Search Publications
No signatures of black hole spin in the X-ray spectrum of the Seyfert 1 galaxy Fairall 9
Turner, T. J.; Yaqoob, T.; Tatum, M. M. +2 more
Fairall 9 is one of several type 1 active galactic nuclei for which it has been claimed that the angular momentum (or spin) of the supermassive black hole can be robustly measured, using the Fe Kα emission line and Compton-reflection continuum in the X-ray spectrum. The method rests upon the interpretation of the Fe Kα line profile and associated …
X-Ray Spectra of the High-mass X-Ray Binary 4U 1700-37 Using BeppoSAX, Suzaku, and RXTE Observations
Titarchuk, Lev; Seifina, Elena; Shaposhnikov, Nikolai
We present an X-ray spectral analysis of the high-mass binary 4U 1700-37 during its hard-soft state evolution. We use BeppoSAX, Suzaku, and Rossi X-ray Timing Explorer observations for this investigation. We argue that the X-ray broadband spectra during all of the spectral states can be adequately reproduced by a model consisting of a low-temperat…
Spatially Resolved Spectroscopy of Submillimeter Galaxies at z ≃ 2
Casey, Caitlin M.; Treister, E.; Bauer, F. E. +9 more
We present near-infrared integral-field spectroscopic observations targeting Hα in eight submillimeter galaxies (SMGs) at z = 1.3-2.5 using the Very Large Telescope/Spectrograph for Integral Field Observations in the Near Infrared, obtaining significant detections for six of them. The star formation rates derived from the Hα emission are ∼100 M
Wave telescope technique for MMS magnetometer
Russell, C. T.; Glassmeier, K. -H.; Anderson, B. J. +18 more
Multipoint measurements are a powerful method in studying wavefields in space plasmas. The wave telescope technique is tested against magnetic field fluctuations in the terrestrial magnetosheath measured by the four Magnetospheric Multiscale (MMS) spacecraft on a spatial scale of about 20 km. The dispersion relation diagram and the wave vector dis…
Multi-wavelength Study of Transition Region Penumbral Subarcsecond Bright Dots Using IRIS and NST
Xu, Yan; Liu, Chang; Wang, Haimin +4 more
Using high-resolution transition region (TR) observations taken by the Interface Region Imaging Spectrograph (IRIS) mission, Tian et al. revealed numerous short-lived subarcsecond bright dots (BDs) above sunspots (mostly located in the penumbrae), which indicate yet unexplained small-scale energy releases. Moreover, whether or not these subarcseco…
The Si/CdTe semiconductor camera of the ASTRO-H Hard X-ray Imager (HXI)
Kokubun, Motohide; Makishima, Kazuo; Nakazawa, Kazuhiro +27 more
The Hard X-ray Imager (HXI) is one of the instruments onboard the ASTRO-H mission [1-4] to be launched in early 2016. The HXI is the focal plane detector of the hard X-ray reflecting telescope that covers an energy range from 5 to 80 keV. It will execute observations of astronomical objects with a sensitivity for point sources as faint as 1/100,00…
Mapping the coronal hydrogen temperature in view of the forthcoming coronagraph observations by Solar Orbiter
Spadaro, D.; Dolei, S.; Ventura, R.
Context. Synergistic visible light and ultraviolet coronagraphic observations are essential to investigate the link of the Sun to the inner heliosphere through the study of the dynamic properties of the solar wind.
Aims: We perform spectroscopic mapping of the outer solar corona to constitute a statistically significant database of neutral hy…
Mid-infrared dust in two nearby radio galaxies, NGC 1316 (Fornax A) and NGC 612 (PKS 0131-36)
Horellou, C.; Jarrett, T. H.; Winkler, H. +1 more
Context. Most radio galaxies are hosted by giant gas-poor ellipticals, but some contain significant amounts of dust, which is likely to be of external origin.
Aims: In order to characterize the mid-IR properties of two of the most nearby and brightest merger-remnant radio galaxies of the Southern hemisphere,
Investigation of the energy dependence of the orbital light curve in LS 5039
Zhang, S.; Kretschmar, P.; Kuulkers, E. +5 more
LS 5039 is so far the best-studied γ-ray binary system at multiwavelength energies. A time-resolved study of its spectral energy distribution (SED) shows that above 1 keV its power output is changing along its binary orbit as well as being a function of energy. To disentangle the energy dependence of the power output as a function of orbital phase…
Narrow-line-width UV Bursts in the Transition Region above Sunspots Observed by IRIS
Fu, Hui; Madjarska, Maria S.; Li, Bo +5 more
Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si IV line profiles as found in observations taken with t…