A computer program for fast non-LTE analysis of interstellar line spectra
F. F. S. van der Tak,F. F. S. van der Tak,John H. Black,Fredrik L. Schöier,D. J. Jansen,E. F. van Dishoeck +5 more
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TLDR
In this paper, the authors present a computer program to calculate the intensities of atomic and molecular lines produced in a uniform medium, based on statistical equilibrium calculations involving collisional and radiative processes and including radiation from background sources.Abstract:
The large quantity and high quality of modern radio and infrared line observations require efficient modeling techniques to infer physical and chemical parameters such as temperature, density, and molecular abundances. We present a computer program to calculate the intensities of atomic and molecular lines produced in a uniform medium, based on statistical equilibrium calculations involving collisional and radiative processes and including radiation from background sources. Optical depth effects are treated with an escape probability method. The program is available on the World Wide Web at http://www.sron.rug.nl/~vdtak/radex/index.shtml . The program makes use of molecular data files maintained in the Leiden Atomic and Molecular Database (LAMDA), which will continue to be improved and expanded. The performance of the program is compared with more approximate and with more sophisticated methods. An Appendix provides diagnostic plots to estimate physical parameters from line intensity ratios of commonly observed molecules. This program should form an important tool in analyzing observations from current and future radio and infrared telescopes. Note: Accepted by AA 18 A4 pages, 11 figures;read more
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CO-dark molecular gas at high redshift: very large H2 content and high pressure in a low-metallicity damped Lyman alpha system
S. A. Balashev,Pasquier Noterdaeme,Hadi Rahmani,V. V. Klimenko,C. Ledoux,Patrick Petitjean,Raghunathan Srianand,A. V. Ivanchik,D. A. Varshalovich +8 more
TL;DR: In this paper, the authors present a detailed analysis of a H$_2$-rich, extremely strong intervening Damped Ly-$\alpha$ Absorption system (DLA) at 2.786$ towards the quasar J$\,$0843+0221, observed with the Ultraviolet and Visual Echelle Spectrograph on the Very Large Telescope.
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ALMA and ROSINA detections of phosphorus-bearing molecules: the interstellar thread between star-forming regions and comets
Victor M. Rivilla,Maria Drozdovskaya,Kathrin Altwegg,Paola Caselli,M. T. Beltrán,Francesco Fontani,F. F. S. van der Tak,F. F. S. van der Tak,Riccardo Cesaroni,A. Vasyunin,Martin Rubin,François Lique,Sarantos Marinakis,Leonardo Testi,Leonardo Testi +14 more
TL;DR: In this paper, the Atacama Large Millimeter/Submillimeter Array (ALMA) observations of PN and PO towards the massive star-forming region AFGL 5142, combined with a new analysis of the data of the comet 67P/Churyumov-Gerasimenko taken with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument onboard Rosetta, revealed that PO is the main carrier of P in the comet, with PO/PN > 10.
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The physical and dynamical structure of Serpens Two very different sub-(proto)clusters ,
Ana Duarte-Cabral,Gary A. Fuller,Nicolas Peretto,Jennifer Hatchell,E. F. Ladd,J. V. Buckle,J. S. Richer,Sarah Graves +7 more
TL;DR: In this paper, the molecular gas in the Serpens North cluster was studied to probe the origin of the most recent burst of star formation in Serpsens. But the results showed that even though they are at a similar stage of evolution, the two Serpns sub-clusters have very different characteristics.
Journal ArticleDOI
'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
Jonathan D. Henshaw,Adam Ginsburg,Thomas J. Haworth,Steven N. Longmore,J. M. D. Kruijssen,Elisabeth A. C. Mills,Vlas Sokolov,D. L. Walker,Ashley T. Barnes,Yanett Contreras,John Bally,Cara Battersby,Henrik Beuther,N. Butterfield,James E. Dale,Th. Henning,James M. Jackson,Jens Kauffmann,T. Pillai,T. Pillai,Sarah Ragan,M. Riener,Qizhou Zhang +22 more
TL;DR: In this article, the authors provide a comprehensive description of the internal dynamics of G0.253+0.016 (a.k.a. "the Brick"), one of the most massive and dense molecular clouds in the Galaxy to lack signatures of widespread star formation.
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Spectroscopically resolved far-IR observations of the massive star-forming region G5.89–0.39
Silvia Leurini,Friedrich Wyrowski,Helmut Wiesemeyer,Antoine Gusdorf,Rolf Güsten,Karl M. Menten,Maryvonne Gerin,François Levrier,Heinz-Wilhelm Hübers,K. Jacobs,O. Ricken,Heiko Richter +11 more
TL;DR: In this article, the authors investigated the contribution of jet and photon-dominated region emission, and of absorption to the [OI](63 mu m) line towards the hot gas around the ultra-compact HII region G5.89-0.39 with the GREAT receiver onboard SOFIA.
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