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Related papers: H I Kinematics and the E(B-V)/N(H I) ratio

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Interstellar dust at high Galactic latitudes can influence astronomical foreground subtraction, produce diffuse scattered light, and soften the ultraviolet spectra of quasars. In a sample of 94 sight lines toward quasars at high latitude…

Astrophysics of Galaxies · Physics 2023-11-21 J. Michael Shull , Georgia V. Panopoulou

We explore the relationship between dust-emission derived reddening \EBV\ and atomic hydrogen column density N(H I) derived from 21 cm emission surveys. We consider measurements at galactic latitude $|b| \ga 20$\degr\ and \EBV\ $\la$ 0.1…

Astrophysics of Galaxies · Physics 2015-06-17 H. S. Liszt

Neutral hydrogen (HI) emission closely traces the dust column density at high Galactic latitudes and is thus a powerful tool for predicting dust extinction. However, the relation between HI column density $N_{\rm HI}$ and high-latitude dust…

Astrophysics of Galaxies · Physics 2025-04-28 Yun-Ting Cheng , Brandon S. Hensley , Tzu-Ching Chang , Olivier Doré

We have determined column densities of H I and/or H_2 for sight lines in the Magellanic Clouds from archival HST and FUSE spectra of H I Lyman-alpha and H_2 Lyman-band absorption. Together with some similar data from the literature, we now…

Astrophysics of Galaxies · Physics 2015-06-03 Daniel E. Welty , Rui Xue , Tony Wong

We have explored the capabilities of dust extinction and $\gamma$ rays to probe the properties of the interstellar medium in the nearby anti-centre region. We have jointly modelled the $\gamma$-ray intensity and the stellar reddening,…

High Energy Astrophysical Phenomena · Physics 2018-08-22 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

The gas-to-dust ratio of reddened stars in the Milky Way (MW), the Magellanic Clouds, and in general is usually expressed as a linear relation between the hydrogen column density, N(H), and the reddening, E(B-V), or extinction in the V band…

Astrophysics of Galaxies · Physics 2021-04-21 Robert E. Butler , Samir Salim

We derived the dust-to-HI ratio of the intermediate-velocity clouds (IVCs), the high-velocity clouds (HVCs), and the local HI gas, by carrying out a multiple-regression analysis of the 21cm HI emission combined with the sub-mm dust optical…

Astrophysics of Galaxies · Physics 2024-01-24 Takahiro Hayakawa , Yasuo Fukui

We present empirical relations between the global dust reddening and other physical galaxy properties including the Halpha luminosity, Halpha surface brightness, metallicity and axial ratio for star-forming disc galaxies. The study is based…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-12 Ting Xiao , Tinggui Wang , Huiyuan Wang , Hongyan Zhou , Honglin Lu , Xiaobo Dong

We consider the structure of the N(H I) - E(B-V) relationship when H I is measured in the 21 cm radio line and \EBV\ is defined by far-IR dust-derived measures. We derive reddening-dependent corrections to N(H I) based on interferometric…

Astrophysics of Galaxies · Physics 2015-06-18 Harvey Liszt

We present a new map of interstellar reddening, covering the 39\% of the sky with low {\rm HI} column densities ($N_{\rm HI} < 4\times10^{20}\,\rm cm^{-2}$ or $E(B-V)\approx 45\rm\, mmag$) at $16\overset{'}{.}1$ resolution, based on all-sky…

Astrophysics of Galaxies · Physics 2017-09-06 Daniel Lenz , Brandon S. Hensley , Olivier Doré

There is evidence in 21cm HI emission for voids several kpc in size centered approximately on the Galactic centre, both above and below the Galactic plane. These appear to map the boundaries of the Galactic nuclear wind. An analysis of HI…

Astrophysics of Galaxies · Physics 2016-08-17 Felix J. Lockman , N. M. McClure-Griffiths

(Abridged) Context: The assumption of a gas-to-dust mass ratio (\gamma) is a common approach to estimate the basic properties of molecular clouds, such as total mass and column density of molecular hydrogen, from (sub)mm continuum…

Astrophysics of Galaxies · Physics 2017-11-01 A. Giannetti , S. Leurini , C. Koenig , J. S. Urquhart , T. Pillai , J. Brand , J. Kauffmann , F. Wyrowski , K. M. Menten

Very sensitive HI 21cm observations have been made in 860 directions at dec >= -43deg in search of weak, Galactic, high-velocity HI emission lines at moderate and high Galactic latitudes. One-third of the observations were made toward…

Astrophysics · Physics 2009-11-07 Felix J. Lockman , Edward M. Murphy , Sara Petty-Powell , Vincent J. Urick

Observations of interstellar dust are often used as a proxy for total gas column density $N_\mathrm{H}$. By comparing $\textit{Planck}$ thermal dust data (Release 1.2) and new dust reddening maps from Pan-STARRS 1 and 2MASS (Green et al.…

We report the detection of differential gas column densities in three gravitational lenses, MG0414+0534, HE1104-1805, and PKS1830-211. Combined with the previous differential column density measurements in B1600+434 and Q2237+0305 and the…

Astrophysics · Physics 2009-11-13 Xinyu Dai , Christopher S. Kochanek , George Chartas , Smita Mathur

Context. High latitude molecular clouds (hereafter HLMCs) permit the study of interstellar gas dynamics and astrochemistry with good accuracy due to their proximity, generally clear lines of sight, and lack of internal star-forming activity…

Astrophysics of Galaxies · Physics 2023-01-16 Marco Monaci , Loris Magnani , Steven N. Shore

The joint use of accurate near- and mid-infrared photometry from the 2MASS and WISE catalogues has allowed the variations of the extinction law and the dust grain size distribution in high Galactic latitudes (|b|>50) at distances up to 3…

Astrophysics of Galaxies · Physics 2019-10-25 George Gontcharov

We measure reddenings to HII regions in NGC 2903, NGC 1512, M51, NGC 4449 and NGC 6946 from Hubble Space Telescope Pa alpha and H alpha images. Extinctions range from A_V ~ 5 - 0 depending upon the galaxy. For the galaxies with HST images…

Astrophysics · Physics 2009-10-31 A. C. Quillen , Mihoko Yukita

Using the Planck far-infrared and Arecibo GALFA 21-cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass.…

Astrophysics of Galaxies · Physics 2015-10-07 William T. Reach , Carl Heiles , Jean-Philippe Bernard

Context. There are significant amounts of H2 in the Milky Way. Due to its symmetry H2 does not radiate at radio frequencies. CO is thought to be a tracer for H2, however CO is formed at significantly higher opacities than H2. Thus, toward…

Astrophysics of Galaxies · Physics 2020-07-08 P. M. W. Kalberla , J. Kerp , U. Haud
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