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相关论文: Far-ultraviolet Dust Extinction and Molecular Hydr…

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We have measured the extinction curve in the far-ultraviolet wavelength region of (900 -- 1200 A) using spectra obtained with the Berkeley EUV/FUV spectrometer during the ORFEUS-I and the ORFEUS-II missions in 1993 and 1996. From the…

天体物理学 · 物理学 2009-11-07 T. P. Sasseen , M. Hurwitz , W. V. Dixon , S. Airieau

We report optical extinction properties of dust for a sample of 26 early-type galaxies based on the analysis of their multicolour CCD observations. The wavelength dependence of dust extinction for these galaxies is determined and the…

天体物理学 · 物理学 2007-05-23 M. K. Patil , S. K. Pandey , D. K. Sahu , A. K. Kembhavi

We present an extinction analysis of 9 paths through the LMC and SMC based on FUSE observations. To date, just two LMC sight lines have probed dust grain composition and size distributions in the Clouds using spectra including wavelengths…

Using IRAM 30m, SEST 15m, and Nancay radiotelescopes, we have gathered the 1mm continuum emission, spectra of the J=1--0 CO line and of the HI line at 21cm for two samples of IRAS galaxies. Using these data, we have estimated the HI masses,…

天体物理学 · 物理学 2016-08-30 Paola Andreani , Fabienne Casoli , Maryvonne Gerin

The Small Magellanic Cloud (SMC) shows a large variation in ultraviolet (UV) dust extinction curves, ranging from Milky Way-like (MW) to significantly steeper curves with no detectable 2175 A bump. This result is based on a sample of only…

We modelled recent observations of UV absorption of HD and \HH\ in the Milky Way and toward damped/sub-damped Lyman alpha systems at z=0.18 and z $>$ 1.7. N(HD)/N(\HH) ratios reflect the separate self-shieldings of HD and \HH\ and the…

星系天体物理 · 物理学 2015-06-23 H. S. Liszt

We report results from a FUSE survey of interstellar molecular hydrogen (H2) along 45 sight lines to AGN at high Galactic latitudes (|b| > 20 degrees). Most (39 of 45) of the sight lines show detectable Galactic H2 absorption from Lyman and…

天体物理学 · 物理学 2009-11-13 Kristen Gillmon , J. Michael Shull , Jason Tumlinson , Charles Danforth

We have assembled a homogeneous database of 417 ultraviolet (UV) extinction curves for reddened sightlines having International Ultraviolet Explorer (IUE) spectra. We have combined these with optical and 2MASS photometry allowing estimates…

天体物理学 · 物理学 2009-11-10 Lynne A. Valencic , Geoffrey C. Clayton , Karl D. Gordon

The submillimeter opacity of dust in the diffuse Galactic interstellar medium (ISM) has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used three BLAST bands at 250,…

A large number of interstellar absorption features at ~ 4000\AA\ -- 1.8 {\mu}m, known as the "diffuse interstellar bands" (DIBs), remains unidentified. Most recent works relate them to large polycyclic aromatic hydrocarbon (PAH) molecules…

星系天体物理 · 物理学 2017-01-25 F. Y. Xiang , Aigen Li , J. X. Zhong

(abridged) We report a study of the relation between dust and gas over a 100deg^2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J=…

We combine near-infrared (2MASS) and mid-infrared (Spitzer-IRAC) photometry to characterize the IR extinction law (1.2-8 microns) over nearly 150 degrees of contiguous Milky Way midplane longitude. The relative extinctions in 5 passbands…

Our aim is to compare the infrared properties of big, ``classical'' dust grains with visual extinction in the cloud L1642. In particular, we study the differences of grain emissivity between diffuse and dense regions in the cloud. The…

天体物理学 · 物理学 2009-11-13 K. Lehtinen , M. Juvela , K. Mattila , D. Lemke , D. Russeil

We investigate interstellar absorption from molecular hydrogen (H_2) and metals in an intermediate-velocity cloud (IVC) in the direction of the LMC star Sk -68 80 (HD 36521), based on data from the Far Ultraviolet Spectroscopic Explorer…

天体物理学 · 物理学 2011-05-23 P. Richter , K. R. Sembach , J. C. Howk

We put stringent constraints for the first time on the dust properties in the circumburst medium of a gamma-ray burst (GRB) afterglow. This is based on the optical spectrum of GRB 020813 (z=1.255), obtained with Keck I LRIS 4.65 h after the…

天体物理学 · 物理学 2009-11-10 Sandra Savaglio , S. Michael Fall

The dust extinction curve is typically parameterized by a single variable, R(V), in optical and near-infrared wavelengths. R(V) controls the slope of the extinction-vs.-wavelength curve, and is thought to reflect the grain-size distribution…

星系天体物理 · 物理学 2025-06-26 Gregory M. Green , Xiangyu Zhang , Ruoyi Zhang

We present high S/N measurements of the H I Ly alpha absorption line toward 16 Galactic targets which are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove…

星系天体物理 · 物理学 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

Using star-forming galaxies sample in the nearby Universe (0.02<z<0.10) selected from the SDSS (DR7) and GALEX all-sky survey (GR5), we present a new empirical calibration for predicting dust extinction of galaxies from H-alpha-to-FUV flux…

Far Ultraviolet Spectroscopic Explorer (FUSE) data is used to investigate the molecular hydrogen (H_2) content of intermediate-velocity clouds (IVCs) in the lower halo of the Milky Way. We analyze interstellar absorption towards 56 (mostly…

天体物理学 · 物理学 2009-11-07 P. Richter , B. P. Wakker , B. D. Savage , K. R. Sembach

The extinction curve of interstellar dust in the dense molecular cloud cores is crucial for understanding dust properties, particularly size distribution and composition. We investigate the infrared extinction law in four nearby isolated…

星系天体物理 · 物理学 2024-11-04 Jun Li , Bingqiu Chen , Biwei Jiang , He Zhao , Botao Jiang , Xi Chen