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arXiv · 1405.7758

The Brightest Cluster Galaxy in Abell 85: The Largest Core Known so far

O. López-Cruz·C. Añorve·M. Birkinshaw·D. M. Worrall·H. J. Ibarra-Medel·W. A. Barkhouse·J. P. Torres-Papaqui·V. Motta
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Abstract

We have found that the brightest cluster galaxy (BCG) in Abell~85, Holm 15A, displays the largest core so far known. Its cusp radius, $r_γ = 4.57 \pm 0.06$ kpc ($4.26^{\prime\prime}\pm 0.06^{\prime\prime}$), is more than 18 times larger than the mean for BCGs, and $\geq1$ kpc larger than A2261-BCG, hitherto the largest-cored BCG (Postman, Lauer, Donahue, et al. 2012) Holm 15A hosts the luminous amorphous radio source 0039-095B and has the optical signature of a LINER. Scaling laws indicate that this core could host a supermassive black hole (SMBH) of mass $M_{\bullet}\thicksim (10^{9}-10^{11})\,M_{\odot}$. We suggest that cores this large represent a relatively short phase in the evolution of BCGs, whereas the masses of their associated SBMH might be set by initial conditions.

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O. López-Cruz, C. Añorve, M. Birkinshaw, D. M. Worrall, H. J. Ibarra-Medel, W. A. Barkhouse, J. P. Torres-Papaqui, V. Motta. 2014-10-15. The Brightest Cluster Galaxy in Abell 85: The Largest Core Known so far. https://doi.org/10.1088/2041-8205%2F795%2F2%2Fl31

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