Astrophysics Seminars

Accretion-powered X-ray pulsars are neutron stars that accrete matter from a companion star in a binary system, which exhibit fascinating dynamics. The strong magnetic field of the neutron star guides material onto the magnetic poles, which are...

Pulsar timing arrays (PTAs) consist of a set of regularly monitored millisecond pulsars with extremely stable rotational periods. The arrival time of pulses can be altered by the passage of gravitational waves (GWs) between them and the Earth, thus...

Despite the remarkable success of the standard model of cosmology, the lambda CDM model, at predicting the observed structure of the universe over many scales, very little is known about the fundamental nature of its principal constituents: dark...

The albedo of a celestial body is the fraction of incident starlight reflected by it. The study of the albedos of Solar System objects is at least a century old, at least in the Western world. As examples: Bond (1861) speculated on the near-unity...

X-ray binaries are known to exhibit different spectral states which are associated with different black hole accretion modes. In particular the geometry of the hot accretion flow in hard spectral state is still not fully understood. Recent...

Galactic microlensing is the only known method to discover dark objects ranging from isolated stellar-mass black holes (BHs) down to Earth-mass free-floating planets (FFPs). The recent success of interferometric resolution of microlensed images with...

Charge-exchange (CX) collisions of the solar wind (SW) high-ionization-state minor ions with LISM neutrals are responsible for much of X-ray production in the outer heliosphere. In this talk, we discuss numerical modeling of the heliospheric CX X...

Interpreting observations of extreme astrophysical phenomena requires a detailed understanding of particle acceleration in astrophysical environments. These accelerated particles, known as cosmic rays, approximately follow a power-law distribution...

 Gravitational waves have uncovered a treasure trove of nearly 90 merging black holes and neutron stars, each with its own unique story to tell. In this talk, our focus centers on black hole spins, seeking to decipher the secrets hidden within...

I will present a new evidence for dark matter from the measurement of the deceleration of the Galactic bar. Galactic bars are linear structures that form and rotate at the center of galactic disks. In the presence of dark matter haloes, these bars...