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相关论文: Gas-phase H2O and CO2 toward massive protostars

200 篇论文

We observed the Herbig Ae/Be stars UX Ori, HD 34282, HD 100453, HD 101412, HD 104237 and HD 142666, and the T Tauri star HD 319139 and searched for H2 0-0 S(2) emission at 12.278 micron and H2 0-0 S(1) emission at 17.035 micron with VISIR,…

Large scale spectral maps of star forming regions enable the comparative study of the gas excitation around an ensemble of sources at a common frame of reference, providing direct insights in the multitude of processes involved. In this…

太阳与恒星天体物理 · 物理学 2020-09-09 Odysseas Dionatos , Lars. E. Kristensen , Mario Tafalla , Manuel Güdel , Magnus Persson

We report the detection of OH+ and H2O+ in the z=0.89 absorber toward the lensed quasar PKS1830-211. The abundance ratio of OH+ and H2O+ is used to quantify the molecular hydrogen fraction (fH2) and the cosmic-ray ionization rate of atomic…

Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study…

地球与行星天体物理 · 物理学 2015-06-16 Robin Wordsworth , Raymond Pierrehumbert

We present the detection and analysis of molecular hydrogen emission toward ten interstellar regions in the Large Magellanic Cloud. We examined low-resolution infrared spectral maps of twelve regions obtained with the Spitzer infrared…

To understand the origin of water line emission and absorption during high-mass star formation, we decompose high-resolution Herschel-HIFI line spectra toward 19 high-mass star-forming regions into three distinct physical components.…

We investigate the role of carbon monoxide ice in the chemical evolution of prestellar cores using astrochemical rate equation models. We constrain the ratios of the binding energies on CO ice and H$_{2}$O ice for a series of adsorbates…

星系天体物理 · 物理学 2024-08-14 Germán Molpeceres , Kenji Furuya , Yuri Aikawa

The amount of water vapor in the terrestrial atmosphere is highly variable both spatially and temporally. In the tropics it sometimes constitutes 4-5% of the atmosphere. At the same time collisional broadening of spectral lines by water…

大气与海洋物理 · 物理学 2020-01-08 Yan Tan , Roman V. Kochanov , Laurence S. Rothman , Iouli E. Gordon

One of the most outstanding issues in exoplanet characterization is understanding the prevalence of obscuring clouds and hazes in their atmospheres. The ability to predict the presence of clouds/hazes a priori is an important goal when…

地球与行星天体物理 · 物理学 2016-01-29 Kevin B. Stevenson

The formation of interstellar water has been commonly accepted to occur on the surfaces of icy dust grains in dark molecular clouds at low temperatures (10-20 K), involving hydrogenation reactions of oxygen allotropes. As a result of the…

星系天体物理 · 物理学 2014-10-22 Thanja Lamberts , Herma Cuppen , Gleb Fedoseev , Sergio Ioppolo , Ko-Ju Chuang , Harold Linnartz

Galaxies in Hickson Compact Groups (HCGs) are believed to experience morphological transformations from blue, star-forming galaxies to red, early-type galaxies. Galaxies with a high ratio between the luminosities of the warm H2 to the 7.7mu…

星系天体物理 · 物理学 2014-10-15 U. Lisenfeld , P. N. Appleton , M. E. Cluver , P. Guillard , K. Alatalo , P. Ogle

In this Letter we report the CO abundance relative to H2 derived toward the circumstellar disk of the T-Tauri star TW Hya from the HD (1-0) and C18O (2-1) emission lines. The HD (1-0) line was observed by the Herschel Space Observatory…

太阳与恒星天体物理 · 物理学 2015-06-17 Cécile Favre , L. Ilsedore Cleeves , Edwin A. Bergin , Chunhua Qi , Geoffrey A. Blake

We present a set of gas-phase Planck mean and Rosseland mean opacity tables applicable for simulations of star and planet formation, stellar evolution, disk modelling at various metallicities in hydrogen-rich environments. The tables are…

太阳与恒星天体物理 · 物理学 2015-05-13 Ch. Helling , W. Lucas

We have detected the S(1), S(2), S(3), S(4) and S(5) pure rotational lines of molecular hydrogen toward the outflow source HH 54, using the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (ISO). The observed H2…

天体物理学 · 物理学 2007-05-23 David A. Neufeld , Gary J. Melnick , Martin Harwit

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…

天体物理学 · 物理学 2009-11-11 F. Fontani , P. Caselli , A. Crapsi , R. Cesaroni , S. Molinari , L. Testi , J. Brand

Using UV spectra obtained with FUSE, HST, and/or IUE, we determine interstellar column densities of 12CO, 13CO, and/or C_2 for ten Galactic sight lines with 0.37<E(B-V)<0.72. The N(CO)/N(H_2) ratio varies over a factor of 100 in this…

天体物理学 · 物理学 2009-05-29 P. Sonnentrucker , D. E. Welty , J. A. Thorburn , D. G. York

We use a non-equilibrium chemical network to revisit and study the effect of H_{2}, HD and LiH molecular cooling on a primordial element of gas. We solve both the thermal and chemical equations for a gas element with an initial temperature…

天体物理学 · 物理学 2009-02-13 Joaquin P. Prieto , Leopoldo Infante , Raul Jimenez

We present the results of near-infrared spectroscopic observations for a sample of 12 star-forming galaxies at 1.0<z<1.5, drawn from the DEEP2 Galaxy Redshift Survey. H-beta, [OIII], H-alpha, and [NII] emission-line fluxes are measured for…

天体物理学 · 物理学 2009-11-13 Alice E. Shapley , Alison Coil , Chung-Pei Ma , Kevin Bundy

We are aiming at the observational estimation of the relative contribution to the cooling by CO and H2O, as this provides decisive information for the understanding of the oxygen chemistry behind interstellar shock waves. Methods. The high…

We present measurements of interstellar H_2 absorption lines in the continuum spectra of seven early-type stars in the Galactic disk at distances between 1 and 4 kpc. Five of these stars provide lines of sight through the Sagittarius spiral…

天体物理学 · 物理学 2009-10-30 W. Van Dyke Dixon , Mark Hurwitz , Stuart Bowyer