St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Register / Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

The influence of radiative core growth on coronal X-ray emission from pre-main sequence stars

Thumbnail
View/Open
MNRAS_2016_Gregory_mnras_stw259.pdf (1.245Mb)
Date
21/04/2016
Author
Gregory, Scott
Adams, Fred C.
Davies, Claire
Funder
Science & Technology Facilities Council
Science & Technology Facilities Council
PPARC - Now STFC
Science & Technology Facilities Council
Science & Technology Facilities Council
Grant ID
ST/J003255/1
ST/I000666/1
PP/D000890/1
ST/M001296/1
ST/G001006/1
Keywords
Stars: magnetic fields
Stars: pre-main sequence
Stars: coronae
Stars: interiors
Stars: evolution
X-rays: stars
QB Astronomy
QC Physics
3rd-DAS
Metadata
Show full item record
Abstract
Pre-main sequence (PMS) stars of mass ≳ 0.35 M⊙ transition from hosting fully convective interiors to configurations with a radiative core and outer convective envelope during their gravitational contraction. This stellar structure change influences the external magnetic field topology and, as we demonstrate herein, affects the coronal X-ray emission as a stellar analog of the solar tachocline develops. We have combined archival X-ray, spectroscopic, and photometric data for ∼1000 PMS stars from five of the best studied star forming regions; the ONC, NGC 2264, IC 348, NGC 2362, and NGC 6530. Using a modern, PMS calibrated, spectral type-to-effective temperature and intrinsic colour scale, we deredden the photometry using colours appropriate for each spectral type, and determine the stellar mass, age, and internal structure consistently for the entire sample. We find that PMS stars on Henyey tracks have, on average, lower fractional X-ray luminosities (LX/L★) than those on Hayashi tracks, where this effect is driven by changes in LX. X-ray emission decays faster with age for higher mass PMS stars. There is a strong correlation between L★ and LX for Hayashi track stars but no correlation for Henyey track stars. There is no correlation between LX and radiative core mass or radius. However, the longer stars have spent with radiative cores, the less X-ray luminous they become. The decay of coronal X-ray emission from young early K to late G-type PMS stars, the progenitors of main sequence A-type stars, is consistent with the dearth of X-ray detections of the latter.
Citation
Gregory , S , Adams , F C & Davies , C 2016 , ' The influence of radiative core growth on coronal X-ray emission from pre-main sequence stars ' , Monthly Notices of the Royal Astronomical Society , vol. 457 , no. 4 , pp. 3836-3858 . https://doi.org/10.1093/mnras/stw259
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
DOI
https://doi.org/10.1093/mnras/stw259
ISSN
0035-8711
Type
Journal article
Rights
© 2016 The Authors, Published by Oxford University Press on behalf of the Royal Astronomical Society. This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record is available online at: https://dx.doi.org/10.1093/mnras/stw259
Description
SGG acknowledges support from the Science & Technology Facilities Council (STFC) via an Ernest Rutherford Fellowship [ST/J003255/1]. CLD acknowledges support from STFC via a PhD studentship and additional funding via the STFC Studentship Enhancement Programme [ST/J500744/1], and support from the ERC Starting Grant "Image-PlanetFormDiscs" (Grant Agreement No. 639889).
Collections
  • University of St Andrews Research
URI
http://hdl.handle.net/10023/8222

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter