Chemical Characteristics of Embedded Young Stellar Objects

Chandra Observations of Embedded Young Stellar Objects

This paper reviews the results of the Chandra deep exposure observations on star forming regions. The ρ Ophiuchi (ρ Oph) cloud cores B-F reveal ∼ 100 X-ray sources above the detection limit of ∼10 ergs s. About 2/3 of the X-ray sources are identified with an optical and/or infrared (IR) object, including significant numbers of class I sources. The class I sources exhibit higher temperature plas...

Chemical Modelling of Young Stellar Objects, I. Method and Benchmarks

Upcoming facilities such as the Herschel Space Observatory or ALMA will deliver a wealth of molecular line observations of young stellar objects (YSOs). Based on line fluxes, chemical abundances can then be estimated by radiative transfer calculations. To derive physical properties from abundances, the chemical network needs to be modeled and fitted to the observations. This modeling process is...

Unravelling the Chemical Structure of Young Stellar Objects with ALMA

The importance of ALMA to quantitatively trace the evolution of gas and dust from interstellar clouds to planetary systems is discussed and illustrated with recent observational studies of molecules in lowand high-mass young stellar objects. Line surveys using single-dish submillimeter telescopes reveal large chemical variations between different sources, which are likely related to their evolu...

Infrared Classi cation of Young Stellar Objects

IRAC Colors of Young Stellar Objects

We compare the infrared colors predicted by theoretical models of protostellar envelopes and protoplanetary disks with initial observations of young stellar objects made with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope (Werner et al. 2004, Fazio et al. 2004). Disk and envelope models characterized by infall and/or accretion rates found in previous studies can quantitatively ...