ﻻ يوجد ملخص باللغة العربية
We present the results of short baseline interferometry observations at submillimetre wavelengths, using a two-element interferometer comprising the JCMT and CSO, of circumstellar discs around young YSOs. We model data for the Class 0 protostar IRAS03282 and the Class I protostar L1709B with discs and compare them with previously published results. We find evidence for the ratio of the disc mass to envelope mass to increase as the objects evolve.
This prospective chapter gives our view on the evolution of the study of circumstellar discs within the next 20 years from both observational and theoretical sides. We first present the expected improvements in our knowledge of protoplanetary discs a
Galactic cosmic rays are a ubiquitous source of ionisation of the interstellar gas, competing with UV and X-ray photons as well as natural radioactivity in determining the fractional abundance of electrons, ions and charged dust grains in molecular c
Emission lines formed in the circumstellar envelopes of several type of stars can be modeled using first principles of line formation. We present simple ways of calculating line emission profiles formed in circumstellar envelopes having different geo
The initial stages of planet formation in circumstellar gas discs proceed via dust grains that collide and build up larger and larger bodies (Safronov 1969). How this process continues from metre-sized boulders to kilometre-scale planetesimals is a m
In this paper we present simulated observations of massive self-gravitating circumstellar discs using the Atacama Large Millimetre/sub-millimetre Array (ALMA). Using a smoothed particle hydrodynamics model of a $0.2M_{odot}$ disc orbiting a $1M_{odot