Hubble Sees Active Spiral Galaxy: NGC 7172

In this image, the NASA/ESA Hubble Space Telescope has captured the brilliance of the spiral galaxy NGC 7172.

This Hubble image shows NGC 7172, an active spiral galaxy some 110.5 million light-years away in the constellation of Piscis Austrinus. Image credit: NASA / ESA / Hubble / D.J. Rosario / A. Barth / L. Shatz.

NGC 7172 is located approximately 110.5 million light-years away in the constellation of Piscis Austrinus.

The galaxy was discovered on September 23, 1834 by the English astronomer John Herschel.

Otherwise known as ESO 466-38, IRAS 21591-3206 or LEDA 67874, it has a diameter of 85,000 light-years.

NGC 7172 is a member of the Hickson Compact Group 90, a galaxy group that also includes two elliptical galaxies NGC 7173 and NGC 7176 and the spiral galaxy NGC 7174.

“The lane of dust threading its way across NGC 7172 — which is viewed side-on in this image — is obscuring the luminous heart of the galaxy, making NGC 7172 appear to be nothing more than a normal edge-on spiral galaxy,” Hubble astronomers said.

“When we inspected NGC 7172 across the electromagnetic spectrum they quickly discovered that there was more to it than meets the eye,” they added.

“NGC 7172 is a Seyfert galaxy — a type of galaxy with an intensely luminous active galactic nucleus powered by matter accreting onto a supermassive black hole.”

This new image of NGC 7172 is made up of observations from Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) instruments in the infrared and optical parts of the spectrum.

Three filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter.

“This image combines data from two sets of Hubble observations, both of which were proposed to study nearby active galactic nuclei,” the researchers said.

“The image also combines data from two instruments: ACS and WFC3.