A&A 403, 187-203 (2003)
DOI: 10.1051/0004-6361:20030305
An XMM-Newton-based X-ray survey of pre-main sequence stellar emission in the L1551 star-forming complex
F. Favata1, G. Giardino1, G. Micela2, S. Sciortino2 and F. Damiani21 Astrophysics Division - Research and Science Support Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
2 INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
(Received 11 November 2002 / Accepted 21 February 2003 )
Abstract
We present a study of the X-ray sources present in the
nearby L1551 star forming region, based on a deep XMM-Newton observation
complemented with Chandra data for the brightest sources.
Most known pre-main sequence stars in the region have been
detected, most of them with sufficient statistics to allow a
detailed study of the temporal and spectral characteristics of their
X-ray emission. Significant temporal (and spectral) variability on
both short and long time scales is visible for most of the stars. In
particular XZ Tau shows large-amplitude variations on time scales of
several hours with large changes in the intervening absorption,
suggestive of the X-ray emission being eclipsed by the accretion
stream (and thus of the X-ray emission being partly or totally
accretion-induced). The coronal metal abundance of the WTTS sources
is clustered around
, while the CTTS sources span
almost two orders of magnitudes in coronal
Z, even though the
photospheric abundance of all stars in the L1551 is likely to be
very similar. Some individual elements (notably Ne) appear to be
systematically enhanced with respect to Fe in the WTTS stars. The
significant differences between the spectral and temporal
characteristics of the CTTS and WTTS populations suggest that a
different emission mechanism is (at least partly) responsible for
the X-ray emission of the two types of stars.
Key words: ISM: individual objects: L1551 -- stars: formation -- stars: pre-main sequence -- X-rays: stars
Offprint request: F. Favata, Fabio.Favata@rssd.esa.int
SIMBAD Objects
© ESO 2003