Abell 2256

{{Short description|Galaxy cluster in the constellation Ursa Minor}}

{{Infobox galaxy cluster

| name = Abell 2256

| image =

| caption =

| credit =

| epoch = J2000

| constellation = Ursa Minor

| ra = {{RA|17|03|43.5}}{{cite web

| url = http://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Abell+2256&extend=no

| title = NED results for object ABELL 2256

| publisher = NASA/IPAC Extragalactic Database (NED)

| access-date = March 10, 2015

}}

| dec = {{DEC|+78|43|03}}

| brightest_member =

| member_no =

| richness = 1{{cite journal

| last1 = Abell

| first1 = George O.

| author-link1 = George O. Abell

| last2 = Corwin

| first2 = Harold G. Jr.

| author-link2 = Harold G. Corwin

| last3 = Olowin

| first3 = Ronald P.

| author-link3 = Ronald P. Olowin

|date=May 1989

| title = A catalog of rich clusters of galaxies

| journal = Astrophysical Journal Supplement Series

| volume = 70

| issue = May 1989

| pages = 1–138

| issn = 0067-0049

| bibcode = 1989ApJS...70....1A

| doi = 10.1086/191333

| doi-access = free

}}

| velocity_dispersion =

| redshift = 0.058100 (17 418 km/s)

| distance =

| temperature =

| mass =

| luminosity =

| flux =

| other_names =

}}

Abell 2256 is a rich nearby galaxy cluster in the Abell catalogue that exhibits a population of ~ 100 – 200 kpc long steep spectrum synchrotron filaments surrounding the cluster center{{Cite arXiv |eprint = 1102.5539v1|last1 = Clarke|first1 = Tracy E|title = The Curious Case of Abell 2256|last2 = Enßlin|first2 = Torsten|last3 = Finoguenov|first3 = Alexis|last4 = Intema|first4 = Huib|last5 = Pfrommer|first5 = Christoph|author6 = Reinout van Weeren|last7 = Röttgering|first7 = Huub|last8 = Oonk|first8 = Raymond|class = astro-ph.CO|year = 2011}} with significant evidence of merger activity deduced by the presence of two separate X-ray peaks in the X-ray surface brightness distribution.[http://iopscience.iop.org/1538-3881/131/6/2900/fulltext/204934.text.html DEEP 1.4 GHz VERY LARGE ARRAY OBSERVATIONS OF THE RADIO HALO AND RELIC IN ABELL 2256] One feature is a radio 'relic'. The other striking feature in the cluster is a long tail whose morphology suggests it is either a one-sided jet or a twin-tail structure. The bending of the tails takes place very near the galaxy core where one might expect little impact from the galaxy's motion through the intergalactic medium, unless the parent galaxy has undergone extreme stripping.{{Cite journal |arxiv = 1408.5931|last1 = Clarke|first1 = Tracy E|title = Wideband VLA Observations of Abell 2256 I: Continuum, Rotation Measure and Spectral Imaging|journal = The Astrophysical Journal|volume = 794|page = 24|last2 = Enßlin|first2 = Torsten|last3 = Finoguenov|first3 = Alexis|last4 = Intema|first4 = Huib|last5 = Pfrommer|first5 = Christoph|author6 = Reinout van Weeren|last7 = Röttgering|first7 = Huub|last8 = Oonk|first8 = Raymond|year = 2014| issue=1 |doi = 10.1088/0004-637X/794/1/24|bibcode = 2014ApJ...794...24O|s2cid = 117010036}}