Search Publications
AstroSat view of the NLS1 galaxy Mrk 335
Dewangan, Gulab C.; Misra, Ranjeev; Ezhikode, Savithri H.
We present the results from the multi-wavelength monitoring observations of the Narrow-Line Seyfert 1 galaxy Mrk 335 with AstroSat. We analysed both the X-ray (SXT and LAXPC) and UV (UVIT) data of the source at two epochs, separated by
Exploring sub-MeV sensitivity of AstroSat–CZTI for ON-axis bright sources
Rao, A. R.; Bhalerao, Varun; Mithun, N. P. S. +5 more
The Cadmium–Zinc–Telluride Imager (CZTI) onboard AstroSat is designed for hard X-ray imaging and spectroscopy in the energy range of 20–100 keV. The CZT detectors are of 5-mm thickness and hence have good efficiency for Compton interactions beyond 100 keV. The polarisation analysis using CZTI relies on such Compton events and have been verified ex…
On the unified view of extragalactic sources based on their broadband emission properties
Iyida, E. U.; Eya, I. O.; Odo, F. C.
Our understanding of the unification of jetted active galactic nuclei (AGNs) has advanced greatly as the size of extragalactic sources increased. In this paper, based on the large sample of radio sources, we compiled 680 blazars (279 flat spectrum radio quasars (FSRQs) and 401 BL Lacertae (BL Lacs)) from the 3FGL sample and 64 Seyfert galaxies (3 …
The sharpest ultraviolet view of the star formation in an extreme environment of the nearest Jellyfish Galaxy IC 3418
Hota, Ananda; Devaraj, Ashish; Pradhan, Ananta C. +11 more
We present the far ultraviolet (FUV) imaging of the nearest Jellyfish or Fireball galaxy IC3418/VCC 1217, in the Virgo cluster of galaxies, using Ultraviolet Imaging Telescope (UVIT) onboard the AstroSat satellite. The young star formation observed here in the 17 kpc long turbulent wake of IC3418, due to ram pressure stripping of cold gas surround…
U B V I
Akkaya Oralhan, İnci
Fundamental astrophysical parameters have been derived for Berkeley 55 (Be 55) open cluster based on the UBVI charge-coupled device (CCD) photometric data observed using a AZT-22 1.5 m telescope at Maidanak Astronomical Observatory (MAO) in Uzbekistan. The mean reddening is obtained as
Observations of bright stars with AstroSat soft X-ray telescope
Singh, K. P.; Dewangan, G. C.; Bhattacharyya, S. +5 more
We present observations of four bright stars observed with the AstroSat Soft X-ray Telescope (SXT). Visible light from bright stars like these can leak through the very thin filter in front of the CCD in the focal plane CCD camera of the SXT and thus making the extraction of X-ray events difficult. Here, we show how to extract the X-ray events wit…
Selected phenomena that affect the structure of the cometary landscape
Wesołowski, M.
The paper discusses four processes that may be responsible for shaping the relief of the comet landscape. The considerations take into account the following phenomena: intense sublimation of cometary ice, emission of dust from the surface comet and through jets, migration of dust on the cometary surface, and destruction of fragment the nucleus sur…
UOCS. V. UV study of the old open cluster NGC 188 using AstroSat
Sahu, Snehalata; Subramaniam, Annapurni; Pandey, Sindhu +3 more
We present the UV photometry of the old open cluster NGC188 obtained using images acquired with Ultraviolet Imaging Telescope (UVIT) on board the AstroSat satellite, in two far-UV (FUV) and one near-UV (NUV) filters. UVIT data is utilised in combination with optical photometric data to construct the optical and UV colour-magnitude diagrams (CMDs).…
Planetary nebulae with UVIT: A progress report
Rao, N. Kameswara; Sutaria, F.; Murthy, J. +2 more
The spectral region between 1250–3000
Characterisation of cosmic ray induced noise events in AstroSat-CZT imager
Rao, A. R.; Ratheesh, A.; Mithun, N. P. S. +6 more
The Cadmium Zinc Telluride (CZT) Imager onboard AstroSat consists of pixelated CZT detectors, which are sensitive to hard X-rays above 20 keV. The individual pixels are triggered by ionising events occurring in them, and the detectors operate in a self-triggered mode, recording each event separately with information about its time of incidence, de…