ICATE   21876
INSTITUTO DE CIENCIAS ASTRONOMICAS, DE LA TIERRA Y DEL ESPACIO
Unidad Ejecutora - UE
artículos
Título:
Spectroscopic variability and magnetic fields of HgMn stars
Autor/es:
HUBRIG, S.; GONZÁLEZ, J.F.; ILYIN, I.; KORHONEN, H.; SAVANOV, I.; DALL, T.; SCHÖLLER, M.; COWLEY, C. R.; BRIQUET, M.; ARLT, R.
Revista:
ASTRONOMISCHE NACHRICHTEN
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Lugar: Weinheim; Año: 2011 vol. 332 p. 998 - 1007
ISSN:
0004-6337
Resumen:
The discovery of exotic abundances, chemical inhomogeneities, and weak
magnetic fields on the surface of late B-type primaries in spectroscopic
binaries has important implications not only for our understanding of
the formation mechanisms of stars with Hg and Mn peculiarities
themselves, but also for the general understanding of B-type star
formation in binary systems. The origin of the abundance anomalies
observed in late B-type stars with HgMn peculiarity is still poorly
understood. The connection between HgMn peculiarity and membership in
binary and multiple systems is supported by our observations during the
last decade. The important result achieved in our studies of a large
sample of HgMn stars is the finding that most HgMn stars exhibit
spectral variability of various chemical elements, proving that the
presence of an inhomogeneous distribution on the surface of these stars
is a rather common characteristic and not a rare phenomenon. Further, in
the studied systems, we found that all components are chemically
peculiar with different abundance patterns. Generally, He and Si
variable Bp stars possess large-scale organised magnetic fields that in
many cases appear to occur essentially in the form of a single large
dipole located close to the centre of the star. The presence of magnetic
fields in the atmospheres of HgMn stars has been demonstrated in several
studies. In addition to the measurements of longitudinal and quadratic
magnetic fields, this work also showed evidence for a relative magnetic
intensification of Fe II lines produced by different magnetic
desaturations induced by different Zeeman-split components.