Study investigates flaring activity of blazar S5 1803+78

Using various space and ground-based observatories, astronomers have inspected flaring activity observed on a blazar known as S5 1803+78. Results of this multi-wavelength study, published April 10 on the arXiv pre-print server, ...

Blazar Ton 599 investigated by Indian astronomers

Using NASA's Fermi spacecraft, researchers from the Indian Institute of Astrophysics in Bangalore, India, have conducted a gamma-ray flux and spectral variability study of a blazar known as Ton 599, during its recent flaring ...

Nature of unknown gamma-ray sources revealed

An international team of astronomers has unveiled the nature of hundreds of gamma-ray emitting sources, discovering that most of them belong to the class of active galaxies known as blazars.

Astronomers monitor nearby blazar Markarian 501

A team of astronomers from Switzerland and Germany has conducted a long-term multi-band photometric monitoring of a nearby blazar known as Markarian 501. The observational campaign delivered essential information regarding ...

Research examines emission from the blazar TXS 0506+056

Using the Very Energetic Radiation Imaging Telescope Array System (VERITAS), an international team of astronomers has conducted long-term observations of a gamma-ray blazar known as TXS 0506+056. Results of the observational ...

Astronomers discover a 'changing-look' blazar

A University of Oklahoma doctoral student, graduate and undergraduate research assistants, and an associate professor in the Homer L. Dodge Department of Physics and Astronomy in the University of Oklahoma College of Arts ...

page 1 from 6

Blazar

A blazar (blazing quasi-stellar object) is a very compact quasar (quasi-stellar object) associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy. Blazars are among the most energetic phenomena in the universe and are an important topic in extragalactic astronomy.

Blazars are members of a larger group of active galaxies that host active galactic nuclei (AGN). A few rare objects may be "intermediate blazars" that appear to have a mixture of properties from both optically violent variable (OVV) quasars and BL Lac objects. The name "blazar" was originally coined in 1978 by astronomer Edward Spiegel to denote the combination of these two classes.

Blazars are AGN with a relativistic jet that is pointing in the general direction of the Earth. We observe "down" the jet, or nearly so, and this accounts for the rapid variability and compact features of both types of blazars. Many blazars have apparent superluminal features within the first few parsecs of their jets, probably due to relativistic shock fronts.

The generally accepted picture is that OVV quasars are intrinsically powerful radio galaxies while BL Lac objects are intrinsically weak radio galaxies. In both cases the host galaxies are giant ellipticals.

Alternative models, for example, gravitational microlensing, may account for a few observations of some blazars which are not consistent with the general properties.

This text uses material from Wikipedia, licensed under CC BY-SA