Galaxy formation with BECDM - I. Turbulence and relaxation of idealized haloes

Philip Mocz, Mark Vogelsberger, Victor H. Robles, Jesús Zavala, Michael Boylan-Kolchin, Anastasia Fialkov, Lars Hernquist

Rannsóknarafurð: Framlag til fræðitímaritsGreinritrýni

114 Tilvitnanir (Scopus)


We present a theoretical analysis of some unexplored aspects of relaxed Bose-Einstein condensate dark matter (BECDM) haloes. This type of ultralight bosonic scalar field dark matter is a viable alternative to the standard cold dark matter (CDM) paradigm, as it makes the same large-scale predictions as CDM and potentially overcomes CDM's small-scale problems via a galaxy-scale de Broglie wavelength. We simulate BECDM halo formation through mergers, evolved under the Schrödinger-Poisson equations. The formed haloes consist of a soliton core supported against gravitational collapse by the quantum pressure tensor and an asymptotic r-3 NFW-like profile. We find a fundamental relation of the core-to-halo mass with the dimensionless invariant Θ ≡ |E|/M3/(Gm/h)2 or Mc/M ≃ 2.6Θ1/3, linking the soliton to global halo properties. For r ≥ 3.5 rc core radii, we find equipartition between potential, classical kinetic and quantum gradient energies. The haloes also exhibit a conspicuous turbulent behaviour driven by the continuous reconnection of vortex lines due to wave interference. We analyse the turbulence 1D velocity power spectrum and find a k-1.1 power law. This suggests that the vorticity in BECDM haloes is homogeneous, similar to thermally-driven counterflow BEC systems from condensed matter physics, in contrast to a k-5/3 Kolmogorov power law seen in mechanically-driven quantum systems. The mode where the power spectrum peaks is approximately the soliton width, implying that the soliton-sized granules carry most of the turbulent energy in BECDM haloes.

Upprunalegt tungumálEnska
Síður (frá-til)4559-4570
FræðitímaritMonthly Notices of the Royal Astronomical Society
Númer tölublaðs4
ÚtgáfustaðaÚtgefið - nóv. 2017


Funding Information:
This material is based upon work supported by the National Science Foundation (NSF) Graduate Research Fellowship under grant no. DGE-1144152 (PM). PM is supported in part by the NASA Earth and Space Science Fellowship (NNX12AB23C). VHR is supported by a UC MEXUS-CONACYT fellowship. PM would like to thank Jerry Ostriker, Alma Gonzalez, Luis Urena-Lopez and Mikhail Medvedev for valuable discussions, and Sauro Succi for reading of an earlier version of this manuscript. The computations in this paper were run on the Odyssey cluster supported by the FAS Division of Science, Research Computing Group at Harvard University. MV acknowledges support through an MIT RSC award, the support of the Alfred P. Sloan Foundation and support by NASA ATP grant NNX17AG29G. MBK acknowledges support from the NSF (grant AST-1517226) and from NASA through ATP grant NNX17AG29G and HST theory grants (programmes AR-12836, AR-13888, AR-13896, AR-14282 and AR-14554) awarded by the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. JZ acknowledges support by a Grant of Excellence from the Icelandic Research Fund (grant number 173929-051).

Publisher Copyright:
© 2018 The Author(s).


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