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Full-Text Articles in Physics
Characterizing Decaying Dark Matter: X-Ray Emission From Sterile Neutrinos, Murat Hüdaverdi̇
Characterizing Decaying Dark Matter: X-Ray Emission From Sterile Neutrinos, Murat Hüdaverdi̇
Turkish Journal of Physics
Recently, an unknown emission line at E $\sim$3.5 keV from several astrophysical objects has been detected. The line is suggested to be originating from decaying dark matter particles. The results have drawn great attention from the astrophysics and particle physics community. Since the detected line is significantly weak there has also been a long debate over the origin of this mysterious signal. The most accepted scenario is a radiatively decaying sterile neutrino of 7.1 keV in mass producing a monochromatic 3.5 keV line, which is observable in X-ray energy ranges. The problem has not been settled and further observations from …
On The Contribution Of The 6.7 Kev Line Emission Of The Algol Binary System To The 6.7 Kev Line Emission From The Galactic Ridge, Ambrose Chukwudi Eze, Romanus Nwachukwu Chijioke Eze, Sudum Esaenwi
On The Contribution Of The 6.7 Kev Line Emission Of The Algol Binary System To The 6.7 Kev Line Emission From The Galactic Ridge, Ambrose Chukwudi Eze, Romanus Nwachukwu Chijioke Eze, Sudum Esaenwi
Turkish Journal of Physics
We carried out spectroscopic analysis of the extracted stellar flare of the Algol binary system observed using the Suzaku satellite (OBSID: 401093010), and resolved a strong 6.7 keV line emission. The 6.7 keV line emission of the Algol binary system is similar to the 6.7 keV line of the galactic ridge X-ray emission (GRXE). The equivalent width (EW) compared favorably with the EW of the 6.7 keV emission line obtained from different galactic ridge regions. In the galaxy, we have a reasonable number of Algol binary systems and many other stars as strong coronal X-ray emitters characterized by frequent quiescent …
Measurements Of K-Shell Fluorescence Yields For Ti, V, Cr, Fe, Co, Ni And Cu Elements And Their Halogen Compounds, Eli̇f Baydaş, Eli̇f Orhan Öz, Mehmet Büyükyildiz
Measurements Of K-Shell Fluorescence Yields For Ti, V, Cr, Fe, Co, Ni And Cu Elements And Their Halogen Compounds, Eli̇f Baydaş, Eli̇f Orhan Öz, Mehmet Büyükyildiz
Turkish Journal of Physics
K-shell fluorescence yields \omega_K were measured for the elements Ti, V, Cr, Fe, Co, Ni, Cu and F and Cl compounds of these elements. Measurements were carried out at 10 keV excitation energy using secondary excitation method. K x-rays emitted by samples were counted by a Si(Li) detector with 160 eV resolution at 5.9 keV. Measurement of K-shell fluorescence yields \omega_K for these elements are compared with earlier experimental results obtained by other methods.
New Phases Of Ybacugeo Superconductors Identified From X-Ray Diffraction And Infra-Red Absorption Measurements, Ahmed Abo-Arais, Mohamad Ahmad Taher Dawoud
New Phases Of Ybacugeo Superconductors Identified From X-Ray Diffraction And Infra-Red Absorption Measurements, Ahmed Abo-Arais, Mohamad Ahmad Taher Dawoud
Turkish Journal of Physics
X-ray powder diffraction patterns and infra-red absorption spectra have been evaluated and analysed for the Y_1 Ba_2 Cu_3 O_{7-\delta} - Ge_x compound samples prepared by the solid state reaction with x values ranging from 0.0 to 1.13. All samples show bulk superconductivity above liquid nitrogen temperature using the levitation test (Meissner effect). Samples with Ge content up to x = 0.2 have offset T_c between 83K and 92K while the sample with x = 1.13 shows semiconducting behavior above 100K. As a result of the solid state interaction between YBCO and Ge, new phases are observed and determined, mainly three …
Structural, Electrical And Spectral Studies On Double Rare-Earth Orthoferrites La_{1-X}Nd_Xfeo_3, O.M. Hemeda, Mohsen Mohamed Barakat, D. M. Hemeda
Structural, Electrical And Spectral Studies On Double Rare-Earth Orthoferrites La_{1-X}Nd_Xfeo_3, O.M. Hemeda, Mohsen Mohamed Barakat, D. M. Hemeda
Turkish Journal of Physics
Samples of double rare-earth ferrite La_{1-x}Nd_xFeO_3 are synthesized by a high-temperature double sintering ceramic technique. X-ray diffraction shows that all compounds have an orthorhombic structure. The values of lattice parameter and the volume of the unit cell, changes with increasing Nd^{3+} content. The Goldschmidt tolerance factor decreases and goes far from unity with increasing Nd content. The samples containing Nd ions with x = 0.1, 0.2 and 0.3 have higher resistivity than that of LaFeO_{3}, but for x \ge 0.4 the resistivity decreases. The results indicate the presence of extrinsic semiconducting properties up to 100 °C above which the hopping …