Galactic DM contribution to the extragalactic FRBs

We provide an empirical list of the Galactic dispersion measure (DM_Gal_) contribution to the extragalactic fast radio bursts (FRBs) along 72 sightlines. 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. Our measurements provide more complete and accurate estimates of DM_Gal_ independent from the previous studies. We provide a table and a code to retrieve DM_Gal_ for any FRB localized in the sky.

Cone search capability for table J/MNRAS/500/655/tablea1 (DM_hot_ based on the OVII and OVIII measurements of Gupta et al. (2012ApJ...756L...8G, 2017ApJ...836..243G) and DM_cold_ based on the 21-cm measurements of HI4PI Collaboration (2016A&A...594A.116H))

Cone search capability for table J/MNRAS/500/655/tablea2 (DM_hot_ based on the OVII and OVIII measurements of Nicastro et al. (2016) and DM_cold_ based on the 21-cm measurements of HI4PI Collaboration (2016A&A...594A.116H))

Cone search capability for table J/MNRAS/500/655/tablea3 (DM_cold_ and DM_hot_ based on the ionization modelling of Gatuzz & Churazov (2018MNRAS.474..696G))

Cone search capability for table J/MNRAS/500/655/tablea4 (Average and maximum Galactic DM, combining multiple methods and instruments)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/500/655
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/500/655
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/500/655
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/500/655
Provenance
Creator Das S.; Mathur S.; Gupta A.; Nicastro F.; Krongold Y.
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy