Search Publications
X-Ray Eclipse Diagnosis of the Evolving Mass Loss in the Recurrent Nova U Scorpii 2010
Ness, J. -U.; Tsujimoto, M.; Osborne, J. P. +4 more
We report the Suzaku detection of the earliest X-ray eclipse seen in the recurrent nova U Scorpii 2010. A target-of-opportunity observation 15 days after the outburst found a 27% ± 5% dimming in the 0.2-1.0 keV energy band at the predicted center of an eclipse. In comparison with the X-ray eclipse depths seen at two later epochs by XMM-Newton, the…
CO J = 2-1 Emission from Evolved Stars in the Galactic Bulge
Meixner, M.; Patel, N. A.; Sargent, Benjamin A. +3 more
We observe a sample of eight evolved stars in the Galactic bulge in the CO J = 2-1 line using the Submillimeter Array with angular resolution of 1''-4''. These stars have been detected previously at infrared wavelengths, and several of them have OH maser emission. We detect CO J = 2-1 emission from three of the sources in the sample: OH 359.943 +0…
Current Sheet Regulation of Solar Near-relativistic Electron Injection Histories
Lario, D.; Vainio, R.; Dalla, S. +2 more
We present a sample of three large near-relativistic (>50 keV) electron events observed in 2001 by both the ACE and the Ulysses spacecraft, when Ulysses was at high-northern latitudes (>60°) and close to 2 AU. Despite the large latitudinal distance between the two spacecraft, electrons injected near the Sun reached both heliospheric location…
Differential Proper-motion Measurements of the Cygnus Egg Nebula: The Presence of Equatorial Outflows
Ueta, Toshiya; Tomasino, Rachael L.; Ferguson, Brian A.
We present the results of differential proper-motion analyses of the Egg Nebula (RAFGL 2688, V1610 Cyg) based on the archived two-epoch optical data taken with the Hubble Space Telescope. First, we determined that the polarization characteristics of the Egg Nebula are influenced by the higher optical depth of the central regions of the nebula (i.e…
VLBI Observation of Microquasar Cyg X-3 during an X-Ray State Transition from Soft to Hard in the 2007 May-June Flare
Kim, Jeong-Sook; Kim, Soon-Wook; Kurayama, Tomoharu +3 more
We present a radio observation of microquasar Cyg X-3 during an X-ray state transition from ultrasoft to hard state in the 2007 May-June flare using the VLBI Exploration of Radio Astrometry at 22 GHz. During the transition, a short-lived mini-flare of <~ 3 hr was detected prior to the major flare. In such a transition, a jet ejection is believe…
Ultraviolet Spectroscopic Analysis of Transient Mass Flow Outburst in U Cephei
Sahade, Jorge; Kondo, Yoji; Giménez, Alvaro +4 more
Spectra from the International Ultraviolet Explorer taken in 1989 September over one full orbital period of U Cephei (U Cep, HD 5796) are analyzed. The TLUSTY and SYNSPEC stellar atmospheric simulation programs are used to generate synthetic spectra to which U Cep continuum levels are normalized. Absorption lines attributed to the photosphere are …
The Chandra Local Volume Survey: The X-Ray Point-source Population of NGC 404
Skillman, E. D.; Kong, A. K. H.; Weisz, D. R. +4 more
We present a comprehensive X-ray point-source catalog of NGC 404 obtained as part of the Chandra Local Volume Survey. A new 97 ks Chandra ACIS-S observation of NGC 404 was combined with archival observations for a total exposure of ~123 ks. Our survey yields 74 highly significant X-ray point sources and is sensitive to a limiting unabsorbed lumino…
The Relationship between Extreme Ultraviolet Non-thermal Line Broadening and High-energy Particles during Solar Flares
Imada, S.; Kawate, T.
We have studied the relationship between the location of EUV non-thermal broadening and high-energy particles during large flares using the EUV Imaging Spectrometer on board Hinode, the Nobeyama Radio Polarimeter, the Nobeyama Radioheliograph, and the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory. We have analyzed five large …
The Curious Radial Distributions of Horizontal Branch Stars in NGC 6441
Sandquist, Eric L.; Krogsrud, David A.; Kato, Tadafumi
NGC 6441 is one of the most massive and most metal-rich globular clusters in the galaxy, and is noted for an unusual extended horizontal branch that reaches past the instability strip. We find evidence that there are two different populations of stars within the heavily populated red clump. Once a differential reddening correction is applied, a la…
A Gravitational Lens Model for the Lyα Emitter LAE 221724+001716 at z = 3.1 in the SSA 22 Field
Taniguchi, Y.; Kajisawa, M.; Matsuda, Y. +8 more
During the course of our Lyman continuum imaging survey, we found that the spectroscopically confirmed Lyα emitter LAE 221724+001716 at z = 3.10 in the SSA 22 field shows strong Lyman continuum emission (λrest ~ 900 Å) that escapes from this galaxy. However, another recent spectroscopic survey revealed that the supposed Lyman continuum …