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Related papers: NGC 1068: No change in the mid-IR torus structure …

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We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. F. Hoenig , M. Kishimoto , P. Gandhi , A. Smette , D. Asmus , W. Duschl , M. Polletta , G. Weigelt

Context. DG Tau is a low-mass pre-main sequence star, whose strongly accreting protoplanetary disk exhibits a so-far enigmatic behavior: its mid-infrared thermal emission is strongly time-variable, even turning the 10 $\mu$m silicate…

We present diffraction-limited IR images at 11.2 and 20.5 microns of the central 6''x6'' region in NGC 1068, collected with the CAMIRAS instrument mounted at the f/36 IR focus of the CFHT/Hawaii 3.6m telescope and at the f/35 IR focus of…

Astrophysics · Physics 2007-05-23 D. Alloin , E. Pantin , P. O. Lagage

Thermonuclear X-ray bursts occur on the surface of an accreting neutron star (NS), and their characteristics and interplay with the surrounding circumstance could be a clue to understand the nature of the NS and accretion process. For this…

High Energy Astrophysical Phenomena · Physics 2025-02-28 Yu-Peng Chen , Shu Zhang , Long Ji , Shuang-Nan Zhang , Peng-Ju Wang , Ling-Da Kong , Zhi Chang , Jing-Qiang Peng , Qing-Cang Shui , Jian Li , Lian Tao , Ming-Yu Ge , Jin-Lu Qu

We report the results of a 2019-2021 monitoring campaign with Swift and associated target-of-opportunity observations with XMM-Newton and NuSTAR, examining the spectral and timing behavior of the highly variable ultraluminous X-ray source…

We report preliminary results of mid-infrared (MIR) and X-ray observations of GRS 1915+105 that we carried out between 2004 October 2 and 2006 June 5. Our main goals were to study its variability, to detect the presence of dust, and to…

Astrophysics · Physics 2009-04-14 F. Rahoui , S. Chaty , J. Rodriguez , Y. Fuchs , I. F. Mirabel

We report the first NuSTAR hard X-ray observations of the low-luminosity active galactic nucleus NGC 4278. The source is clearly detected beyond 10 keV with a hard X-ray spectrum consistent with a power law of photon index between 2.2 and…

High Energy Astrophysical Phenomena · Physics 2026-03-10 Abhishek Das , Qi Feng , Eleanor Young , Ashwani Pandey , Shigeo S. Kimura , Kohta Murase

AIMS: The main goal of this work is to study possible signs of asymmetry in the bright optical transient in NGC300, with the aim of getting independent information on the explosion mechanism, the progenitor star and its circumstellar…

Solar and Stellar Astrophysics · Physics 2015-05-13 F. Patat , J. R. Maund , S. Benetti , M. -T. Botticella , E. Cappellaro , A. Harutyunyan , M. Turatto

According to recent models, the accretion disk and black hole in active galactic nuclei are surrounded by a clumpy torus. We investigate the NIR flux variation of the torus in response to a UV flash for various geometries. Anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Toshihiro Kawaguchi , Masao Mori

We present a broad-band (~0.3-70 keV) spectral and temporal analysis of NuSTAR observations of the luminous infrared galaxy NGC 6240, combined with archival Chandra, XMM-Newton and BeppoSAX data. NGC 6240 is a galaxy in a relatively early…

We present high spatial resolution Submillimeter Array observations and supplementary single-dish photometry of the molecular gas and dust around IRAS 04158+2805, a young source with spectral type M5-M6 in the Taurus star-forming region. A…

Astrophysics · Physics 2009-11-13 Sean M. Andrews , Michael C. Liu , Jonathan P. Williams , K. N. Allers

Aims: We present mid-infrared observations and photometry of the transitional disks around the young stellar objects DH Tau, DM Tau, and GM Aur, obtained with VISIR/VLT in N band. Our aim is to resolve the inner region and the large-scale…

Solar and Stellar Astrophysics · Physics 2015-05-30 Christian Gräfe , Sebastian Wolf , Veronica Roccatagliata , Jürgen Sauter , Steve Ertel

We present photoionization models of the optical and IR coronal line spectrum in NGC1068 and the Circinus galaxy. The line fluxes have been calculated using (a) a non-thermal (nuclear) continuum source and (b) the non-thermal continuum plus…

Astrophysics · Physics 2007-05-23 L. S. Nazarova , P. T. O'Brien , M. J. Ward

We investigate the limitations of thermonuclear X-ray bursts as a distance indicator for the weakly-magnetized accreting neutron star 4U 1728-34. We measured the unabsorbed peak flux of 81 bursts in public data from the Rossi X-Ray Timing…

Astrophysics · Physics 2009-11-07 Duncan K. Galloway , Dimitrios Psaltis , Deepto Chakrabarty , Michael P. Muno

The most luminous X-ray source in the Local Group is associated with the nucleus of M33. This source, M33 X-8, appears modulated by ~20% over a ~106 day period, making it unlikely that the combined emission from unresolved sources could…

Astrophysics · Physics 2009-10-31 G. Dubus , K. S. Long , P. A. Charles

We present the first mid-infrared interferometric measurements of FU Orionis. We clearly resolve structures that are best explained with an optically thick accretion disk. A simple accretion disk model fits the observed SED and visibilities…

We present high spatial resolution mid-IR images of the nuclear region of NGC 5128 (Centaurus A). Images were obtained at 8.8 micron, N-band (10.4 micron), and 18.3 micron using the mid-IR imager/spectrometer T-ReCS on Gemini South. These…

Context: We investigate mid-infrared and X-ray properties of the dusty torus invoked in the unification scenario for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain the geometry and…

Astrophysics · Physics 2009-11-13 Hannes Horst , Poshak Gandhi , Alain Smette , Wolfgang J. Duschl

We report on the \nustar{} observation of the Z-type neutron star low-mass X-ray binary Cygnus X--2 performed on 7 January 2015. During this observation, the source exhibited sudden decrease in count rate (dips) and stronger variability in…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Aditya S. Mondal , Gulab C. Dewangan , Mayukh Pahari , Biplab Raychaudhuri

Spectral measurements of thermonuclear (type-I) X-ray bursts from low mass X-ray binaries have been used to measure neutron star (NS) masses and radii. A number of systematic issues affect such measurements and have raised concerns as to…

High Energy Astrophysical Phenomena · Physics 2014-09-24 Juri Poutanen , Joonas Nättilä , Jari J. E. Kajava , Outi-Marja Latvala , Duncan Galloway , Erik Kuulkers , Valery Suleimanov
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