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Related papers: Theoretical HDO emission from low-mass protostella…

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Recent interferometer observations have found that the D2O/HDO abundance ratio is higher than that of HDO/H2O by about one order of magnitude in the vicinity of low-mass protostar NGC 1333-IRAS 2A, where water ice has sublimated. Previous…

Astrophysics of Galaxies · Physics 2016-02-10 K. Furuya , E. F. van Dishoeck , Y. Aikawa

We have coupled a chemical model with two dynamical models of collapsing low mass star-forming cores to predict abundances across the core of the commonly used infall tracers, CS and HCO$^+$, at various stages of the collapse. The models…

Solar and Stellar Astrophysics · Physics 2015-05-19 Julia F. Roberts , Hugh A. W. Stace , Jonathan M. C. Rawlings

How protostars accrete mass is one of the fundamental problems of star formation. High column densities and complex kinematical structures make direct observations challenging and they only provide a snapshot. Chemical tracers provide an…

We present the detection and modeling of more than 70 far-IR pure rotational lines of water vapor, including the 18O and 17O isotopologues, towards Orion KL. Observations were performed with the Long Wavelength Spectrometer Fabry-Perot…

Seven Class 0 sources mapped with SCUBA at 850 and 450 micron are modeled using a one dimensional radiative transfer code. The modeling takes into account heating from an internal protostar, heating from the ISRF, realistic beam effects,…

Astrophysics · Physics 2009-09-28 Yancy L. Shirley , Neal J. Evans , Jonathan M. C. Rawlings

We present new observations of near-infrared molecular hydrogen (H2) line emission in a sample of 18 Class I and flat-spectrum low mass protostars, primarily in the Tau- Aur and {\rho} Oph dark clouds. The line emission is extended by up to…

Solar and Stellar Astrophysics · Physics 2015-05-20 Thomas P. Greene , Mary Barsony , David A. Weintraub

We use Herschel spectrophotometry of BHR71, an embedded Class 0 protostar, to provide new constraints on its physical properties. We detect 645 (non-unique) spectral lines amongst all spatial pixels. At least 61 different spectral lines…

Solar and Stellar Astrophysics · Physics 2017-02-08 Yao-Lun Yang , Neal J. Evans , Joel D. Green , Michael M. Dunham , Jes K. Jørgensen

We estimated the ortho-{\rm{H$_2$O}} abundances of G267.9--1.1, G268.4--0.9, G333.1--0.4 and G336.5--1.5, four of the brightest ortho-{\rm{H$_2$O}} sources in the southern sky observed by the Submillimeter Wave Astronomy Satellite…

Astrophysics of Galaxies · Physics 2017-04-28 Bing-Ru Wang , Lei Qian , Di Li , Zhi-Chen Pan

We have measured the deuterium fractionation (through the column density ratio N(N2D+)/N(N2H+)) and the CO depletion factor (ratio between expected and observed CO abundance) in a sample of 10 high-mass protostellar candidates, in order to…

Astrophysics · Physics 2009-11-11 F. Fontani , P. Caselli , A. Crapsi , R. Cesaroni , S. Molinari , L. Testi , J. Brand

We present a systematic single-dish search for molecular outflows toward a sample of 9 candidate low-luminosity protostars and 30 candidate Very Low Luminosity Objects (VeLLOs; L_int < 0.1 L_sun). The sources are identified using data from…

Solar and Stellar Astrophysics · Physics 2015-06-11 Kamber R. Schwarz , Yancy L. Shirley , Michael M. Dunham

OH is a key species in the water chemistry of star-forming regions, because its presence is tightly related to the formation and destruction of water. This paper presents OH observations from 23 low- and intermediate-mass young stellar…

We compare estimates of atmospheric precipitation during the Martian Noachian-Hesperian boundary 3.8 Gyr ago as calculated in a radiative-convective column model of the atmosphere with runoff values estimated from a geomorphological…

Earth and Planetary Astrophysics · Physics 2015-06-23 P. von Paris , A. Petau , J. L. Grenfell , E. Hauber , D. Breuer , R. Jaumann , H. Rauer , D. Tirsch

Although water is an essential and widespread molecule in star-forming regions, its chemical formation pathways are still not very well constrained. Observing the level of deuterium fractionation of OH, a radical involved in the water…

Astrophysics of Galaxies · Physics 2015-06-04 B. Parise , F. Du , F. -C. Liu , A. Belloche , H. Wiesemeyer , R. Güsten , K. M. Menten , H. W. Hübers , B. Klein

We present a survey for water maser emission toward a sample of 44 low-luminosity young objects, comprising (proto-)brown dwarfs, first hydrostatic cores (FHCs), and other young stellar objects (YSOs) with bolometric luminosities lower than…

Solar and Stellar Astrophysics · Physics 2017-04-26 Jose F. Gomez , Aina Palau , Lucero Uscanga , Guillermo Manjarrez , David Barrado

This paper presents a millimeter wavelength aperture-synthesis study of the spatial variations of the chemistry in the envelope around the deeply embedded low-mass protostar L483-mm on 1000 AU (5") scales. Lines of 8 molecular species…

Astrophysics · Physics 2009-11-10 Jes K. Jorgensen

We present Odin observations of the AGB star W Hya in the ground-state transition of ortho-H2O, 1(10)-1(01), at 557GHz. The line is clearly of circumstellar origin. Radiative transfer modelling of the water lines observed by Odin and ISO…

Astronomers have yet to establish whether high-mass protostars form from high-mass prestellar cores, similar to their lower-mass counterparts, or from lower-mass fragments at the heart of a pre-protostellar cluster undergoing large-scale…

Astrophysics of Galaxies · Physics 2022-01-12 R. L. Pitts , L. E. Kristensen , J. K. Jørgensen , S. J. van der Walt

We examine emission from a young protostellar object (YPO) with three-dimensional ideal MHD simulations and three-dimensional non-local thermodynamic equilibrium (non-LTE) line transfer calculations, and show the first results. To calculate…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Yamada , M. N. Machida , S. Inutsuka , K. Tomisaka

The study of warm molecular gas in the inner regions of protoplanetary disks is of key importance for the study of planet formation and especially for the transport of H2O and organic molecules to the surfaces of rocky planets/satellites.…

Earth and Planetary Astrophysics · Physics 2014-11-20 R. Meijerink , K. M. Pontoppidan , G. A. Blake , D. R. Poelman , C. P. Dullemond

The availability of exquisite data and the development of new analysis techniques have enabled the study of emitting heights in proto-planetary disks. In this paper we introduce a simple model linking the emitting height of CO to the disk…