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相关论文: Non--LTE Excitation of H$_2$ in Magnetised Molecul…

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We consider collisional excitation of H$_2$ molecules in C-type shocks propagating in dense molecular clouds. New data on collisional rate coefficients for (de-)excitation of H$_2$ molecule in collisions with H atoms and new H$_2$…

星系天体物理 · 物理学 2019-09-18 A. V. Nesterenok , D. Bossion , Y. Scribano , F. Lique

HST NICMOS narrowband images of the shocked molecular hydrogen emission in OMC-1 are analyzed to reveal new information on the BN/KL outflow. The outstanding morphological feature of this region is the array of molecular hydrogen…

天体物理学 · 物理学 2009-11-13 Sean W. J. Colgan , A. S. B. Schultz , M. J. Kaufman , E. F. Erickson , D. J. Hollenbach

We perform the non-local thermodynamic equilibrium (NLTE) calculations for Ca I-II with the updated model atom that includes new quantum-mechanical rate coefficients for Ca I + H I collisions from two recent studies, that is, by Barklem and…

太阳与恒星天体物理 · 物理学 2017-09-13 L. Mashonkina , T. Sitnova , A. K. Belyaev

We evaluate the effect of variations in the electron-impact excitation cross sections on the non-LTE line formation for hydrogen in early-type stars. While the Balmer lines are basically unaffected by the choice of atomic data, the Brackett…

天体物理学 · 物理学 2009-11-11 Norbert Przybilla , Keith Butler

We investigate differences in the molecular abundances between magnetically super- and sub-critical prestellar cores, performing three-dimensional non-ideal magnetohydrodynamical (MHD) simulations with varying densities and magnetic field…

星系天体物理 · 物理学 2019-07-17 Felix D. Priestley , James Wurster , Serena Viti

The non-LTE line formation for Al I and Si I was calculated with model atmospheres corresponding to F-G-K type stars of different metallicity. To account for inelastic collisions with H I, for the first time we applied the cross sections…

太阳与恒星天体物理 · 物理学 2016-06-22 Lyudmila Mashonkina , Andrey K. Belyaev , Jianrong Shi

We discuss aspects of non-LTE line formation for hydrogen in early-type stars. We evaluate the effect of variations in the electron-impact excitation cross sections in model atoms of differing complexity by comparison with observation.…

天体物理学 · 物理学 2009-11-10 Norbert Przybilla , Keith Butler

(Abridged) Organic molecules are important constituents of protoplanetary disks. Their ro-vibrational lines observed in the near- and mid-infrared are commonly detected toward T Tauri disks. These lines are the only way to probe the…

太阳与恒星天体物理 · 物理学 2015-06-23 Simon Bruderer , Daniel Harsono , Ewine F. van Dishoeck

We present an analysis of Spitzer-IRS observations of H2O, OH, HCN, C2H2, and CO2 emission, and Keck-NIRSPEC observations of CO emission, from a diverse sample of T Tauri and Herbig Ae/Be circumstellar disks. We find that detections and…

星系天体物理 · 物理学 2015-03-19 C. Salyk , K. M. Pontoppidan , G. A. Blake , J. R. Najita , J. S. Carr

In this paper we discuss two approximate methods previously suggested for modeling hyperfine spectral line emission for molecules whose collisional transitions rates between hyperfine levels are unknown. Hyperfine structure is seen in the…

星系天体物理 · 物理学 2015-05-18 Eric Keto , George Rybicki

The numerical studies of the interplanetary coupling between multiple magnetic clouds (MCs) are continued by a 2.5-dimensional ideal magnetohydrodynamic (MHD) model in the heliospheric meridional plane. The interplanetary direct collision…

太阳与恒星天体物理 · 物理学 2009-11-03 Ming Xiong , Huinan Zheng , Shui Wang

We examine a sample of 106 galaxies for which the total luminosities of the two fine structure lines $^{3}P_1$$\rightarrow $$^{3}P_{0}$, and $^{3}P_2$$\rightarrow $$^{3}P_{1}$ of neutral atomic carbon (C) are available, and find their…

星系天体物理 · 物理学 2021-12-22 Padelis Papadopoulos , Loretta Dunne , Steve Maddox

We present JWST NIRSpec and MIRI MRS observations of the central kiloparsec of M58 (NGC 4579), a nearby LINER galaxy hosting a low-luminosity AGN (LLAGN; $L_\mathrm{bol} \sim 10^{42}$ erg s$^{-1}$) with a low-power jet. These data provide…

The influence of the uncertainties in the rate coefficient data for electron-impact excitation and ionization on non-LTE Li line formation in cool stellar atmospheres is investigated. We examine the electron collision data used in previous…

太阳与恒星天体物理 · 物理学 2015-05-27 Y. Osorio , P. S. Barklem , K. Lind , M. Asplund

Magnetic flux emergence has been shown to be a key mechanism for unleashing a wide variety of solar phenomena. However, there are still open questions concerning the rise of the magnetized plasma through the atmosphere, mainly in the…

太阳与恒星天体物理 · 物理学 2020-01-15 D. Nóbrega-Siverio , F. Moreno-Insertis , J. Martínez-Sykora , M. Carlsson , M. Szydlarski

When a fast moving star or a protostellar jet hits an interstellar cloud, the surrounding gas gets heated and illuminated: a bow shock is born which delineates the wake of the impact. In such a process, the new molecules that are formed and…

星系天体物理 · 物理学 2017-11-27 L. N. Tram , P. Lesaffre , S. Cabrit , A. Gusdorf , P. T. Nhung

We present the first results of the expected variations of the molecular line emission arising from material recently affected by C-shocks (shock precursors). Our parametric model of the structure of C-shocks has been coupled with a…

星系天体物理 · 物理学 2011-02-11 I. Jimenez-Serra , J. Martin-Pintado , P. Caselli , S. Viti , A. Rodriguez-Franco

The modelling of emission spectra of molecules seen in interstellar clouds requires the knowledge of collisional rate coefficients. Among the commonly observed species, N$_2$H$^+$ is of particular interest since it was shown to be a good…

星系天体物理 · 物理学 2015-06-23 François Lique , Fabien Daniel , Laurent Pagani , Nicole Feautrier

Integral-field spectroscopy of molecular hydrogen in the optical wavelength region and complementary long-slit near-infrared spectroscopy are presented towards HH91A.The detection of some 200 H_2 lines arising from ro-vibrational levels up…

天体物理学 · 物理学 2009-11-13 Roland Gredel

We performed the non-local thermodynamic equilibrium (non-LTE) calculations for Ti I-II with the updated model atom that includes quantum-mechanical rate coefficients for inelastic collisions with hydrogen atoms. We have calculated for the…

太阳与恒星天体物理 · 物理学 2020-05-19 T. M. Sitnova , S. A. Yakovleva , A. K. Belyaev , L. I. Mashonkina
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