IALP   13078
INSTITUTO DE ASTROFISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Pre-main-sequence stars in the Lagoon Nebula (M8)
Autor/es:
ARIAS, J; BARBA, R; MORRELL, NIDIA IRENE
Revista:
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Referencias:
Año: 2007 vol. 374 p. 1253 - 1263
ISSN:
0035-8711
Resumen:
We report the discovery of new pre-main-sequence (PMS) stars in the
Lagoon Nebula (M8) at a distance of 1.25 kpc, based on
intermediate-resolution spectra obtained with the Boller & Chivens
spectrograph at the 6.5-m Magellan I Telescope (Las Campanas
Observatory, Chile). According to the spectral types, the presence of
emission lines and the lithium λ6708 absorption line, we are able
to identify 27 classical T Tauri stars, seven weak-lined T Tauri stars
and three PMS emission objects with spectral type G, which we include in
a separate stellar class denominated `PMS Fe/Ge class'. Using
near-infrared photometry either from the Two-Micron All-Sky Survey or
from our own previous work, we derive effective temperatures and
luminosities for these stars and locate them in the Hertzsprung-Russell
diagram, in order to estimate their masses and ages. We find that almost
all of our sample stars are younger than 3 × 106 yr and
span over a range of masses between 0.8 and 2.5 Msolar. A
cross-correlation between our spectroscopic data and the X-ray sources
detected with the Chandra ACIS instrument is also presented.