Astrometry in the solar neighbourhood, preparation and exploration of space missions
Photoionized nebulae, stars and the chemical evolution of galaxies
Spatially resolved planetary nebulae: characterizing (micro) structures of low-ion...
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| Author(s): |
Total Authors: 4
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| Affiliation: | [1] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil
[2] Inst Astrophys, F-75014 Paris - France
[3] Univ Fed Sao Carlos, BR-13565905 Sao Carlos, SP - Brazil
Total Affiliations: 3
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| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 448, n. 1, p. 119-134, MAR 21 2015. |
| Web of Science Citations: | 2 |
| Abstract | |
We studied a sample of stars associated with the Sh 2-296 nebula, part of the reflection nebulae complex in the region of Canis Major R1 (CMa R1). Our sample corresponds to optical counterparts of X-ray sources detected from observations with the XMM-Newton satellite, which revealed dozens of possible low-mass young stars not yet known in this region. A sample of 58 young star candidates were selected based on optical spectral features, mainly H alpha and lithium lines, observed with multiobjects spectroscopy performed by the Gemini South telescope. Among the candidates, we find 41 confirmed T Tauri and 15 very likely young stars. Based on the H alpha emission, the T Tauri stars were distinguished between classical (17 per cent) and weak-lined (83 per cent), but no significant difference was found in the age and mass distribution of these two classes. The characterization of the sample was complemented by near- and mid-infrared data, providing an estimate of ages and masses from the comparison with pre-main-sequence evolutionary models. While half of the young stars have an age of 1-2 Myr or less, only a small fraction (similar to 25 per cent) shows evidence of IR excess revealing the presence of circumstellar discs. This low fraction is quite rare compared to most young star-forming regions, suggesting that some external factor has accelerated the disc dissipation. (AU) | |
| FAPESP's process: | 10/50930-6 - Chemical evolution and galactic and extragalactic stellar populations, by means of spectroscopy and imaging |
| Grantee: | Beatriz Leonor Silveira Barbuy |
| Support Opportunities: | Research Projects - Thematic Grants |