The study of the spectral energy distribution (SED) of active galactic nuclei (AGN) plays an important role in several aspects of the evolution of the galaxy. In this work, we model the black hole (BH) accretion flow for a wide range of BH mass and accretion rate. The accretion flow is divided into two regimes based on the Eddington-normalized accretion rate value - the ADAFs for low accretion ...
The discovery of neutrino oscillation established a non-zero mass of neutrino. The origin of neutrino and its non-zero mass is an one of the most important experimental clues to the new physics beyond the standard model. Neutrinos are ubiquitous in the universe, accompanying most of the weak-interacting physics processes. I shall review natural and artificial sources of neutrinos with an emph...
Being the first spectral line of HI, Lyman-alpha permeates the cosmic web in emission. It has been largely used to study the close environment of galaxies and QSOs (Lyman-alpha blobs/nebulae); but being a resonant line it should scatter through the intergalactic medium. This should make Lyman-alpha an interesting candidate for Intensity Mapping (IM): the study of large-scale by integrating the ...
Weak G-band stars, or carbon-deficient red giants (CDGs), characterised by weak or absent G-band absorption of the CH molecule driven by low carbon abundances, have remained mysterious for decades. Here, we present a significant increase in the known CDG population identified through systematic spectroscopic surveys. This expanded sample confirms their rarity (
Circumstellar disks as young as 0.5 Myr bear gaps and rings as tentative planet signposts, which aligns with accumulating evidence of early planet formation. However, such young disks are poorly understood both observationally and theoretically. They are likely affected by the star formation environment becoming warped or eccentric. The disk flow can become peculiar, and various instabilities f...