Search Publications
SAXJ1808.4-3658: high-resolution spectroscopy and decrease of pulsed fraction at low energies
Wijnands, R.; Rea, Nanda; van der Klis, M. +3 more
XMM-Newton observed the accreting millisecond pulsar SAX J1808.4-3658 during its 2008 outburst. We present timing and spectral analyses of this observation, in particular the first pulse profile study below 2keV, and the high-resolution spectral analysis of this source during the outburst. Combined spectral and pulse profile analyses suggest the p…
The rotation of Janus and Epimetheus
Burns, Joseph A.; Thomas, Peter C.; Tiscareno, Matthew S.
Epimetheus, a small moon of Saturn, has a rotational libration (an oscillation about synchronous rotation) of 5.9°±1.2°, placing Epimetheus in the company of Earth's Moon and Mars' Phobos as the only natural satellites for which forced rotational libration has been detected. The forced libration is caused by the satellite's slightly eccentric orbi…
Role of Galaxy Mergers in Cosmic Star Formation History
Rieke, George; Shi, Yong; Lotz, Jennifer +1 more
We present a morphology study of intermediate-redshift (0.2 < z<1.2) luminous infrared galaxies (LIRGs) and general field galaxies in the GOODS fields using a revised asymmetry measurement method optimized for deep fields. By taking careful account of the importance of the underlying sky-background structures, our new method does not suffer …
Plasma wave measurements with STEREO S/WAVES: Calibration, potential model, and preliminary results
Bale, S. D.; Goetz, K.; Maksimovic, Milan +3 more
The S/WAVES experiments on the two STEREO spacecraft measure waves, both in situ plasma waves and remotely generated waves such as Type II and Type III solar bursts. A part of the experiment is aimed at understanding the generation of electromagnetic waves from electrostatic Langmuir waves. For this, rapid measurements of plasma density, sufficien…
Hard X-ray Emission in Kinking Filaments
Liu, Rui; Alexander, David
We present an observational study on the impact of the dynamic evolution of kinking filaments on the production of hard X-ray (HXR) emission. The investigation of two kinking-filament events in this paper, occurring on 2003 June 12 and 2004 November 10, respectively, combined with our earlier study on the failed filament eruption of 2002 May 27, s…
Suzaku Observations of the Circinus Galaxy
Yang, Y.; Matt, G.; Wilson, A. S. +2 more
We report Suzaku observations of the active, Compton-thick Circinus galaxy. Observations were obtained with both the X-ray imaging spectrometer (XIS) and the hard X-ray detector (HXD). Below 10 keV, the nuclear spectrum is dominated by radiation reflected from cold dense gas of high column density, while above 13 keV the radiation is directly tran…
Statistics of multispacecraft observations of chorus dispersion and source location
Breneman, Aaron W.; Kletzing, Craig A.; Pickett, Jolene +2 more
We report emission characteristics of 52 chorus events on 23 August 2003 and 10 events on three other days, modeled with a ray tracing technique. Chorus waves have a characteristic frequency/time variation that is a combination of frequency separation by propagation dispersion and a time-dependent source frequency emission drift. A cross-correlati…
Fe XIII Density Diagnostics in the EIS Observing Wavelengths
Young, P. R.; Hara, H.; Watanabe, T. +6 more
The diagnostic capability of Fe XIII line features seen in the 170-210 Å waveband of the EUV Imaging Spectrometer (EIS) on Hinode is investigated, with emphasis on density diagnostics applied to solar active regions. Four diagnostic line pairs are found to yield consistent densities ranging from 108.5 to 109.5 cm-3…
Upflows in Funnel-like Legs of Coronal Magnetic Loops
He, Jiansen; Tian, Hui; Marsch, Eckart +1 more
The prominent blueshifts of Ne VIII associated with the junctions of the magnetic network in the quiet Sun are still not well understood. By comparing the coronal magnetic-field structures as obtained by a potential-field reconstruction with the conspicuous blueshift patches on the Dopplergram of Ne VIII as observed in an equatorial quiet-Sun regi…
No Observational Constraints from Hypothetical Collisions of Hypothetical Dark Halo Primordial Black Holes with Galactic Objects
Qian, Lei; Abramowicz, Marek A.; Becker, Julia K. +3 more
It was suggested by several authors that hypothetical primordial black holes (PBHs) may contribute to the dark matter (DM) in our Galaxy. There are strong constraints based on the Hawking evaporation that practically exclude PBHs with masses m pbh ~ 1015to1016 g and smaller as significant contributors to the Galact…