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相关论文: N(H I)/E(B-V)

200 篇论文

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…

星系天体物理 · 物理学 2015-06-18 Harvey Liszt

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.…

The $\lambda 21$cm H I emission that is used to trace the gas to dust ratio at high Galactic latitudes has contributions from material beyond the Milky Way disk, with uncertain and likely sub-Solar metallicity and dust content. These…

星系天体物理 · 物理学 2024-09-09 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…

星系天体物理 · 物理学 2017-09-06 Daniel Lenz , Brandon S. Hensley , Olivier Doré

Despite the vastly different angular scales on which they are measured, the integrated $\lambda$21 cm \HI\ optical depth measured interferometrically, \WHI, is a good proxy for the optical reddening derived from IR dust emission, with…

星系天体物理 · 物理学 2019-08-14 Harvey S Liszt

Hydrogen column densities inferred from X-ray absorption are typically 5 - 30 times larger than the neutral atomic hydrogen column densities derived from 21cm HI absorption toward radio-loud active galactic nuclei. Some part of the…

星系天体物理 · 物理学 2021-02-24 Harvey Liszt

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…

宇宙学与河外天体物理 · 物理学 2012-03-12 Ting Xiao , Tinggui Wang , Huiyuan Wang , Hongyan Zhou , Honglin Lu , Xiaobo Dong

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…

星系天体物理 · 物理学 2023-11-21 J. Michael Shull , Georgia V. Panopoulou

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…

星系天体物理 · 物理学 2021-04-21 Robert E. Butler , Samir Salim

Interstellar reddening corrections are necessary to reconstruct the intrinsic spectral energy distributions (SEDs) of accreting protostellar systems. The stellar SED determines the heating and chemical processes that can occur in…

The ability to robustly determine galaxy properties such as masses, ages and star-formation rates is critically limited by the ability to accurately measure dust attenuation. Dust reddening is often characterized by comparing observations…

星系天体物理 · 物理学 2023-11-29 Daniel Maschmann , Claus Leitherer , Andreas L. Faisst , Janice C. Lee , Rebecca Minsley

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,…

高能天体物理现象 · 物理学 2018-08-22 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

A linear relation between the hydrogen column density (N_H) and optical extinction (A_V) in the Galaxy has long been observed. A number of studies found differing results in the slope of this relation. Here, we utilize the data on 22…

星系天体物理 · 物理学 2015-05-13 Tolga Guver , Feryal Ozel

By employing two different spectroscopic techniques we have mapped out the variable ISM dust extinction endemic to globular cluster M4. We derive an average E(B-V) reddening of 0.33 +/- 0.01 and R = 3.4 +/- 0.4, both in good agreement with…

天体物理学 · 物理学 2007-05-23 I. I. Ivans , C. Sneden , R. P. Kraft , N. B. Suntzeff , V. V. Smith , G. E. Langer , J. P. Fulbright

We use a large sample of galaxies at z~3 to establish a relationship between reddening, neutral gas covering fraction (fcov(HI)), and the escape of ionizing photons at high redshift. Our sample includes 933 galaxies at z~3, 121 of which…

星系天体物理 · 物理学 2016-09-21 Naveen A. Reddy , Charles C. Steidel , Max Pettini , Milan Bogosavljevic , Alice Shapley

We present a large compilation of reddening estimates from broad-line Balmer decrements for active galactic nuclei (AGNs) with measured X-ray column densities. The median reddening is E(B-V) ~ 0.77 +/- 0.10 for type-1 to type-1.9 AGNs with…

星系天体物理 · 物理学 2021-12-14 Gunnar W. Jaffarian , C. Martin Gaskell

We investigate the relation between the optical extinction ($A_V$) and the hydrogen column density ($N_H$) determined from X-ray observations of a large sample of Galactic sightlines toward 35 supernova remnants, 6 planetary nebulae, and 70…

星系天体物理 · 物理学 2017-08-30 Hui Zhu , Wenwu Tian , Aigen Li , Mengfei Zhang

Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of…

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…

天体物理学 · 物理学 2009-10-31 A. C. Quillen , Mihoko Yukita

We derive the mean wavelength dependence of stellar attenuation in a sample of 239 high redshift (1.90 < z < 2.35) galaxies selected via Hubble Space Telescope (HST) WFC3 IR grism observations of their rest-frame optical emission lines. Our…

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