Open AccessThe extended Hα‐emitting filaments surrounding NGC 4696, the central galaxy of the Centaurus cluster
Author(s) -
Crawford C. S.,
Hatch N. A.,
Fabian A. C.,
Sanders J. S.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09463.x
Subject(s) - physics , astrophysics , intracluster medium , centaurus a , galaxy cluster , astronomy , ram pressure , cluster (spacecraft) , galaxy , dust lane , brightest cluster galaxy , cooling flow , radio galaxy , star formation , computer science , programming language
We present images of NGC 4696, the central galaxy in the Centaurus cluster, showing the large extent of cool filaments that are bright in Hα line emission. These filaments share the detailed structure of both the central dust lane and the inner regions of the arc‐like plumes seen in soft X‐ray emission. The X‐ray gas is at its coolest and most absorbed in this same region. The smoothness of the features implies that the local environment is not strongly turbulent. We suggest that these filaments are shaped either by confinement due to a strong magnetic field, or by bulk flows within the intracluster medium. We propose that, like similar filamentary systems in the core of clusters, these cooler components have been drawn out of the central galaxy behind buoyant gas bubbles from previous episodes of radio activity. We find a spur of low‐frequency radio emission leading to a region of low X‐ray pressure within the intracluster medium, supporting this interpretation.