Disc clearing of young stellar objects: evidence for fast inside-out dispersal

Author(s)

C. M. Koepferl, B. Ercolano, J. Dale, P. S. Teixeira, T. Ratzka, L. Spezzi

Abstract

The time-scale over which and the modality by which young stellar

objects (YSOs) disperse their circumstellar discs dramatically influence

the eventual formation and evolution of planetary systems. By means of

extensive radiative transfer modelling, we have developed a new set of

diagnostic diagrams in the infrared colour-colour plane (K - [24] versus

K - [8]), to aid with the classification of the evolutionary stage of

YSOs from photometric observations. Our diagrams allow the

differentiation of sources with unevolved (primordial) discs from those

evolving according to different clearing scenarios (e.g. homologous

depletion versus inside-out dispersal), as well as from sources that

have already lost their disc. Classification of over 1500 sources in 15

nearby star-forming regions reveals that approximately 39 per cent of

the sources lie in the primordial disc region, whereas between 31 and 32

per cent disperse from the inside-out and up to 22 per cent of the

sources have already lost their disc. Less than 2 per cent of the

objects in our sample lie in the homogeneous draining regime.

Time-scales for the transition phase are estimated to be typically a few

105 yr independent of stellar mass. Therefore, regardless of

spectral type, we conclude that currently available infrared photometric

surveys point to fast (of the order of 10 per cent of the global disc

lifetime) inside-out clearing as the preferred mode of disc dispersal.

Organisation(s)

Department of Astrophysics

External organisation(s)

Ludwig-Maximilians-Universität München, Excellence Cluster Universe, European Southern Observatory (Germany)

Journal

Monthly Notices of the Royal Astronomical Society

Volume

428

Pages

3327-3354

No. of pages

28

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/sts276

Publication date

02-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/14d62154-3844-4607-b8c4-55cca2169b3b