IALP   13078
INSTITUTO DE ASTROFISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Simultaneous K- and L-band Spectroscopy of Be Stars: Circumstellar Envelope Properties from Hydrogen Emission Lines
Autor/es:
GRANADA, A.; ARIAS, M. L.; CIDALE, L. S.
Revista:
ASTRONOMICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Año: 2010 vol. 139 p. 1983 - 1992
ISSN:
0004-6256
Resumen:
We present medium-resolution K- and L-band spectra of a sample of eight
Be stars, obtained with Gemini/NIRI. The IR K and L bands contain many
lines of different hydrogen series that are used as a diagnosis to the
physical conditions in the circumstellar environments. We make an
analysis on the optical depths of the line-forming regions based on the
intensity ratios of Pfγ and Brα lines, the behavior of
Humphreys' series, and the fluxes of Brα and Brγ lines. All
our targets show spectroscopic and photometric long-term variability;
thus, time-resolved K- and L-band spectroscopy is an ideal tool for
studying the structure and evolution of the innermost regions of the
envelope and to test models on the disk-forming mechanism. We note that
the instrumental configuration used allowed us to obtain good quality IR
observations and to take profit of Gemini band 3 observing time
(allocation time for ranked programs in which the observing conditions
are relaxed).