Conveners
High energy astrophysics: Monday block 1
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
High energy astrophysics: Monday block 2
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
High energy astrophysics: Tuesday block 1
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
High energy astrophysics: Tuesday block 2
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
High energy astrophysics: Thursday block 1
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
High energy astrophysics: Thursday block 2
- Marat Gilfanov (MPA, Garching & IKI, Moscow)
Description
The session will aim to provide a venue for discussion of a broad range of topics of modern high energy astrophysics. These will include highlights from major X-ray and gamma-ray missions, their multi-messenger synergies and future prospects, as well as recent theoretical breakthroughs. It is envisaged that the topics will include but will be not limited to: compact objects on all mass scales, ultra-luminous X-ray sources, spectral formation in the vicinity of relativistic compact objects, transient phenomena of Galactic and extragalactic origin - ranging from X-ray novae to tidal disruption events. Synergies with other wavebands and with gravitational wave and neutrino astronomy will be also in the focus of the meeting. The session will be built around several invited and review talks with ample time left for shorter contributions.
After more than two years of scanning the sky the eROSITA X-ray telescope aboard SRG orbital observatory produced the best ever X-ray maps of the sky and discovered more than three million X-ray sources, of which about 20% are stars with active coronas in the Milky Way, and most of the rest are galaxies with active nuclei, quasars and clusters of galaxies. eROSITA detected over 10^3 sources...
An overview of highlights and discoveries from Mikhail Pavlinsky ART-XC telescope on board the SRG observatory is presented. Since 2019 SRG/ART-XC has conducted several full all sky surveys as well as a deep survey of our Galaxy. As a result, we obtained the catalogue of hard X-ray sources detected at the all sky, which includes more than one and a half thousand objects, most of them are...
AstroSat is a multiwavelength astronomy satellite with a suite of instruments facilitating simultaneous observations of cosmic objects in the optical, ultraviolet, soft X-ray, and hard X-ray ranges. The capabilities of these science payloads include a large collection area, high time resolution, excellent imaging, and hard X-ray polarization. AstroSat has observed varieties of cosmic...
The launch of the Einstein Probe mission in January 2024 has marked a significant leap forward in the exploration of the transient X-ray Universe. Led by the Chinese Academy of Sciences and in collaboration with the European Space Agency, the Max Planck Institute for Extraterrestrial Physics and the French space agency, the mission consists of two instruments: the Wide-field X-ray Telescope,...
The X-ray spectra of isolated neutron stars (INSs) typically include a thermal component, that comes from the cooling surface, and a non-thermal component, produced by highly-relativistic particles accelerated in the stellar magnetosphere. Hot spots from returning currents can also be detected.
Middle-aged pulsars exhibit a mixture of these components, but other flavours of INSs, that show...
The ESA INTEGRAL satellite, devoted to high resolution spectroscopy coupled to good imaging capabilities over a wide field of view in the 15 keV - 10 MeV range, was launched in October 2002. After more than two decades, its four instruments are still working well, and they provide unique capabilities in the study of high-energy phenomena.
In this talk I will give a brief overview of the...
We present a sample of 99 dwarf galaxies (stellar mass < 10^9.5 M⊙) with X-ray activity in their central regions. The sample was obtained from a match of the SRG/eROSITA X-ray catalogue in the eastern galactic hemisphere with the MPA-JHU SDSS catalogue. The obtained matches were cleaned rigorously with the help of external optical catalogues to increase the purity of the sample. This work is...
Extracting nonlinear nature of astrophysical systems, particularly
from observed data, has long been considering for various kinds of sources.
Accretion disks around compact objects are one of them. Our group
has been working on it for more than two decades: for GRS 1915+105,
Sco X-1, Cyg X-1,2,3, IGR J17091–3624, etc. Sources exhibit sometimes
chaotic/deterministic and sometimes...
We explore the X-ray emission from PSR B1055–52 using observations from XMM-Newton taken in 2019 and 2000. Traditional models of neutron star atmospheres fail to adequately describe the phase-integrated X-ray emission of this pulsar. Instead, our findings suggest a dual blackbody model with differing temperatures and areas, supplemented by a nonthermal power-law component, fits best. Our...
Magnetars are isolated young neutron stars that exhibit the most intense magnetic fields known in the Universe and are characterized by a wide variety of high-energy emissions. The birth of rapidly rotating magnetars is also a promising scenario to power outstanding explosive transients. The formation process of these objects, as well as the origin of their ultra-strong magnetic fields,...
In this work, we study the properties of dissipative shocks for fully relativistic accretion flows around spinning black holes. In an accretion flow harbouring a dissipative shock (formally known as radiative shock), a significant portion of the thermal energy may get released from the post-shock corona. A stellar-mass black hole may therefore emit hard X-rays from the inner edge of the disc....
Numerous studies suggest that high-energy (HE) neutrinos and ultra-high-energy (UHE) cosmic rays could originate from extremely high-synchrotron peaked (EHSP) BL Lacs, which have been identified as effective particle accelerators. Due to the discovery of HE-neutrinos by the IceCube telescope, these hypotheses may shortly have the opportunity to be tested. In this work, we use a two-zone...
Iron fluorescence emission lines from X-ray binaries and active galactic nuclei are important diagnostic tools for studying the physical processes near the event horizon of both the stellar-mass black holes in X-ray binaries and the supermassive black holes in active galactic nuclei. In this work, we investigate the line profile of the relativistic broad iron lines from the cool accretion disk...
Magnetic fields in regions of strong gravity play a crucial role in the explanation of various astrophysical phenomena, such as e.g. the formation and collimation of relativistic jets observed in black hole systems of different mass scales. In this presentation, I will discuss the influence of magnetic fields on dynamical environments of supermassive black holes from both theoretical and...
Usually, when we talk about gravitational lensing we either speak of gravitational lensing of light or gravitational waves. However, in the presence of a black hole also massive particles like neutrinos can be gravitationally lensed. While nowadays most neutrino detectors are not sensitive enough to resolve neutrino events with an angular resolution that is high enough so that we can...
The orbital decay of binary pulsars is a very precise tool for testing general relativity and modified theories of gravity and for constraining the existence of additional neutron star charges. The orbital decay has been used for constraining scalar-tensor theories (STT) decades ago. In the present talk we demonstrate that the same simple methodology used for constraining STT can be applied to...
Ultraluminous X-ray sources are the X-ray binaries with X-ray luminosity exceeding the Eddington limit of a 10 solar mass black hole. Recent consensus is that these sources are powered mainly by super-Eddington accretion onto stellar-mass compact objects. An increasing number of discovered pulsating ULXs further advocate a possible scenario that neutron stars dominate a significant fraction of...
The large-scale structures such as Fermi Bubbles and eROSITA Bubbles provide a unique opportunity to study our Milky Way. However, the nature and origin of these large structures are still under debate. In this talk, I will present the identification of several kpc-scale magnetised structures based on their polarized radio emission and their gamma-ray counterparts, which can be interpreted as...
Observations and numerical simulations indicate that non-homogeneous magnetic fields are ubiquitous in astrophysical settings. However, in most models of astrophysical non-thermal radiation they are not treated as non-homogeneous. Here we present our analysis of non-homogeneous magnetic field of radio supernovae. Flat topped radio spectra around synchrotron self-absorption frequency points to...
The INTEGRAL hard X-ray surveys have proven to be of fundamental importance. In more than twenty years of operation, the INTEGRAL observatory has given us a sharper view of the hard X-ray sky, and provided the triggers for many follow-up campaigns from radio frequencies to gamma-rays. In addition to conducting a census of hard X-ray sources across the entire sky, INTEGRAL has carried out...
Stochastic (i.e. the achromatic component of timing noise unrelated to interstellar propagation) and secular variations in the spin frequency $\nu$ of a rotation-powered pulsar complicate the interpretation of the measured second derivative of the spin frequency $\ddot{\nu}$, and hence the braking index, $n$, in terms of a power-law spin-down torque $\propto \nu^{n_{\rm pl}}$. Both...
