Search Publications
Radio Galaxy 3C 230 Observed with Gemini Laser Adaptive-optics Integral-field Spectroscopy
Steinbring, Eric
The Altair laser-guide-star adaptive optics facility combined with the near-infrared integral-field spectrometer on Gemini North have been employed to study the morphology and kinematics of 3C 230 at z = 1.5, the first such observations of a high-redshift radio galaxy. These suggest a bi-polar outflow spanning 0farcs9 (~16 kpc projected distance f…
X-Ray Study of Rekindled Accretion in the Classical Nova V2491 Cygni
Drake, Jeremy J.; Tsujimoto, Masahiro; Ness, Jan-Uwe +5 more
We conducted an X-ray spectroscopic study of the classical nova V2491 Cygni using our target-of-opportunity observation data with the Suzaku and XMM-Newton satellites as well as archived data with the Swift satellite. Medium-resolution (
The Infrared Jet in 3C 31
Jones, Christine; Kraft, Ralph P.; Forman, William R. +5 more
We report the detection of infrared emission from the jet of the nearby Fanaroff-Riley type I radio galaxy 3C 31. The jet was detected with the IRAC instrument on Spitzer at 4.5 µm, 5.8 µm, and 8.0 µm out to 30'' (13 kpc) from the nucleus. We measure radio, infrared, optical, and X-ray fluxes in three regions along the jet determ…
Acoustic Power Absorption and its Relation to Vector Magnetic Field of a Sunspot
Venkatakrishnan, P.; Gosain, S.; Mathew, S. K.
The distribution of acoustic power over sunspots shows an enhanced absorption near the umbra - penumbra boundary. Previous studies revealed that the region of enhanced absorption coincides with the region of strongest transverse potential field. The aim of this paper is to i) utilize the high-resolution vector magnetograms derived using Hinode SOT…
Swift follow-up of unidentified X-ray sources in the XMM-Newton Slew Survey
Read, A. M.; Esquej, P.; O'Brien, P. T. +8 more
We present deep Swift follow-up observations of a sample of 94 unidentified X-ray sources from the XMM-Newton Slew Survey. The X-ray Telescope (XRT) on-board Swift detected 29 per cent of the sample sources; the flux limits for undetected sources suggest the bulk of the Slew Survey sources are drawn from one or more transient populations. We repor…
Coronal Jets, Magnetic Topologies, and the Production of Interplanetary Electron Streams
van Driel-Gesztelyi, L.; Owen, C. J.; Li, C. +2 more
We investigate the acceleration source of the impulsive solar energetic particle (SEP) events on 2007 January 24. Combining the in situ electron measurements and remote-sensing solar observations, as well as the calculated magnetic fields obtained from a potential-field source-surface model, we demonstrate that the jets associated with the hard X-…
Properties of energetic particle bursts at dawnside magnetosheath: Cassini observations during the 1999 Earth swing-by
Krupp, N.; Mitchell, D. G.; Armstrong, T. P. +2 more
During Cassini's Earth swing-by in 1999, the Low-Energy Magnetospheric Measurement System (LEMMS) detected energetic particles at the distant dawn magnetosheath. LEMMS identified 9 electron bursts and continuous proton flux surges at least up to 100 keV at X = -72 Re to -102 Re during the southward turning of the interplanetary magnetic field. All…
Fast Timing Analysis of Cygnus X-1 Using the SPectrometer on the International Gamma-Ray Astrophysics Laboratory
Jourdain, Elisabeth; Roques, Jean-Pierre; Cabanac, Clément
We report for the first time the high-frequency analysis of Cyg X-1 up to hard X-ray using the spectrometer on International Gamma-Ray Astrophysics Laboratory (INTEGRAL). After analyzing the possible contribution from the background, and using the INTEGRAL archive from 2005 March to 2008 May, power density spectra were obtained up to 130 keV. Firs…
Data Characterization Using Artificial-Star Tests: Performance Evaluation
Deng, Licai; de Grijs, Richard; Liu, Qiang +1 more
Traditional artificial-star tests are widely applied to photometry in crowded stellar fields. However, to obtain reliable binary fractions (and their uncertainties) of remote, dense, and rich star clusters, one needs to recover huge numbers of artificial stars. Hence, this will consume much computation time for data reduction of the images to whic…
Overview of Saturn Lightning Observations
Gurnett, D. A.; Kurth, W. S.; Barry, T. +8 more
The lightning activity in Saturn's atmosphere has been monitored by Cassini for more than six years. The continuous observations of the radio signatures called SEDs (Saturn Electrostatic Discharges) combine favorably with imaging observations of related cloud features as well as direct observations of flash-illuminated cloud tops. The Cassini RPWS…