Search Publications
Superflare on a rapidly-rotating solar-type star captured in X-rays
Sunyaev, Rashid; Gilfanov, Marat; Bikmaev, Ilfan +5 more
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
Detection of polarized Fermi-bubble synchrotron and dust emission
Keshet, Uri
The elusive polarized microwave signal from the Fermi bubbles is disentangled from the more extended polarized lobes, which similarly emanate from the Galactic plane but stretch farther west of the bubbles. The projected
The properties of the Galactic hard X-ray and soft γ-ray background based on 20 years of INTEGRAL/IBIS observations
Krivonos, Roman; Sazonov, Sergey; Shtykovskaya, Ekaterina
We present results of a study of the Galactic hard X-ray and soft γ-ray background emission performed with the IBIS telescope aboard the INTEGRAL observatory using data obtained over more than 20 years of operations. The study of the Galactic background at energies between 10 keV and a few MeV is problematic due to the contribution of point source…
Evidence for 3XMM J185246.6+003317 as a massive magnetar with a low magnetic field
Rodrigues, Claudia V.; de Lima, Rafael C. R.; Pereira, Jonas P. +10 more
3XMM J185246.6+003317 is a transient magnetar located in the vicinity of the supernova remnant Kes79. So far, observations have only set upper limits to its surface magnetic field and spindown, and there is no estimate for its mass and radius. Using ray-tracing modelling and Bayesian inference for the analysis of several light curves spanning a pe…
LISA and LISA-like mission test-mass charging for gamma-ray burst detection
Grimani, Catia; Villani, Mattia; Fabi, Michele +1 more
Cubic gold-platinum test-masses (TMs) play the role of free-falling geodesic reference and interferometer end mirrors of the future Laser Interferometer Space Antenna (LISA) observatory for low-frequency gravitational wave detection in space. A similar arrangement has been proposed for the Chinese missions Taiji and TianQin and for the LISA follow…
A multiwavelength study of the most distant gamma-ray detected BL Lacertae object 4FGL J1219.0+3653 (z = 3.59)
Domínguez, A.; Gallego, J.; Cardiel, N. +3 more
BL Lac objects are a class of jetted active galactic nuclei that do not exhibit or have weak emission lines in their optical spectra. Recently, the first γ-ray emitting BL Lac beyond
The challenge of identifying INTEGRAL sources on the Galactic plane
Ubertini, Pietro; Bazzano, Angela; Fiocchi, Mariateresa +6 more
The International Gamma-ray Astrophysics Laboratory (INTEGRAL) has been surveying the sky above 20 keV since its launch in 2002 providing new insights into the nature of the sources that populate our Universe at soft γ-ray energies. The latest IBIS/ISGRI survey lists 929 hard X-ray sources, of which 113 are reported as unidentified, i.e. lacking a…
Probing the nova shock physics with future gamma-ray observations of the upcoming outburst from T Coronae Borealis
Liu, Ruo-Yu; Zheng, Jian-He; Zhang, Hai-Ming +2 more
Nova shocks behave like scaled-down supernova remnant shocks with a lifetime of only a few weeks or months, thereby providing a unique opportunity to study the dynamics of non-relativistic shocks as well as the shock acceleration physics. Recently, GeV and TeV gamma-ray emissions from an outburst of the recurrent nova RS Ophiuchi have been observe…
Gamma rays from nebulae around recurrent novae
Bednarek, W.; Sitarek, J.
Novae were discovered to emit transient γ rays during the period of several days to a few weeks after initial explosion, indicating presence of acceleration processes of particles in their expanding shells. In the case of recurrent novae, electrons can be in principle accelerated in the nova shells for the whole recurrence period of nova producing…
Response of the Fe Kα line emission to the X-ray continuum variability in the changing-look active galactic nucleus NGC 1566
Shu, X. W.; Wang, J. X.; Jiang, N. +5 more
NGC 1566 is a changing look AGN known to exhibit recurrent X-ray outbursts with each lasting for several years. The most recent X-ray outburst is observed on 2018, with a substantial increase of 2-10 keV flux by a factor of ∼24 than the historical minimum. We re-analyze the XMM-Newton and NuSTAR observations covering the pre-outburst, outburst and…