Search Publications
A detailed study of dwarf galaxies in the core of the Coma Cluster
Hasan, S. N.; Poloji, Nagamani; Hasan, Priya
In an earlier paper, we determined the morphological types of galaxies in the Coma Cluster using data from the HST/ACS Coma Cluster treasury survey. Of the 132 members, 51 are non-dwarfs and 81 are dwarfs. We define dwarfs to have an absolute luminosity
Detection of polycyclic aromatic hydrocarbons on a sample of comets
Bhardwaj, Anil; Ramachandran, R.; Hill, H. +6 more
We present the spectral properties of a selection of comets from both the Jupiter family and Oort cloud in the ultraviolet (UV) and mid-infrared (IR) wavelength regions. Spectroscopic measurements are retrieved from public archival data of the International Ultraviolet Explorer (IUE) and Hubble Space Observatory (HST) in the near-UV (NUV) and far-…
The central region of the enigmatic Malin 1
Saha, Kanak; Barway, Sudhanshu; Dhiwar, Suraj +2 more
Malin 1, being a class of giant low surface galaxies, continues to surprise us even today. The HST/F814W observation has shown that the central region of Malin 1 is more like a normal SB0/a galaxy, while the rest of the disk has the characteristic of a low surface brightness system. The AstroSat/UVIT observations suggest scattered recent star form…
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…
Planetary nebulae with UVIT: A progress report
Rao, N. Kameswara; Sutaria, F.; Murthy, J. +2 more
The spectral region between 1250–3000
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…
A pair of UV nuclei or a compact star-forming region near the active nucleus in Mrk 766?
Singh, K. P.; Dewangan, G. C.; Deka, P. P. +1 more
We report the discovery of a bright, compact ultraviolet source at a projected separation of 1.1 kpc from the known active galactic nucleus (AGN) in Mrk 766 based on AstroSat/UVIT observations. We perform radial profile analysis and derive the UV flux almost free from the nearby contaminating sources. The new source is about 2.5 and 5.6 times fain…
Study of dynamical status of the globular cluster NGC 1851 using ultraviolet imaging telescope
Yadav, R. K. S.; Sahu, Snehalata; Subramaniam, Annapurni +1 more
We present the study of dynamical status of the globular cluster NGC 1851. A combination of multi-wavelength space and ground-based data sets are used for the present analysis. In order to select the genuine cluster members, we used the astro-photometric data available from HST and GAIA-DR2 catalogs. The BSS radial distribution of the cluster is p…
The horizontal branch morphology of the globular cluster NGC 1261 using AstroSat
Rao, N. Kameswara; Subramaniam, Annapurni; Rani, Sharmila +2 more
We present the results obtained from the UV photometry of the globular cluster NGC 1261 using far-UV (FUV) and near-UV (NUV) images acquired with the Ultraviolet Imaging Telescope (UVIT) on-board the AstroSat satellite. We utilized the UVIT data combined with HST, GAIA, and ground-based optical photometric data to construct the different UV colour…
Gamma-ray emitting narrow-line Seyfert 1 galaxies: Past, present, and future
Paliya, Vaidehi S.
This article reviews our current understanding about