skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Collisions of dark matter axion stars with astrophysical sources

Abstract

If QCD axions form a large fraction of the total mass of dark matter, then axion stars could be very abundant in galaxies. As a result, collisions with each other, and with other astrophysical bodies, can occur. We calculate the rate and analyze the consequences of three classes of collisions, those occurring between a dilute axion star and: another dilute axion star, an ordinary star, or a neutron star. In all cases we attempt to quantify the most important astrophysical uncertainties; we also pay particular attention to scenarios in which collisions lead to collapse of otherwise stable axion stars, and possible subsequent decay through number changing interactions. Collisions between two axion stars can occur with a high total rate, but the low relative velocity required for collapse to occur leads to a very low total rate of collapses. On the other hand, collisions between an axion star and an ordinary star have a large rate, $$\Gamma_\odot \sim 3000$$ collisions/year/galaxy, and for sufficiently heavy axion stars, it is plausible that most or all such collisions lead to collapse. We identify in this case a parameter space which has a stable region and a region in which collision triggers collapse, which depend on the axion number ($N$) in the axion star, and a ratio of mass to radius cubed characterizing the ordinary star ($$M_s/R_s^3$$). Finally, we revisit the calculation of collision rates between axion stars and neutron stars, improving on previous estimates by taking cylindrical symmetry of the neutron star distribution into account. Finally, collapse and subsequent decay through collision processes, if occurring with a significant rate, can affect dark matter phenomenology and the axion star mass distribution.

Authors:
 [1];  [2];  [2];  [2];  [2]
  1. Univ. of Cincinnati, Cincinnati, OH (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  2. Univ. of Cincinnati, Cincinnati, OH (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1343964
Report Number(s):
FERMILAB-PUB-17-006-T; arXiv:1701.01476
Journal ID: ISSN 1029-8479; 1507976; TRN: US1700532
Grant/Contract Number:
AC02-07CH11359
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2017; Journal Issue: 4; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; cosmology of theories beyond the SM; classical theories of gravity

Citation Formats

Eby, Joshua, Leembruggen, Madelyn, Leeney, Joseph, Suranyi, Peter, and Wijewardhana, L. C. R. Collisions of dark matter axion stars with astrophysical sources. United States: N. p., 2017. Web. doi:10.1007/JHEP04(2017)099.
Eby, Joshua, Leembruggen, Madelyn, Leeney, Joseph, Suranyi, Peter, & Wijewardhana, L. C. R. Collisions of dark matter axion stars with astrophysical sources. United States. doi:10.1007/JHEP04(2017)099.
Eby, Joshua, Leembruggen, Madelyn, Leeney, Joseph, Suranyi, Peter, and Wijewardhana, L. C. R. Tue . "Collisions of dark matter axion stars with astrophysical sources". United States. doi:10.1007/JHEP04(2017)099. https://www.osti.gov/servlets/purl/1343964.
@article{osti_1343964,
title = {Collisions of dark matter axion stars with astrophysical sources},
author = {Eby, Joshua and Leembruggen, Madelyn and Leeney, Joseph and Suranyi, Peter and Wijewardhana, L. C. R.},
abstractNote = {If QCD axions form a large fraction of the total mass of dark matter, then axion stars could be very abundant in galaxies. As a result, collisions with each other, and with other astrophysical bodies, can occur. We calculate the rate and analyze the consequences of three classes of collisions, those occurring between a dilute axion star and: another dilute axion star, an ordinary star, or a neutron star. In all cases we attempt to quantify the most important astrophysical uncertainties; we also pay particular attention to scenarios in which collisions lead to collapse of otherwise stable axion stars, and possible subsequent decay through number changing interactions. Collisions between two axion stars can occur with a high total rate, but the low relative velocity required for collapse to occur leads to a very low total rate of collapses. On the other hand, collisions between an axion star and an ordinary star have a large rate, $\Gamma_\odot \sim 3000$ collisions/year/galaxy, and for sufficiently heavy axion stars, it is plausible that most or all such collisions lead to collapse. We identify in this case a parameter space which has a stable region and a region in which collision triggers collapse, which depend on the axion number ($N$) in the axion star, and a ratio of mass to radius cubed characterizing the ordinary star ($M_s/R_s^3$). Finally, we revisit the calculation of collision rates between axion stars and neutron stars, improving on previous estimates by taking cylindrical symmetry of the neutron star distribution into account. Finally, collapse and subsequent decay through collision processes, if occurring with a significant rate, can affect dark matter phenomenology and the axion star mass distribution.},
doi = {10.1007/JHEP04(2017)099},
journal = {Journal of High Energy Physics (Online)},
number = 4,
volume = 2017,
place = {United States},
year = {Tue Apr 18 00:00:00 EDT 2017},
month = {Tue Apr 18 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 4works
Citation information provided by
Web of Science

Save / Share:
  • This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 μ eV . The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Finally, ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.
  • This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 μ eV . The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Finally, ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.
  • The nature of the cosmic dark matter is unknown. The most compelling hypothesis is that dark matter consists of weakly interacting massive particles (WIMPs) in the 100 GeV mass range. Such particles would annihilate in the galactic halo, producing high-energy gamma rays which might be detectable in gamma ray telescopes such as the GLAST satellite. We investigate the ability of GLAST to distinguish between the WIMP annihilation spectrum and the spectrum of known astrophysical source classes. Focusing on the emission from the galactic satellite halos predicted by the cold dark matter model, we find that the WIMP gamma-ray spectrum ismore » unique; the separation from known source classes can be done in a convincing way. We discuss the follow-up of possible WIMP sources with Imaging Atmospheric Cerenkov Telescopes. Finally we discuss the impact that Large Hadron Collider data might have on the study of galactic dark matter.« less
  • The origin of the cosmic gamma-ray background (CGB) is a longstanding mystery in high-energy astrophysics. Possible candidates include ordinary astrophysical objects such as unresolved blazars, as well as more exotic processes such as dark matter annihilation. While it would be difficult to distinguish them from the mean intensity data alone, one can use anisotropy data instead. We investigate the CGB anisotropy both from unresolved blazars and dark matter annihilation (including contributions from dark matter substructures), and we find that the angular power spectra from these sources are very different. We then focus on detectability of dark matter annihilation signals usingmore » the anisotropy data by treating the unresolved blazar component as a known background. We find that the dark matter signature should be detectable in the angular power spectrum of the CGB from two-year all-sky observations with the Gamma Ray Large Area Space Telescope (GLAST), as long as the dark matter annihilation contributes to a reasonable fraction, e.g., > or approx. 0.3, of the CGB at around 10 GeV. We conclude that the anisotropy measurement of the CGB with GLAST should be a powerful tool for revealing the CGB origin, and potentially for the first detection of dark matter annihilation.« less