Dispersion measures of fast radio burst host galaxies derived from IllustrisTNG simulation
Abstract
We calculate the dispersion measures (DMs) contributed by host galaxies of fast radio bursts (FRBs). Based on a few host galaxy observations, a large sample of galaxy with similar properties to observed ones has been selected from the IllustrisTNG simulation. They are used to compute the distributions of host galaxy DMs for repeating and nonrepeating FRBs. For repeating FRBs, we infer the DM$ _{\mathrm{host}} $ for FRBs like FRB 121102 and FRB 180916 by assuming that the burst sites are tracing the star formation rates in host galaxies. The median DM$_{\mathrm{host}}$ are $35 (1+z)^{1.08}$ and $96(1+z)^{0.83}$ pc cm$^{3}$ for FRBs like FRB 121102 and FRB 180916, respectively. In another case, the median of DM$_{\mathrm{host}}$ is about $30  70$ pc cm$^{3}$ for nonrepeating FRBs in the redshift range $z=0.11.5$, assuming that the burst sites are the locations of binary neutron star mergers. In this case, the evolution of the median DM$_{\mathrm{host}}$ can be calculated by $33(1+z)^{0.84}$ pc cm$^{3}$. The distributions of DM$_{\mathrm{host}}$ of repeating and nonrepeating FRBs can be well fitted with the lognormal function. Our results can be used to infer redshifts of nonlocalized FRBs.
 Publication:

arXiv eprints
 Pub Date:
 July 2020
 arXiv:
 arXiv:2007.13935
 Bibcode:
 2020arXiv200713935Z
 Keywords:

 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 19 pages, 8 figures, 2 tables, accepted for publication in ApJ