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We have analyzed the 9.7 and ``18'' micron interstellar silicate absorption features along the line of sight toward four heavily extincted galactic WC-type Wolf-Rayet (WR) stars. We construct two interstellar extinction curves from 1.25 to…

Astrophysics · Physics 2009-11-13 J. E. Chiar , A. G. G. M. Tielens

The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation…

Materials Science · Physics 2009-11-13 F. Messina , S. Agnello , R. Boscaino , M. Cannas , S. Grandi , E. Quartarone

We observed IGR J16194-2810 in the low/hard state with the Suzaku X-ray satellite in 2009. The source is a Symbiotic X-ray Binary (SyXB) classified as a category of a Low-Mass X-ray Binary (LMXB), since the system is composed of an M-type…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Yuiko Kitamura , Hiromitsu Takahashi , Yasushi Fukazawa

We report the detection and successful modeling of the unusual 9.7\mum Si--O stretching silicate emission feature in the type 1 (i.e. face-on) LINER nucleus of M81. Using the Infrared Spectrograph (IRS) instrument on Spitzer, we determine…

Astrophysics of Galaxies · Physics 2015-05-18 Howard A. Smith , Aigen Li , M. P. Li , M. Koehler , M. L. N. Ashby , G. Fazio , J-S Huang , M. Marengo , Z. Wang , S. Willner , A. Zezas , L. Spinoglio , Y. L. Wu

Context. Although heavily obscured active galactic nuclei (AGNs) have been found by many observational studies, the properties of the surrounding dust are poorly understood. Using AKARI/IRC spectroscopy, we discover a new sample of a…

Astrophysics of Galaxies · Physics 2019-07-03 T. Tsuchikawa , H. Kaneda , S. Oyabu , T. Kokusho , K. Morihana , H. Kobayashi , M. Yamagishi , Y. Toba

Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 E. Gatuzz , J. García , C. Mendoza , T. R. Kallman , M. A. Bautista , T. W. Gorczyca

We report the discovery of narrow X-ray absorption features from the dipping low-mass X-ray binary X 1624-490 during an XMM-Newton observation in 2001 February. The features are identified with the K alpha absorption lines of Fe xxv and Fe…

Astrophysics · Physics 2009-11-07 A. N. Parmar , T. Oosterbroek , L. Boirin , D. Lumb

Using 10 sightlines observed with the Hubble Space Telescope/Cosmic Origins Spectrograph, we study the circumgalactic medium (CGM) and outflows of IC1613, which is a low-mass ($M_*\sim10^8~M_\odot$), dwarf irregular galaxy on the outskirts…

Astrophysics of Galaxies · Physics 2021-01-06 Yong Zheng , Andrew Emerick , Mary E. Putman , Jessica K. Werk , Evan N. Kirby , Joshua E. G. Peek

We report the detection of interstellar silicate dust in the z_abs=0.685 absorber along the sightline toward the gravitationally lensed blazar TXS 0218+357. Using Spitzer Space Telescope Infrared Spectrograph data we detect the 10 micron…

Astrophysics of Galaxies · Physics 2015-06-18 M. C. Aller , V. P. Kulkarni , D. G. York , D. E. Welty , G. Vladilo , N. Liger

Systematic studies of the gradual fabrication by means of carbon ion-implantation of high-quality 6H-SiC layers on silicon surfaces have been carried out. The fluence of carbon ions varied from 5*10^15 cm-2 to 10^17 cm-2. Results of…

Infrared carbon stars without visible counterparts are generally known as extreme carbon stars. We have selected a subset of these stars with absorption features in the 10-13 $\mu$m range, which has been tentatively attributed to silicon…

We present a study of the Silicon-bearing species detected in a line confusion limited survey towards Orion KL performed with the IRAM 30-m telescope, which ranges from 80 to 280 GHz. Our aim is to derive physical and chemical conditions…

Astrophysics of Galaxies · Physics 2015-05-20 B. Tercero , L. Vincent , J. Cernicharo , S. Viti , N. Marcelino

We present a comprehensive study of the silicate features at 9.7 and 18 micron of a sample of almost 800 active galactic nuclei (AGN) with available spectra from the Spitzer InfraRed Spectrograph (IRS). We measure the strength of the…

Astrophysics of Galaxies · Physics 2015-06-23 Evanthia Hatziminaoglou , Antonio Hernán-Caballero , Anna Feltre , Nuria Piñol-Ferrer

We report a detection of the 9.7 micrometer silicate absorption feature in a damped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The feature shows…

Astrophysics · Physics 2009-06-23 Varsha P. Kulkarni , Donald G. York , Giovanni Vladilo , Daniel E. Welty

Silicate minerals belong to the most abundant solids in space. Their formation becomes difficult at the transition from the oxygen rich chemistry of M-stars to the carbon rich chemistry of C-stars. In the intermediate type S-stars oxygen…

Solar and Stellar Astrophysics · Physics 2015-06-11 Steffen Wetzel , Markus Klevenz , Hans-Peter Gail , Annemarie Pucci , Mario Trieloff

We have investigated the electronic structure of Ba$_5$AlIr$_2$O$_{11}$ within the density functional theory using the generalized gradient approximation while considering strong Coulomb correlations in the framework of the fully…

Strongly Correlated Electrons · Physics 2025-04-21 D. A. Kukusta , L. V. Bekenov , V. N. Antonov

We have obtained a deep, simultaneous observation of the bright, nearby Seyfert galaxy IC 4329A with Suzaku and NuSTAR. Through a detailed spectral analysis, we are able to robustly separate the continuum, absorption and distant reflection…

The silicon suboxide SiOx (x<2.0) offers promising industrial application possibilities ranging from electrodes in lithium-ion batteries, which are used widely in electrical vehicles and portable devices to sensing applications. Therefore,…

Materials Science · Physics 2025-03-18 Seref Kalem

We present a Suzaku observation of the dwarf Seyfert galaxy NGC4395 with an estimated black hole mass of ~10^5 Msun. Rapid and strong X-ray variability with an rms amplitude of ~60 per cent is observed in the 0.4-10 keV band with the XIS…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-02 K. Iwasawa , Y. Tanaka , L. C. Gallo