Probing relativistic jets and high energy emission through Multi-wavelength observation analysis

• Grant number: 15/13933-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2016
• End date: June 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Elisabete Maria de Gouveia Dal Pino
• Grantee: Pankaj Kushwaha
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/10559-5 - Investigation of high energy and plasma astrophysics phenomena: theory, numerical simulations, observations, and instrument development for the Cherenkov Telescope Array (CTA), AP.ESP

Abstract

Astrophysical sources, both galactic and extragalactic that are believed to be powered by black holes are often found to have relativistic jets (e.g., GRS 1915+105, M87,Cen A). These relativistic jets are found to exhibit extreme behavior with a wide rangeof phenomena in energy (e.g. radio to TeV ³-ray emission, M87), time (e.g. variability from minutes to decades, OJ 287) and spatial domains (e.g. highly collimated Mpcscale jets, OJ 287), and at all scales. In the last few decades, signicant progress hasbeen made in understanding of jet launching mechanisms which favors magnetohydrodynamical origins (Begelman 1995) and processes associated with it through observations and numerical simulations/studies (de Gouveia Dal Pino 2005). However, thedetails of jet formation, collimation, propagation and acceleration of particles to relativistic energies remain elusive so far. In a particular subclass of active galactic nuclei(AGNs) called blazars, the observed characteristics are dominated by a relativistic jet, oriented at very small angles (< 15o) to the observer's line of sight. Study of blazarsthus offers a unique sample to probe and understand the enigmatic processes associatedwith jets and its connections with central engine and its environment. Our study aimsto address these issues using multi-wavelength observations and theoretical modelingof broadband spectral energy distributions and light curves. We intend to investigatethe nature and origin of high energy emission (X-rays and gamma-rays) and physical processes governing it via a systematic study of sources that are well observed across theelectromagnetic spectrum. The spectral and temporal modeling of data provides inputsabout the physical conditions (magnetic field, spatial scales, particle energies etc.)within the source/emission-region and thus valuable information for a more realisticnumerical simulation of jets. Further, this two fold strategy has potential to unravelthe physical processes happening within the jet by eliminations and observational con-straints and may provide some novel insights on these processes. Observations in theGeV-TeV range by the upcoming Cerenkov Telescope Array (CTA) and its precursor -the ASTRI CTA Mini-Array will provide crucial tests of our current understanding ofhigh energy emission, matter content of jets, and particle acceleration. This project also foresees the help in the preparation of the Mini-Array and CTA Science case in the framework of relativistic extragalactic sources, as well as the performance of Mount Carlo simulations forthe determination of the best arry congurations. (AU)

Scientific publications

(11)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PAL, MAIN; KUSHWAHA, PANKAJ; DEWANGAN, G. C.; PAWAR, P. K.. Strong Soft X-Ray Excess in 2015 XMM-Newton Observations of BL Lac OJ 287. ASTROPHYSICAL JOURNAL, v. 890, n. 1, FEB 10 2020. (15/13933-0)

GUPTA, ALOK C.; MANGALAM, ARUN; WIITA, PAUL J.; KUSHWAHA, P.; GAUR, H.; ZHANG, H.; GU, M. F.; LIAO, M.; DEWANGAN, G. C.; HO, L. C.; et al. A peculiar multiwavelength flare in the blazar 3C 454.3. Monthly Notices of the Royal Astronomical Society, v. 472, n. 1, p. 788-798, NOV 2017. (15/13933-0)

SHAH, ZAHIR; SAHAYANATHAN, S.; MANKUZHIYIL, NIJIL; KUSHWAHA, PANKAJ; MISRA, RANJEEV; IQBAL, NASEER. Clues on high-energy emission mechanism from blazar 3C 454.3 during 2015 August flare. Monthly Notices of the Royal Astronomical Society, v. 470, n. 3, p. 3283-3299, SEP 2017. (15/13933-0)

KUSHWAHA, PANKAJ; GUPTA, ALOK C.; WIITA, PAUL J.; PAL, MAIN; GAUR, HARITMA; DE GOUVEIA DAL PINO, E. M.; KURTANIDZE, O. M.; SEMKOV, E.; DAMLJANOVIC, G.; HU, S. M.; et al. The ever-surprising blazar OJ 287: multiwavelength study and appearance of a new component in X-rays. Monthly Notices of the Royal Astronomical Society, v. 479, n. 2, p. 1672-1684, SEP 2018. (13/10559-5, 15/13933-0)

RODRIGUEZ-RAMIREZ, J. C.; KUSHWAHA, P.; DE GOUVEIA DAL PINO, E. M.; SANTOS-LIMA, R.. A hadronic emission model for black hole-disc impacts in the blazar OJ 287. Monthly Notices of the Royal Astronomical Society, v. 498, n. 4, p. 5424-5436, NOV 2020. (13/10559-5, 15/13933-0, 17/12188-5)

KUSHWAHA, PANKAJ. A Multi-Wavelength View of OJ 287 Activity in 2015-2017: Implications of Spectral Changes on Central-Engine Models and MeV-GeV Emission Mechanism. GALAXIES, v. 8, n. 1, MAR 2020. (15/13933-0)

GUPTA, ALOK C.; TRIPATHI, ASHUTOSH; WIITA, PAUL J.; KUSHWAHA, PANKAJ; ZHANG, ZHONGLI; BAMBI, COSIMO. Detection of a quasi-periodic oscillation in gamma-ray light curve of the high-redshift blazar B2 1520+31. Monthly Notices of the Royal Astronomical Society, v. 484, n. 4, p. 5785-5790, APR 2019. (15/13933-0)

GUPTA, ALOK C.; GAUR, HARITMA; WIITA, PAUL J.; PANDEY, A.; KUSHWAHA, P.; HU, S. M.; KURTANIDZE, O. M.; SEMKOV, E.; DAMLJANOVIC, G.; GOYAL, A.; et al. Characterizing Optical Variability of OJ 287 in 2016-2017. ASTRONOMICAL JOURNAL, v. 157, n. 3, MAR 2019. (15/13933-0)

KUSHWAHA, PANKAJ; GUPTA, ALOK C.; MISRA, RANJEEV; SINGH, K. P.. Multiwavelength temporal variability of the blazar 3C 454.3 during 2014 activity phase. Monthly Notices of the Royal Astronomical Society, v. 464, n. 2, p. 2046-2052, JAN 2017. (15/13933-0)

KUSHWAHA, PANKAJ; SINHA, ATREYEE; MISRA, RANJEEV; SINGH, K. P.; DE GOUVEIA DAL PINO, E. M.. Gamma-Ray Flux Distribution and Nonlinear Behavior of Four LAT Bright AGNs. ASTROPHYSICAL JOURNAL, v. 849, n. 2, NOV 10 2017. (13/10559-5, 15/13933-0)

KUSHWAHA, PANKAJ; GUPTA, ALOK C.; WIITA, PAUL J.; GAUR, HARITMA; DE GOUVEIA DAL PINO, E. M.; BHAGWAN, JAI; KURTANIDZE, O. M.; LARIONOV, V. M.; DAMLJANOVIC, G.; UEMURA, M.; et al. Multiwavelength temporal and spectral variability of the blazar OJ 287 during and after the 2015 December flare: a major accretion disc contribution. Monthly Notices of the Royal Astronomical Society, v. 473, n. 1, p. 1145-1156, JAN 2018. (13/10559-5, 15/13933-0)