background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

in this study, analysis is presented in two steps. in the first step, the theoretical s-wave displacement spectra, conditioned by frequency-independent q, was fitted with the observed displacement spectra. therefore corner frequency, moment magnitude and frequency-independent q for each record were estimated simultaneously and the estimate of error is given in the root-mean-square sense over al...

The spectra of several X–ray binary pulsars display a clear soft excess, which in most cases can be described with a blackbody model, above the main power–law component. While in the high–luminosity sources it is usually characterized by low temperature (kT < 0.5 keV) and large emission radius (R > 100 km), in the two persistent and low–luminosity pulsars 4U 0352+309 and RX J0146.9+6121 this co...

Cet article revient en d&#233;tail sur l&#8217;exp&#233;rience de saisie collective d&#8217;une source administrative et sa transformation base donn&#233;es. Il se donne pour objectif d&#8217;analyser ce moment la recherche historique soulevant les enjeux organisationnels, m&#233;thodologiques &#233;pist&#233;mologiques qu&#8217;il soul&#232;ve, effets connaissance produit. Ce faisant, il inter...

We observed the compact central object CXOU J085201.4–461753 in the supernova remnant G266.2–1.2 (RX J0852.0–4622) with the Chandra ACIS detector in timing mode. The spectrum of this object can be described by a blackbody model with the temperature kT = 404± 5 eV and radius of the emitting region R = 0.28±0.01 km, at a distance of 1 kpc. Power-law and thermal plasma models do not fit the source...

We report on the XMM-Newton observations of the 143 ms pulsar PSR J0538+2817. We present evidence for the first detections of pulsed X-rays from the source at a frequency which is consistent with the predicted radio frequency. The pulse profile is broad and asymmetric, with a pulse fraction of 18 ± 3%. We find that the spectrum of the source is well-fit with a blackbody with T ∞ = (2.12 +0.04 −...

We report on the XMM-Newton observations of the 143 ms pulsar PSR J0538+2817. We present evidence for the first detections of pulsed X-rays from the source at a frequency which is consistent with the predicted radio frequency. The pulse profile is broad and asymmetric, with a pulse fraction of 18 ± 3%. We find that the spectrum of the source is well-fit with a blackbody with T ∞ = (2.12 +0.04 −...

We report on observations of the neutron star (NS) residing in the low-mass X-ray binary 1RXS J180408.934205 taken 2015 March by NuSTAR and XMM-Newton while the source was in the hard spectral state. We find multiple reflection features (Fe Kα detected with NuSTAR; N VII, O VII, and O VIII detected in the RGS) from different ionization zones. Through joint fits using the self consistent relativ...

In an experiment described by Fishman et al. [1994], high energy photons of atmospheric origin were detected by the Burst and Transient Source Experiment (BATSE) detectors, located on the Compton Gamma Ray Observatory (CGRO). In this paper we assess the possibility that the bursts may be bremsstrahlung produced by relativistic (>1 MeV) runaway electron beams accelerated in an avalanche process ...