Multiwavelength Observations of AB Doradus

Basit Öğe Kaydı
dc.authoridJohnston-Hollitt, Melanie/0000-0003-2756-8301
dc.contributor.authorSlee, O. B.
dc.contributor.authorErkan, N.
dc.contributor.authorJohnston-Hollitt, M.
dc.contributor.authorBudding, E.
dc.date.accessioned2025-01-27T21:05:44Z
dc.date.available2025-01-27T21:05:44Z
dc.date.issued2014
dc.departmentÇanakkale Onsekiz Mart Üniversitesi
dc.description.abstractWe have observed the bright, magnetically active multiple star AB Doradus in a multiwavelength campaign centring around two large facility allocations in November 2006 and January, 2007. Our observations have covered at least three large flares. These flares were observed to produce significant hardening of the X-ray spectra during their very initial stages. We monitored flare-related effects using the Suzaku X-ray satellite and the Australia Telescope Compact Array (ATCA) at 3.6 and 6 cm. Observations at 11 and 21 cm were also included, but they were compromised by interference. Optical monitoring was also provided by broadband B and V photometry and some high-dispersion spectrograms. From this multiwavelength coverage we find that the observed flare effects can be mainly associated with a large active region near longitude zero. The second major X-ray and microwave flare of Jan 8, 2007 was observed with a favourable geometry that allowed its initial high-energy impulsive phase to be observed in the higher frequency range of Suzaku's XIS detectors. The fractional circular polarisation (Stokes V/I) was measured in the uv data for the complete runs, for 25 min integrations and, at 4.80 GHz, for 5 min integrations, using the radio data of Nov 21 2006 and Jan 08 2007. Most of the full data sets showed V/I fractions from AB Dor B that were significant at greater than the 3 sigma level. In several of the 5 min integrations at 4.80 and 8.64 GHz this fraction reached a significance level between 3 and 9 sigma. Lack of angular resolution prevented identification of these high V/I values with one or other of the two low-mass red-dwarf components of AB Dor B.
dc.description.sponsorshipEU Erasmus Programme
dc.description.sponsorshipWe thank the time allocation committee of the Australia Telescope National Facility for two generous allocations on the ATCA to support this multiwavelength campaign. The original proposal and arrangements for acquiring time on the Suzaku satellite actually came from Dr Mark Audard, of Geneva; to whom we express our gratitude for his early inputs and suggestions. Dr Grigor Tsarevsky of the Sternberg Institute, Moscow also contributed greatly with advice and observational assistance. We thank also the staff of the Armagh Observatory, who helped N.E. progress this work, particularly Dr G. Ramsay in relation to the processing of the Suzaku data and subsequent comments on its discussion. N.E.'s study leave in Armagh was supported by the EU Erasmus Programme. Detailed comments from a reviewer have led to a much more substantiated presentation.
dc.identifier.doi10.1017/pasa.2014.16
dc.identifier.issn1323-3580
dc.identifier.issn1448-6083
dc.identifier.scopus2-s2.0-84901497228
dc.identifier.scopusqualityQ1
dc.identifier.urihttps://doi.org/10.1017/pasa.2014.16
dc.identifier.urihttps://hdl.handle.net/20.500.12428/27774
dc.identifier.volume31
dc.identifier.wosWOS:000339713800001
dc.identifier.wosqualityQ2
dc.indekslendigikaynakWeb of Science
dc.indekslendigikaynakScopus
dc.language.isoen
dc.publisherCambridge Univ Press
dc.relation.ispartofPublications of The Astronomical Society of Australia
dc.relation.publicationcategoryinfo:eu-repo/semantics/openAccess
dc.rightsinfo:eu-repo/semantics/openAccess
dc.snmzKA_WoS_20250125
dc.subjectastrophysical data
dc.subjectmultiwavelength observations
dc.subjectstars
dc.subjectcool, active
dc.subjectstars
dc.subjectindividual: AB Dor
dc.titleMultiwavelength Observations of AB Doradus
dc.typeArticle

Dosyalar

Koleksiyon

WoS İndeksli Yayınlar Koleksiyonu
Scopus İndeksli Yayınlar Koleksiyonu