Leadership Instincts: Disappearance of Women researchers in Authorship during Pandemic  |  Technology Inceptions: MIT developed a New Successor for Mini Cheetah Robot  |  Science Innovations: IISc team develops novel computational model to predict ‘change blindness’  |  Science Innovations: Immune System Responds Better to Vaccination in Morning Hours  |  Teacher Insights: Training in Childhood Education, New Pedagogy Enabled Innovation in Teaching  |  International Policy: UNESCO Prize for Girls’ and Women’s Education 2021  |  Leadership Instincts: UNESCO Prize for Girls’ and Women’s Education 2021  |  Health Monitor: Intensive therapy better for Cerebral Palsy  |  Parent Interventions: Intensive therapy better for Cerebral Palsy  |  Science Innovations: Intensive therapy better for Cerebral Palsy  |  International Edu News: TutorComp- a new platform for online tutoring in UAE.  |  Higher Studies: IIT Hyderabad Announces 3 New Industry-Oriented BTech Programmes  |  Leadership Instincts: Innovation Hub of IIT Hyderabad and ARAI sign MoU for India Specific AV Tech  |  International Edu News: Nobel Peace Prize Laureates of 20th Century  |  International Edu News: Nobel Peace Prize 2021 for Safeguarding Freedom of Expression  |  
April 20, 2020 Monday 04:30:12 PM IST

Study on gamma-ray flux variability nature on different types of blazars

Science Innovations

Researchers from the Indian Institute of Astrophysics (IIA), Bangalore, an autonomous institute of the Department of Science & Technology, Govt. of India, have conducted the first systematic study on the gamma-ray flux variability nature on different types of blazars. Their study could provide clues to the processes happening close to the black hole, not visible through direct imaging. The research work based on characterizing the flux variability nature on month-like time scales in the high energy gamma-ray (100 MeV to 300 GeV) band for different types of blazars has been published in the journal Astronomy and Astrophysics. The knowledge on the flux variability nature in the high energy gamma-rays on a month like timescales is limited. The results of this work will thus fill the gap on the knowledge of the high energy flux variability nature of blazars.

Blazars are the most luminous and energetic objects in the known universe were found to be emitters of gamma-rays in the 1990s. It is only with the capability of Fermi Gamma-ray space telescope (launched in 2008) to scan the entire sky once in three hours one is able to probe the flux variability characteristics of blazars on a range of time scales. One of the open problems in high energy astrophysics is to localize the site for the production of gamma-rays. Variability studies in the high energy gamma-ray band can help one to locate the high energy emission site and the high energy emission process. Therefore, the variability analysis in the gamma-ray band carried out in this work is significant.

Gamma-ray band is one of the bands of the electromagnetic spectrum on which there is limited knowledge on the flux variability of blazars. But this band needs to be explored as this is the energy range where the high energy emission from blazars peaks. Exploring this band of the electromagnetic spectrum will provide key inputs to constrain the high energy production site as well as the high energy emission processes. This is the key idea behind this work. Several explanations are available in the literature on the cause of the high energy emission in blazars.

With the availability of near-simultaneous data covering the gamma-ray, X-ray, ultra-violet, optical, and infrared bands, the existing notion on high energy emission in blazars is challenged. One of the ways to test the high energy emission in blazars is to look for similarities and differences in the gamma-ray flux variability characteristics of different types of blazars, and this forms the basic idea to carry out this work.


This particular research by IIA researchers characterised the amplitude and time scale of flux variations and then look for similarity and/or differences in the amplitude and time scale between different types of blazars. The reduction of large volumes of data for a large number of sources was accomplished by the use of the High-Performance Computing facility of the Indian Institute of Astrophysics, Bangalore.

The results obtained from this particular piece of work will provide key inputs to the problem of finding the high energy gamma-ray production site in blazars. Thus it will have direct relevance to the enhancement of the knowledge on blazars. The expertise of handling high energy data from celestial sources gained in this work will build capacity to interpret the gamma-ray data that will emerge from India's upcoming facility, the Major Atmospheric Cerenkov Experiment Telescope as well as from any X-ray missions by India in the future.



Comments