Galactic halo size in the light of recent AMS-02 data
Abstract
Context. The vertical diffusive halo size of the Galaxy, L, is a key parameter for dark matter indirect searches. It can be better determined thanks to recent AMS-02 data.
Aims: We set constraints on L from Be/B and 10Be/Be data, and we performed a consistency check with positron data. We detail the dependence of Be/B and 10Be/Be on L and forecast on which energy range better data would be helpful for future L improvements.
Methods: We used USINE V3.5 for the propagation of nuclei, and e+ were calculated with the pinching method.
Results: The current AMS-02 Be/B (∼3% precision) and ACE-CRIS 10Be/Be (∼10% precision) data bring similar and consistent constraints on L. The AMS-02 Be/B data alone constrain L = 5-2+3 kpc at a 68% confidence level (spanning different benchmark transport configurations), a range for which most models do not overproduce positrons. Future experiments need to deliver percent-level accuracy on 10Be/9Be anywhere below 10 GV to further constrain L.
Conclusions: Forthcoming AMS-02, HELIX, and PAMELA 10Be/9Be results will further test and possibly tighten the limits derived here. Elemental ratios involving radioactive species with different lifetimes (e.g. Al/Mg and Cl/Ar) are also awaited to provide complementary and robuster constraints.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2020
- DOI:
- 10.1051/0004-6361/202038064
- arXiv:
- arXiv:2004.00441
- Bibcode:
- 2020A&A...639A..74W
- Keywords:
-
- astroparticle physics;
- cosmic rays;
- Galaxy: halo;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 15 pages, 10 figures, 6 tables. Additional references and few clarifications (matches A&