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Combining the 12CO(1-0), 13CO(1-0), and C18O(1-0) data with IRAS four band data, we here estimate the physical parameters such as size, viral mass, and CO J=1-0 isotopic and infrared luminosities for 29 dense molecular clouds from two…

Astrophysics of Galaxies · Physics 2014-11-20 Yan Sun , Yu Gao

Galactic chemical evolution (GCE) is important for understanding the composition of the present-day interstellar medium (ISM) and of our solar system. In this paper, we aim to track the GCE by using the 29Si/30Si ratios in evolved stars and…

We present Very Large Array observations of the 33 GHz radio continuum emission from 22 local ultraluminous and luminous infrared (IR) galaxies (U/LIRGs). These observations have spatial (angular) resolutions of 30--720 pc (0.07"-0.67") in…

We derive molecular-gas-phase $^{12}$C/$^{13}$C isotope ratios for the central few 100 pc of the three nearby starburst galaxies NGC 253, NGC 1068, and NGC 4945 making use of the $\lambda$ $\sim$ 3 mm $^{12}$CN and $^{13}$CN $N$ = 1--0…

Infrared Dark Clouds are expected to harbor sources in different, very young evolutionary stages. To better characterize these differences, we observed a sample of 43 massive Infrared Dark Clouds, originally selected as candidate high-mass…

Astrophysics · Physics 2019-08-19 H. Beuther , T. K. Sridharan

Ams: We study the 12C/13C isotopic ratio in the disk of the central molecular zone and in the halo to trace gas accretion toward the Galactic center region in the Milky Way. Methods: Using the IRAM 30m telescope, we observe the J=1-0…

Astrophysics of Galaxies · Physics 2015-05-19 D. Riquelme , M. A. Amo-Baladron , J. Martin-Pintado , R. Mauersberger , S. Martin , L. Bronfman

Context. Investigations of abundances of carbon and nitrogen in the atmospheres of evolved stars of open clusters may provide comprehensive information on chemical composition changes caused by stellar evolution. Aims. Our main aim is to…

Solar and Stellar Astrophysics · Physics 2012-03-30 Šarūnas Mikolaitis , Gražina Tautvaišienė , Raffaele Gratton , Angela Bragaglia , Eugenio Carretta

We report new radio observations of SDSS J090122.37+181432.3, a strongly lensed star-forming galaxy at $z=2.26$. We image 1.4 GHz (L-band) and 3 GHz (S-band) continuum using the VLA and 1.2 mm (band 6) continuum with ALMA, in addition to…

Rich in HII regions, giant molecular clouds are natural laboratories to study massive stars and sequential star formation. The Galactic star forming complex W33 is located at l=~12.8deg and at a distance of 2.4 kpc, has a size of ~10 pc and…

We present very high signal-to-noise ratio absorption-line observations of CN and CH+ along 13 lines of sight through diffuse molecular clouds. The data are examined to extract precise isotopologic ratios of 12CN/13CN and 12CH+/13CH+ in…

Astrophysics of Galaxies · Physics 2015-03-17 A. M. Ritchey , S. R. Federman , D. L. Lambert

In recent years, a plethora of high spectral resolution observations of sub-mm and FIR transitions of methylidene (CH), have demonstrated this radical to be a valuable proxy for H2, that can be used for characterising molecular gas within…

Astrophysics of Galaxies · Physics 2020-08-26 Arshia M. Jacob , Karl M. Menten , Helmut Wiesemeyer , Rolf Guesten , Friedrich Wyrowski , Bernd Klein

Multiline observations of C18O and SiO isotopomers toward 33 molecular peaks in the Galactic center region, taken at the SEST, JCMT and HHT telescopes, are presented. The C18O presumably traces the total H_2 column density, while the SiO…

Astrophysics · Physics 2007-05-23 S. Huettemeister , G. Dahmen , R. Mauersberger , C. Henkel , T. L. Wilson , J. Martin-Pintado

We investigate the morphology of the [CII] emission in a sample of "normal" star-forming galaxies at $5<z<7.2$ in relation to their UV (rest-frame) counterpart. We use new ALMA observations of galaxies at $z\sim6-7$ as well as a careful…

We have compiled a large sample of O, Ne, S, Cl, and Ar abundances which have been determined for 85 galactic planetary nebulae in a consistent and homogeneous manner using spectra extending from 3600-9600 Angstroms. Sulfur abundances have…

Astrophysics · Physics 2009-11-10 R. B. C. Henry , K. B. Kwitter , Bruce Balick

Isomerism in complex organic molecules provides key insights into the formation mechanisms and physical conditions of the interstellar medium (ISM). Among the C$_2$H$_5$NO isomers, only acetamide and trans-N-methylformamide (trans-NMF) have…

Context. The abundances of the three main isotopes of oxygen are altered in the course of the CNO-cycle. When the first dredge-up mixes the burning products to the surface, the nucleosynthesis processes can be probed by measuring oxygen…

Solar and Stellar Astrophysics · Physics 2015-06-11 Thomas Lebzelter , Oscar Straniero , Kenneth Hinkle , Walter Nowotny , Bernhard Aringer

Abridged. The 12CO/13CO ratio in the circumstellar envelope (CSE) of asymptotic giant branch (AGB) stars has been extensively used as the tracer of the photospheric 12C/13C ratio. However, spatially-resolved ALMA observations of R Scl, a…

Solar and Stellar Astrophysics · Physics 2017-03-01 M. Saberi , M. Maercker , E. De Beck , W. H. T. Vlemmings , H. Olofsson , T. Danilovich

We measured carbon abundances and the $^{12}\mathrm{C}/^{13}\mathrm{C}$ ratio in 31 giant branch stars with previous CN and CH band measurements that span -2.33 $<$ M$_{\rm V}$ $<$ 0.18 in the globular cluster M10 (NGC 6254). Abundances…

Solar and Stellar Astrophysics · Physics 2019-06-14 Z. G. Maas , J. M. Gerber , Alex Deibel , C. A. Pilachowski

Aims: The goal is to obtain a census of S-bearing species using interferometric images, towards SVS13-A, a Class I object associated with a hot corino rich in interstellar complex organic molecules. Methods: We used data at 3mm and 1.4mm…

The fundamental process of star formation in galaxies involves the interplay between the fueling of star formation via molecular gas and the feedback from recently formed massive stars. This process, by which galaxies evolve, is also…

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