Results 51 to 60 of about 368,263 (301)
An estimate of the time variation of the O/H radial gradient from planetary nebulae [PDF]
, 2002 Radial abundance gradients are a common feature of spiral galaxies, and in the case of the Galaxy both the magnitude of the gradients and their variations are among the most important constraints of chemical evolution models.
Alibés +47 more
core +2 more sources
A Catalog of Young Stellar Objects from the LAMOST and ZTF Surveys
The Astrophysical Journal Supplement Series, 2023 As astronomical data sets become too large for traditional analysis approaches, more machine-learning algorithms are employed in astronomy. A wealth of light variation data have been accumulated, which provide rich samples for astronomers to study ...
Jingyi Zhang +4 more
doaj +1 more source
So What IS the Astronomy Major? [PDF]
, 2003 We present a statistical description of the astronomy major as it is offered in U.S. colleges and universities. There is substantial variation from institution to institution, but the physics requirements for the astronomy major are more uniform than the
Cabanela, Juan E., Partridge, Bruce
core +1 more source
No magnetic field variation with pulsation phase in the roAp star gamma Equulei
, 2004 We present an analysis of 210 high-resolution time-resolved spectropolarimetric observations of the roAp star gamma Equ obtained over three nights in August and September 2003.
Kochukhov, O. +2 more
core +1 more source
Mass-radius relation for magnetized strange quark stars [PDF]
, 2010 We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag ...
A. P. MARTÍNEZ +4 more
core +2 more sources
RXTE observations of single pulses of PSR B0531+21 I: Flux variations [PDF]
, 2001 This article is the first in the series that analyze about 1.87 million periods of PSR B0531+21 (Crab pulsar), observed by the PCA detector aboard the RXTE x-ray observatory. The Crab pulsar's x-ray light curve shows little variation over time scales ranging from days to a period (33.46 milli seconds). The standard deviation of its x-ray flux variation
arxiv +1 more source
In vivo transit dosimetry methodology for whole breast intensity modulated radiation therapy
Journal of Applied Clinical Medical Physics, EarlyView.Abstract Background In vivo transit dosimetry using an electronic portal imaging device (EPID‐IVTD) is an important tool for verifying the accuracy of radiation therapy treatments. Despite its potential, the implementation of EPID‐IVTD in breast intensity modulated radiation therapy (IMRT) treatments has not yet been standardized, limiting its clinical
Lucia Zirone +8 more
wiley +1 more source
Journal of Imaging, 2020 The measurement of night sky quality has become an important task in night sky conservation. Modern measurement techniques involve mainly a calibrated digital camera or a spectroradiometer.
Zoltán Kolláth +3 more
doaj +1 more source
Journal of Applied Clinical Medical Physics, EarlyView.Abstract Introduction The use of radioactive materials in the United States has been tightly regulated by the Nuclear Regulatory Commission and other entities for many decades. In 2015, however, the Joint Commission began to require hospital‐based nuclear medicine departments to conduct shielding designs and evaluations for radioactive material areas ...
Michael Oumano +12 more
wiley +1 more source
Photometric Study of Contact Binary AW UMa [PDF]
Journal of Astronomy and Space Sciences, 1995 BVRI observations of AW UMa were made from March to April during 13 nights in 1994 using the 35cm schmidt-Cassegrain telescope of Department of Astronomy and Space Science, Chungbuk National University.
Jo Ryeong Yim, Jang Hae Jeong
doaj