English
Related papers

Related papers: The tiny-scale atomic structure: gas cloudlets or …

200 papers

We report on interferometric observations of a face-on accretion system around the High-Mass young stellar object, G353.273+0.641. The innermost accretion system of 100 au radius was resolved in a 45 GHz continuum image taken with the…

Aims: We offer a new, simpler picture of the local interstellar medium, made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected…

Astrophysics of Galaxies · Physics 2014-09-05 Cecile Gry , Edward B. Jenkins

The accuracy of ground-based astronomical photometry is limited by two factors: photon statistics and stellar scintillation arising when star light passes through Earth's atmosphere. This paper examines the theoretical role of the outer…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Victor Kornilov

HL Tau is a Class I-II protostar embedded in an infalling and rotating envelope and possibly associated with a planet forming disk, and it is co-located in a 0.1 pc molecular cloud with two nearby young stellar objects. Our ALMA…

Solar and Stellar Astrophysics · Physics 2019-03-13 Hsi-Wei Yen , Shigehisa Takakuwa , Pin-Gao Gu , Naomi Hirano , Chin-Fei Lee , Hauyu Baobab Liu , Sheng-Yuan Liu , Chun-Ju Wu

While massive quiescent galaxies are known to be poor in atomic hydrogen (HI), their true HI content remains poorly constrained due to the limited sensitivity and morphological biases of existing surveys. We present deep HI observations…

Astrophysics of Galaxies · Physics 2025-10-20 Xiao Li , Cheng Li , Cheng Cheng , Houjun Mo , Jing Wang , Amélie Saintonge

We present new observations of [CII] fine structure line emission from an isolated molecular cloud using the upGREAT instrument onboard SOFIA. These data are analyzed together with archival CO=1-0 and HI 21 cm emission spectra to…

Astrophysics of Galaxies · Physics 2022-12-21 Mark Heyer , Paul F. Goldsmith , Robert Simon , Rebeca Aladro , Oliver Ricken

We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z= 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Joseph Ribaudo , Nicolas Lehner , J. Christopher Howk , Jessica K. Werk , Todd M. Tripp , J. Xavier Prochaska , Joseph D. Meiring , Jason Tumlinson

We review the theory of measuring spectral lines in emission/absorption observations and apply it to a new survey of the 21-cm line against 79 continuum sources. We develop an observing technique and least-squares procedure to determine the…

Astrophysics · Physics 2009-11-07 Carl Heiles , T. H. Troland

Understanding the distribution of gas in and around galaxies is vital for our interpretation of galaxy formation and evolution. As part of the Arecibo Galaxy Environment Survey (AGES) we have observed the neutral hydrogen (HI) gas in and…

Astrophysics of Galaxies · Physics 2017-03-29 Olivia Keenan , Jonathan Davies , Rhys Taylor , Robert Minchin

A new method, based on simulated annealing technique and aimed at the inverse problem in the analysis of intergalactic or interstellar complex spectra of hydrogen and metal lines, is outlined. We consider the process of line formation in…

Astrophysics · Physics 2007-05-23 Sergei A. Levshakov

Understanding the timescales of atomic gas turbulence is crucial to understanding the interplay between star formation and the interstellar medium (ISM). To investigate the timescales of turbulence low-mass galaxies…

Results from new observations of pulsars using the Ooty Radio Telescope (ORT) are used for investigating the structure of the Local Interstellar Medium (LISM). The observations show anomalous scintillation effects towards several nearby…

Astrophysics · Physics 2007-05-23 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao , P. B. Preethi

A statistical analysis of the space-time distribution of absorption-line systems (ALSs) observed in QSO spectra within the cosmological redshift interval $z$=0.0--3.7 is carried out on the base of our catalog of absorption systems…

Astrophysics · Physics 2008-11-26 A. I. Ryabinkov , A. D. Kaminker , D. A. Varshalovich

We present the analysis of five O VI absorbers identified across a redshift path of z $\sim (0.6 - 1.3)$ towards the background quasar PG $1522+101$ with information on five consecutive ionization stages of oxygen from O II to O VI. The…

An absorption feature is occasionally reported around 11 microns in astronomical spectra, including those of forming stars. Candidate carriers include water ice, polycyclic aromatic hydrocarbons (PAHs), silicon carbide, crystalline…

Solar and Stellar Astrophysics · Physics 2016-11-02 Christopher M Wright , Tho Do Duy , Warrick Lawson

A set of HI sources extracted from the north Galactic polar region by the ongoing ALFALFA survey has properties that are consistent with the interpretation that they are associated with isolated minihalos in the outskirts of the Local Group…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Riccardo Giovanelli , Martha P. Haynes , Brian R. Kent , Elizabeth K. Adams

We present new ATCA 21-cm line observations of the neutral hydrogen in the nearby radio galaxy Centaurus A. We image in detail (with a resolution down to 7", ~100pc) the distribution of HI along the dust lane. Our data have better velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. Struve , T. A. Oosterloo , R. Morganti , L. Saripalli

We examined the sizes of the absorption clouds in a z=1.3911 damped Ly-alpha absorber (DLA) in the double image lensed quasar Q0957+561 A,B (separation 135 pc at the absorber redshift). Using HIRES/Keck spectra, we studied the MgII…

Astrophysics · Physics 2009-11-07 Chris Churchill , Rick Mellon , Jane Charlton , Steve Vogt

Aims: Understanding the fragmentation and collapse properties of the dense gas during the onset of high-mass star formation. Methods: We observed the massive (~800M_sun) starless gas clump IRDC18310-4 with the Plateau de Bure Interferometer…

Astrophysics of Galaxies · Physics 2015-09-23 H. Beuther , Th. Henning , H. Linz , S. Feng , S. E. Ragan , R. J. Smith , S. Bihr , T. Sakai , R. Kuiper

We present six new and two previously published high-resolution spectra of the quasar HS 1603+3820 (z_em = 2.542) taken over an interval of 4.2 years (1.2 years in the quasar rest frame). The observations were made with the High-Dispersion…

Astrophysics · Physics 2011-02-11 Toru Misawa , Michael Eracleous , Jane C. Charlton , Nobunari Kashikawa