Vivek Kumar Jha

Vivek Kumar Jha
Aryabhatta Research Institute of Observational Sciences | ARIES · Department of Astronomy

MSc Physics

About

13
Publications
535
Reads
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4
Citations
Additional affiliations
March 2018 - present
Aryabhatta Research Institute of Observational Sciences
Position
  • Fellow
August 2017 - February 2018
Indian Institute of Astrophysics
Position
  • Research intern
June 2014 - September 2014
University of Delhi
Position
  • Intern
Education
July 2015 - June 2017
Banaras Hindu University
Field of study
  • Space Physics
July 2011 - June 2014
University of Delhi
Field of study
  • Physics

Publications

Publications (13)
Preprint
Full-text available
We present the accretion disk size estimates for a sample of 19 active galactic nuclei (AGN) using the optical , , and band light curves obtained from the Zwicky Transient Facility (ZTF) survey. All the AGN have reliable supermassive black hole (SMBH) mass estimates based on previous reverberation mapping measurements. The multi-band light curves a...
Article
Full-text available
We present a comparative study of the physical properties of a homogeneous sample of 144 Narrow line Seyfert 1 (NLSy1) and 117 Broad-line Seyfert 1 (BLSy1) galaxies. These two samples are in a similar luminosity and redshift range and have optical spectra available in the 16th data release of Sloan Digital Sky Survey (SDSS-DR16) and X-ray spectra i...
Preprint
Full-text available
To quantify the role of radio jets for Intra-Night Optical Variability (INOV) in Radio-Loud Narrow-Line Seyfert 1 (RLNLSy1) galaxies, we report the first systematic comparative INOV study of 23 RLNLSy1 galaxies, with 15 RLNLSy1s having confirmed detection of jets (jetted) and the remaining 8 RLNLSy1s having no detection of jets (non-jetted) based o...
Poster
Full-text available
Despite the discovery of a large number of quasars using all sky surveys, the dynamics of matter in the innermost regions remains poorly understood. The 4DE1 formalism established by Boroson and Greene, 1992, provides a way to understand the physical properties of AGN in a statistical context. Whether the NlSy1 galaxies are a part of this only or f...
Article
In this research, we report the effect of humidity and film thickness on the photoemission, optical and morphological properties of CsI thin films prepared by the thermal evaporation technique. The absolute quantum efficiency of CsI thin films has been obtained by using photoemission measurement in the spectral range of 150 nm–200 nm. The degradati...
Article
To quantify the role of radio jets for Intra-Night Optical Variability (INOV) in Radio-Loud Narrow-Line Seyfert 1 (RLNLSy1) galaxies, we report the first systematic comparative INOV study of 23 RLNLSy1 galaxies, with 15 RLNLSy1s having confirmed detection of jets (jetted) and the remaining 8 RLNLSy1s having no detection of jets (non-jetted) based o...
Poster
Full-text available
An estimate of the size of accretion disks in AGN can be done by making use of continuum reverberation mapping. Recent results have shown that even though the disk sizes inferred from the wavelength-dependent interband reverberation lags follow the standard Shakura Sunyaev (SS) disk model, the magnitude of these lags is larger by a factor of 3-4 ti...
Article
We present the accretion disk size estimates for a sample of 19 active galactic nuclei (AGN) using the optical g, r, and i band light curves obtained from the Zwicky Transient Facility (ZTF) survey. All the AGN have reliable supermassive black hole (SMBH) mass estimates based on previous reverberation mapping measurements. The multi-band light curv...
Preprint
Full-text available
We present a comparative study of the physical properties of a homogeneous sample of 144 Narrow line Seyfert 1 (NLSy1) and 117 Broad-line Seyfert 1 (BLSy1) galaxies. These two samples are in a similar luminosity and redshift range and have optical spectra available in the 16 ℎ data release of Sloan Digital Sky Survey (SDSS-DR16) and X-ray spectra i...
Conference Paper
Full-text available
A comparative study of a representative sample of Broad and Narrow line Seyfert galaxies is presented. These galaxies have been selected from the 16 th data release of the Sloan Digital Sky Survey (SDSS-DR16). Some of the properties derived from single epoch spectrum vary significantly between the two populations. We find that the emission regions...
Article
Full-text available
A comparative study of a representative sample of Broad and Narrow line Seyfert galaxies is presented. These galaxies have been selected from the 16th data release of the Sloan Digital Sky Survey (SDSS-DR16). Some of the properties derived from single epoch spectrum vary significantly between the two populations. We find that the emission regions o...
Poster
Full-text available
With the goal to investigate the nature and structure of the Broad Line Region and to estimate the masses of the central Black Holes in low luminosity AGN, a narrow band Photometric Reverberation Mapping (PRM) campaign has been started using the newly installed telescopes at the Devasthal Observatory. The expected BLR size for such AGN using scalin...

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Projects

Project (1)
Project
The main aim is to understand: (i) BLR geometry of AGN (ii) Impact on the black hole bulge relation (iii) On the size of AGN dust torus (iv) The physics of accretion disk based on accretion disk reverberation mapping. This is the the first such monitoring program of its kind in the country as till now only spectroscopic survey has been done for RM campaigns.