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Spectra, taken with the heterodyne instrument, HIFI, aboard the Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part of the guaranteed time key program HIFISTARS are presented. The aim of this program is…

We present maps of atomic carbon [CI](1-0) and [CI](2-1) at a linear resolution ~1kpc scale for a sample of one HII, six LINER, three Seyfert and five starburst galaxies observed with Herschel. We compare spatial distributions of two [CI]…

Astrophysics of Galaxies · Physics 2019-08-14 Qian Jiao , Yinghe Zhao , Nanyao Lu , Yu Gao , Dragan Salak , Ming Zhu , Zhiyu Zhang , Xuejian Jiang , Qinghua Tan

We have carried out a multi-epoch simultaneous survey of 22 GHz H$_2$O and 44 GHz Class I CH$_3$OH masers toward 103 ultracompact HII regions (UCHIIs) between 2010 and 2017. We detected H$_2$O and CH$_3$OH maser emission in 74 (72%) and 55…

Solar and Stellar Astrophysics · Physics 2019-09-04 Won-Ju Kim , Kee-Tae Kim , Kwang-Tae Kim

Recently, we introduced detailed isotopic chemistry into the KOSMA-tau model for photon-dominated regions (PDRs) to give theoretical predictions for the abundance of the carbon isotopologues as a function of PDR parameters. Combined with…

Astrophysics of Galaxies · Physics 2015-06-12 V. Ossenkopf , M. Röllig , D. A. Neufeld , P. Pilleri , D. C. Lis , A. Fuente , F. F. S. van der Tak , E. Bergin

We report results of 6.7 GHz methanol maser monitoring of 139 star-forming sites with the Torun 32 m radio telescope from June 2009 to February 2013. The targets were observed at least once a month, with higher cadences of 2-4 measurements…

Astrophysics of Galaxies · Physics 2017-12-20 Marian Szymczak , Mateusz Olech , Rafał Sarniak , Paweł Wolak , Anna Bartkiewicz

Models are presented for CO rotational line emission by high redshift starburst galaxies. The influence of the cosmic microwave background on the thermal balance and the level populations of atomic and molecular species is explicitly…

Astrophysics · Physics 2009-10-30 Joseph Silk , Marco Spaans

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

Solar and Stellar Astrophysics · Physics 2014-09-05 Zhiyuan Ren , Yuefang Wu , Tie Liu , Lixin Li , Di Li , Binggang Ju

Recombination line profile shapes are derived for ionized spherical stellar winds at radio wavelengths. It is assumed that the wind is optically thick owing to free-free opacity. Emission lines of arbitrary optical depth are obtained…

Solar and Stellar Astrophysics · Physics 2018-11-07 R Ignace

The NGC 2024 FIR 6 region was observed in the water maser line at 22 GHz and the methanol class I maser lines at 44, 95, and 133 GHz. The water maser spectra displayed several velocity components and month-scale time variabilities. Most of…

Astrophysics of Galaxies · Physics 2015-06-11 Minho Choi , Miju Kang , Do-Young Byun , Jeong-Eun Lee

Molecular hydrogen is now understood to be the main coolant of the primordial gas clouds leading to the formation of the very first stars and galaxies. The line emissions associated with molecular hydrogen should then be a good tracer of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Yan Gong , Asantha Cooray , Mario G. Santos

We have investigated line profiles in a large sample of Cepheid spectra, and found four stars that show unusual (for Cepheids) line profile structure (bumps or/and asymmetries). The profiles can be phase dependent but the behavior persists…

Astrophysics · Physics 2011-05-23 V. V. Kovtyukh , S. M. Andrievsky , R. E. Luck , N. I. Gorlova

Recent observational and theoretical investigations have emphasised the importance of filamentary networks within molecular clouds as sites of star formation. Since such environments are more complex than those of isolated cores, it is…

Solar and Stellar Astrophysics · Physics 2014-08-29 Roxana-Adela Chira , Rowan J. Smith , Ralf S. Klessen , Amelia M. Stutz , Rahul Shetty

Velocity profiles of ground state lines of H2D+, HC18O+ and N2H+, observed previously with the CSO and IRAM 30m telescopes, are modeled with a Monte Carlo radiative transfer program to study the temperature, density and velocity structure…

Astrophysics · Physics 2009-11-11 F. F. S. van der Tak , P. Caselli , C. Ceccarelli

We selected 90 massive star-forming clumps with strong N2H+, HCO+, HCN, and HNC emission from the Millimetre Astronomy Legacy Team 90 GHz survey. We obtained Herschel data for all 90 sources and NRAO VLA Sky Survey data for 51 of them. We…

Astrophysics of Galaxies · Physics 2019-07-25 Mingyue Li , Jianjun Zhou , Jarken Esimbek , Donghui Quan , Yuxin He , Qiang Li , Chunhua Zhu

To characterize the initial conditions for intermediate- to high-mass star formation, we observed two Infrared Dark Clouds (IRDCs) that remain absorption features up to 70mum wavelength, with the PdBI in the 3.23mm dust continuum as well as…

Solar and Stellar Astrophysics · Physics 2015-05-13 Henrik Beuther , Thomas Henning

High spectral resolution and long exposure times are providing unprecedented levels of data quality of massive stars at X-ray wavelengths. A key diagnostic of the X-ray emitting plasma are the fir lines for He-like triplets. In particular,…

Solar and Stellar Astrophysics · Physics 2019-06-19 R. Ignace , Z. Damrau , K. T. Hole

Methanol and water vapour masers are signposts of early stages of high-mass star formation but it is generally thought that due to different excitation processes they probe distinct parts of stellar environments. Here we present…

Solar and Stellar Astrophysics · Physics 2016-04-05 M. Szymczak , M. Olech , P. Wolak , A. Bartkiewicz , M. Gawronski

IRAS 19312+1950 is a unique SiO maser source, exhibiting a rich set of molecular radio lines, although SiO maser sources are usually identified as oxygen-rich evolved stars, in which chemistry is relatively simple comparing with carbon-rich…

Astrophysics · Physics 2009-11-13 Jun-ichi Nakashima , Shuji Deguchi , Hiroshi Imai , Athol Kemball

We present high resolution spectroscopic observations of the massive X-ray binary system LS I+65 010=2S 0114+650 in the optical wavelength region. A correlation between equivalent width and radial velocity of photospheric absorption lines…

While the best tracer of the molecular component and its dynamics in galaxies is the CO molecule, which excitation is revealed by its isotopic and (2-1)/(1-0) ratios, the denser gas is revealed by molecules such as HCN, HNC, HCO+ or CN,…

Astrophysics · Physics 2007-09-25 F. Combes
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