An L'-band survey for circumstellar discs around low-mass stars in the young σ Orionis cluster

Jeffries, Robin; Oliveira, Joana; Van Loon, Jacco

Abstract

We present new K- and L'-band imaging of a representative sample of members of the young 3-5 Myr old sigma Orionis cluster. We identified objects with (K-L') excess by analysing colour-colour diagrams and comparing the observations with empirical main-sequence colours. The derived disk frequency depends on the method used: (54 +/- 15)% if measured directly from the JHKL' colour-colour diagram; or (46 +/-14)% if excesses are computed with respect to predicted photospheric colours (according to the objects spectral types, 2-sigma excess detections). We compare the (K-L') excess with other indicators and show that this is a robust and reliable disk indicator. We also compare the derived disk frequency with similarly aged clusters and discuss possible implications for disk lifetimes. The computed age of the sigma Ori cluster is very important: a cluster age of 3 Myr would support the overall disk lifetime of 6 Myr proposed in the literature, while an age > 4 Myr would point to a slower disk destruction rate.

Citation

Jeffries, R., Oliveira, J., & Van Loon, J. (2004). An L'-band survey for circumstellar discs around low-mass stars in the young σ Orionis cluster. Monthly Notices of the Royal Astronomical Society, 347(4), 1327 -1336. https://doi.org/10.1111/j.1365-2966.2004.07315.x

• Journal Article Type: Article
• Acceptance Date: Oct 20, 2003
• Online Publication Date: Feb 1, 2004
• Publication Date: 2004-02
• Publicly Available Date: May 26, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 347
• Issue: 4
• Pages: 1327 -1336
• DOI: https://doi.org/10.1111/j.1365-2966.2004.07315.x
• Keywords: Astrophysics
• Publisher URL: http://dx.doi.org/10.1111/j.1365-2966.2004.07315.x