Cosmological structure formation in scalar field dark matter with repulsive self-interaction

Autor(en): Paul R. Shapiro, Taha Dawoodbhoy, Tanja Rindler-Daller
Abstrakt: Scalar field dark matter (SFDM) comprised of ultralight (≳ 10^-22 eV) bosons is an alternative to standard, collisionless cold dark matter (CDM) that is CDM-like on large scales but inhibits small-scale structure formation. As a Bose-Einstein condensate, its free-field ('fuzzy') limit (FDM) suppresses structure below the de Broglie wavelength, λ_deB, creating virialized haloes with central cores of radius ~ λ_deB, surrounded by CDM-like envelopes, and a halo mass function (HMF) with a sharp cut-off on small scales. With a strong enough repulsive self-interaction (SI), structure is inhibited, instead, below the Thomas-Fermi (TF) radius, R_TF (the size of an SI-pressure-supported (n = 1)-polytrope), when R_TF > λ_deB. Previously, we developed tools to describe SFDM dynamics on scales above λ_deB and showed that SFDM-TF haloes formed by Jeans-unstable collapse from non-cosmological initial conditions have R_TF-sized cores, surrounded by CDM-like envelopes. Revisiting SFDM-TF in the cosmological context, we simulate halo formation by cosmological infall and collapse, and derive its transfer function from linear perturbation theory to produce cosmological initial conditions and predict statistical measures of structure formation, such as the HMF. Since FDM and SFDM-TF transfer functions both have small-scale cut-offs, we can align them to let observational constraints on FDM proxy for SFDM-TF, finding FDM with particle masses 1 ≲ m/(10^-22 eV/c²) ≲ 30 corresponds to SFDM-TF with 10 ≳ R_TF/(1 pc) ≳ 1, favouring subgalactic (sub-kpc) core size. The SFDM-TF HMF cuts off gradually, however, leaving more small-mass haloes: Its Jeans mass shrinks so fast that scales filtered early can still recover and grow!
Organisation(en): Institut für Astrophysik
Externe Organisation(en): University of Texas, Austin
Journal: Monthly Notices of the Royal Astronomical Society
Band: 509
Seiten: 145-173
Anzahl der Seiten: 29
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stab2884
Publikationsdatum: 01-2022
Peer-reviewed: Ja
ÖFOS 2012: 103003 Astronomie, 103004 Astrophysik, 103044 Kosmologie
Schlagwörter
Link zum Portal: https://ucrisportal.univie.ac.at/de/publications/2097c775-9bfc-4467-940b-98ff1e54575d

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