Related papers: Thundercloud Project: Exploring high-energy phenom…
A potential difference of 1.3 Giga-Volts (GV) was inferred across a thundercloud using data from the GRAPES-3 muon telescope (G3MT) [1]. This was the first-ever estimation of gigavolt potential in thunderstorms, confirming prediction of…
We present a 5 month NICER X-ray monitoring campaign for two low luminosity active galactic nuclei (LLAGNs) -- NGC 4594 and IC 1459 -- with complementary Swift and NuSTAR observations. Utilizing an absorbed power law and thermal source…
We have estimated fluxes of neutrinos and gamma-rays that are generated from decays of charged and neutral pions from a pulsar surrounded by supernova ejecta in our galaxy, including an effect that has not been taken into consideration,…
Recent observations by the Large Area Telescope (LAT) onboard the Fermi satellite have revealed bright gamma-ray emission from middle-aged supernova remnants (SNRs) inside our Galaxy. These remnants, which also possess bright non-thermal…
Massive stars can explode as supernovae at the end of their life cycle, releasing neutrinos whose total energy reaches $10^{53}$ erg. Moreover, neutrinos play key roles in supernovae, heating and reviving the shock wave as well as cooling…
A large area (0.5~m $\times$ 0.5~m) thermal neutron detector was developed based on 0.32~mm-thick $^{6}$LiF:ZnS(Ag) scintillator sheets. The detector was constructed for measurements of seasonal variations in low intensity thermal neutron…
On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the…
A multi-messenger approach with gravitational-wave transients and high-energy neutrinos is expected to open new perspectives in the study of the most violent astrophysical processes in the Universe. In particular, gamma-ray bursts are of…
GRB 221009A is the brightest Gamma Ray Burst (GRB) ever observed. The observed extremely high flux of high and very-high-energy photons provide a unique opportunity to probe the predicted neutrino counterpart to the electromagnetic…
We report recent results of the CANGAROO Collaboration on very high energy gamma ray emission from pulsars, their nebulae, SNR and AGN in the southern sky. Observations are made in South Australia using the imaging technique of detecting…
The Tunka Radio Extension (Tunka-Rex) is a digital radio array operating in the frequency band of 30-80 MHz and detecting radio emission from air-showers produced by cosmic rays with energies above 100 PeV. The experiment is installed at…
We search for electron anti-neutrinos ($\overline{\nu}_e$) from long and short-duration gamma-ray bursts~(GRBs) using data taken by the KamLAND detector from August 2002 to June 2013. No statistically significant excess over the background…
We report a new scenario of time-of-flight (TOF) technique in which fast neutrons and delayed gamma-ray signals were both recorded in a millisecond time window in harsh environments induced by high-intensity lasers. The delayed gamma…
We introduce the GENJI program (Gamma-ray Emitting Notable AGN Monitoring by Japanese VLBI), which is a monitoring program of gamma-ray bright AGNs with the VERA array (VLBI Exploration of Radio Astrometry). The GENJI programme aims a dense…
A direct detection of gravitational waves is one of the most exciting frontiers for modern astronomy and astrophysics. Gravitational wave signals combined with classical electro-magnetic observations, known as multi-messenger astronomy,…
High-energy photons are a powerful probe for astrophysics and for fundamental physics in extreme conditions. During the recent years, our knowledge of the most violent phenomena in the Universe has impressively progressed thanks to the…
A self-consistent two-dimensional model is proposed to account for the transient mesospheric nighttime optical emissions associated to possible intra-cloud (IC) lightning occurring in the Venusian troposphere. The model calculates the…
We have performed targeted searches of known extragalactic transient events at millimetre wavelengths using nine seasons (2013--2021) of 98, 150, and 229\,GHz Atacama Cosmology Telescope (ACT) observations that mapped ${\sim}40$ per cent of…
The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is designed to record air showers produced by cosmic rays and gamma rays between 100 GeV and 100 TeV. Because of its large field of view and high livetime, HAWC is well-suited…
Young core-collapse supernovae with dense-wind progenitors may be able to accelerate cosmic-ray hadrons beyond the knee of the cosmic-ray spectrum, and this may result in measurable gamma-ray emission. We searched for gamma-ray emission…