514 research outputs found
On the origin of H2CO abundance enhancements in low-mass protostars
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Does IRAS 16293-2422 have a hot core? Chemical inventory and abundance changes in its protostellar environment
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Envelope structure of deeply embedded young stellar ojects in the Serpens molecular cloud
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
From Molecular Cores to Planet-forming Disks: An SIRTF Legacy Program
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Envelope structure on 700 AU scales and the molecular outows of low - mass young stellar objects
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
ISO Spectroscopy of Young Stellar Objects
Observations of gas-phase and solid-state species toward
young stellar objects (YSOs) with the spectrometers
on board the Infrared Space Observatory
are reviewed. The excitation and abundances of
the atoms and molecules are sensitive to the changing
physical conditions during star-formation. In
the cold outer envelopes around YSOs, interstellar
ices contain a significant fraction of the heavy element
abundances, in particular oxygen. Different ice
phases can be distinguished, and evidence is found for
heating and segregation of the ices in more evolved
objects. The inner warm envelopes around YSOs are
probed through absorption and emission of gas-phase
molecules, including CO, CO_2, CH_4 and H_2O. An
overview of the wealth of observations on gas-phase
H_2O in star-forming regions is presented. Gas/solid
ratios are determined, which provide information on
the importance of gas-grain chemistry and high temperature
gas-phase reactions. The line ratios of molecules
such as H_2, CO and H_2O are powerful probes
to constrain the physical parameters of the gas. Together
with atomic and ionic lines such as [0 I]
63 µm, [S I] 25 µm and (Si II] 35 µm, they can also
be used to distinguish between photon- and shock-heated
gas. Finally, spectroscopic data on circumstellar
disks around young stars are mentioned. The
results are discussed in the context of the physical
and chemical evolution of YSOs
Sub - arcsec imaging at 267 GHz of a young binary system: detection of a dust disk of radius less than 70 AU around T Tauri N
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
ISO-LWS Spectra of T Tauri and Herbig AeBe stars
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
2D/3D Continuum Modeling of Proto-Planetary Disks Observed in the c2d Spitzer Legacy Program
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
Submillimeter lines from circumstellar disks around pre-main sequence stars
Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe
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