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Related papers: Interstellar 12C/13C from CH+ absorption lines: Re…

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Measuring the temperature and abundance patterns of clouds in the interstellar medium (ISM) provides an observational basis for models of the physical conditions within the clouds, which play an important role in studies of star and planet…

Astrophysics of Galaxies · Physics 2019-06-26 Nicholas Kruczek , Kevin France , Keri Hoadley , Brian Fleming , Nicholas Nell

Using samples drawn from the Sloan Digital Sky Survey, we study for the first time the relation between large-scale environments (Clusters, Groups and Voids) and the stellar Initial Mass Function (IMF). We perform an observational approach…

Astrophysics of Galaxies · Physics 2019-04-29 Elham Eftekhari , Moein Mosleh , Alexandre Vazdekis , Saeed Tavasoli

We present mid-infrared (5--16micron) images and spectra of a sequence of interacting galaxies, observed by ISOCAM. The galaxies were selected as being at progressive stages in the time evolution of a merging event, following what is known…

Astrophysics · Physics 2007-05-23 V. Charmandaris , O. Laurent , I. F. Mirabel , P. Gallais , J. Houck

The strength of gravity-sensitive absorption lines in the integrated light of old stellar populations is one of the few direct probes of the stellar initial mass function (IMF) outside of the Milky Way. Owing to the advent of fully depleted…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Pieter van Dokkum , Charlie Conroy

It is the purpose of this paper to rediscuss the circumstellar properties of S stars and to put these properties in perspective with our current understanding of the evolutionary status of S stars, in particular the intrinsic/extrinsic…

Astrophysics · Physics 2009-10-30 A. Jorissen , G. R. Knapp

Standard stellar evolution theory poorly predicts the surface abundances of chemical species in low-mass, red giant branch (RGB) stars. Observations show an enhancement of p-p chain and CNO cycle products in red giant envelopes, which…

The cold interstellar medium (ISM) plays a central role in the galaxy evolution process. It is the reservoir that fuels galaxy growth via star formation, the repository of material formed by these stars, and a sensitive tracer of internal…

Astrophysics of Galaxies · Physics 2022-09-07 Amelie Saintonge , Barbara Catinella

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

The interstellar medium (ISM) has a number of tracers such as the Na I D 5890, 5896 AA absorption lines that are evident in the spectra of galaxies but also in those of individual astrophysical sources such as stars, novae or quasars. Here,…

At redshifts z_abs < 2, quasar absorption-line constraints on space-time variations in the fine-structure constant, alpha, rely on the comparison of MgII and FeII transition wavelengths. One potentially important uncertainty is the relative…

Astrophysics · Physics 2008-11-26 Y. Fenner , M. T. Murphy , B. K. Gibson

Our unified chemical and spectrophotometric evolution code allows to simultaneously study the ISM abundances of a series of elements and the spectral properties of the stellar population in our model galaxies. We use stellar evolutionary…

Astrophysics · Physics 2007-05-23 Uta Fritze - v. Alvensleben

The diffuse interstellar medium (ISM) is an integral part of the evolution of the entire Galaxy. Metals are produced by stars and their abundances are the direct testimony of the history of stellar evolution. However, the interstellar dust…

Astrophysics of Galaxies · Physics 2014-03-20 C. Pinto , J. S. Kaastra , E. Costantini , C. de Vries

Using the 13.7 m telescope of Purple Mountain Observatory (PMO), a survey of J=1-0 lines of CO and its isotopes was carried out towards 98 methanol maser sources in January 2008. Eighty-five sources have infrared counterparts within one…

Solar and Stellar Astrophysics · Physics 2015-06-04 Tie Liu , Yue-Fang Wu , Ke Wang

We present a study of molecular outflows using six molecular lines (including 12CO/13CO/C18O/HCO+(J = 1-0) and SiO/CS(J = 2-1)) toward nine nearby high-mass star-forming regions with accurate known distances. This work is based on the…

Astrophysics of Galaxies · Physics 2021-03-10 De-Jian Liu , Ye Xu , Ying-Jie Li , Sheng Zheng , Deng-Rong Lu , Chao-Jie Hao , Ze-Hao Lin , Shuai-Bo Bian , Li-Ming Liu

(abridged) The far-UV wavelength range (912-2000A) provides access to atomic and molecular transitions of many species the interstellar medium (ISM), circumgalactic medium (CGM), and intergalactic medium, within phases spanning a wide range…

The star forming processes strongly influence the ISM chemistry. Nowadays, there are available many high-quality databases at millimeter wavelengths. Using them, it is possible to carry out studies that review and deepen previous results.…

Astrophysics of Galaxies · Physics 2023-10-16 N. C. Martinez , S. Paron

We have obtained high resolution (FWHM = 4.4 km/s) Keck spectra of images A and C of the gravitationally lensed QSO Q1422+231. The images are separated by 1.3" on the sky. In an absorption system at z = 3.538 gas column density variations…

Astrophysics · Physics 2007-05-23 Michael Rauch , Wallace L. W. Sargent , Thomas A. Barlow

We introduce a stochastic halo formation model to compute the early chemical enrichment of the interstellar medium (ISM) of the halo. Contrary to 1-zone chemical evolution models, we are able to resolve local inhomogeneities in the ISM…

Astrophysics · Physics 2007-05-23 D. Argast , M. Samland , O. E. Gerhard , F. -K. Thielemann

Aims. The comparative study of several molecular species at the origin of the gas phase chemistry in the diffuse interstellar medium (ISM) is a key input in unraveling the coupled chemical and dynamical evolution of the ISM. Methods. The…

Astrophysics of Galaxies · Physics 2015-05-19 Benjamin Godard , Edith Falgarone , Maryvonne Gerin , Pierre Hily-Blant , Massimo De Luca

We present the N-band (8-13 micron) spectrum of the hidden compact radio super-star cluster in NGC 5253, C2, obtained with TIMMI2 on the ESO 3.6m telescope. The spectrum is characterised by a rising continuum due to warm dust, a silicate…

Astrophysics · Physics 2009-11-10 N. L. Martin-Hernandez , D. Schaerer , M. Saugave