Search Publications
Dusty Quasars at High Redshifts
Weedman, Daniel; Sargsyan, Lusine
A population of quasars at z ∼ 2 is determined based on dust luminosities νL ν (7.8 µm) that includes unobscured, partially obscured, and obscured quasars. Quasars are classified by the ratio νL ν (0.25 µm)/νL ν (7.8 µm) = UV/IR, assumed to measure obscuration of UV luminosity by the dust that …
Doppler Shift of the Quiet Region Measured by Meridional Scans with the EUV Imaging Spectrometer on board Hinode
Hara, H.; Kitagawa, N.; Yokoyama, T.
Spatially averaged (> 50") EUV spectral lines in the transition region of solar quiet regions are known to be redshifted. Because the mechanism underlying this phenomenon is unclear, we require additional physical information on the lower corona in order to limit the theoretical models. To acquire this information, we measured the Doppler shift…
AMiBA: Cluster Sunyaev-Zel’dovich Effect Observations with the Expanded 13-element Array
Koch, Patrick M.; Umetsu, Keiichi; Ho, Paul T. P. +35 more
The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) is a co-planar interferometer array operating at a wavelength of 3 mm to measure the Sunyaev-Zel’dovich effect (SZE) of galaxy clusters at arcminute scales. The first phase of operation—with a compact 7-element array with 0.6 m antennas (AMiBA-7)—observed six clusters at angular s…
Statistically Determined Dispersion Relations of Magnetic Field Fluctuations in the Terrestrial Foreshock
Nakariakov, V. M.; Hnat, B.; O'Connell, D. +1 more
We obtain dispersion relations of magnetic field fluctuations for two crossings of the terrestrial foreshock by Cluster spacecraft. These crossings cover plasma conditions that differ significantly in their plasma β and in the density of the reflected ion beam, but not in the properties of the encountered ion population, both showing shell-like di…
Inflow Generated X-Ray Corona around Supermassive Black Holes and a Unified Model for X-Ray Emission
Cen, Renyue; Wang, Lile
Three-dimensional hydrodynamic simulations are performed, which cover the spatial domain from hundreds of Schwarzschild radii to 2 pc around the central supermassive black hole of mass {10}8{M}⊙ , with detailed radiative cooling processes. The existence of a significant amount of shock heated, high temperature (≥slant {10}
Is the Line-like Optical Afterglow SED of GRB 050709 Due to a Flare?
Jin, Zhi-Ping; Wei, Da-Ming; Liu, Cong
Recently, Jin et al. reanalyzed the optical observation data of GRB 050709 and reported a line-like spectral energy distribution (SED) component observed by the Very Large Telescope at t ∼ 2.5 days after the trigger of the burst, which had been interpreted as a broadened line signal arising from a macronova dominated by an iron group. In this work…
First Search for an X-Ray-Optical Reverberation Signal in an Ultraluminous X-Ray Source
Cenko, S. Bradley; Gandhi, Poshak; Mushotzky, Richard F. +3 more
Using simultaneous optical (VLT/FORS2) and X-ray (XMM-Newton) data of NGC 5408, we present the first ever attempt to search for a reverberation signal in an ultraluminous X-ray source (NGC 5408 X-1). The idea is similar to active galactic nucleus broad line reverberation mapping where a lag measurement between the X-ray and the optical flux combin…