NASA's SOFIA instrument observes cool dust around active galactic nuclei

Almost all large galaxies have supermassive black holes at their centers. The supermassive black hole at the center of the Milky Way is relatively quiet, but some galaxies have supermassive black holes that are consuming large amounts of material leading to emissions of huge amounts of energy. These are known as "active galactic nuclei", and the dust typically forms a toroidal structure around the black hole. NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) has discovered some surprising findings about these active galactic nuclei.

The ring of dust surrounding the supermassive black holes are denser than previously thought. The ring shaped structures are about thirty percent smaller than predicted. The peak emissions from the dust in the infrared range of frequencies is at longer wavelengths than estimated. More observations are necessary to check if all the emissions originate from the tori, or there are some previously unknown elements causing the emissions at the active galactic nuclei. The water vapour in the atmosphere absorbs a significant portion of the infrared radiation, but SOFIA is a telescope mounted on a modified Boeing 747SP jet, which flies above 99 percent of the water vapour in the atmosphere.

The Sofia observatory. Image: Nasa.

The Sofia observatory. Image: Nasa.

Lindsay Fuller, graduate student at the University of Texas San Antonio and lead author of the published paper says "Using SOFIA, we were able to obtain the most spatially detailed observations possible at these wavelengths, allowing us to make new discoveries on the characterization of active galactic nuclei dust tori." The research has been published in the Monthly Notices of the Royal Astronomical Society.

Published Date: Jun 14, 2017 09:47 am | Updated Date: Jun 14, 2017 09:47 am

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