Pre-main sequence stars in the Lagoon Nebula (M8)

Julia I. Arias; Rodolfo H. Barba; Nidia I. Morrell

doi:10.1111/j.1365-2966.2006.11217.x

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arXiv · astro-ph/0611150

Pre-main sequence stars in the Lagoon Nebula (M8)

Julia I. Arias·Rodolfo H. Barba·Nidia I. Morrell

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Abstract

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 6708A absorption line, we are able to identify 27 classical T Tauri stars, 7 weak-lined T Tauri stars and 3 PMS emission objects with spectral type G, which we include in a separated stellar class denominated "PMS Fe/Ge class". Using near-infrared photometry either from 2MASS 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 10^6 years and span over a range of masses between 0.8 and 2.5 Msun. A cross-correlation between our spectroscopic data and the X-ray sources detected with the Chandra ACIS instrument is also presented.

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Julia I. Arias, Rodolfo H. Barba, Nidia I. Morrell. 2006-11-05. Pre-main sequence stars in the Lagoon Nebula (M8). https://doi.org/10.1111/j.1365-2966.2006.11217.x

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