Search Publications
On the Origin of the Solar Moreton Wave of 2006 December 6
Temmer, M.; Veronig, A. M.; Vršnak, B. +12 more
We analyzed ground- and space-based observations of the eruptive flare (3B/X6.5) and associated Moreton wave (~850 km s-1 ~270° azimuthal span) of 2006 December 6 to determine the wave driver—either flare pressure pulse (blast) or coronal mass ejection (CME). Kinematic analysis favors a CME driver of the wave, despite key gaps in corona…
On Calibrations Using the Crab Nebula and Models of the Nebular X-Ray Emission
Guainazzi, M.; O'Dell, S. L.; Weisskopf, M. C. +5 more
Motivated by a paper of Kirsch et al. on possible use of the Crab Nebula as a standard candle for calibrating X-ray response functions, we examine consequences of intrinsic departures from a single (absorbed) power law upon such calibrations. We limit our analyses to three more modern X-ray instruments—the ROSAT/PSPC, the RXTE/Proportional Counter…
Temporal and Physical Connection Between Coronal Mass Ejections and Flares
Chen, James; Kunkel, Valbona
The physical connection between the eruption of coronal mass ejections (CMEs) and associated flare energy release is examined. The trajectories of five CMEs are determined using LASCO/SOHO or SECCHI/STEREO data, and the associated soft X-ray (SXR) light curves are obtained from GOES 1-8 Å data. As the theoretical description of CME physics, the ex…
Spatial, Temporal, and Spectral Properties of X-ray Emission from the Magnetar SGR 0501+4516
Kouveliotou, Chryssa; Göǧüş, Ersin; Kaneko, Yuki +3 more
SGR 0501+4516 was discovered with the Swift satellite on 2008 August 22 after it emitted a series of very energetic bursts. Since then, the source was extensively monitored with Swift and the Rossi X-ray Timing Explorer (RXTE) and observed with Chandra and XMM-Newton, providing a wealth of information about its outburst behavior and burst-induced …
Accelerating Waves in Polar Coronal Holes as Seen by EIS and SUMER
Teriaca, L.; Gupta, G. R.; Banerjee, D. +2 more
We present EIS/Hinode and SUMER/SOHO observations of propagating disturbances detected in coronal lines in inter-plume and plume regions of a polar coronal hole. The observation was carried out on 2007 November 13 as part of the JOP196/HOP045 program. The SUMER spectroscopic observation gives information about fluctuations in radiance and on both …
The Type Ia Supernova Rate in Redshift 0.5-0.9 Galaxy Clusters
Donahue, Megan; Voit, G. Mark; Filippenko, Alexei V. +14 more
Supernova (SN) rates are potentially powerful diagnostics of metal enrichment and SN physics, particularly in galaxy clusters with their deep, metal-retaining potentials and relatively simple star formation histories. We have carried out a survey for SNe in galaxy clusters, at a redshift range of 0.5 < z < 0.9, using the Advanced Camera for …
The Nascent Fast Solar Wind Observed by the EUV Imaging Spectrometer on Board Hinode
He, Jiansen; Tian, Hui; Marsch, Eckart +2 more
The origin of the solar wind is one of the most important unresolved problems in space and solar physics. We report here the first spectroscopic signatures of the nascent fast solar wind on the basis of observations made by the EUV Imaging Spectrometer on Hinode in a polar coronal hole in which patches of blueshift are clearly present on Dopplergr…
Multi-stranded and Multi-thermal Solar Coronal Loops: Evidence from Hinode X-ray Telescope and EUV Imaging Spectrometer Data
Golub, L.; Schmelz, J. T.; DeLuca, E. E. +4 more
Data from the X-Ray Telescope (XRT) and the EUV Imaging Spectrometer (EIS) on the Japanese/USA/UK Hinode spacecraft were used to investigate the spatial and thermal properties of an isolated quiescent coronal loop. We constructed differential emission measure (DEM) curves using Monte Carlo based, iterative forward fitting algorithms. We studied th…
The Bottom of the White Dwarf Cooling Sequence in the Old Open Cluster NGC 2158
Salaris, M.; Anderson, J.; Bedin, L. R. +3 more
We use 10 orbits of Advanced Camera for Surveys observations to reach the end of the white dwarf (WD) cooling sequence in the solar-metallicity open cluster NGC 2158. Our photometry and completeness tests show that the end falls at magnitude m F606W = 27.5 ± 0.15, which implies an age between ~1.8 and ~2.0 Gyr, consistent with the age o…
Bright Points and Jets in Polar Coronal Holes Observed by the Extreme-Ultraviolet Imaging Spectrometer on Hinode
Landi, E.; Doschek, G. A.; Warren, H. P. +1 more
We present observations of polar coronal hole bright points (BPs) made with the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. The data consist of raster images of BPs in multiple spectral lines from mostly coronal ions, e.g., Fe X-Fe XV. The BPs are observed for short intervals and thus the data are snapshots of the BPs …