Search Publications
Neutral interstellar hydrogen in the inner heliosphere under the influence of wavelength-dependent solar radiation pressure
Bzowski, M.; Tarnopolski, S.
Context: With the plethora of detailed results from heliospheric missions such as Ulysses and SOHO and at the advent of the first mission dedicated to in situ studies of neutral heliospheric atoms IBEX, we have entered the era of precision heliospheric studies. Interpretation of these data requires precision modeling, with second-order effects qua…
Temperature Tomography of a Coronal Sigmoid Supporting the Gradual Formation of a Flux Rope
Young, Peter R.; Tripathi, Durgesh; Kliem, Bernhard +2 more
Multiwavelength observations of a sigmoidal (S-shaped) solar coronal source by the EUV Imaging Spectrometer and the X-Ray Telescope aboard the Hinode spacecraft and by the EUV Imager aboard STEREO are reported. The data reveal the coexistence of a pair of J-shaped hot arcs at temperatures T>2 MK with an S-shaped structure at somewhat lower temp…
Time-resolved optical observations of five cataclysmic variables detected by INTEGRAL
Pretorius, Magaretha L.
The European Space Agency γ-ray telescope, INTEGRAL, is detecting relatively more intrinsically rare cataclysmic variables (CVs) than were found by surveys at lower energies. Specifically, a large fraction of the CVs that are INTEGRAL sources consists of asynchronous polars and intermediate polars (IPs). IP classifications have been proposed for t…
The Dusty Nuclear Torus in NGC 4151: Constraints from Gemini Near-Infrared Integral Field Spectrograph Observations
Storchi-Bergmann, Thaisa; Riffel, Rogemar A.; McGregor, Peter J.
We have used a near-infrared (near-IR) nuclear spectrum (covering the Z, J, H, and K bands) of the nucleus of NGC 4151 obtained with the Gemini Near-Infrared Integral Field Spectrograph (NIFS) and adaptive optics, to isolate and constrain the properties of a near-IR unresolved nuclear source whose spectral signature is clearly present in our data.…
Modelling the spectral response of the Swift-XRT CCD camera: experience learnt from in-flight calibration
Campana, S.; Cusumano, G.; Moretti, A. +11 more
Context: Since its launch in November 2004, Swift has revolutionised our understanding of gamma-ray bursts. The X-ray telescope (XRT), one of the three instruments on board Swift, has played a key role in providing essential positions, timing, and spectroscopy of more than 300 GRB afterglows to date. Although Swift was designed to observe GRB afte…
Hydrostatic Gas Constraints on Supermassive Black Hole Masses: Implications for Hydrostatic Equilibrium and Dynamical Modeling in a Sample of Early-type Galaxies
Gebhardt, Karl; Humphrey, Philip J.; Buote, David A. +2 more
We present new mass measurements for the supermassive black holes (SMBHs) in the centers of three early-type galaxies. The gas pressure in the surrounding, hot interstellar medium (ISM) is measured through spatially resolved spectroscopy with the Chandra X-ray Observatory, allowing the SMBH mass (M BH) to be inferred directly under the …
X-ray Spectroscopy of the Core of the Perseus Cluster with Suzaku: Elemental Abundances in the Intracluster Medium
Fabian, A. C.; Mitsuda, K.; Sanders, J. S. +7 more
The results from Suzaku observations of the central region of the Perseus cluster are presented. Deep exposures with the X-ray Imaging Spectrometer provide high-quality X-ray spectra from the intracluster medium. X-ray lines from helium-like Cr and Mn have been detected significantly for the first time in clusters. In addition, elemental abundance…
Quasi-Periodic Releases of Streamer Blobs and Velocity Variability of the Slow Solar Wind near the Sun
Feng, S. W.; Chen, Y.; Song, H. Q. +2 more
We search for persistent and quasi-periodic release events of streamer blobs during 2007 with the Large Angle Spectrometric Coronagraph on the Solar and Heliospheric Observatory and assess the velocity of the slow solar wind along the plasma sheet above the corresponding streamer by measuring the dynamic parameters of blobs. We find ten quasi-peri…
LoCuSS: luminous infrared galaxies in the merging cluster Abell1758 at z = 0.28
Smith, G. P.; Okabe, N.; Egami, E. +5 more
We present the first galaxy evolution results from the Local Cluster Substructure Survey (LoCuSS), a multiwavelength survey of 100 X-ray selected galaxy clusters at 0.15 <= z <= 0.3. LoCuSS combines far-ultraviolet (UV) through far-infrared (IR) observations of cluster galaxies with gravitational lensing analysis and X-ray data to investigat…
Statistics of convective collapse events in the photosphere and chromosphere observed with the Hinode SOT
Lites, B. W.; de Wijn, A. G.; Fischer, C. E. +2 more
Convective collapse, a theoretically predicted process that intensifies existing weak magnetic fields in the solar atmosphere, was first directly observed in a single event by Nagata et al. (2008, ApJ, 677, L145) using the high resolution Solar Optical Telescope (SOT) of the Hinode satellite. Using the same space telescope, we observed 49 such eve…