# On the possibility of observable signatures of $ \mu p $ and $ (\mu ^4\mathrm{He})^{+} $ lines on the spectra of astrophysical sources

## TL;DR

This paper investigates the potential for detecting muonic hydrogen and helium ion spectral lines as observable signatures in astrophysical sources, considering luminescence processes induced by X-ray backgrounds.

## Contribution

It introduces a model for muonic atom luminescence in astrophysical environments and evaluates the detectability of their spectral lines.

## Key findings

- Luminescent lines can be prominent in astrophysical spectra.
- Luminescence intensity depends on quantum yield and background radiation.
- Detectability varies with different pumping mechanisms.

## Abstract

We examine the processes of the luminescence in subordinate lines of muonic hydrogen $ \mu p $ and muonic helium ion $ (\mu ^4\mathrm{He})^{+} $ in the presence of background source of X-ray emission. It is supposed that a certain amount of muonic atoms existing in the vicinity of astrophysical source reemits absorbed radiation in the subordinate lines. The intensity of luminescence of such a process is proportional to the quantum yield which was calculated for different pumping channels and different models of spectra. It is shown that the luminescent lines of muonic hydrogen and muonic helium ion can be very noticeable in the spectrum of background source.