高能天体物理现象

Even though the prompt emission of gamma-ray bursts (GRBs) is highly beamed, high-latitude emission still produces a distinct light curve break after the intrinsic emission ceases and the edge of the jet comes into view. This curvature…

Magnetars are among the most extreme laboratories in the universe, harboring surface magnetic fields reaching $10^{15}$~G. At these supercritical scales, Maxwell's linear electrodynamics is superseded by Nonlinear Electrodynamics (NLED).…

We present near-infrared (NIR) and optical observations of the highly reddened and moderately energetic Type Ib supernova (SN) 2023dbc, {\bf covering a period from} 2 to 136 days after the explosion. By comparing its color {\bf evolution},…

During the propagation of cosmic rays in the solar system, the Sun will block those particles and form a shadow whose position and depth are very important probe of the magnetic fields in the Sun's corona, in the interplanetary space, and…

We detail the spectral analysis of a 170 ks XRISM Resolve observation of the core of Cygnus A. The high spectral resolution of Resolve have enabled us to probe the inner accretion region of Cygnus A by analyzing the 6.4 keV Fe K$\alpha$…

We investigate how cosmic ray (CR) transport in molecular clouds and their substructures can be probed using multi-wavelength observations. The detailed microphysics regulating the penetration and coupling of CRs in dense molecular…

Accreting millisecond X-ray pulsars (AMXPs) are transient X-ray sources likely to be in the final evolutionary phases of low-mass X-ray binaries (LMXBs). In this work, we have investigated the torque and X-ray luminosity variations of five…

We present VLA observations of 16 Type IIn and Type II-L supernovae (SNe IIn and SNe II-L) at ~1000--7000 days after explosion, probing circumstellar matter (CSM) at distances >10^16 cm from the progenitor corresponding to mass-loss over…

Gravitational-wave observations are playing an instrumental role in understanding the population of binary compact objects in the Universe. These observations have begun to hint at the mass distribution of binary black holes (BBHs), with…

We present late-time ($\delta t > 3000$ d) optical (Keck), X-ray (Chandra and NuSTAR), and radio (VLA, ALMA, and the uGMRT) observations of the Type Ic-BL SN 2012ap. Previous studies of this SN suggested that it stands out as a key example…

Wide-angle outflows, or winds, are associated with a broad range of astrophysical systems, including protostars, massive stars, X-ray binaries, tidal disruption events (TDEs), luminous fast blue optical transients (LFBOTs), and starburst…

Stars in the initial and carbon-oxygen core mass ranges of $\sim140-260$ and $50-130$ M$_\odot$, respectively, with low metallicity are predicted to experience copious electron-positron pair production in their cores, leading to a runaway…

GW231123 is a short, massive binary-black-hole event whose source properties show strong waveform dependence. We use this event to test gravitational-wave polarization birefringence, modeled as a frequency-dependent rotation of the…

Gravitational waves (GWs) from distant sources such as inspiralling and merging stellar-mass compact binaries, intermediate-mass and supermassive-binary-black-hole can be gravitationally lensed by intervening objects, ranging from stars and…

We present a multi-wavelength analysis of the nearby millisecond pulsar PSR J0437--4715, combining Hubble Space Telescope (HST) far-ultraviolet, ROSAT soft X-ray, and XMM-Newton X-ray data, to model its broadband emission and…

Gamma-ray bursts (GRBs) are the most energetic bursts of light in our universe, and rapid progenitor association of these events can lead to targeted and optimized follow-up observations, ultimately providing better insights about the…

We propose that changing-look AGN transitions arise from variations in the size of the inner ADAF disk. The AGN accretion disk consists of an outer thin disk and an inner thick ADAF component, whose size is intrinsically unstable and…

Microquasars such as SS 433 are considered potential contributors to cosmic rays up to the knee of the cosmic ray energy spectrum ($\sim4\,\mathrm{PeV}$), where a transition in the dominant acceleration processes is expected. The SS 433…

Type Ia supernovae (SNe), thermonuclear explosions of white dwarfs in binary systems, are widely used as standard candles owing to the empirical width-luminosity relation of their light curves. Recent theoretical and observational studies…

We present the distribution of the intrinsic duration of gamma-ray bursts' prompt emission. This expands upon the analysis of Bromberg et al., 2012 and Bromberg et al. 2013 who showed evidence for collapsar progenitors based on the presence…