Search Publications
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…
Observations of AR Sco with Chandra and AstroSat soft X-ray telescope
Singh, K. P.; Buckley, D. A. H.; Rana, V. +6 more
We present our AstroSat soft X-ray observations of a compact binary system, AR Sco, and analysis of its X-ray observations with Chandra that were taken only about a week before the AstroSat observations. An analysis of the soft X-ray (0.3–2.0 keV) data limits the modulation of the spin, orbital, or beat periods to less than 0.03 counts s
Study of Galactic structure using UVIT/AstroSat star counts
Pradhan, Ananta C.; Ghosh, S. K.; Piridi, Sonika +3 more
The structure of our Galaxy has been studied from ultraviolet (UV) star counts obtained with the Ultra-Violet Imaging Telescope (UVIT) on board the AstroSat satellite, in Far-UV (FUV) and Near-UV (NUV) bands. The F154W (BaF2) and N263M (NUVB4) filters were used in the FUV and NUV bands, respectively. The point sources are separated from…
UV photometry of spotted stars in the horizontal branch of the globular cluster NGC 2808 using AstroSat
Sahu, Snehalata; Subramaniam, Annapurni; Prabhu, Deepthi S.
A recent study of hot (20,000 to 30,000 K) extreme horizontal branch (EHB) stars in globular clusters (GCs) has led to the discovery of their variability. It is suggested that this variability is driven by the projected rotation of magnetic spots on the stellar surfaces and is expected to have higher amplitudes at shorter wavelengths. Here, we pre…