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dc.contributor.authorHill, C. A.
dc.contributor.authorCarmona, A.
dc.contributor.authorDonati, J.-F.
dc.contributor.authorHussain, G. A. J.
dc.contributor.authorGregory, S. G.
dc.contributor.authorAlencar, S. H. P.
dc.contributor.authorBouvier, J.
dc.contributor.authorMaTYSSE Collaboration
dc.date.accessioned2017-11-06T11:30:10Z
dc.date.available2017-11-06T11:30:10Z
dc.date.issued2017-12-01
dc.identifier251475947
dc.identifier6f96dc83-b2e0-4c87-81ca-3a23cd49638c
dc.identifier000413082900036
dc.identifier85050797681
dc.identifier.citationHill , C A , Carmona , A , Donati , J-F , Hussain , G A J , Gregory , S G , Alencar , S H P , Bouvier , J & MaTYSSE Collaboration 2017 , ' Magnetic activity and radial velocity filtering of young Suns : the weak-line T-Tauri stars Par 1379 and Par 2244 ' , Monthly Notices of the Royal Astronomical Society , vol. 472 , no. 2 , pp. 1716-1735 . https://doi.org/10.1093/mnras/stx2042en
dc.identifier.issn0035-8711
dc.identifier.otherRIS: urn:AB33A2FDF4B131B82934FED7250C7BB5
dc.identifier.urihttps://hdl.handle.net/10023/12001
dc.descriptionThe authors thank the IDEX initiative at Université Fédérale Toulouse Midi-Pyrénées (UFTMiP) for funding the STEPS collaboration programme between IRAP/OMP and ESO and for allocating a ‘Chaire d'Attractivité’ to GAJH, allowing her to regularly visit Toulouse to work on MaTYSSE data. SGG acknowledges support from the Science & Technology Facilities Council (STFC) via an Ernest Rutherford Fellowship [ST/J003255/1]. SHPA acknowledges financial support from CNPq, CAPES and Fapemig. This work has made use of the VALD, operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna, and the SVO Filter Profile Service supported from the Spanish MINECO through grant AyA2014-55216en
dc.description.abstractWe report the results of our spectropolarimetric monitoring of the weak-line T-Tauri stars (wTTSs) Par 1379 and Par 2244, within the MaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant Exoplanets) programme. Both stars are of a similar mass (1.6 and 1.8 M⊙) and age (1.8 and 1.1 Myr), with Par 1379 hosting an evolved low-mass dusty circumstellar disc, and with Par 2244 showing evidence of a young debris disc. We detect profile distortions and Zeeman signatures in the unpolarized and circularly polarized lines for each star, and have modelled their rotational modulation using tomographic imaging, yielding brightness and magnetic maps. We find that Par 1379 harbours a weak (250 G), mostly poloidal field tilted 65° from the rotation axis. In contrast, Par 2244 hosts a stronger field (860 G) split 3:2 between poloidal and toroidal components, with most of the energy in higher order modes, and with the poloidal component tilted 45° from the rotation axis. Compared to the lower mass wTTSs, V819 Tau and V830 Tau, Par 2244 has a similar field strength, but is much more complex, whereas the much less complex field of Par 1379 is also much weaker than any other mapped wTTS. We find moderate surface differential rotation of 1.4× and 1.8× smaller than Solar, for Par 1379 and Par 2244, respectively. Using our tomographic maps to predict the activity-related radial velocity (RV) jitter, and filter it from the RV curves, we find RV residuals with dispersions of 0.017 and 0.086 km s−1 for Par 1379 and Par 2244, respectively. We find no evidence for close-in giant planets around either star, with 3σ upper limits of 0.56 and 3.54 MJup (at an orbital distance of 0.1 au).
dc.format.extent20
dc.format.extent4392601
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Societyen
dc.subjectTechniques: polarimetricen
dc.subjectStars: formationen
dc.subjectStars: imagingen
dc.subjectStars: individual: Par 1379en
dc.subjectStars: individual: Par 2244en
dc.subjectStars: magnetic fielden
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.subject3rd-NDASen
dc.subject.lccQBen
dc.subject.lccQCen
dc.titleMagnetic activity and radial velocity filtering of young Suns : the weak-line T-Tauri stars Par 1379 and Par 2244en
dc.typeJournal articleen
dc.contributor.sponsorScience & Technology Facilities Councilen
dc.contributor.institutionUniversity of St Andrews. School of Physics and Astronomyen
dc.identifier.doihttps://doi.org/10.1093/mnras/stx2042
dc.description.statusPeer revieweden
dc.identifier.grantnumberST/J003255/1en


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