Classical T Tauri stars with VPHAS+ – I. H α andu-band accretion rates in the Lagoon Nebula M8

Kalari, V. M.; Vink, J. S.; Drew, J. E.; Barentsen, G.; Drake, J. J.; Eislöffel, J.; Martín, E. L.; Parker, Q. A.; Unruh, Y. C.; Walton, N. A.; Wright, N. J.

Abstract

We estimate the accretion rates of 235 Classical T Tauri star (CTTS) candidates in the Lagoon Nebula using ugri H α photometry from the VST Photometric H α survey+. Our sample consists of stars displaying H α excess, the intensity of which is used to derive accretion rates. For a subset of 87 stars, the intensity of the u-band excess is also used to estimate accretion rates. We find the mean variation in accretion rates measured using H α and u-band intensities to be ∼0.17 dex, agreeing with previous estimates (0.04–0.4 dex) but for a much larger sample. The spatial distribution of CTTS align with the location of protostars and molecular gas suggesting that they retain an imprint of the natal gas fragmentation process. Strong accretors are concentrated spatially, while weak accretors are more distributed. Our results do not support the sequential star-forming processes suggested in the literature.

Citation

Kalari, V. M., Vink, J. S., Drew, J. E., Barentsen, G., Drake, J. J., Eislöffel, J., …Wright, N. J. (2015). Classical T Tauri stars with VPHAS+ – I. H α andu-band accretion rates in the Lagoon Nebula M8. Monthly Notices of the Royal Astronomical Society, 453(1), 1026-1046. https://doi.org/10.1093/mnras/stv1676

• Journal Article Type: Article
• Online Publication Date: Aug 22, 2015
• Publication Date: Oct 11, 2015
• Deposit Date: May 30, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 453
• Issue: 1
• Pages: 1026-1046
• DOI: https://doi.org/10.1093/mnras/stv1676
• Keywords: Space and Planetary Science; Astronomy and Astrophysics