Please use this identifier to cite or link to this item:
|Title:||X-ray orbital modulation of a white dwarf accreting from an L dwarf: The system SDSS J121209.31+013627.7|
De Martino, D.
Casewell, S. L.
Wynn, G. A.
|Publisher:||EDP Sciences for European Southern Observatory (ESO), Springer Verlag|
|Citation:||Astronomy and Astrophysics, 2017, 598, L6|
|Abstract:||In an XMM-Newton observation of the binary SDSS J121209.31+013627.7, consisting of a white dwarf and an L dwarf, we detect X-ray orbital modulation as proof of accretion from the substellar companion onto the magnetic white dwarf. We constrain the system geometry (inclination as well as magnetic and pole-cap angle) through modelling of the X-ray light curve, and we derive a mass accretion rate of 3.2 × 10-14MȮ/ yr from the X-ray luminosity (~3 × 1029 erg/s). From X-ray studies of L dwarfs, a possible wind driven from a hypothesized corona on the substellar donor is orders of magnitude too weak to explain the observed accretion rate, while the radius of the L dwarf is comparable to its Roche lobe (0.1 RȮ), making Roche-lobe overflow the likely accretion mechanism in this system.|
|Rights:||Copyright © 2017, EDP Sciences for European Southern Observatory (ESO), Springer Verlag. Deposited with reference to the publisher’s open access archiving policy.|
|Appears in Collections:||Published Articles, Dept. of Physics and Astronomy|
Files in This Item:
|1701.02894v1.pdf||Post-review (final submitted author manuscript)||358.37 kB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.