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Related papers: Optical Reddening, Integrated HI Optical Depth, To…

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The Galactic neutral hydrogen (HI) sky at high Galactic latitudes is suffused with linear structure. Particularly prominent in narrow spectral intervals, these linear HI features are well aligned with the plane-of-sky magnetic field…

Astrophysics of Galaxies · Physics 2018-04-18 S. E. Clark

We present new measurements of the temperature-density (T-rho) relation for neutral hydrogen in the 2.0 < z < 2.8 intergalactic medium (IGM) using a sample of ~6000 individual HI absorbers fitted with Voigt profiles constrained in all cases…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Gwen C. Rudie , Charles C. Steidel , Max Pettini

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 employ 76 type Ia supernovae with optical spectrophotometry within 2.5 days of B-band maximum light obtained by the Nearby Supernova Factory to derive the impact of Si and Ca features on supernovae intrinsic luminosity and determine a…

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

Large-scale dust heating and cooling in the diffuse medium of M31 is studied using the HiRes IRAS maps in conjunction with UV, optical (UBV) and the HI maps. A dust heating/cooling model is developed based on a radiative transfer model…

Astrophysics · Physics 2009-10-28 Cong Xu , George Helou

We report on the abundance of interstellar neutral nitrogen (NI) for 30 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST). NI column densities are derived by measuring the…

Astrophysics · Physics 2008-11-26 Adam G. Jensen , Brian L. Rachford , Theodore P. Snow

Water is an important molecule in interstellar and circumstellar environments. Previous observations of mid-infrared rotational lines of OH suggest that these lines may be used to probe the photodissociation of water. In this work, cross…

Astrophysics of Galaxies · Physics 2021-06-30 Benoît Tabone , Marc C. van Hemert , Ewine F. van Dishoeck , John H. Black

Both the Galactic 21-cm line flux from neutral hydrogen (HI) in interstellar medium and the far-infrared (FIR) emission from Galactic dust grains have been used to estimate the strength of Galactic reddening of distant sources. In this work…

Astrophysics of Galaxies · Physics 2015-06-15 J. E. G. Peek

We have used archival far-ultraviolet spectra from observations made by HST/STIS and FUSE to determine the column densities and rotational excitation temperatures for CO and H2, respectively, along the lines of sight to 23 Galactic O and B…

Astrophysics · Physics 2009-01-19 Eric B. Burgh , Kevin France , Stephan R. McCandliss

We establish correlations between equivalent widths of eight diffuse interstellar bands (DIBs), and examine their correlations with atomic hydrogen, molecular hydrogen, and EB-V . The DIBs are centered at \lambda\lambda 5780.5, 6204.5,…

Mapping of the neutral hydrogen (HI) 21-cm intensity fluctuations across redshifts promises a novel and powerful probe of cosmology. The neutral hydrogen gas mass density, $\Omega_{\rm HI}$ and bias parameter, $b_{\rm HI}$ are key…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-10 Hamsa Padmanabhan , T. Roy Choudhury , Alexandre Refregier

We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the OverWhelmingly Large Simulations (OWLS) project. The base simulation includes…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-04 Gabriel Altay , Tom Theuns , Joop Schaye , Neil H. M. Crighton , Claudio Dalla Vecchia

We report the detection of a deep broad HI 21 cm absorption system at z = 0.78 toward the radio source [HB89] 2351+456 (4C+45.51) at z = 1.992. The HI absorption was identified in a blind spectral line survey conducted at the Green Bank…

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

The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the ``Synthetic Field Method'' from Gonzalez et al (1998) and Holwerda et al. (2005a).…

Astrophysics · Physics 2009-11-11 B. W. Holwerda , R. A. González , Ronald J. Allen , P. C. van der Kruit

We report on a comparison between 21 cm rotation measure (RM) and the optically-thin atomic hydrogen column density (N_HI) measured towards unresolved extragalactic sources in the Galactic plane of the northern sky. HI column densities…

Astrophysics of Galaxies · Physics 2015-06-16 Tyler Foster , Roland Kothes , Joanne Brown

Comparison analyses between the gas emission data (HI 21cm line and CO 2.6 mm line) and the Planck/IRAS dust emission data (optical depth at 353 GHz tau353 and dust temperature Td) allow us to estimate the amount and distribution of the…

Astrophysics of Galaxies · Physics 2017-04-12 Ryuji Okamoto , Hiroaki Yamamoto , Kengo Tachihara , Takahiro Hayakawa , Katsuhiro Hayashi , Yasuo Fukui

We have carried out an extremely long integration-time (9000 s/beam) 21-cm blind survey of 60 square degrees in Centaurus using the Parkes multibeam system. We find that the noise continues to fall as sqrt(t) throughout, enabling us to…

Recent submillimeter and far-infrared wavelength observations of absorption in the rotational ground-state lines of various simple molecules against distant Galactic continuum sources have opened the possibility of studying the chemistry of…

Astrophysics of Galaxies · Physics 2017-02-21 B. Winkel , H. Wiesemeyer , K. M. Menten , M. Sato , A. Brunthaler , F. Wyrowski , D. Neufeld , M. Gerin , N. Indriolo