Related papers: A Magnetar Flare in the BATSE Catalog?
We present a long-term study of the 2011 outburst of the magnetar Swift J1834.9-0846 carried out using new Chandra observations, as well as all the available Swift, RXTE, and XMM-Newton data. The last observation was performed on 2011…
New BeppoSAX observations of the nearby archetypical starburst galaxies (SBGs) NGC253 and M82 are presented. The main observational result is the unambiguous evidence that the hard (2-10 keV) component is (mostly) produced in both galaxies…
Magnetars are neutron stars with superstrong magnetic fields which can exceed 1e15 G. Some magnetars (the so-called soft gamma-repeaters) demonstrate occasionally very powerful processes of energy release, which result in exceptionally…
Magnetar is a neutron star with an ultrahigh magnetic field ($\sim 10^{14}-10^{15}$ G). The magnetar SGR J1935+2154 is not only one of the most active magnetars detected so far, but also the unique confirmed source of fast radio bursts…
The majority of short gamma-ray bursts (SGRBs) are thought to originate from the merger of compact binary systems collapsing directly to form a black hole. However, it has been proposed that both SGRBs and long gamma-ray bursts (LGRBs) may,…
SGRs denote ``soft $\gamma$-ray repeaters'', a small class of slowly spinning neutron stars with strong magnetic fields. On 27 December 2004, a giant flare was detected from magnetar SGR 1806-20. The initial spike was followed by a…
We report on the long term X-ray monitoring with Swift, RXTE, Suzaku, Chandra, and XMM-Newton of the outburst of the newly discovered magnetar Swift J1822.3-1606 (SGR 182-1606), from the first observations soon after the detection of the…
The study is devoted to search for flare stars among confirmed members of Galactic open clusters using high-cadence photometry from {\it TESS} mission. We analyzed 957 high-cadence light curves of members from 136 open clusters. As a…
We report the radio and high-energy properties of a new outburst from the radio-loud magnetar 1E 1547.0$-$5408. Following the detection of a short burst from the source with Swift-BAT on 2022 April 7, observations by NICER detected an…
In this work, we studied X-ray source SRGe~J021932.4$-$040154 (SRGe J021932), which we associated with a single X-ray active star of spectral class G2V-G4V and the rotational period $\rm P_{rot} < 9.3$ days. Additional analysis of TESS…
We report the discovery of 3.76-s pulsations from a new burst source near Sgr A* observed by the NuSTAR Observatory. The strong signal from SGR J1745-29 presents a complex pulse profile modulated with pulsed fraction 27+/-3 % in the 3-10…
The recurrent fast radio burst FRB 180916 was recently shown to exhibit a 16 day period (with possible aliasing) in its bursting activity. Given magnetars as widely considered FRB sources, this period has been attributed to precession of…
Context: Very-high-energy (VHE; E>100 GeV) {\gamma}-ray emission from blazars inevitably gives rise to electron-positron pair production through the interaction of these {\gamma}-rays with the Extragalactic Background Light (EBL). Depending…
We observed strong superflares (defined as flares with energy in excess of 10^33 erg) on three late-M dwarfs: 2MASS J08315742+2042213 (hereafter 2M0831+2042; M7 V), 2MASS J08371832+2050349 (hereafter 2M0837+2050; M8 V) and 2MASS…
The bright gamma-ray quasar 4C +55.17 is a distant source ($z = 0.896$) with a hard spectrum at GeV energies as observed by the Large Area Telescope (LAT) on board the {{\it Fermi}} satellite. This source is identified as a good source…
We investigate the angular distribution of the $\gamma$-ray bursts in the publicly available BATSE catalogue, using the measures of burst brightness $B$ and short time scale ($\simless$ 0.3 s) variability $V$ which we introduced earlier. We…
NGC 2071 is a star-forming region that overlaps with three $\gamma$-ray sources detected by the Fermi Space Telescope. We propose that strong flare activity in T Tauri stars could produce $\gamma$-ray emission in a way that makes them a…
Gamma-ray bursts have been proved to be detectable up to distances much larger than any other astrophysical object, providing the most effective way, complementary to ordinary surveys, to study the high redshift universe. To this end, we…
We perform a search for sources of gamma-rays with energies E>100 GeV at low Galactic latitudes |b|<10 deg using the data of Fermi telescope. To separate compact gamma-ray sources from the diffuse emission from the Galaxy, we use the…
X-ray observations play a crucial role in understanding the emission mechanism and relevant physical phenomena of magnetars. We report X-ray observations of a young magnetar SGR 1900+14 made in 2016, which is famous for a giant flare in…