Identifying Variability in Deeply Embedded Protostars with ALMA and CARMA
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...
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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...
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We present 1 resolution CARMA observations of the 3mm continuum and 95GHz CH3OH masers toward 14 candidate high mass protostellar objects (HMPOs). Dust continuum emission is detected toward seven HMPOs, and CH3OH masers toward 5 sources. The 3mm continuum sources have diameters < 2× 10AU, masses between 21 and 1200M⊙, and volume densities > 10 8 cm. Most of the 3mm continuum sources are spatial...
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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...
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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...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2019
ISSN: 1538-4357
DOI: 10.3847/1538-4357/aaf972