高能天体物理现象

High-resolution X-ray spectroscopy with XRISM gives an unprecedented view of the ``central engine'' in active galactic nuclei, providing unique insights into black hole accretion and feedback. We present an analysis of the first…

In recent years, astrophysical observations have placed tight constraints on key properties of the nuclear equation of state (EoS). Using 45 two-dimensional simulations for three different EoS compatible with the current tight constraints,…

The disks of Active Galactic Nuclei (AGN) have in recent years been recognized as possible sites for gravitational wave sources, leading to a series of numerical studies on the evolution of disk-embedded black hole binaries. The majority of…

The Pierre Auger and Telescope Array joint Working Group on the UHECR energy spectrum was established in 2012 to analyze energy scale uncertainties in both experiments and to in vestigate their systematic differences, particularly in the…

This study presents an X-ray spectropolarimetric characterisation of the Z-source GX 340+0 during the normal branch (NB) and compares it with that obtained for the horizontal branch (HB), using IXPE, NICER and NuSTAR observations. The…

The association between long gamma-ray bursts (LGRBs) and core-collapse supernovae (SNe) has been well established since the discovery of SN 1998bw, which was linked to the low-luminosity LGRB 980425. However, long-term monitoring of…

The fundamental nature of dark matter (DM) remains unknown, with significant uncertainties in its density profile. DM environments surrounding massive binary black holes (BBHs) modify their orbital dynamics, thereby altering gravitational…

We present a search for spatio-temporal clusters in 16 years of Fermi-LAT very-high-energy (VHE; $E>100$~GeV) data using the DBSCAN algorithm, focusing on high Galactic latitude ($|b|>10^{\circ}$) clusters with $\geq5$ events and transient…

Fast X-ray transients (FXRTs) are short-lived X-ray outbursts with diverse progenitor scenarios, including compact object mergers, stellar core-collapses and tidal disruption events. The Einstein Probe (EP) has enabled the rapid discovery…

Astrophysical transients can be powered by a broad range of energy sources including shock-heating (internal and external shocks), decay of radioactive isotopes, and long-lived central engines (magnetar and fallback). The dominant energy…

The origin of TeV-PeV neutrinos detected by IceCube remains largely unknown. The most significant individual neutrino source is the close-by Seyfert galaxy NGC 1068 at 4.2$\sigma$ level with a soft spectral index. Another notable candidate…

Time series analysis is fundamental to characterizing the variability inherent in multi-wavelength emissions from blazars. However, a major observational challenge lies in the need for well-sampled, temporally uniform data, which is often…

The $^{63}$Ga(p,$\gamma$)$^{64}$Ge and $^{64}$Ge(p,$\gamma$)$^{65}$As thermonuclear reactions connect the ZnGa and GeAs cycles by diverting the flow of the rapid proton capture process from $^{63}$Ga to $^{65}$As. Changes in these two…

Powerful ionized accretion disk winds are often observed during episodic outbursts in Galactic black hole transients. Among those X-ray absorbers, \fexxvi\ doublet structure (Ly$\alpha_1$+Ly$\alpha_2$ with $\sim 20$eV apart) has a unique…

In the vicinity of neutron star mergers (NSMs), it is possible for the neutrino self-interaction potential to cancel with the matter potential leading to matter neutrino resonance (MNR). MNR is one of the most interesting mechanisms by…

In this thesis, we introduce novel methods for analyzing pulsar populations using a variety of mathematical techniques. These tools-particularly graph theory-have been thoroughly validated in advanced mathematics, enabling us to overcome…

Dipping neutron star low-mass X-ray binaries (NS LMXBs) are systems that exhibit periodic drops in their X-ray light curves. These are believed to be caused by material at the impact point of the gas stream onto the accretion disk, the…

Eighteen years after their discovery, the astronomical sources and radiation mechanisms of fast radio bursts remain mysterious. Their radiation is as bright as that of pulsars, with brightness temperatures as high as $\sim 10^{36}$ K,…

Nova Scorpii 2023 was first detected as a luminous supersoft X-ray source (SSS) 93 days after outburst and continued emitting soft X-rays for over two months, until it was too close to the Sun to observe. The nova was monitored with the…

Relativistic macroscopic plasma dynamics can be described by general-relativistic magnetohydrodynamics. In many high-energy astrophysical settings, such as the interior dynamics of magnetized stars, the ideal GRMHD approximation, in which…