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Related papers: E(B-V), N(H I) and N(H_2)

200 papers

We present high resolution [NII] 205 micrometer ^3P_1-^3P_0 spectra obtained with Herschel-HIFI towards a small sample of far-infrared bright star forming regions in the Galactic plane: W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4),…

We report the first detection of the v=1--0, R(0) ro-vibrational transition of HF at 2.499385 microns arising from interstellar gas. The line is seen in absorption toward 3 background sources---HD 154368, Elias 29, and AFGL 2136 IRS 1---all…

Astrophysics of Galaxies · Physics 2015-06-12 Nick Indriolo , D. A. Neufeld , A. Seifahrt , M. J. Richter

WSRT observations have provided a first inventory of the incidence of HI 21 cm line absorption associated with AGN at redshifts up to z=1.0. There is a large range in line depths, from tau=0.44 to tau less than 0.001, and a substantial…

Astrophysics · Physics 2007-05-23 R. C. Vermeulen

We characterise the relation between the gas and dust content of the interstellar medium towards young stellar objects in the Orion Nebula Cluster. X-ray observations provide estimates of the absorbing equivalent hydrogen column density N_H…

Solar and Stellar Astrophysics · Physics 2016-08-31 Birgit Hasenberger , Jan Forbrich , Joao Alves , Scott Wolk , Stefan Meingast , Konstantin Getman , Ignazio Pillitteri

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

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…

Astrophysics of Galaxies · Physics 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

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 report on atomic gas (HI) and molecular gas (as traced by CO(2-1)) redshifted absorption features toward the nuclear regions of the closest powerful radio galaxy, Centaurus A (NGC 5128). Our HI observations using the Very Long Baseline…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 D. Espada , A. B. Peck , S. Matsushita , K. Sakamoto , C. Henkel , D. Iono , F. P. Israel , S. Muller , G. Petitpas , Y. Pihlstroem , G. B. Taylor , D. V. Trung

The baryonic processes in galaxy evolution include gas infall onto galaxies to form neutral atomic hydrogen (HI), the conversion of HI to the molecular state (H$_2$), and, finally, the conversion of H$_2$ to stars. Understanding galaxy…

Astrophysics of Galaxies · Physics 2022-08-05 Aditya Chowdhury , Nissim Kanekar , Jayaram Chengalur , Shiv Sethi , K. S. Dwarakanath

We report conclusive verification of the detection of associated HI 21 cm absorption in the early-type host galaxy of the compact radio source PMNJ2054-4242. We estimate an effective spectral line velocity width of 418 +/- 20 km s^{-1} and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 J. R. Allison , S. J. Curran , E. M. Sadler , S. N. Reeves

Different physical processes in galaxy evolution, such as galaxy mergers that lead to coalescence of dual Active Galactic Nuclei (AGN) and outflows emanating from the narrow line region, can leave their imprint on the optical spectra of AGN…

Astrophysics of Galaxies · Physics 2022-09-08 Rajeshwari Dutta , Raghunathan Srianand

We report the results of a survey for HI 21-cm absorption at z < 0.4 in a new sample of radio sources with the Giant Metrewave Radio Telescope. Of the 11 sources for which there are good data, we obtain zero detections, where four are…

Astrophysics of Galaxies · Physics 2019-01-16 S. J. Curran , R. W. Hunstead , H. M. Johnston , M. T. Whiting , E. M. Sadler , J. R. Allison , R. Athreya

Using the recently completed Giant Meterwave Radio Telescope, we have detected the HI 21 cm-line absorption from the peculiar galaxy C153 in the galaxy cluster Abell 2125. The HI absorption is at a redshift of 0.2533, with a peak optical…

Astrophysics · Physics 2009-11-06 K. S. Dwarakanath , F. N. Owen

We present a high resolution (R~500) X-ray spectrum of the bright quasar H1821+643 (z=0.297), obtained in a 470 ksec Chandra observation. We search for X-ray absorption by highly ionized metal species, OVII and OVIII in particular, at the…

Astrophysics · Physics 2008-11-26 Smita Mathur , David Weinberg , Xuelei Chen , .

We analyze intergalactic HI and OVI absorbers with v<5000 km/s in HST and FUSE spectra of 76 AGNs. The baryons traced by HI/OVI absorption are clearly associated with the extended surroundings of galaxies; for impact parameters <400 kpc…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 B. P. Wakker , B. D. Savage

Within the last 10 years, strong, narrow Na I absorption has appeared at v_sun ~ -38 km/s toward the halo star HD 219188; that absorption has continued to strengthen, by a factor 2-3, over the past three years. The line of sight appears to…

Astrophysics · Physics 2009-11-06 Daniel E. Welty , Edward L. Fitzpatrick

Using long-slit optical spectra obtained with the 2-m telescope at IUCAA Girawali Observatory, we show that the radio source J094221.98+062335.2 (z=0.123) is associated with a galaxy pair undergoing a major merger. Its companion is a normal…

Astrophysics of Galaxies · Physics 2015-08-06 R. Srianand , N. Gupta , E. Momjian , M. Vivek

We present measurements of the 3.4-micron hydrocarbon dust absorption feature, and four visual diffuse interstellar bands, for twelve highly reddened (9.0<A(V)<15.8), early-type stars identified from the Stephenson (1992) catalogue,…

Astrophysics · Physics 2009-11-07 M. G. Rawlings , A. J. Adamson , D. C. B. Whittet

We present the early science results from a blind search of the extragalactic HI 21-cm absorption lines at z $\leqslant$ 0.09 with the drift-scan observation of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We carried…

We have searched for HI 21-cm absorption in 11 strong MgII systems ($W_{\rm r}$(MgII $\lambda 2796$) $\ge 1$ \AA) at $0.3<z<0.5$ using the Giant Metrewave Radio Telescope. We have detected HI 21-cm absorption in two of these. From the…

Astrophysics of Galaxies · Physics 2017-04-12 Rajeshwari Dutta , Raghunathan Srianand , Neeraj Gupta , Ravi Joshi