Astronomers report most distant blazar ever observed

Although it may have a difficult designation to remember, PSO J030947.49+271757.31, the most distant blazar observed to date, reveals important details about ancient black holes and places tight constraints on theories of ...

Quasi-periodic variability observed in two blazars

An international team of astronomers reports the detection of quasi-periodic variability in optical and gamma-ray light curves of two blazars, namely 3C 66A and B2 1633+38. The discovery could be helpful in advancing our ...

New extremely X-ray-weak blazar discovered

Astronomers from Italy and Spain have detected a new blazar by analyzing data from two astronomical surveys. The newly found object, designated DESJ014132.4-542749.9, turns out to be an extremely X-ray-weak blazar at high ...

Gamma-ray blazars in the sky

When the supermassive black holes at the center of galaxies accrete material, they can eject powerful jets of charged particles at speeds approaching that of light. These particles in turn emit radiation across the electromagnetic ...

page 1 from 4

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