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Related papers: Distribution of Water Vapor in Molecular Clouds

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Aims: Our aim is to determine the critical parameters in water chemistry and the contribution of water to the oxygen budget by observing and modelling water gas and ice for a sample of eleven low-mass protostars, for which both forms of…

Astrophysics of Galaxies · Physics 2014-12-03 M. Schmalzl , R. Visser , C. Walsh , T. Albertsson , E. F. van Dishoeck , L. E. Kristensen , J. C. Mottram

Nowadays there are several observational studies about the 13CO/C18O abundance ratio (X) towards nearby molecular clouds. These works give observational support to the C18O selective photodissociation due to the interaction between the FUV…

Astrophysics of Galaxies · Physics 2020-01-08 M. B. Areal , S. Paron , M. E. Ortega , L. Duvidovich

We report ALMA high-resolution observations of water emission lines $p-{\rm{H_2O}} (2_{02}-1_{11}$), $o-{\rm{H_2O}} (3_{21}-3_{12})$, $p-{\rm{H_2O}} (4_{22}-4_{13})$, in the strongly lensed galaxy HATLASJ113526.2-01460 at redshift z $\sim$…

We measure the parsec-scale relationship between integrated CO intensity (I_CO) and visual extinction (A_V) in 24 local molecular clouds using maps of CO emission and dust optical depth from Planck. This relationship informs our…

$Aims.$ We characterize the molecular-line emission of three clouds whose star-formation rates span one order of magnitude: California, Perseus, and Orion A. $Methods.$ We use stratified random sampling to select positions representing the…

Astrophysics of Galaxies · Physics 2023-11-29 M. Tafalla , A. Usero , A. Hacar

Since the emission of water molecules cannot be observed from Earth, less abundant isotopologues, such as H$_2^{18}$O and HDO, are used to trace water in star-forming regions. The main aim of this study is to determine HDO abundance in the…

Solar and Stellar Astrophysics · Physics 2025-06-05 Maria. S. Kirsanova , Anastasiia A. Farafontova

Chemical reactions in starless molecular clouds are heavily dependent on interactions between gas phase material and solid phase dust and ices. We have observed the abundance and distribution of molecular gases in the cold, starless core DC…

Astrophysics of Galaxies · Physics 2013-01-15 E. E. Hardegree-Ullman , J. Harju , M. Juvela , O. Sipila , D. C. B. Whittet , S. Hotzel

We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (Av = 3 - 60 magnitudes). We compare deep Herschel-based measurements of dust extinction with…

Astrophysics of Galaxies · Physics 2021-02-24 John Arban Lewis , Charles Lada , John Bieging , Anoush Kazarians , João Alves , Marco Lombardi

Using the PMO-13.7 m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of $^{12}$CO, $^{13}$CO, and C$^{18}$O $J=1-0$ emission toward the sky region centered at $l$=$209.7^\circ$,…

Astrophysics of Galaxies · Physics 2020-09-15 Chong Li , Hongchi Wang , Miaomiao Zhang , Yuehui Ma , Lianghao Lin

Velocity fields of molecular clouds (MCs) can provide crucial information on the merger and split between clouds, as well as their internal kinematics and maintenance, energy injection and redistribution, even star formation within clouds.…

Astrophysics of Galaxies · Physics 2024-03-12 Lixia Yuan , Ji Yang , Xuepeng Chen , Yang Su , Shaobo Zhang , Xin Zhou , Zhiwei Chen , Qing-Zeng Yan , Min Fang , Fujun Du , Yan Sun , Hongchi Wang , Ye Xu

Ions (e.g., H$_3^+$, H$_2$O$^+$) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of CRIR in low-to-intermediate density gas environments are rare, especially when…

Astrophysics of Galaxies · Physics 2023-01-19 Gan Luo , Zhi-Yu Zhang , Thomas G. Bisbas , Di Li , Ningyu Tang , Junzhi Wang , Ping Zhou , Pei Zuo , Nannan Yue , Jing Zhou , Lingrui Lin

Water vapor has been detected in protoplanetary disks. In this work we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust…

Solar and Stellar Astrophysics · Physics 2014-08-12 Fujun Du , Edwin A. Bergin

The current Venus climate is largely regulated by globally-covered concentrated sulfuric acid clouds from binary condensation of sulfuric acid (H2SO4) and water (H2O). To understand this complicated H2SO4-H2O gas-cloud system, previous…

Earth and Planetary Astrophysics · Physics 2022-07-22 Longkang Dai , Xi Zhang , Wencheng D. Shao , Carver J. Bierson , Jun Cui

We expand our study on the dispersion of polarization angles in molecular clouds. We show how the effect of signal integration through the thickness of the cloud as well as across the area subtended by the telescope beam inherent to dust…

Astrophysics of Galaxies · Physics 2014-11-20 Martin Houde , John E. Vaillancourt , Roger H. Hildebrand , Shadi Chitsazzadeh , Larry Kirby

A molecular dynamics simulation of water confined in a silica pore is performed in order to compare it with recent experimental results on water confined in porous Vycor glass at room temperature. A cylindrical pore of 40 A is created…

Statistical Mechanics · Physics 2009-10-31 M. Rovere , M. A. Ricci , D. Vellati , F. Bruni

Context. The earliest phases of high-mass star formation are poorly understood. Aims. Our goal is to determine the physical conditions and kinematic structure of massive star-forming cloud clumps. Methods. We analyze H$_2$O 557 GHz line…

Solar and Stellar Astrophysics · Physics 2014-10-15 Russell F. Shipman , Floris F. S van der Tak , Friedrich Wyrowski , Fabrice Herpin , Wilfred Frieswijk

We present deep Herschel-PACS spectroscopy of far-infrared water lines from a sample of four protoplanetary disks around solar-mass stars, selected to have strong water emission at mid-infrared wavelengths. By combining the new Herschel…

The degree to which the properties of protostars are affected by environment remains an open question. To investigate this, we look at the Orion A and B molecular clouds, home to most of the protostars within 500 pc. At ~400 pc, Orion is…

We have searched for emission from the 557 GHz ortho-water line in the interstellar medium of six nearby starburst galaxies. We used the Odin satellite to observe the 1_10-1_01 transition of o-H2O in the galaxies NGC253, IC342, M82,…

We report the results of initial FUSE observations of molecular hydrogen (H2) in translucent clouds. These clouds have greater optical depth than any of the diffuse clouds previously observed for far-UV H2 absorption, and provide new…