نتایج جستجو برای: x ray spectrograph
تعداد نتایج: 667381 فیلتر نتایج به سال:
background and objective: chest x-ray is usually the first radiography performed for a newborn. this test is easily accessible and yet a basic screening method. different results have been reported in various studies regarding the diagnostic value of chest x-ray in cardiovascular disease in children. materials and methods: the study was carried out retrospectively using the medical files of 100...
Introduction: The Republic of Korea has developed a national standard based on which diagnostic X-ray equipment must be tested every 3 years. Accordingly, the performance of X-ray equipment used in all hospitals is evaluated by national certification bodies in compliance with the safety management regulations for X-ray equipment. However, if the equipment i...
Context. In quiescence, the proposed optical counterpart to the neutron star low mass X-ray binary 4U 2129+47 (V1727 Cyg) shows a spectrum consistent with a late F-type subgiant and no radial velocity variations on the 5.24 hour binary period. This could imply that V1727 Cyg is a chance line of sight interloper. Radial velocity measurements, however, showed evidence for a longer term ∼40 km s−1...
Context. In quiescence, the proposed optical counterpart to the neutron star low-mass X-ray binary system 4U2129+47 (V1727 Cyg) shows no radial velocity variations on the binary period. This could imply that V1727 Cyg is a chance line-of-sight interloper. Radial velocity measurements, however, showed evidence of a longer term ∼40 km s−1 shift, which suggested that 4U2129+47 could be a hierarchi...
We present a Hubble Space Telescope Space Telescope Imaging Spectrograph spectrum of ASASSN-14li, the first rest-frame ultraviolet (UV) spectrum of a tidal disruption flare (TDF). The underlying continuum is well fit by a blackbody with T 3.5 10 UV 4 = ́ K, an order of magnitude smaller than the temperature inferred from X-ray spectra (and significantly more precise than previous efforts based ...
Fabrication of intrinsically fluorescent porous nanocarriers that are simultaneously stable in aqueous solutions and photostable is critical for their application in drug delivery and optical imaging but remains a challenge. In this study, fluorescent porous zinc sulfide nanospheres were synthesized by a facile gum arabic-assisted hydrothermal procedure. The morphology, composition and properti...
We have obtained mid-infrared spectra of nine cool-core galaxy clusters with the Infrared Spectrograph aboard the Spitzer Space Telescope. X-ray, ultraviolet and optical observations have demonstrated that each of these clusters hosts a cooling flow which seems to be fueling vigorous star formation in the brightest cluster galaxy. Our goal is to use the advantages of the mid-infrared band to im...
With the aim of locating the boundary for the onset of chromospheric emission in the H-R diagram we have undertaken a spectroscopic study of the hydrogen Ly-α, using the IUE short wavelength spectrograph in the high resolution mode. We report here on the analysis of IUE spectra of 11 A–F type stars. We have detectedLy-α emission in stars as early asA7 (B–V = 0.19), establishing a new limit for ...
The systematics of OB spectra are reviewed in the optical domain, dominated by photospheric lines, and in the far ultraviolet (both IUE and FUSE ranges), in which the stellar-wind profiles dominate. First, the two-dimensional (temperature, luminosity) trends in normal spectra are surveyed. Then, the normal reference frame having been established, various categories of peculiar objects can be di...
The M dwarf Proxima~Centauri is known to be magnetically active and it hosts a likely Earth-like planet in its habitable zone. Understanding the characteristics of stellar radiation by understanding properties emitting plasma paramount importance for proper assessment conditions on Proxima~Centauri~b exoplanets around dwarfs general. We determine temperature structure coronal transition region ...
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