# NGC 6166

NGC 6166
Galaxy NGC 6166
Observation data (J2000 epoch)
Constellation Hercules
Right ascension 16h 28m 38.276s
Declination +39° 33′ 04.97″
Redshift z = −0.030354
(minus sign
indicates blueshift)
Distance 490 Mly
(142 mpc)
Apparent magnitude (V) 12.78 [1]
Absolute magnitude (V) −24.1
Characteristics
Type cD2 pec.
Apparent size (V) 1.9’ x 1.4’
Other designations
UGC 10409 CGCG 2205.6+3107 0504 MCG +07 -34-060 058 265 338
NGC 6166

NGC 6166 is an elliptical galaxy in the Abell 2199 cluster. It lies 490 million light years away in the constellation Hercules. The primary galaxy in the cluster, it is one of the most luminous galaxies known in terms of X-ray emissions.[2]

Close-up of galaxy NGC 6166, by HST (ACS, WFPC2).
Dust lanes at Galaxy NGC 6166 core, by HST (ACS, WFPC2).

## Description

NGC 6166 is a supermassive, type cD galaxy, with several smaller galaxies within its envelope.[3]

Suspected to have formed through a number of galaxy collisions, NGC 6166 has a large number of globular clusters (estimated as between 6,200 and 22,000 in 1996)[4] orbiting the galaxy.[5] A 2016 study, however, gave an even higher number (around 39,000) suggesting also that the halo of this galaxy blends smoothly with the intra-cluster medium[6]

The galaxy harbors a supermassive black hole at its center with a mass of nearly 30 billion ${\displaystyle {\begin{smallmatrix}M_{\odot }\end{smallmatrix}}}$ based on dynamical modelling. [7]

NGC 6166 is known to host an active nucleus, classified as an FR I source, which powers two symmetric parsec-scale radio jets and radio lobes and it is caused by the infall of gas into its center caused by a cooling flow that deposits 200 solar masses of gas every year there.[8]

It has been proposed that a number of O-type stars may be present in the center of NGC 6166[9]