Dark Matter searches through cross-correlations of gamma rays with neutral-hydrogen intensity mapping

Elena Pinetti

doi:10.1088/1742-6596/1468/1/012051

Abstract

In this work we derive the first theoretical prediction of the cross-correlation signal between the unresolved gamma-ray background and the 21-cm line originated by the spin-flip transition of neutral hydrogen atoms, by taking as benchmark experiment the space telescope Fermi-LAT for gamma rays and the next-generation radio telescope Square Kilometer Array (SKA) as well as its precursor MeerKAT for the 21-cm emission. The attainable bounds in the dark matter (DM) parameter space are envisioned to be competitive already with the combination Fermi-LAT × MeerKAT, but SKA will allow to go deeper and probe a thermal DM particle up to masses of 130 GeV. A future gamma-ray detector with better angular resolution and larger exposure together with an ungraded radio telescope will have the potentiality to probe a DM candidate with thermal annihilation cross-section and masses up to the TeV scale.

Highlights

This work relates to the synergies across the electromagnetic spectrum for dark matter indirect detection searches and is based on Ref. [1]
The cross-correlation signal has been summed over 12 gamma-ray energy bins from 0.5 GeV to 1 TeV and integrated in two redshift bands, corresponding to low redshift (z < 0.58 for MeerKAT and z < 0.5 for Square Kilometer Array (SKA)) and high redshift (0.4 < z < 1.45 for MeerKAT and 0.35 < z < 3 for SKA)
The dashed curves refer to the astrophysical contributions, the purple solid line shows the signal originated by annihilation events of dark matter (DM) particles with thermal cross-section σv = 3 × 10−26 cm3 s−1 and mass mχ = 100 GeV for the bb channel, the solid black line denotes the total signal due to the sum of all the contributions

Summary

Introduction

This work relates to the synergies across the electromagnetic spectrum for dark matter indirect detection searches and is based on Ref. [1]. 3. Results The cross-correlation signal has been summed over 12 gamma-ray energy bins from 0.5 GeV to 1 TeV and integrated in two redshift bands, corresponding to low redshift (z < 0.58 for MeerKAT and z < 0.5 for SKA) and high redshift (0.4 < z < 1.45 for MeerKAT and 0.35 < z < 3 for SKA).

Results

Conclusion