高能天体物理现象

Gamma-ray bursts are the most luminous electromagnetic events in the universe. Their prompt gamma-ray emission has typical durations between a fraction of a second and several minutes. A rare subset of these events have durations in excess…

In high-energy astrophysics, interpreting observed spectra hinges on understanding the competition between energy gains and radiative losses. To progress along these lines, we report on particle-in-cell simulations of particle acceleration…

Gravitational-wave measurements of the binary black hole population provide insights into the evolution of merging binaries. We explore potential correlation between mass and mass ratio with phenomenological population models where the…

Fast X-ray Transients (FXTs) are short-lived extra-galactic X-ray sources. Recent progress through multi-wavelength follow-up of Einstein Probe discovered FXTs has shown that several are related to collapsars, which can also produce…

A theory of cosmic-ray transport in multi-phase diffusive media is developed, with the specific application to cases in which the cosmic-ray diffusion coefficient has large spatial fluctuations that may be inherently multi-scale. We…

Recently discovered supermassive black holes with masses of $\sim10^8\,M_\odot$ at redshifts $z\sim9$-$11$ in active galactic nuclei (AGN) pose severe challenges to our understanding of supermassive black hole formation. One proposed…

We present ultraviolet (UV) spectroscopic observations covering three distinct accretion states of the low-mass X-ray binary (LMXB) MAXI J1820+070: the luminous hard state, a hard-intermediate state and the soft state. Our observations were…

Fast radio bursts (FRBs) are sufficiently energetic to be detectable from luminosity distances up to at least seven billion parsecs (redshift $z > 1$). Probing the maximum energies and luminosities of FRBs constrains their emission…

We investigate the effect of spin on equal and unequal mass binary neutron star mergers using finite-temperature, composition-dependent Steiner-Fischer-Hempel equation of state with parameter set ``o'' (SFHo), via 3+1 general relativistic…

Using the data from the all-sky survey in soft X-rays performed by the eROSITA telescope onboard the Spectrum-Roentgen-Gamma observatory we identified known radio and $\gamma$-ray pulsars in the eastern half of the sky. As a result, new…

A prominent, 200-pc-scale high-energy nebula surrounding the microquasar V4641~Sgr is the brightest known gamma-ray source in the Southern sky at $E > 100\,\mathrm{TeV}$. In this paper, we develop self-consistent leptonic, hadronic, and…

In the innermost regions of active galactic nuclei, where the accretion disk, corona, and jet processes are closely coupled, X-ray observations offer a direct probe to study the physics of disk-jet coupling and the mechanisms driving…

We present the timing solutions for three radio pulsars discovered with the Green Bank North Celestial Cap (GBNCC) and 350-MHz Green Bank Telescope drift-scan surveys. These pulsars were initially discovered through their single-pulse…

Magnetic field evolution in neutron star cores is not fully understood. We describe the field evolution both for one barotropic fluid as well as two collisionally coupled barotropic fluids with different density profiles using the anelastic…

A recent analysis of pulsar timing data has reported evidence for a massive ($\sim 6 \times 10^7 M_{\odot}$) dark matter subhalo located only $\sim 0.8$ kpc from Earth. This candidate implies an exceptionally large $J$-factor of $\sim…

We present the first X-ray polarimetric measurement of the neutron star low-mass X-ray binary system AX J1745.6-2901 conducted by the Imaging X-ray Polarimetry Explorer (IXPE) satellite. This transient source, located within $ \sim $1.5' of…

Stellar-mass binary black holes (sBBHs) formed in globular clusters (GCs) are promising sources for multiband gravitational wave (GW) observations, particularly with low- and middle-frequency detectors. These sBBHs can retain detectable…

A complete understanding of the cosmic-ray energy spectrum remains a challenge to theory that must be met by comprehensive modeling efforts. One of these is the subject of the present study, namely, an explanation of the recently discovered…

Based on broadband timing analysis of Insight-HXMT and NICER data from the 2019 outburst of the black hole X-ray binary (BHXRB) MAXI J1348-630, we report the detection of the coexistence and competitive interplay between type-C and type-B…

MAXI J1957+032 is an accreting millisecond X-ray pulsar that shows brief, recurrent outbursts in an ultra-compact ~1 h orbit. We characterise the 2025 outburst using X-ray timing and spectroscopy from XMM-Newton and Swift (and a late-time…