CONTINUUM VARIABILITY OF DEEPLY EMBEDDED PROTOSTARS AS A PROBE OF ENVELOPE STRUCTURE
نویسندگان
چکیده
منابع مشابه
Observations of nitrogen isotope fractionation in deeply embedded protostars.
CONTEXT The terrestrial planets, comets, and meteorites are significantly enriched in 15N compared to the Sun and Jupiter. While the solar and jovian nitrogen isotope ratio is believed to represent the composition of the protosolar nebula, a still unidentified process has caused 15N-enrichment in the solids. Several mechanisms have been proposed to explain the variations, including chemical fra...
متن کاملThe gas / solid methane abundance ratio toward deeply embedded protostars ?
We present the detection of ro-vibrational absorption lines of the deformation mode of gaseous CH 4 toward the massive protostars W 33A, and NGC 7538 : IRS9, using the SWS spectrometer on board of the Infrared Space Observatory. The observed lines indicate that the CH 4 gas is warm (T ∼ 90 K), and has a low abundance (∼ 4 10 −7). The CH 4 ice in these lines of sight is embedded in a polar matri...
متن کاملEnvelope structure of deeply embedded young stellar objects in the Serpens Molecular Cloud.
Aperture-synthesis and single-dish (sub-) millimeter molecular-line and continuum observations reveal in great detail the envelope structure of deeply embedded young stellar objects (SMM 1 = FIRS 1, SMM 2, SMM 3, SMM 4) in the densely star-forming Serpens Molecular Cloud. SMM 1, 3, and 4 show partially resolved (>2" = 800 AU) continuum emission in the beam of the Owens Valley Millimeter Array a...
متن کاملTracing high energy radiation with molecular lines near deeply embedded protostars
Aims. The aim is to probe high energy radiation emitted by deeply embedded protostars. Methods. Submillimeter lines of CN, NO, CO and SO, and upper limits on SH and N2O are observed with the James Clerk Maxwell Telescope in two high-mass and up to nine low-mass young stellar objects and compared with chemical models. Results. Constant fractional abundances derived from radiative transfer modeli...
متن کاملStellar Properties of Embedded Protostars
Protostars are precursors to the nearly fully assembled T-Tauri and Herbig Ae/Be type stars undergoing quasi-static contraction towards the zero-age main sequence; they are in the process of acquiring the majority of their stellar mass. Although numerous young stars with spatially extended envelope-like structures appear to fit this description, their high extinction has inhibited observers fro...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2013
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/765/2/133