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RESEARCH PRODUCT
Can QCD Axion Stars explain Subaru HSC microlensing?
Tsutomu T. YanagidaEnrico D. Schiappacassesubject
Cosmology and Nongalactic Astrophysics (astro-ph.CO)Andromeda GalaxyPhysics::Instrumentation and DetectorsastrofysiikkaDark matterFOS: Physical sciencesPrimordial black holeAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicshiukkasfysiikkaGravitational microlensingkosmologia01 natural sciences114 Physical sciencesGravitationpimeä aineHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciences010306 general physicsAxionAstrophysics::Galaxy AstrophysicsPhysicsQuantum chromodynamics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyHigh Energy Physics - PhenomenologyStarskvanttiväridynamiikkaAstrophysics::Earth and Planetary AstrophysicsAstrophysics - Cosmology and Nongalactic Astrophysicsdescription
A non-negligible fraction of the QCD axion dark matter may form gravitationally bound Bose Einstein condensates, which are commonly known as axion stars or axion clumps. Such astrophysical objects have been recently proposed as the cause for the single candidate event reported by Subaru Hyper Suprime-Cam (HSC) microlensing search in the Andromeda galaxy. Depending on the breaking scale of the Peccei-Quinn symmetry and the details of the dark matter scenario, QCD axion clumps may form via gravitational condensation during radiation domination, in the dense core of axion miniclusters, or within axion minihalos around primordial black holes. We analyze all these scenarios and conclude that the microlensing candidate detected by the Subaru HSC survey is likely not caused by QCD axion stars.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2021-11-16 |