Galactic DM contribution to the extragalactic FRBs

It is independent of any model of the Galaxy, i.e. we do not assume the density of the disc or the halo, spatial extent of the halo, baryonic mass content, or any such external constraints to measure DM_Gal_. We use 21-cm, UV, EUV, and X-ray data to account for different phases, and find that DM_Gal_ is dominated by the hot phase probed by X-ray absorption.

We improve upon the measurements of N(OVII) and f_OVII_ compared to previous studies, thus providing a better estimate of the hot phase contribution. The median DM_Gal_=64^+20^_-23_cm^-3^pc, with a 68 per cent (90 per cent) confidence interval of 33-172(23-660)cm^-3^pc. The DM_Gal_ does not appear to follow any trend with the Galactic longitude or latitude, and there is a large scatter around the values predicted by simple disc + spherical halo models.