Blazars

Study of optical properties of super-massive black-hole can provide a clue to emission mechanism from its close vicinity

Context

Through 153 nights, 17 scientists from 9 countries in Europe and Asia including researchers from Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, an autonomous institution of the Department of Science and Technology (DST), Government of India took 2263 image frames and observed the changes in a very high energy gamma-ray emitting blazar ‘1ES 0806+524’ using seven optical telescopes in Europe and Asia.

Blazar

A blazar is a feeding super-massive black-hole (SMBH) in the heart of a distant galaxy that produces a high-energy jet viewed face-on from Earth. Blazars are one of the most luminous and energetic objects in the known universe with a jet composed of ionized matter traveling at nearly the speed of light directed very nearly towards an observer.
Blazars are among one of the most favourite astronomical transient objects because they emit radiation in the complete EM spectrum, and their flux and polarization are highly variable.

Study

The team studied in great detail 1ES 0806+524’ flux, colour, and spectral index variations within a day and long timescales of the blazer and explained the mechanism behind the variations.
They explained the large flares as the result of the propagation of a shock in the relativistic jet that accelerates electrons to high energies followed by subsequent cooling.
According to their study, the small amplitude changes can be understood to arise from small variations in the viewing angle, and hence in the Doppler factor, caused by either wiggling or helical jets or the motion of the most intense emitting region on a roughly helical trajectory within the jet.
Variations on intra-day timescales can be explained by the turbulence expected in a relativistic plasma jet according to the study.
In this age of multi-wavelength (MW) time-domain astronomy in which transient astronomical sources are of great interest due to their rapid change in flux and polarization.
Simultaneous MW observation of a particular transient source over an extended period of time is important for understanding the emission mechanism in different electromagnetic (EM) bands.

Source: PIB

Join Our Telegram

Same-sex Marriage under the Special Marriage Act, 1954

Same-sex Marriage under the Special Marriage Act, 1954

03 Dec, 22
SHARE

Same-sex Marriage under the Special Marriage Act, 1954 In response to a petition filed by two gay couples seeking recognition of same-sex marriage under the Special Marriage Act of 1954, the Supreme Court has served notice to the Indian Government and Attorney General. A two-judge panel led by Chief Justice of India D Y Chandrachud issued t

Periodic Labour Force Survey 2022

03 Dec, 22
SHARE

Periodic Labour Force Survey 2022 The Periodic Labour Force Survey (PLFS) was just released by the National Statistical Office (NSO). In metropolitan areas, the unemployment rate decreased from 9.8% in July-September 2021 to 7.2% in July-September 2022. What are the main conclusions of the PLFS (July–September 2022)? Unemp

CITES COP19

02 Dec, 22
SHARE

CITES COP19 The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is holding its 19th Conference of the Parties (CoP19) meeting in Panama City. A second name for CoP19 is the World Wildlife Conference. What were the Conference's High Points? 52 suggestions that would change the laws gover

Prevention of Cruelty to Animal Act

02 Dec, 22
SHARE

Prevention of Cruelty to Animal Act The Union Government recently proposed 61 amendments to the Prevention of Cruelty to Animals Act 1960. More on the news The Ministry of Fisheries, Animal Husbandry, and Dairy has prepared the draught Prevention of Cruelty to Animals Act, (Amendment) Bill-2022. The following are the draft's ke

Dispute on the Assam-Meghalaya Border

02 Dec, 22
SHARE

Dispute on the Assam-Meghalaya Border The killing of six people in an Assam police shooting comes ahead of the second phase of talks between the two states to resolve their boundary dispute, and there are fears that it will cast a long shadow over the talks. Background During the British colonial era, undivided Assam included moder