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Related papers: Gas-phase H2O and CO2 toward massive protostars

200 papers

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

Astrophysics of Galaxies · Physics 2015-06-16 Paul F. Goldsmith

We study the properties of gas inside and around galaxy haloes as a function of radius and halo mass, focussing mostly on z=2, but also showing some results for z=0. For this purpose, we use a suite of large cosmological, hydrodynamical…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Freeke van de Voort , Joop Schaye

UV irradiation of simple ices is proposed to efficiently produce complex organic species during star- and planet-formation. Through a series of laboratory experiments, we investigate the effects of the H2O concentration, the dominant ice…

Astrophysics of Galaxies · Physics 2015-05-19 Karin I. Oberg , Ewine F. van Dishoeck , Harold Linnartz , Stefan Andersson

First detections of thermal water vapor absorption lines have been made toward Orion IRc2 using the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (ISO). Grating spectra covering wavelengths 25-45 micron yield…

We have computed a grid of hydrostatic spherical COMARCS models for C stars covering metallicities from [Z/H]=0 to -2 and values of the carbon excess [C-O] from 6.41 to 9.15, plus some temperature sequences, where the amount of oxygen and…

Solar and Stellar Astrophysics · Physics 2019-05-23 Bernhard Aringer , Paola Marigo , Walter Nowotny , Leo Girardi , Marko Mecina , Ambra Nanni

The detection of high gas-phase abundances of SO2 and SO in the cold envelope of an intermediate mass protostar suggests that these molecules might form on icy dust grains and subsequently desorb to the gas phase by non-thermal desorption…

Models for the structure of protoplanetary disks have so far been based on the assumption that the gas and the dust temperature are equal. The gas temperature, an essential ingredient in the equations of hydrostatic equilibrium of the disk,…

Astrophysics · Physics 2009-11-10 I. Kamp , C. P. Dullemond

The high cosmic abundance and the intermediate volatility and chemical properties of sulfur allow the use of sulfur-bearing species as a tracer of the chemical processes in the atmospheres of hot Jupiter exoplanets. Nevertheless, despite…

Earth and Planetary Astrophysics · Physics 2023-03-01 J. Polman , L. B. F. M. Waters , M. Min , Y. Miguel , N. Khorshid

Gas-phase complex organic molecules have been detected toward a range of high- and low-mass star-forming regions at abundances which cannot be explained by any known gas-phase chemistry. Recent laboratory experiments show that UV…

Astrophysics of Galaxies · Physics 2015-05-18 Karin I. Oberg , Sandrine Bottinelli , Jes K. Jorgensen , Ewine F. van Dishoeck

Near-infrared observations towards the luminous IRAS source IRAS11101-5928 and the associated Herbig-Haro objects HH135/HH136 are presented. The observations reveal the presence of a well-collimated, parsec-sized H$_2$ outflow with a total…

Astrophysics · Physics 2009-11-11 Roland Gredel

In previous warm-up chemical models of the low-mass star-forming region L1527, we investigated the evolution of carbon-chain unsaturated hydrocarbon species when the envelope temperature is slightly elevated to $T\approx 30$ K. These models…

Solar and Stellar Astrophysics · Physics 2015-06-03 George E. Hassel , Nanase Harada , Eric Herbst

We present IRAM 30m and JCMT observations of HDO lines towards the solar-type protostar IRAS 16293-2422. Five HDO transitions have been detected on-source, and two were unfruitfully searched for towards a bright spot of the outflow of IRAS…

Context. The formation of water on the dust grains in the interstellar medium may proceed with hydrogen peroxide (H2O2) as an intermediate. Recently gas-phase H2O2 has been detected in {\rho} Oph A with an abundance of ~1E-10 relative to…

Astrophysics of Galaxies · Physics 2015-06-03 Fujun Du , Berengere Parise , Per Bergman

The thermochemistry of H2 and HD in non-collapsed, non-reionized primordial gas up to the end of the dark age is investigated with recent radiation-matter and chemical reaction rates taking into account the efficient coolant HD, and the…

Astrophysics · Physics 2009-11-07 D. Pfenniger , D. Puy

The most usual tracer of molecular gas is line emission from CO. However, the reliability of that tracer has long been questioned in environments different from the Milky Way. We study the relationship between H2 and CO abundances using a…

Astrophysics of Galaxies · Physics 2015-05-18 S. C. O. Glover , M. -M. Mac Low

We present observations of methanol lines in a sample of Class 0 low mass protostars. Using a 1-D radiative transfer model, we derive the abundances in the envelopes. In two sources of the sample, the observations can only be reproduced by…

Astrophysics · Physics 2007-05-23 S. Maret , C. Ceccarelli , A. G. G. M. Tielens , E. Caux , B. Lefloch , A. Faure , A. Castets , D. R. Flower

The mobility of atoms, molecules and radicals in icy grain mantles regulate ice restructuring, desorption, and chemistry in astrophysical environments. Interstellar ices are dominated by H2O, and diffusion on external and internal (pore)…

We present ~2'x2' spectral-maps of Orion BN/KL outflows taken with Herschel at ~12'' resolution. For the first time in the far-IR domain, we spatially resolve the emission associated with the bright H2 shocked regions "Peak 1" and "Peak 2"…

Using a broadband, high spectral resolution survey toward Orion KL acquired with Herschel/HIFI as part of the HEXOS key program, we derive the abundances of H$_2$O and HDO in the different spatial/velocity components associated with this…

Astrophysics of Galaxies · Physics 2015-06-15 Justin L. Neill , Shiya Wang , Edwin A. Bergin , Nathan R. Crockett , Cécile Favre , René Plume , Gary J. Melnick