au. We determine the spectral type, gravity, and effective temperature via comparison with models and observational templates of young brown dwarfs. In addition, we detect and characterize accretion using several accretion tracers. We find SR 12 C to be a brown dwarf of spectral type L0 ± 1, log g = 4 ± 0.5, an effective temperature of 2600 ± 100 K. Our spectra provide clear evidence for accretion at a rate of ∼10−10 M⊙ yr−1. This makes SR 12 one of the few sub-stellar companions with a reliable estimate for its accretion rate. A comparison of the ages and accretion rates of sub-stellar companions with young isolated brown dwarfs does not reveal any significant differences. If further accretion rate measurements of a large number of substellar companions can confirm this trend, this would hint towards a similar formation mechanism for substellar companions at large separations and isolated brown dwarfs.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | accretion; accretion discs; brown dwarfs; stars: pre-main-sequence |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number LEVERHULME TRUST (THE) ECF-2016-316 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 23 Feb 2018 13:09 |
Last Modified: | 16 Mar 2020 16:05 |
Published Version: | https://doi.org/10.1093/mnras/stx3325 |
Status: | Published |
Publisher: | Oxford University Press |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stx3325 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:127598 |