NGC 6166

{{Infobox galaxy

| name = NGC 6166

| image = File:Monster Galaxies Lose Their Appetite With Age 03.jpg

| caption = NGC 6166 by Spitzer Space Telescope

| epoch = J2000

| type = cD2 pec.

| mass =

| stars =

| ra = {{RA|16|28|38.276}}

| dec = {{DEC|+39|33|04.97}}

| dist_ly = 490 Mly
(142 Mpc)

| z = z = −0.030354
(minus sign
indicates blueshift)

| h_radial_v = −9100 km/s

| appmag_v = 12.78{{Cite web|url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC%20%206166|title=SIMBAD query result}}

| size_v = 1.9’ x 1.4’

| constellation name = Hercules

| absmag_v = −24.1

| names = UGC 10409, PGC 58265, CGCG 2205.6+3107 0504, MCG +07-34-060, 3C 338

}}

File:NGC6166-sm.jpg

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.{{cite journal |last1=Bridges |first1=T.J. |last2=Cater |first2=D |date=April 26, 1996 |title=B-R Colors of Globular Clusters in NGC 6166 (A2199) |journal=The Astrophysical Journal |volume= 281|issue=4 |pages=1290–1296 |arxiv=astro-ph/9604159v1|bibcode = 1996MNRAS.281.1290B |doi=10.1093/mnras/281.4.1290 |doi-access=free |s2cid=119458738 }}

Description

NGC 6166 is a supermassive, type cD galaxy, with several smaller galaxies within its envelope.[http://ned.ipac.caltech.edu/cgi-bin/nph-datasearch?search_type=Note_id&objid=57565&objname=NGC%206166&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1&of=table Notes for object NGC 6166 (NED)]

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) orbiting the galaxy.{{cite journal | bibcode = 1990ApJ...355..410P | title=A globular cluster system surrounding the cD galaxy NGC 6166 | journal=The Astrophysical Journal | volume=355 | page=410 | year=1990 |author1=Pritchet, C. J. |author2=Harris, William E. | doi=10.1086/168774}} 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.

{{cite journal

| volume = 817

| issue = 1

| pages = 17pp

| last1 = Harris

| first1 = William E.

| last2 = Blakeslee

| first2 = John P.

| last3 = Whitmore

| first3 = Bradley C.

| last4 = Gnedin

| first4 = Oleg Y.

| last5 = Geisler

| first5 = Douglas

| last6 = Rothberg

| first6 = Barry

| title = Globular Cluster Systems in Brightest Cluster Galaxies. II. NGC 6166

| journal = The Astrophysical Journal

| year = 2016

|bibcode = 2016ApJ...817...58H

|arxiv = 1511.08493 |doi = 10.3847/0004-637X/817/1/58| s2cid = 118501801

| doi-access = free

}}

Because of that, the galaxy has the richest globular cluster system known.

The galaxy harbors a supermassive black hole at its center with a mass of nearly 30 billion {{Solar mass|link=y}} based on dynamical modelling.

{{cite journal|last1=Magorrian|first1=J.|last2=Tremaine|first2=S.|last3=Richstone|first3=D.|last4=Bender|first4=R.|last5=Bower|first5=G.|last6=Dressler|first6=A.|last7=Faber|first7=S.~M.|last8=Gebhardt|first8=K.|last9=Green|first9=R.|last10=Grillmair|first10=C.|last11=Kormendy|first11=J.|last12=Lauer|first12=T.|title=The Demography of Massive Dark Objects in Galaxy Centers|journal=The Astronomical Journal|date=June 1998|volume=115|issue=6|pages=2285–2305|doi=10.1086/300353|arxiv = astro-ph/9708072 |bibcode = 1998AJ....115.2285M |s2cid=17256372}}

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. These are caused by the infall of gas into its center due to a cooling flow that deposits 200 solar masses of gas every year there.{{cite journal |last1=Di Matteo |first1=Tiziana|author1-link=Tiziana Di Matteo (astrophysicist) |last2=Johnstone |first2=Roderick M |date=March 8, 2001 |title=Accretion onto Nearby Supermassive Black Holes: Chandra Constraints on the Dominant Cluster Galaxy NGC 6166 |journal=The Astrophysical Journal |volume=550 |issue=1 |page=L19 |arxiv= astro-ph/0012194|bibcode = 2001ApJ...550L..19D |doi = 10.1086/319489 |s2cid=15581216 }}

It has been proposed that a number of O-type stars may be present in the center of NGC 6166.{{cite journal

| author=Fisher, David

| author2=Illingworth, Garth

| author3=Franx, Marijn

| title=Kinematics of 13 brightest cluster galaxies

| journal=The Astrophysical Journal Letters

| date=1995

| volume=438

| number=2

| pages=539–562

| bibcode=1995ApJ...438..539F

| doi=10.1086/175100}}{{Cite journal |last1=Bertola |first1=F. |last2=Gregg |first2=M. D. |last3=Gunn |first3=J. E. |last4=Oemler |first4=A., Jr. |date=1986-04-01 |title=The Stellar Population of NGC 6166 |url=https://ui.adsabs.harvard.edu/abs/1986ApJ...303..624B |journal=The Astrophysical Journal |volume=303 |pages=624 |doi=10.1086/164111 |bibcode=1986ApJ...303..624B |issn=0004-637X}}

File:NGC 6166 Wiki ACS 475 814 WFPC2 555.jpg|Close-up of galaxy NGC 6166, by HST (ACS, WFPC2).

File:NGC 6166 Wiki ACS 475 814 WFPC2 555 detal.jpg|Dust lanes at Galaxy NGC 6166 core, by HST (ACS, WFPC2).