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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,…

We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\rm \mu m$. We study the variation in absorption profiles with volume fractions of inclusions.…

Astrophysics of Galaxies · Physics 2016-07-22 Ranjan Gupta , Dipak B. Vaidya , Rajeshwari Dutta

We have studied the dust along the line-of-sight towards the Galactic Center using Short Wavelength Spectrometer (SWS) data obtained with the Infrared Space Observatory (ISO). We focussed on the wavelength region from 8-13 micron which is…

Astrophysics · Physics 2009-11-10 F. Kemper , W. J. Vriend , A. G. G. M. Tielens

We present an X-ray absorption line spectroscopic study of the large-scale hot interstellar medium (HISM) in the Galaxy. We detect Ne IX K$_\alpha$ absorption lines in the {\sl Chandra} grating spectra of seven Galactic low-mass X-ray…

Astrophysics · Physics 2009-11-10 Yangsen Yao , Q. Daniel Wang

Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and…

We present K-band spectroscopy for several regions of three nearby spiral galaxies, NGC 613, NGC 628 and NGC 7741. Analysis of the depth of the 2.293 micron CO absorption feature in these spectra reveals that some regions have deep…

Astrophysics · Physics 2007-05-23 P. A. James , M. S. Seigar

The X-ray Imaging Spectroscopy Mission (XRISM) provides the best spectral resolution with which to study Sulfur (S) K-shell photoabsorption features from the interstellar medium (ISM). For the first time, we demonstrate the high-signal…

Near infrared (NIR) and optical surface photometric analyses of the dusty galaxy NGC972 are presented. The photometric profiles in the BVRJHK bands can be fitted with a combination of gaussian and exponential profiles, corresponding to a…

Astrophysics · Physics 2009-10-30 Y. D. Mayya , Swara Ravindranath , L. Carrasco

We present the results of a narrow-band infrared imaging survey of a narrow strip (12' wide) around the galactic equator between 6 deg and 21 deg of galactic longitude aimed at detecting field stars with strong CO absorption, mainly…

Astrophysics · Physics 2009-11-10 F. Comeron , J. Torra , C. Chiappini , F. Figueras , V. D. Ivanov , S. J. Ribas

Depletion studies provide a way to understand the chemical composition of interstellar dust grains. We here examine 23 gamma-ray bursts (GRB) optical afterglow spectra (spanning 0.6<z<5.0) and compare their silicon and iron dust-phase…

Astrophysics of Galaxies · Physics 2019-10-16 T. Zafar , K. E. Heintz , A. Karakas , J. Lattanzio , A. Ahmad , Macquarie Uni , Austalia , Uni. Iceland , Iceland , Monash Uni , Australia

Many Seyfert galaxies are known to exhibit significant X-ray spectral variations and seemingly broad iron K-emission line features. In this paper, we show that the "variable partial covering model", which has been successfully proposed for…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Naoki Iso , Ken Ebisawa , Hiroaki Sameshima , Misaki Mizumoto , Takehiro Miyakawa , Hajime Inoue , Hiroki Yamasaki

We present an XMM-Newton observation of the massive edge-on Sb galaxy NGC 2613. We discover that this galaxy contains a deeply embedded active nucleus with a 0.3-10 keV luminosity of 3.3x10^40 erg/s and a line-of-sight absorption column of…

Astrophysics · Physics 2009-11-11 Zhiyuan Li , Q. Daniel Wang , Judith A. Irwin , Tara Chaves

The structure of the adsorbed layer of alkali ions on the surface of colloidal silica solutions with a particle size of ~27 nm has been studied by reflectometry and diffuse scattering of synchrotron radiation with a photon energy of about…

We present evidence of a >10-sigma detection of the 10 micron silicate dust absorption feature in the spectrum of the gravitationally lensed quasar PKS 1830-211, produced by a foreground absorption system at redshift 0.886. We have examined…

Astrophysics of Galaxies · Physics 2015-06-03 Monique C. Aller , Varsha P. Kulkarni , Donald G. York , Giovanni Vladilo , Daniel E. Welty , Debopam Som

High resolution X-ray spectroscopy of the warm absorber in the nearby X-ray bright Seyfert 1 galaxy, Mrk 1040 is presented. The observations were carried out in the 2013-2014 timeframe using the Chandra High Energy Transmission Grating with…

High Energy Astrophysical Phenomena · Physics 2017-03-08 James Reeves , Valentina Braito , Ehud Behar , Travis Fischer , Steve Kraemer , Andrew Lobban , Emanuele Nardini , Delphine Porquet , Jane Turner

We report on a simultaneous Chandra and RossiXTE observation of the low-mass X-ray binary atoll bursting source MXB 1728-34 performed on 2002 March 3-5. We fit the 1.2-35 keV continuum spectrum with a blackbody plus a Comptonized component.…

The 10-micron silicate feature observed with Spitzer in active galactic nuclei (AGN) reveals some puzzling behavior. It (1) has been detected in emission in type 2 sources, (2) shows broad, flat-topped emission peaks shifted toward long…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Robert Nikutta , Moshe Elitzur , Mark Lacy

There is growing evidence for the presence of blueshifted Fe K absorption lines in a number of radio-quiet AGNs and QSOs. These may be fundamental to probe flow dynamics near supermassive black holes. Here we aim at verifying and better…

High Energy Astrophysical Phenomena · Physics 2015-05-13 M. Cappi , F. Tombesi , S. Bianchi , M. Dadina , M. Giustini , G. Malaguti , L. Maraschi , G. G. C. Palumbo , P. O. Petrucci , G. Ponti , C. Vignali , T. Yaqoob

The soft X-ray background shows a general enhancement toward the inner region of the Galaxy. But whether this enhancement is a local feature (e.g., a superbubble within a distance of <= 200 pc) and/or a phenomenon related to energetic…

Astrophysics · Physics 2007-07-26 Yangsen Yao , Q. Daniel Wang

Flax fibres are valuable reinforcements for tomorrow's composites. However, defects called kink-bands, which mainly appear on fibres during the extraction and transformation phases, might affect their mechanical properties. Defects induced…