AGN tagged posts

Mystery resolved: Blackhole Feeding and Feedback at the Center of an Active Galaxy

An international research team has recently observed the Circinus galaxy, which is one of the closest galaxies to the Milky Way, with high enough resolution to gain further insights into the gas flows to and from the black hole at its galactic nucleus.

An international research team led by Takuma Izumi, an assistant professor at the National Astronomical Observatory of Japan, has observed in high resolution (approximately 1 light year) the active galactic nucleus of the Circinus Galaxy — one of the closest major galaxies to the Milky Way. The observation was made possible by the Atacama Large Millimeter/Submillimeter Array (ALMA) astronomical observatory in Chile.

This breakthrough marks the world’s first quantitative measurement at this scale of gas flows and their structures o...

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Astronomers discover a ‘Changing-look’ Blazar

Sloan Digital Sky Survey archival image from March 2004 (top) and the image from the authors' observation campaign of the blazar, B2 1420+32, taken in January 2020 using ASAS-SN (bottom). The blazar brightness increased by a factor of 100.
Sloan Digital Sky Survey archival image from March 2004 (left) and the image from the authors’ observation campaign of the blazar, B2 1420+32, taken in January 2020 using ASAS-SN (right). The blazar brightness increased by a factor of 100.

Astronomers describe a ‘changing-look’ blazar — a powerful active galactic nucleus powered by supermassive blackhole at the center of a galaxy. 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 and Sciences are lead authors on a paper describing a “changing-look” blazar – a powerful active galactic nucleus powered by supermassive blackhole at the center of a galaxy...

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Blazar Variability

An artist’s conception of a blazar, a galay powered by an active nucleus. Blazars are the most common sources detected by NASA’s Fermi gamma-ray spacecraft. Astronomers have modeled the bright, variable emission from the blazar CTA102 between 2013-2017 using data taken from the gamma-ray to radio bands. They are able to explain the multiuwavelegnth variability observed using a geometrical model for the rapidly moving jets. Credit: M. Weiss/CfA

Active galactic nuclei (AGN) are supermassive black holes at the centers of galaxies that are accreting material. These AGN emit jets of charged particles that move at speeds close to that of light, transporting huge amounts of energy away from the central black hole region and radiating across the electromagnetic spectrum...

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Dust Clouds can explain Puzzling features of Active Galactic Nuclei

An artist's impression of what an active galactic nucleus might look like close up. The accretion disk produces the brilliant light in the center. The broad-line region is just above the accretion disk and lost in the glare. Dust clouds are being driven upward by the intense radiation. Credit: Peter Z. Harrington

An artist’s impression of what an active galactic nucleus might look like close up. The accretion disk produces the brilliant light in the center. The broad-line region is just above the accretion disk and lost in the glare. Dust clouds are being driven upward by the intense radiation. Credit: Peter Z. Harrington

Mysterious features seen in light emitted from active galactic nuclei may be due to partial obscuration by dust clouds. Many large galaxies have a bright central region called an active galactic nucleus (AGN), powered by matter spiraling into a supermassive black hole...

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