New constraints on the millimetre emission of six debris discs

Marshall, Jonathan P. and Maddison, S. T. and Thilliez, E. and Matthews, B. C. and Wilner, D. J. and Greaves, J. S. and Holland, W. S. (2017) New constraints on the millimetre emission of six debris discs. Monthly Notices of the Royal Astronomical Society, 468 (3). pp. 2719-2725. ISSN 0035-8711


Abstract

The presence of dusty debris around main-sequence stars denotes the existence of planetary systems. Such debris discs are often identified by the presence of excess continuum emission at infrared and (sub-)millimetre wavelengths, with measurements at longer wavelengths tracing larger and cooler dust grains. The exponent of the slope of the disc emission at submillimetre wavelengths, ‘q’, defines the size distribution of dust grains in the disc. This size distribution is a function of the rigid strength of the dust producing parent planetesimals. As a part of the survey ‘PLAnetesimals around TYpical Pre-main seqUence Stars’, we observed six debris discs at 9 mm using the Australian Telescope Compact Array. We obtain marginal (∼3σ) detections of three targets: HD 105, HD 61005 and HD 131835. Upper limits for the three remaining discs, HD 20807, HD 109573 and HD 109085 provide further constraint of the (sub-)millimetre slope of their spectral energy distributions. The values of q (or their limits) derived from our observations are all smaller than the oft-assumed steady-state collisional cascade model (q = 3.5), but lie well within the theoretically expected range for debris discs q ∼ 3–4. The measured q values for our targets are all <3.3, consistent with both collisional modelling results and theoretical predictions for parent planetesimal bodies being ‘rubble piles’ held together loosely by their self-gravity.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Historic - Computational Engineering and Science Research Centre (CESRC) (1 Jul 2013 - 31 Jul 2018)
Faculty/School / Institute/Centre: Historic - Computational Engineering and Science Research Centre (CESRC) (1 Jul 2013 - 31 Jul 2018)
Date Deposited: 30 Jun 2022 22:38
Last Modified: 03 Jul 2022 23:48
Uncontrolled Keywords: circumstellar matter, stars: individual: HD 105, stars: individual: HD 20807, stars: individual: HD 61005, stars: individual: HD 109085, stars: individual: HD 109573, stars: individual: HD 131835, planetary systems
Fields of Research (2008): 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020109 Space and Solar Physics
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020101 Astrobiology
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
51 PHYSICAL SCIENCES > 5199 Other physical sciences > 519999 Other physical sciences not elsewhere classified
51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510101 Astrobiology
Identification Number or DOI: https://doi.org/10.1093/mnras/stx645
URI: http://eprints.usq.edu.au/id/eprint/49382

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