TY - JOUR
T1 - The Lifetime of Protoplanetary Discs: Observations and Theory
AU - Ercolano, Barbara
AU - Koepferl, Christine
PY - 2014
Y1 - 2014
N2 - The time-scale over which and modality by which young stellar objects
(YSOs) disperse their circumstellar discs dramatically influences the
eventual formation and evolution of planetary systems. By means of
extensive radiative transfer (RT) modelling, we have developed a new set
of diagnostic diagrams in the infrared colour-colour plane (K - [24] vs.
K - [8]), to aid with the classification of the evolutionary stage of
YSOs from photometric observations. Our diagrams allow the
differentiation of sources with un-evolved (primordial) discs from those
evolving according to different clearing scenarios (e.g. homologous
depletion vs. inside-out dispersal), as well as from sources that have
already lost their disc. Classification of over 1,500 sources in 15
nearby star-forming regions reveals that approximately 39 % of the
sources lie in the primordial disc region, whereas between 31 and 32 %
disperse from the inside-out and up to 22 % of the sources have already
lost their disc. Less than 2 % 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 years independent of
stellar mass. Therefore, regardless of spectral type, we conclude that
currently available infrared photometric surveys point to fast (of order
10 % of the global disc lifetime) inside-out clearing as the preferred
mode of disc dispersal.
AB - The time-scale over which and modality by which young stellar objects
(YSOs) disperse their circumstellar discs dramatically influences the
eventual formation and evolution of planetary systems. By means of
extensive radiative transfer (RT) modelling, we have developed a new set
of diagnostic diagrams in the infrared colour-colour plane (K - [24] vs.
K - [8]), to aid with the classification of the evolutionary stage of
YSOs from photometric observations. Our diagrams allow the
differentiation of sources with un-evolved (primordial) discs from those
evolving according to different clearing scenarios (e.g. homologous
depletion vs. inside-out dispersal), as well as from sources that have
already lost their disc. Classification of over 1,500 sources in 15
nearby star-forming regions reveals that approximately 39 % of the
sources lie in the primordial disc region, whereas between 31 and 32 %
disperse from the inside-out and up to 22 % of the sources have already
lost their disc. Less than 2 % 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 years independent of
stellar mass. Therefore, regardless of spectral type, we conclude that
currently available infrared photometric surveys point to fast (of order
10 % of the global disc lifetime) inside-out clearing as the preferred
mode of disc dispersal.
KW - Physics
U2 - 10.1007/978-3-319-03041-8_11
DO - 10.1007/978-3-319-03041-8_11
M3 - Article
VL - 36
SP - 63
JO - The Labyrinth of Star Formation, Astrophysics and Space Science Proceedings
JF - The Labyrinth of Star Formation, Astrophysics and Space Science Proceedings
ER -