Iglesias, DP, Panić, O, van den Ancker, M et al. (6 more authors) (Cover date: March 2023) X-shooter survey of young intermediate-mass stars – I. Stellar characterization and disc evolution. Monthly Notices of the Royal Astronomical Society, 519 (3). pp. 3958-3975. ISSN 0035-8711
Abstract
Intermediate-mass stars (IMSs) represent the link between low-mass and high-mass stars, and cover a key mass range for giant planet formation. In this paper, we present a spectroscopic survey of 241 young IMS candidates with IR-excess, the most complete unbiased sample to date within 300 pc. We combined VLT/X-Shooter spectra with BVR photometric observations and Gaia DR3 distances to estimate fundamental stellar parameters such as Teff, mass, radius, age, and luminosity. We further selected those stars within the intermediate-mass range 1.5 ≤ M⋆/M⊙ ≤ 3.5, and discarded old contaminants. We used 2MASS and WISE photometry to study the IR-excesses of the sample, finding 92 previously unidentified stars with IR-excess. We classified this sample into ‘protoplanetary’, ‘hybrid candidates’, and ‘debris’ discs based on their observed fractional excess at 12 μm, finding a new population of 17 hybrid disc candidates. We studied inner disc dispersal time-scales for λ<10μm and found very different trends for IMSs and low-mass stars (LMSs). IMSs show excesses dropping fast during the first 6 Myr independently of the wavelength, while LMSs show consistently lower fractions of excess at the shortest wavelengths, and increasingly higher fractions for longer wavelengths with slower dispersal rates. In conclusion, this study demonstrates empirically that IMSs dissipate their inner discs very differently than LMSs, providing a possible explanation for the lack of short period planets around IMSs.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | stars: circumstellar matter, stars: early-type, stars: evolution, stars: fundamental parameters, stars: pre-main-sequence |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number STFC (Science and Technology Facilities Council) ST/T000287/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 25 Jan 2023 14:16 |
Last Modified: | 25 Jun 2023 23:14 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/stac3619 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:195617 |