Draco Group - Blog Posts

The Seyfert galaxy NGC 5985 (on the left) contains an Active Galactic Nucleus (AGN).

AGN are so. Amazing.

In the dead center of the galaxy lies a supermassive black hole—and a large amount of other matter spiraling into it, caught in the gravitational well. As matter falls in, it accelerates to relativistic speeds, ripping apart until even atoms are split into plasma, and because plasma is not electrically neutral the metaphorical whirlwind of it generates an extremely strong electromagnetic field.

That field blasts matter away from the black hole in jets. These can be truly enormous. A single jet emanating from the black hole in the monstrous elliptical galaxy M87 is roughly ten times the length of our entire Milky Way Galaxy.

Seyfert galaxies are calmer than that, but the mechanism is the same. Bright, powerful AGN tend to be found in galaxies further from our own, while Seyferts dominate the AGN population in our local universe.

At BSU, we've imaged Markarian 421, a type of AGN called a blazar, so-named because the jet is aimed almost directly toward Earth.: "blazing" bright. We're in the process of studying our data, but the eventual goal is to determine limits for the mass of the black hole powering it. The student who spearheaded that research is now pursuing a Ph.D. at Purdue University!

2023 July 1

Three Galaxies in Draco Image Credit & Copyright: David Vernet , Jean-François Bax , Serge Brunier, OCA/C2PU

Explanation: This tantalizing trio of galaxies sometimes called the Draco Group, is located in the northern constellation of (you guessed it) Draco, the Dragon. From left to right are face-on spiral NGC 5985, elliptical galaxy NGC 5982, and edge-on spiral NGC 5981, all found within this single telescopic field of view that spans a little more than the width of the full moon. While the group is far too small to be a galaxy cluster, and has not been catalogued as a compact galaxy group, the three galaxies all do lie roughly 100 million light-years from planet Earth. Not as well known as other tight groupings of galaxies, the contrast in visual appearance still makes this triplet an attractive subject for astroimagers. On close examination with spectrographs, the bright core of striking spiral NGC 5985 shows prominent emission in specific wavelengths of light, prompting astronomers to classify it as a Seyfert, a type of active galaxy. This impressively deep exposure hints at a faint dim halo along with sharp-edged shells surrounding elliptical NGC 5982, evidence of past galactic mergers. It also reveals many even more distant background galaxies.

∞ Source: apod.nasa.gov/apod/ap230701.html