Dr. Jonathan Marshall (ASIAA)
"The architectures of planetary systems as revealed by resolved imaging at far-infrared and millimetre wavelengths"
時間/地點: 2019-10-18 14:00 [S4-1013]
摘要:
Alongside planets, asteroids and comets form in the gas- and dust-rich
protoplanetary discs that surround young stars. These asteroids and
comets (called planetesimals) lie in belts around their host star and
produce dust in collisions or through sublimation, hence they are
called "debris discs". Gravitational interaction between planetary
companions and the dust-producing planetesimals sculpts the location
and width of these debris discs, leading to visible signatures of
planetary companions in the dusty debris.
Recent studies of resolved debris discs at millimetre wavelengths has
revealed a trend in the radii of the discs with the stellar
luminosity. The observed trend is consistent with the location of
planetesimal formation being linked to the CO ice line in the
primordial protoplanetary disc. Here I will report initital findings
of the extension to that study, the Resolved Emission with ALMA and
SMA Observations of Nearby Stars (REASONS) targetting 68 nearby debris
discs, and an archival study of far-infrared wavelength observations
by Herschel of over 100 resolved debris discs. Comparison of the
far-infrared and millimetre studies shows the same trend present in
both data sets, and evidence that the width of the debris belts being
correlated with the presence of a perturbing planet.