Search Publications
The X-ray Power Spectral Density Function of the Seyfert Active Galactic Nucleus NGC 7469
Markowitz, A.
We present the broadband X-ray power spectral density (PSD) function of the X-ray-luminous Seyfert 1.2 NGC 7469, measured from Rossi X-ray Timing Explorer monitoring data and two XMM-Newton observations. We find significant evidence for a turnover in the 2-10 keV PSD at a temporal frequency of 2.0+3.0 -0.8 × 10-6 H…
Quasi-Periodic Oscillations in Lasco Coronal Mass Ejection Speeds
Cho, K. -S.; Moon, Y. -J.; Shanmugaraju, A. +6 more
Quasi-periodic oscillations in the speed profile of coronal mass ejections (CMEs) in the radial distance range 2-30 solar radii are studied. We considered the height-time data of the 307 CMEs recorded by the Large Angle and Spectrometric Coronagraph (LASCO) during 2005 January-March. In order to study the speed-distance profile of the CMEs, we hav…
Physical Conditions in the Ultraviolet Absorbers of IRAS F22456-5125
Kraemer, S. B.; Dunn, Jay P.; Crenshaw, D. Michael +1 more
We present the ultraviolet (UV) and X-ray spectra observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) and the XMM-Newton satellite, respectively, of the low-z Seyfert 1 galaxy IRAS F22456 - 5125. This object shows absorption from five distinct, narrow kinematic components that span a significant range in velocity (~0 to -700 km s-…
Location and Magnetospheric Mapping of Saturn's Mid-latitude Infrared Auroral Oval
Cowley, Stanley W. H.; Melin, Henrik; Miller, Steve +2 more
Previous observations of Saturn's infrared aurorae have shown that a mid-latitude aurora exists significantly equatorward of the main auroral oval. Here, we present new results using data from four separate observing runs in 1998, 2003, 2008, and 2010. When combined, these provide a view of the mid-latitude aurora under a considerable range of vie…
A Transition Region Explosive Event Observed in He II with the MOSES Sounding Rocket
Kankelborg, Charles C.; Thomas, Roger J.; Fox, J. Lewis
Transition region explosive events (EEs) have been observed with slit spectrographs since at least 1975, most commonly in lines of C IV (1548 Å, 1550 Å) and Si IV (1393 Å, 1402 Å). We report what we believe to be the first observation of a transition region EE in He II 304 Å. With the Multi-Order Solar EUV Spectrograph (MOSES) sounding rocket, a n…
The Three-Dimensional Morphology of a Corotating Interaction Region in the Inner Heliosphere
Howard, R. A.; Wood, B. E.; Socker, D. G. +1 more
In its three years of operation, the HI2 imagers on the two Solar TErrestrial RElations Observatory (STEREO) spacecraft have imaged many corotating interaction regions (CIRs) in the interplanetary medium, allowing the study of their three-dimensional (3D) morphology. Using an entirely empirical analysis technique, we construct a 3D model of one CI…
CMEs from AR 10365: Morphology and Physical Parameters of the Ejections and of the Associated Current Sheet
Romoli, M.; Poletto, G.; Schettino, G.
We study the evolution and physical parameters of three consecutive coronal mass ejections (CMEs) that occurred at the west limb of the Sun on 2003 June 2 at 00:30, 08:54, 16:08 UT, respectively. The Large Angle and Spectrometric Coronagraph Experiment (LASCO) CME catalog shows that the CMEs entered the C2 field of view with position angles within…
The Optical Depth of White-light Flare Continuum
Fletcher, Lyndsay; Hudson, Hugh; Potts, Hugh +1 more
The white-light continuum emission of a solar flare remains a puzzle as regards its height of formation and its emission mechanism(s). This continuum and its extension into the near-UV contain the bulk of the energy radiated by a flare, and so its explanation is a high priority. We describe a method to determine the optical depth of the emitting l…
Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer Observations of the GLIMPSE9 Stellar Cluster
Kudritzki, R. P.; Rich, R. Michael; MacKenty, John +4 more
We present Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer photometry, and low-resolution K-band spectra of the GLIMPSE9 stellar cluster. The newly obtained color-magnitude diagram shows a cluster sequence with H - KS = ~1 mag, indicating an interstellar extinction A _K_s = 1.6 ± 0.2 mag. The spectra of the thr…
Three-dimensional Reconstructions and Mass Determination of the 2008 June 2 LASCO Coronal Mass Ejection Using STELab Interplanetary Scintillation Observations
Jackson, B. V.; Buffington, A.; Hick, P. P. +4 more
We examine and reconstruct the interplanetary coronal mass ejection (ICME) first seen in space-based coronagraph white-light difference images on 2008 June 1 and 2. We use observations of interplanetary scintillation (IPS) taken with the Solar-Terrestrial Environment Laboratory (STELab), Japan, in our three-dimensional (3D) tomographic reconstruct…