Results 121 to 130 of about 1,327,251 (363)

Positions and sizes of X-ray solar flare sources [PDF]

, 2010
We investigate the positions and source sizes of X-ray solar flare sources taking into account Compton backscattering (albedo). Using a Monte Carlo simulation of X-ray photon transport including photo-electric absorption and Compton scattering, we calculate the apparent source sizes and positions of X-ray sources at the solar disk for various source ...
arxiv   +1 more source

Effects of cardiac motion on dose distribution during stereotactic arrhythmia radioablation treatment: A simulation and phantom study

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose Cardiac motion may degrade dose distribution during stereotactic arrhythmia radioablation using the CyberKnife system, a robotic radiosurgery system. This study evaluated the dose distribution changes using a self‐made cardiac dynamic platform that mimics cardiac motion. Methods The cardiac dynamic platform was operated with amplitudes
Takayuki Miyachi, Takeshi Kamomae, Fumitaka Kawabata, Kuniyasu Okudaira, Mariko Kawamura, Shunichi Ishihara, Shinji Naganawa   +6 more
wiley   +1 more source

Brightening and Fading in the Youngest Galactic Supernova Remnant G1.9+0.3: 13 Years of Monitoring with the Chandra X-Ray Observatory

The Astrophysical Journal
We report 13 years of Chandra monitoring of the youngest Galactic supernova remnant G1.9+0.3, the only remnant known to be increasing in brightness. We confirm the spatially integrated rate of flux increase of (1.2 ± 0.2)% yr ^−1 (1–7 keV), but find ...
Kazimierz J. Borkowski, Stephen P. Reynolds, David A. Green, Robert Petre   +3 more
doaj   +1 more source

A Chandra X-ray Study of the Globular Cluster M80

, 2003
We report our analysis of a Chandra X-ray observation of the rich globular cluster M80, in which we detect some 19 sources to a limiting 0.5-2.5 keV X-ray luminosity of 7*10^30 ergs/s within the half-mass radius.
Auwers G. F., Brocato E., C. O. Heinke, D. A. Lloyd, H. N. Cohn, Hakala P. J., J. E. Grindlay, Johnston H. M., P. D. Edmonds, P. M. Lugger, Predehl P., S. S. Murray, Verbunt F.   +12 more
core   +1 more source

Measurement of CT radiation beam width with a pencil ionization chamber and radiopaque mask

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose This study compares fan beam CT scanner radiation beam widths measured with a pencil ionization chamber‐radiopaque mask technique with commonly used film and computed radiography (CR) measurements. Methods For a given fan beam CT scanner x‐ray beam, the ionization chamber‐mask technique determines the radiation beam width by exposing a
Rani Al‐Senan, David M. Gauntt, Gary T. Barnes   +2 more
wiley   +1 more source

A Precessing Stellar Disk Model for Superorbital Modulations of the Gamma-Ray Binary LS I+61° 303

The Astrophysical Journal
Gamma-ray binary LS I+61° 303 consists of a neutron star orbiting around a Be star with a period of P _orb ≃ 26.5 days. Apart from orbital modulations, the binary shows long-term flux variations with a superorbital period of ${P}_{\sup }\simeq 4.6\,{\rm ...
A. M. Chen, J. Takata, Y. W. Yu
doaj   +1 more source

X-ray sources in omega Centauri and other globular clusters [PDF]

arXiv, 2001
X-ray bursts from bright sources in globular clusters of our galaxy show that at least 11 (of a total 13) of these sources are neutron stars. One of the low-luminosity X-ray sources in omega Cen is a neutron star accreting at a low rate. Together with the discoveries that M~15 contains two bright X-ray sources, and that 47 Tuc and NGC 6440 contain 2 ...
arxiv  

The Chandra Local Volume Survey: The X-ray Point Source Catalog of NGC 300

, 2012
We present the source catalog of a new Chandra ACIS-I observation of NGC 300 obtained as part of the Chandra Local Volume Survey. Our 63 ks exposure covers ~88% of the D25 isophote (R~6.3 kpc) and yields a catalog of 95 X-ray point sources detected at ...
A. K. H. Kong, B. Binder, B. F. Williams, Belczynski, Binder, Binder, Blair, Broos, Colbert, D. R. Weisz, Dalcanton, Deharveng, E. D. Skillman, Eracleous, Freeman, Gibson, Gogarten, Hornschemeier, J. J. Dalcanton, Kilgard, Kim, Kong, Kong, Larsen, Lasota, Long, M. Eracleous, Maíz-Apellániz, Muñoz-Mateos, P. P. Plucinsky, Pannuti, Park, Plucinsky, Prestwich, S. F. Anderson, Singh, Skrutskie, Smith, Soria, T. J. Gaetz, Trudolyubov, Tüllmann, Vila-Costas, Williams, Williams, Wilms, Yi   +46 more
core   +1 more source

Feasibility study of skin dosimetry with TLD sheets for measuring the effect of 3D printed bolus in radiotherapy

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract The thermoluminescence dosimeter (TLD) sheet is a measurement device coated with manganese‐doped LiB3O5 in sheet form. The sheet is 0.2‐mm thick and flexible. Hence, it can fit and be installed on irregular surfaces. The current study aimed to evaluate the feasibility of measuring patient surface doses during radiation therapy using TLD sheets.
Yuya Miyasaka, Mayumi Ichikawa, Takagi Akira, Yoshifumi Yamazawa, Hongbo Chai, Hikaru Souda, Miyu Ishizawa, Hiraku Sato, Takeo Iwai   +8 more
wiley   +1 more source

The Chandra Source Catalog Release 2 Series

The Astrophysical Journal Supplement Series
The Chandra Source Catalog (CSC) is a virtual X-ray astrophysics facility that enables both detailed individual source studies and statistical studies of large samples of X-ray sources detected in Advanced CCD Imaging Spectrometer and High Resolution ...
Ian N. Evans, Janet D. Evans, J. Rafael Martínez-Galarza, Joseph B. Miller, Francis A. Primini, Mojegan Azadi, Douglas J. Burke, Francesca M. Civano, Raffaele D’Abrusco, Giuseppina Fabbiano, Dale E. Graessle, John D. Grier, John C. Houck, Jennifer Lauer, Michael L. McCollough, Michael A. Nowak, David A. Plummer, Arnold H. Rots, Aneta Siemiginowska, Michael S. Tibbetts   +19 more
doaj   +1 more source