Search Publications
A study on the evolutionary period changes of short-period type II cepheids
Pastukhova, Elena N.; Yacob, Alemiye Mamo; Berdinkov, Leonid N.
We investigate the period changes of 13 short-period Type II Cepheids using the O-C method over a century-long data baseline. The O-C diagrams for these stars exhibit a parabolic trend, indicating both increasing and decreasing period changes over time. These observed period changes are consistent with recent theoretical models based on horizontal…
The Positron Puzzle
Siegert, Thomas
The Positron Puzzle is a half-century old conundrum about the origin of the Galactic
Radioactive isotopes in the interstellar medium
Diehl, Roland
Radioactive components of the interstellar medium provide an entirely-different and new aspect to the studies of the interstellar medium. Injected from sources of nucleosynthesis, unstable nuclei decay along their trajectories. Measurements can occur through characteristic gamma rays that are emitted with the decay, or in cosmic material samples t…
Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT
Li, Gang; Li, Xiaobo; Tuo, Youli +10 more
Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, i…
A search for evolutionary changes in the pulsation period of the classical Cepheid V609 Cygni
Dambis, A. K.; Berdnikov, L. N.; Pastukhova, E. N.
A total of 820 magnitude estimates were made for the long-period classical Cepheid V609 Cyg (
Study of eclipsing binary and multiple systems in OB associations V: MQ Cen in Crux OB1
Bakış, Volkan; Bilir, Selçuk; Nitschelm, Christian +6 more
The early-type massive binary MQ Cen (
The broad-band spectrum of the narrow-line Seyfert 1 NGC 4748: from UV to hard X-ray
Vasylenko, A. A.
We report the results obtained by a broad-band (0.5–500 keV) data analysis of narrow-line Seyfert 1 galaxy NGC 4748 observed with an XMM-Newton/PN, INTEGRAL/ISGRI and SWIFT/BAT telescopes. This galaxy has a soft X-ray excess that is typical for the class of narrow-line Seyfert 1. The question of the origin of soft excess in such objects is still u…
Possible gamma-ray burst radio detections by the Square Kilometre Array. New perspectives
Capozziello, Salvatore; Ruggeri, Alan Cosimo
The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of Gamma Ray Bursts (GRBs). By the SKA, it will be possible to perform the follow up of GRBs even for several mo…
X-ray spectral parameters for a sample of 95 active galactic nuclei
Vasylenko, A. A.; Fedorova, E. V.; Zhdanov, V. I.
We present a broadband X-ray analysis of a new homogeneous sample of 95 active galactic nuclei (AGN) from the 22-month Swift/BAT all-sky survey. For this sample we treated jointly the X-ray spectra observed by XMM-Newton and INTEGRAL missions for the total spectral range of 0.5–250 keV. Photon index
Sub-arcsecond radio and optical observations of the likely counterpart to the gamma-ray source 2FGL J2056.7+4939
Luque-Escamilla, P. L.; Martí, J.; Muñoz-Arjonilla, A. J. +1 more
We have searched and reviewed all multi-wavelength data available for the region towards the gamma-ray source 2FGL J2056.7+4939 in order to constrain its possible counterpart at lower energies. As a result, only a point-like optical/infrared source with flat-spectrum radio emission is found to be consistent with all X-ray and gamma-ray error circl…