Issue |
A&A
Volume 585, January 2016
|
|
---|---|---|
Article Number | A136 | |
Number of page(s) | 18 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/201527224 | |
Published online | 11 January 2016 |
X-Shooter study of accretion in Chamaeleon I⋆
1 Scientific Support Office, Directorate of Science and Robotic Exploration, European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
e-mail: cmanara@cosmos.esa.int
2 INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
3 Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
4 Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, Beijing 100871, PR China
5 Universtität Wien, Institut für Astrophysik, Türkenschanzstrasse 17, 1180 Vienna, Austria
Received: 21 August 2015
Accepted: 23 October 2015
We present the analysis of 34 new VLT/X-Shooter spectra of young stellar objects in the Chamaeleon I star-forming region, together with four more spectra of stars in Taurus and two in Chamaeleon II. The broad wavelength coverage and accurate flux calibration of our spectra allow us to estimate stellar and accretion parameters for our targets by fitting the photospheric and accretion continuum emission from the Balmer continuum down to ~700 nm. The dependence of accretion on stellar properties for this sample is consistent with previous results from the literature. The accretion rates for transitional disks are consistent with those of full disks in the same region. The spread of mass accretion rates at any given stellar mass is found to be smaller than in many studies, but is larger than that derived in the Lupus clouds using similar data and techniques. Differences in the stellar mass range and in the environmental conditions between our sample and that of Lupus may account for the discrepancy in scatter between Chamaeleon I and Lupus. Complete samples in Chamaeleon I and Lupus are needed to determine whether the difference in scatter of accretion rates and the lack of evolutionary trends are not influenced by sample selection.
Key words: stars: pre-main sequence / stars: variables: T Tauri, Herbig Ae/Be / accretion, accretion disks / protoplanetary disks / open clusters and associations: individual: Chamaeleon I
© ESO, 2016
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