English
Related papers

Related papers: Small-Scale Interstellar Na I Structure Toward M92

200 papers

We present results from MUSE observations of a 21-cm HI absorption system detected with the Australian Square Kilometre Array Pathfinder radio telescope at redshift $z = 0.4503$ towards the $z = 1.71$ quasar PKS 1610-771. We identify four…

We used the multiplex capabilities of the AAOmega spectrograph at the Anglo-Australian Telescope to create a half-square-degree map of the neutral and low-ionized ISM in front of the nearby (~5 kpc), most massive Galactic globular cluster,…

Astrophysics of Galaxies · Physics 2009-10-16 Jacco Th. van Loon , Keith T. Smith , Iain McDonald , Peter J. Sarre , Stephen J. Fossey , Robert G. Sharp

We combine CaII/NaI absorption and HI 21 cm emission line measurements to analyse the metal abundances, the distribution, the small-scale structure, and the physical conditions of intermediate- and high-velocity gas in the Galactic halo.

Astrophysics · Physics 2015-05-13 N. Ben Bekhti , M. Murphy , P. Richter , T. Westmeier

The increasing availability of high quality spectra of QSO absorption line systems at resolutions of only a few km/s is expected to facilitate the translation of the kinematics of components comprising the lines into the spatial…

Astrophysics · Physics 2009-10-28 David V. Bowen , J. Chris Blades , Max Pettini

Wavelengths of absorption lines in the spectra of galaxies along the line-of-sight to distant quasars can be used to probe the variablility of the fine structure constant, $\alpha$, at high redshifts, provided that the laboratory…

Instrumentation and Methods for Astrophysics · Physics 2020-12-22 Gillian Nave , Christian Clear

The [CII] 157.74 $\mu$m fine structure transition is one of the brightest and most well-studied emission lines in the far-infrared (FIR), produced in the interstellar medium (ISM) of galaxies. We study its properties in sub-pc resolution…

Astrophysics of Galaxies · Physics 2024-03-05 Alon Gurman , Chia-Yu Hu , Amiel Sternberg , Ewine F. van Dishoeck

We briefly discuss the relevance of Lyman alpha forest observations for measuring cosmological parameters, comparing the properties of high z QSO spectra with those of artifical spectra from hydrodynamic simulations, based on hierarchical…

Astrophysics · Physics 2007-05-23 Michael Rauch

Context. The earliest phases of high-mass star formation are poorly understood. Aims. Our goal is to determine the physical conditions and kinematic structure of massive star-forming cloud clumps. Methods. We analyze H$_2$O 557 GHz line…

Solar and Stellar Astrophysics · Physics 2014-10-15 Russell F. Shipman , Floris F. S van der Tak , Friedrich Wyrowski , Fabrice Herpin , Wilfred Frieswijk

We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional…

Astrophysics · Physics 2008-11-26 Paul F. Goldsmith , Di Li , Marko Krco

H$_{\rm I}$ 21-cm and $^{12}$CO 2.6-mm line emissions respectively trace the atomic and molecular gas phases, but they miss most of the opaque H$_{\rm I}$ and diffuse H$_2$ present in the Dark Neutral Medium (DNM) at the transition between…

High Energy Astrophysical Phenomena · Physics 2018-03-28 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

We present an analysis of multi-wavelength observations of an area of 0.27 deg x 0.27 deg around the Galactic HII region G18.88-0.49, which is powered by an O-type star (age ~10^5 years). The Herschel column density map reveals a shell-like…

Astrophysics of Galaxies · Physics 2020-11-04 L. K. Dewangan , D. K. Ojha , Saurabh Sharma , S. del Palacio , N. K. Bhadari , A. Das

Guided by the duality of turbulence (random versus coherent we seek coherent structures in the turbulent velocity field of molecular clouds, anticipating their importance in cloud evolution. We analyse a large map (40' by 20') obtained with…

Astrophysics of Galaxies · Physics 2015-05-13 Pierre Hily-Blant , Edith Falgarone

Progenitors of Type Ia supernovae (SNe) have been predicted to modify their ambient circumstellar (CSM) and interstellar environments through the action of their powerful winds. While there is X-ray and optical evidence for circumstellar…

Solar and Stellar Astrophysics · Physics 2011-02-11 K. J. Borkowski , J. M. Blondin , S. P. Reynolds

In the SSA22 field which exhibits a large-scale proto-cluster at $z=3.1$, we carried out a spectroscopic survey for Lyman Break Galaxies (LBGs) with the VLT/VIMOS and identified 78 confident LBGs at $z=2.5$--4. We stacked their spectra in…

Aims: By utilising spectra of early-type stellar probes of known distances in the same region of the sky, the large and small-scale (pc) structure of the Galactic ISM can be investigated. This paper determines the variation in line strength…

Astrophysics of Galaxies · Physics 2015-11-11 J. V. Smoker , F. P. Keenan , A. J. Fox

Diffuse interstellar bands (DIBs) are weak absorption features of interstellar origin present in the optical and infrared spectra of stars. Their use as a tool to trace the structure of the Galactic ISM is gaining relevance in the recent…

Astrophysics of Galaxies · Physics 2015-11-19 A. Monreal-Ibero , R. Lallement , L. Puspitarini , P. Bonifacio , L. Monaco

We present Westerbork Synthesis Radio Telescope HI images, Lovell Telescope multibeam HI wide-field mapping, Wisconsin H-alpha Mapper facility images, William Herschel Telescope longslit echelle CaII observations, and IRAS ISSA 60 and 100…

Astrophysics · Physics 2009-11-07 J. V. Smoker , L. M. Haffner , F. P. Keenan , R. D. Davies , D. Pollacco

Studying the composition of dust in the interstellar medium (ISM) is crucial in understanding the cycle of dust in our galaxy. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied…

We present spectroscopic imaging observations of the molecular and HI 21cm absorbing cloud at z = 0.885 toward the `Einstein ring' radio source PKS 1830-211. We derive a cloud size between 10 h^{-1} pc and 600 h^{-1} pc, and M(H_2) >…

Astrophysics · Physics 2007-05-23 C. L. Carilli , K. M. Menten , M. J. Reid , M. Rupen , M. Claussen

We investigated HI absorption toward a single pulsar, PSR J1644$-$4559, and its variability over timescales from days to years, using Murriyang, CSIRO's Parkes Radio Telescope. Our 19 epochs of spectral observations, spanning 1.2 years with…

‹ Prev 1 8 9 10 Next ›