Search results
Results from the WOW.Com Content Network
The Circinus Galaxy, a Type II Seyfert galaxy. Seyfert galaxies are one of the two largest groups of active galaxies, along with quasar host galaxies. They have quasar-like nuclei (very luminous sources of electromagnetic radiation that are outside of our own galaxy) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, [1] but unlike quasars, their ...
Size (left) and distance (right) of a few well-known galaxies put to scale. There are an estimated 100 billion galaxies in all of the observable universe. [1] On the order of 100,000 galaxies make up the Local Supercluster, and about 51 galaxies are in the Local Group (see list of nearest galaxies for a complete list).
1ES 1927+654 was first cataloged during the Einstein Slew Survey, which aimed to identify X-ray sources in the sky. It was classified as a Seyfert galaxy due to its emission-line features. [15] A dramatic increase in brightness was detected in 2017, with the galaxy brightening by a factor of about 40 in the ultraviolet spectrum.
The most accepted theory for the energy source of Seyfert galaxies is the presence of an accretion disk around a supermassive black hole. The supermassive hole in the nucleus of NGC 7682 is estimated to be 17–62 million (10 7.56 ± 0.33 ) M ☉ . [ 7 ]
It is classified as a Type 2 Seyfert galaxy [4] and was discovered by Francis Leavenworth in 1886. [1] [7] The galactic plane is inclined at an angle of 73°, giving it an oval, nearly edge-on appearance with the major axis aligned along a position angle of 150°. [4] Seyfert galaxies such as NGC 5793 are known to house megamasers.
Seyfert's Sextet is a group of galaxies about 190 million light-years away [2] in the constellation Serpens. The group appears to contain six members, but one of the galaxies, NGC 6027d , is a background object (700 million light years behind the group) and another "galaxy," NGC 6027e , is actually a part of the tail from galaxy NGC 6027 .
This page was last edited on 26 October 2024, at 12:06 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
Members of this class of objects became known as Seyfert galaxies, and they were noted to have a higher than normal surface brightness in their nuclei. NGC 3516 is believed to host a supermassive black hole whose mass is estimated to be (4.27 ± 1.46) × 10 7 M ☉ based on broad emission-line reverberation mapping [ 5 ] or 23 000 000 M ☉ as ...