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Extreme Radio-wave Scattering Associated with Hot Stars

Walker, Mark A. and Tuntsov, Artem V. and Bignall, Hayley and Reynolds, Cormac and Bannister, Keith W. and Johnston, Simon and Stevens, Jamie and Ravi, Vikram (2017) Extreme Radio-wave Scattering Associated with Hot Stars. Astrophysical Journal, 843 (1). Art. No. 15. ISSN 1538-4357. https://resolver.caltech.edu/CaltechAUTHORS:20170627-102141920

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Abstract

We use data on extreme radio scintillation to demonstrate that this phenomenon is associated with hot stars in the solar neighborhood. The ionized gas responsible for the scattering is found at distances up to 1.75 pc from the host star, and on average must comprise ~10^5 distinct structures per star. We detect azimuthal velocities of the plasma, relative to the host star, up to 9.7 km s^(-1), consistent with warm gas expanding at the sound speed. The circumstellar plasma structures that we infer are similar in several respects to the cometary knots seen in the Helix and in other planetary nebulae. There the ionized gas appears as a skin around tiny molecular clumps. Our analysis suggests that molecular clumps are ubiquitous circumstellar features, unrelated to the evolutionary state of the star. The total mass in such clumps is comparable to the stellar mass.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.3847/1538-4357/aa705cDOIArticle
http://iopscience.iop.org/article/10.3847/1538-4357/aa705c/metaPublisherArticle
https://arxiv.org/abs/1705.00964arXivDiscussion Paper
ORCID:
AuthorORCID
Ravi, Vikram0000-0002-7252-5485
Additional Information:© 2017 The American Astronomical Society. Received 2017 March 22; revised 2017 April 26; accepted 2017 April 26; published 2017 June 27. Hats off to Ger de Bruyn and Jane Dennett-Thorpe for spotting, very early on, the possibility of a connection between Vega and J1819+3845. The referee's thoughtful comments helped to sharpen our presentation.
Subject Keywords:circumstellar matter – ISM: structure – local interstellar matter – scattering – stars: massive
Issue or Number:1
Record Number:CaltechAUTHORS:20170627-102141920
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20170627-102141920
Official Citation:Mark A. Walker et al 2017 ApJ 843 15
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78604
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:27 Jun 2017 19:42
Last Modified:03 Oct 2019 18:10

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