THE CLOSE T TAURI BINARY SYSTEM V4046 Sgr: ROTATIONALLY MODULATED X-RAY EMISSION FROM ACCRETION SHOCKS
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The American Astronomical Society, find out more The American Astronomical Society, find out more The Institute of Physics, find out more The Institute of Physics, find out more THE CLOSE T TAURI BINARY SYSTEM V4046 Sgr: ROTATIONALLY MODULATED X-RAY EMISSION FROM ACCRETION SHOCKS C. Argiroffi1,2, A. Maggio2, T. Montmerle3, D. P. Huenemoerder4, E. Alecian5, M. Audard6,7, J. Bouvier8, F. Damiani2, J.-F. Donati9, S. G. Gregory10Show full author list Published 2012 May 31 • © 2012. The American Astronomical Society. All rights reserved. The Astrophysical Journal, Volume 752, Number 2 Download Article PDF Figures Tables References Download PDF 1037 Total downloads 26 26 total citations on Dimensions. Turn on MathJax Get permission to re-use this article Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Hide article information Author e-mails argi@astropa.unipa.it Author affiliations 1 Dipartimento di Fisica, Università di Palermo, Piazza del Parlamento 1, I-90134 Palermo, Italy 2 INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134 Palermo, Italy 3 Institut d'Astrophysique de Paris, 98bis bd Arago, FR-75014 Paris, France 4 MIT, Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA 5 Observatoire de Paris, LESIA, 5, place Jules Janssen, F-92195 Meudon Principal Cedex, France 6 ISDC Data Center for Astrophysics, University of Geneva, Ch. d'Ecogia 16, CH-1290 Versoix, Switzerland 7 Observatoire de Genève, University of Geneva, Ch. des Maillettes 51, CH-1290 Versoix, Switzerland 8 UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, F-38041, Grenoble, France 9 IRAP-UMR 5277, CNRS & Université de Toulouse, 14 Av. E. Belin, F-31400 Toulouse, France 10 Astronomy Department, California Institute of Technology, MC 249-17, Pasadena, CA 91125, USA 11 Department of Astronomy, University of Vienna, Trkenschanzstrasse 17, A-1180 Vienna, Austria 12 ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany 13 Center for Imaging Science, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA Dates Received 2011 May 26 Accepted 2012 April 4 Published 2012 May 31 Citation C. Argiroffi et al 2012 ApJ 752 100 Create citation alert DOI https://doi.org/10.1088/0004-637X/752/2/100 Keywords accretion, accretion disks; stars: individual (V4046 Sgr) ; stars: magnetic field; stars: pre-main sequence; stars: variables: T Tauri, Herbig Ae/Be; X-rays: stars Journal RSS feed Create or edit your corridor alerts What are corridors? This link opens in a new tab. Abstract We report initial results from a quasi-simultaneous X-ray/optical observing campaign targeting V4046 Sgr, a close, synchronous-rotating classical T Tauri star (CTTS) binary in which both components are actively accreting. V4046 Sgr is a strong X-ray source, with the X-rays mainly arising from high-density (n e~ 1011-1012 cm–3) plasma at temperatures of 3-4 MK. Our multi-wavelength campaign aims to simultaneously constrain the properties of this X-ray-emitting plasma, the large-scale magnetic field, and the accretion geometry. In this paper, we present key results obtained via time-resolved X-ray-grating spectra, gathered in a 360 ks XMM-Newton observation that covered 2.2 system rotations. We find that the emission lines produced by this high-density plasma display periodic flux variations with a measured period, 1.22 ± 0.01 d, that is precisely half that of the binary star system (2.42 d). The observed rotational modulation can be explained assuming that the high-density plasma occupies small portions of the stellar surfaces, corotating with the stars, and that the high-density plasma is not azimuthally symmetrically distributed with respect to the rotational axis of each star. These results strongly support models in which high-density, X-ray-emitting CTTS plasma is material heated in accretion shocks, located at the base of accretion flows tied to the system by magnetic field lines.