Generalized Two-component Flow solution of Chakrabarti and his collaborators (1990-2013) describing accretion processes around a stellar mass black hole.
The Department of Astrophysics and Cosmology pursues theoretical, observational and experimental research works on modern topics of astronomy, astrophysics, space science and cosmology.
In Astrophysics, the major thrust continues to be the physics of accretion processes on black holes in galactic and extra-galactic systems and properties of emitted radiations from accretion disk around black holes. In ionospheric research, the propagation of radio waves in the earth-ionosphere wave-guide is pursued. In Cosmology, the work on primordial black holes, gravitational lensing, dark matter and dark energy are being pursued. There is an ongoing DST Project on Quantum Information Science.
In observational and experimental astronomy, works are being pursued to understand some of the outstanding problems on extra-solar planets, brown dwarfs, stellar evolution, binary stars, variable stars, formation of complex molecules in variety of astrophysical sources, study of various physical parameters by simulating dense interstellar medium in the laboratory.
Some departmental members are collaborating with members of the Indian Centre for Space Physics (ICSP) for RXTE/NASA data analysis, VLF observations, balloon borne experiments and Astrochemistry/Astrobiology related work; Physical Research Laboratory (PRL), Indian Institute of Astrophysics (IIA), and Aryabhatta Research Institute of Observational Sciences (ARIES) for observational studies.
Left: Optical colour composite image of NGC 2282 (blue: 5007Å (OIII); green: 6563Å (Hα); red: 6724Å [S II]) obtained using 2-m Himalaya Chandra Telescope. The cluster centre is marked with red cross. Right: Near-IR colour composite image of NGC 2282 (blue: K band; green: 3.6 μm; red: 4.5 μm). All the spectroscopically studied objects are numbered with black circles (Duttta, S. et al., 2015, MNRAS, 454, 3597).
Best-fit CLOUDY photoionization model spectra (grey line) plotted over the quiescence phase spectra (black line) of the recurrent nova RS Ophiuchi observed on 2007 April 26. Few of the strong features have been marked. The model spectrum was obtained by adding contributions from a white dwarf (T=104.2 K), an accretion disk (semi height = 108 cm) and secondary red giant of spectral type M2 III (Mondal A. et al., 2017, MNRAS (under revision)).
Astrophysics laboratory – meant to simulate dense interstellar medium which is believed to be the birth place of stars like sun. The setup consists of a Ultra High Vacuum experimental chamber which routinely reaches a base pressure of 2 × 10-10 Torr. The experimental chamber is equipped with a residual mass analyzer, two number of all-metal leak valves. An Olivine sample cooled to ~ 6 K, with more than 90 % forsterite content to simulate interstellar dust grain is currently used.
Setting up of our first astronomical observatory: We are in the process to install our centre’s first astronomical observatory. In phase-I few small size (0.7 m) telescopes will be installed on the top of Panchet hill, Purulia district, about 200 km away from Kolkata. This facility will be dedicated to detect the extra-solar planets by transit method.
In phase-II, a larger sized telescope (2 m class) will be installed at a suitable site. This larger aperture telescope will be used for multi-wavelength (optical and infrared) observations of different kinds of astronomical objects.
Astronomical Instrumentation Laboratory: will be used to build astronomical instruments for the upcoming telescopes. It will also be used as data-acquisition and data-analysis centre.