Conveners
Short Talks: Session 1
- Shivappa Gudennavar (CHRIST (Deemed to be University), Bengaluru)
Short Talks: Session 2
- Sunder Sahayanathan (Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai)
Astrophysical black holes are remarkably simple objects, described completely by just two parameters – mass and spin. Although it is easy to determine the mass of a black hole from the far-field gravitational influence, the determination of spin is more subtle and it requires one to probe the strong gravity region close to the event horizon where the GR effects are prominent. However, to study...
The source XTE J1859+226 is a black hole X-ray binary, which underwent outburst in 1999-2000. This source serves as a rich astrophysical laboratory to understand the connection between accretion disk and radio jet since it exhibits different types of Low Frequency Quasi Periodic Oscillations (LFQPOs) along with multiple radio flares.
We re-investigate the timing and spectral propertise of...
Giant radio quasars (GRQs) are radio-loud active galactic nuclei (AGN) that propel megaparsec jets with projected linear sizes of more than 0.7 Mpc. We report the discovery of a sample consisting of more than a hundred giant radio quasars at high redshift (z >= 1) through crossmatching the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1). Due to the good sensitivity and high...
Type Ia supernova (SN Ia) arises from the thermonuclear explosion of at least one carbon-oxygen white dwarf in a binary system. The most favored explosion model is the delayed detonation in a Chandrasekhar mas WD (single degenerate scenario). This explosion produces a stratification in the abundance structure of the elements present in the ejecta. The heavier elements, like Ni-56 and Fe, are...
The time-averaged spectrum of Gamma-Ray Burst(GRB) is often well fitted by an empirical smooth broken power-law function term as the Band model. However, the physical interpretation of this Band function is still being debated. Two competitive models are the synchrotron emission from a non-thermal particle distribution accelerated at a shock front (synchrotron shock model) or a...
Be/X-ray binaries (BeXRBs) form a major subclass of high-mass X-ray binaries that consist of a Be star and a compact object. The possible compact objects can be neutron stars, white dwarfs or black holes. However, neutron stars are the most frequently observed companion than other types. We performed a follow-up study (Bhattacharyya et al. 2022) on the recent detection of two X-ray flaring...
The broadband spectral energy distribution (SED) of blazars shows a two-hump structure. Understanding blazar SEDs has become increasingly possible over the last decade due to the capability to acquire near-simultaneous data from low-energy radio to high-energy gamma rays. Though the low energy hump in the broadband SED of blazars is understood to be from synchrotron emission processes, the...
We report the analysis of the Z-track NS-LMXB GX 17+2 using the simultaneous data from the AstroSat (LAXPC/SXT) and NICER mission data. On segmenting the HID into three slices—horizontal branch, hard apex, and normal branch- we investigate the source's variability and spectral state evolution throughout the observation. We performed the timing analysis in all the branches separately to probe...
This study examines the inflows and outflows of stars and gas in double-barred discs. For this, a 3D gravitational model has been set up and studied from the viewpoint of chaotic scattering in open Hamiltonian systems. In the phase space, a bar-driven outflow mechanism has been identified near the primary bar ends and further visualized using Poincaré maps to locate regular or chaotic basins....
Hybrid Morphology Radio Galaxies (HyMoRS) are found to be very rare subclass of radio galaxies. HyMoRS exhibits differing Fanaroff & Riley morphologies (FR I/II) in each of the two lobes. FR-I jets are generally shorter, have a high proportion of entrainment of thermal plasma close to the core region of the galaxy. On the other hand, FR-II radio galaxies are much extended (in the order of...
TCP J18224935-2408280 is a transient discovered by Tadashi Kojima in May 2021 and later classified as a symbiotic star. Our follow-up study shows that the newly discovered symbiotic star (TCP J1822) was undergoing a Z-And type outburst (classical symbiotic outburst). To understand the nature of the outburst, low-resolution spectroscopic observations from HCT were obtained from May 2021 to...
