Spitzer Space Telescope spectroscopy of ices toward low-mass embedded protostars

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Bands of solid CO_2 in the 2-3 mu m spectrum of S 140:IRS1

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Infra-red spectra of complex organic molecules in astronomically relevant ice matrices

Laboratory astrophysics and astrochemistr

Infrared spectroscopic survey of the quiescent medium of nearby clouds. II. Ice formation and grain growth in Perseus and Serpens

Interstellar matter and star formatio

Infrared spectra of complex organic molecules in astronomically relevant ice mixtures: IV. Methylamine

Laboratory astrophysics and astrochemistr

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

Disk Evolution in Serpens After c2d Spitzer Mapping

LPI Contribution No. 128

Accretion in the inner regions of disks around massive Young Stellar Objects

Interstellar matter and star formatio