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

Grant number: 15/13933-0
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): April 01, 2016
Effective date (End): March 31, 2018
Field of knowledge:Physical Sciences and Mathematics - Astronomy
Principal Investigator:Elisabete Maria de Gouveia Dal Pino
Instituição-sede : 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.TEM


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
(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)
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. Web of Science Citations: 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. Web of Science Citations: 1.

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