We report on a $\sim 5\sigma$ detection of polarized 3-6 keV X-ray emission from the supernova remnant Cassiopeia A with Imaging Polarimetry Explorer (IXPE). The overall polarization degree $1.8 \pm 0.3$% is detected by summing over large region, assuming circular symmetry for vectors. measurements imply an average synchrotron component 2.5$%, and close to 5% synchrotron-domimated forward-shock...

We estimate the detection rate of ultrahigh-energy cosmic rays on ground-based arrays by assuming that the cosmic-ray sources are active galactic nuclei. We analyze the cases of detection of clusters, several particles that arrived, within the error limits, from the same area of the sky. The adopted model is shown to explain the detection rate of clusters on the AGASA array.

We present a ray-tracing application in the modeling of an optical detection element employed as a sensor of refractive index of surrounding fluids or gases. The detection element is a solid glass microstructure having a surface of the second order. We exploit the sensitivity of internal reflection of light on the element’s surface to the refractive index of the surrounding medium, operation ne...

I report on the X-ray detection of Gl 569 Bab. During a 25 ksec Chandra observation the binary brown dwarf is for the first time spatially separated in X-rays from the flare star primary Gl 569 A. Companionship to Gl 569 A constrains the age of the brown dwarf pair to 300 − 800 Myr. The observation presented here is only the second X-ray detection of an evolved brown dwarf. About half of the ob...

Image preprocessing and image segmentation are two important and broad research areas. Image denoising is one of the research fields in the research area of image preprocessing which is used to remove noise from the images. This paper proposed a method to identify the best filter and best edge detection algorithm for digital x-ray bone images. Comparisons of various filters such as Mean, Median...