DOI: 10.5281/zenodo.16414128
title: Supplementaries - Secondary emission spectra for Heavy WIMPs

description: The uploads contain the following material:





Paper.zip - The figures from the paper are provided here.




Secondary_emission_numeric_data_mass_channel_Einasto_core.zip - The secondary emission (Synchrotron + IC) numeric data in txt. files with Energy axis (in eV) and total flux (in erg/cm2/s) for three WIMP annihilation channels (W, b, and tau) and for the WIMP masses of 1, 10, 100 and 1000 TeV/c2. Two cases of DM density profiles are considered- a cuspy Einasto profile (10pc core radius) and a cored Einasto (1kpc core radius) distribution.


Spatial_flux_bands.zip - The numeric data and figures showing the expected secondary emission fluxes in 1 deg angular bands around the Galactic Centre (up to 7 deg) are provided for all cases of WIMP mass, channel, and density profiles as mentioned in Pt. 2



Total_emission.zip - This includes the numeric data and figures considering both the prompt emission and secondary emission for the different cases as mentioned in Pt. 2. Files named as data_mass_channel_core_radius.




 Single_zone_vs_3D_approach.zip - Shows a comparison of this work with the methodology used in Djuvsland et al. (2023) (single-zone approach). A figure showing the comparison with radio emission expected from near the Galactic Centre is also provided.




Validation_checks.zip - The robustness of this work under different resolutions of the simulation setup is presented by showing the output for 49, 121 (default) and 441 grid points (i.e., number of columns) in X-Y.  A figure shows the fraction of secondary emission luminosity (as high as 45 %) to the total emission (IC+Synchrotron+ prompt emission). With a more realistic 3D spatial modelling approach in the current work, the IC luminosity fraction reduces, but is still significant, as shown with the comparison figures. Furthermore, the secondary radiation output under different scenarios of external radiation and magnetic fields is presented in another figure. Also provided are figures validating the similarity between PPPC and HDM calculation obtained fluxes (considering the single-zone approach). Note that all the remaining results mentioned here use HDM calculations. We considered a cuspy Einasto profile for simulating most of the results.


GC_environment.zip - Includes some example figures showing the magnetic field strength (in micro Gauss) and radiation field (in cm-3 erg-1) distribution across the Z axis for some X-Y positions. These are the field strength values used in the 'simulation columns' for computing IC and Synchrotron radiation. 
description: ###README

The data and figures produced in this study consider the central 2x2x2 kpc3 region of the Galactic Centre, providing fluxes in erg cm-2 s-1 (or TeV cm-2 s-1). The results approximate the the total emission expected from hypothesized WIMP annihilations within a 12 degree angular region centred at the GC (normalization corresponding to a J factor computed with a solid angle extending 12 degrees around the GC). Two cases of Dark Matter density distribution - cuspy and cored Einasto - are implemented.The aim of this study is to highlight the importance of  secondary emission from annihilation-produced direct electrons (electrons+positrons) in indirect WIMP searches, besides the prompt (direct) gamma ray emission. It includes the Synchrotron and inverse Compton emission, taking into account a realistic Galactic Centre environment. The figures (and numeric data) provided for secondary emission show the two Gaussian-like emission phenomena - the one emitting at low energies is dominated by Synchrotron radiation, while the one at high energies is dominated by IC radiation. The total emission includes the prompt gamma ray emission, and it dominates the radiation at the highest energies, acquiring a low energy shoulder from the IC radiation.

The prompt gamma ray photons and direct electrons used in this work are obtained from HDM, which is similar in spirit to the widely used calculations from PPPC4DMID. We use the radiation field and magnetic field models as prescribed by C. C. Popescu et al. and Jansson & Farrar, respectively, and computations of electron cooling and radiation are implemented with GAMERA.