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Related papers: The H$\alpha$ sky in three dimensions

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The lack of success of Lyman-alpha searches for high-redshift (z>2) field galaxies may be due to extinction by dust, suggesting that surveys based on lines of longer wavelength, particularly H-alpha, may be more effective. To test the dust…

Astrophysics · Physics 2015-06-24 A. J. Bunker , S. J. Warren , P. C. Hewett , D. L. Clements

We investigate the Lyman alpha line transfer in nearby and high redshift starbursting galaxies, where the effect of high optical depths and the role of dust in the scattering medium are expected to be conspicuous and should be treated in a…

Astrophysics · Physics 2009-10-31 Sang-Hyeon Ahn , Hee-Won Lee , Hyung Mok Lee

Hydrogen emission lines can provide extensive information about star-forming galaxies in both the local and high-redshift Universe. We present a detailed Lyman continuum (LyC), Lyman-alpha (Ly{\alpha}), and Balmer line (H{\alpha} and…

We derive the distribution of neutral and ionized gas in high redshift clouds which are optically thick to hydrogen ionizing radiation, using published data on Lyman-limit and Damped Lyman-alpha absorption systems in the redshift range 1.75…

Astrophysics · Physics 2009-10-31 Edvige Corbelli , Edwin E. Salpeter , Rino Bandiera

Accurately reproducing the thin cold gas discs observed in nearby spiral galaxies has been a long standing issue in cosmological simulations. Here, we present measurements of the radially resolved HI scale height in 22 non-interacting Milky…

The Planck survey has quantified polarized Galactic foregrounds and established that they are a main limiting factor in the quest for the cosmic microwave background (CMB) B-mode signal induced by primordial gravitational waves during…

The combination of dispersion measures of pulsars, distances from the model of Cordes and Lazio (2002) and emission measures from the WHAM survey enabled a statistical study of electron densities and filling factors of the diffuse ionized…

Astrophysics · Physics 2009-11-11 E. M. Berkhuijsen , D. Mitra , P. Mueller

Aims: We aim to study the effects of an inhomogeneous interstellar medium (ISM) on the strength and the shape of the Lyman alpha (Lya) line in starburst galaxies. Methods: Using our 3D Monte Carlo Lya radiation transfer code, we study the…

Astrophysics of Galaxies · Physics 2015-06-15 Florent Duval , Daniel Schaerer , Göran Östlin , Peter Laursen

Characterizing the structure of the Galactic interstellar medium (ISM) in three dimensions is of high importance for accurate modeling of dust emission as a foreground to the Cosmic Microwave Background (CMB). At high Galactic latitude,…

Astrophysics of Galaxies · Physics 2020-10-22 G. V. Panopoulou , D. Lenz

We present a new method to directly measure the opacity from HI Lyman limit (LL) absorption k_LL along quasar sightlines by the intergalactic medium (IGM). The approach analyzes the average (``stacked'') spectrum of an ensemble of quasars…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 J. Xavier Prochaska , Gabor Worseck , John M. O'Meara

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3-D HI volume density distribution…

Astrophysics · Physics 2009-11-13 P. M. W. Kalberla , L. Dedes , J. Kerp , U. Haud

We use high-resolution UV spectra taken by the Space Telescope Imaging Spectrograph instrument on board the Hubble Space Telescope to study the 5.5 pc line of sight to the K0 V star 36 Oph A. The one interstellar component detected for this…

Astrophysics · Physics 2009-10-31 Brian E. Wood , Jeffrey L. Linsky , Gary P. Zank

We discuss the dust distribution within photoionized regions. Assuming a geometry with a central dust cavity, which is strongly suggested by the literature, we can estimate the cavity's radius from the ratio of the infrared and radio fluxes…

Astrophysics · Physics 2009-11-07 Akio K. Inoue

We use newly developed 3D kinetic MHD models of the heliosphere to predict heliospheric H I Lyman-alpha absorption for various lines of sight. These predictions are compared with actual Lyman-alpha spectra from the Hubble Space Telescope,…

Astrophysics · Physics 2011-02-11 Brian E. Wood , Vladislav V. Izmodenov , Jeffrey L. Linsky , Dmitry Alexashov

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density…

Astrophysics · Physics 2009-10-31 Nickolay Y. Gnedin

We combine a high-resolution hydro-simulation of the LambdaCDM cosmology with two radiative transfer schemes (for continuum and line radiation) to predict the properties, spectra and spatial distribution of fluorescent Ly-alpha emission at…

Astrophysics · Physics 2009-11-10 Sebastiano Cantalupo , Cristiano Porciani , Simon J. Lilly , Francesco Miniati

We investigate the intrinsic opacity of high-redshift galaxies to outgoing ionising photons using high-quality photometry of a sample of 27 spectroscopically-identified galaxies of redshift 1.9<z<3.5 in the Hubble Deep Field. Our…

Astrophysics · Physics 2009-11-07 A. Fernandez-Soto , K. M. Lanzetta , H. -W. Chen

We propose to infer ionising continuum leaking properties of galaxies by looking at their Lyman-alpha line profiles. We carry out Lyman-alpha radiation transfer calculations in two models of HII regions which are porous to ionising…

Astrophysics of Galaxies · Physics 2015-05-27 A. Verhamme , I. Orlitova , D. Schaerer , M. Hayes

Where dust and gas are uniformly mixed, atomic hydrogen can be traced through the detection of far-infrared (FIR) or UV emission of dust. We considered, for the origin of discrepancies observed between various direct and indirect tracers of…

Astrophysics of Galaxies · Physics 2022-11-30 Jean-Marc Casandjian , Jean Ballet , Isabelle Grenier , Quentin Remy

A thorough analysis of well studied giant HII regions on galactic discs for which we know the ionizing stellar population, the gas metallicity and the Wolf-Rayet population, leads to photoionization models which can only match all observed…

Astrophysics · Physics 2007-05-23 M. Castellanos , A. I. Diaz , G. Tenorio-Tagle