Axion Echos from the Supernova Graveyard

Abstract

Stimulated decays of axion dark matter, triggered by a source in the sky, could produce a photon flux along the continuation of the line of sight, pointing backward to the source. The strength of this so-called axion "echo" signal depends on the entire history of the source and could still be strong from sources that are dim today but had a large flux density in the past, such as supernova remnants (SNRs). This echo signal turns out to be most observable in the radio band. We study the sensitivity of radio telescopes such as the Square Kilometer Array (SKA) to echo signals generated by SNRs that have already been observed, and show that SKA could reach axion-photon couplings of order $g_{a\gamma \gamma }\sim \mathcal{O}(10^{-11}){\mathrm{GeV}}^{-1}$ for axion masses $m_a\lesssim 10^{-5}\mathrm{eV}$. In addition, we show projections of the detection reach for signals coming from old SNRs and from newly born supernovae that could be detected in the future. Intriguingly, an observable echo signal could come from old "ghost" SNRs which were very bright in the past but are now so dim that they haven't been observed.

36 pages, 11 figures, matching the published version

References in corpus (7)

• Search for "Invisible" Axion Dark Matter in the $3.3\text{-}4.2\mu$eV Mass Range
• Galactic axions search with a superconducting resonant cavity
• Piezoelectrically Tuned Multimode Cavity Search for Axion Dark Matter
• The Distance to SS433/W50 and its Interaction with the ISM
• The Radio Luminosity-Risetime Function of Core-Collapse Supernovae
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Cited by in corpus (6)

• Detecting Axion Dark Matter with Black Hole Polarimetry
• Warm and Fuzzy Dark Matter: Free Streaming of Wave Dark Matter
• Listening for echo from the stimulated axion decay with the 21 CentiMeter Array
• On the Galactic radio signal from stimulated decay of axion dark matter
• Echoes in multi-ALP scenarios
• Physics beyond the Standard Model with the DSA-2000