Aspherical ULDM collapse

Autor(en)

Emily Kendall, Mateja Gosenca, Richard Easther

Abstrakt

Ultralight dark matter (ULDM) is an interesting alternative to the cold dark matter (CDM) paradigm. Due to the extremely low mass of the constituent particle (∼10^-22 eV), ULDM can exhibit quantum effects up to kiloparsec scales. In particular, runaway collapse in the centres of ULDM haloes is prevented by quantum pressure, providing a possible resolution to the 'core-cusp problem' of CDM. However, the the detailed relationship between the ULDM core mass and that of the overall halo is poorly understood. We simulate the collapse of both spherical and aspherical isolated ULDM overdensities using AxioNyx, finding that the central cores of collapsed haloes undergo sustained oscillatory behaviour, which affects both their peak density and overall morphology. The asphericity of the post-collapse core fluctuates both quantitatively and qualitatively, with oblate initial overdensities generating cores, which fluctuate between prolate and oblate configurations, and more complicated dynamics arising in triaxial scenarios. Furthermore, the peak central densities are higher in spherical configurations. Consequently, astrophysically realistic haloes may exhibit substantial departures from theoretical core-halo profiles and we would expect a significant variance of the properties of haloes with the same mass.

Organisation(en)

Gravitationsphysik

Externe Organisation(en)

University of Auckland

Journal

Monthly Notices of the Royal Astronomical Society

Band

526

Seiten

1046-1056

Anzahl der Seiten

11

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stad2733

Publikationsdatum

11-2023

Peer-reviewed

Ja

ÖFOS 2012

103036 Theoretische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c1a76daf-ff03-48b3-a0c8-64396d4ab936