TY - JOUR
T1 - Measuring the variance of the Macquart relation in redshift-extragalactic dispersion measure modeling
AU - Baptista, Jay
AU - Prochaska, J. Xavier
AU - Mannings, Alexandra G.
AU - James, C. W.
AU - Shannon, R. M.
AU - Ryder, Stuart D.
AU - Deller, A. T.
AU - Scott, Danica R.
AU - Glowacki, Marcin
AU - Tejos, Nicolas
N1 - Copyright © 2024. The Author(s). Published by the American Astronomical Society. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
PY - 2024/4/1
Y1 - 2024/4/1
N2 - The Macquart relation describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and the redshift z of their host galaxies. The scatter of the Macquart relation is sensitive to the distribution of baryons in the intergalactic medium including those ejected from galactic halos through feedback processes. The variance of the distribution in DMs from the cosmic web (DMcosmic) is parameterized by a fluctuation parameter F. In this work, we present a new measurement of F using 78 FRBs of which 21 have been localized to host galaxies. Our analysis simultaneously fits for the Hubble constant H0 and the DM distribution due to the FRB host galaxy. We find that the fluctuation parameter is degenerate with these parameters, most notably H0, and use a uniform prior on H0 to measure log10F > −0.86 at the 3σ confidence interval and a new constraint on the Hubble constant H0 = 85.3−8.1+9.4kms−1Mpc−1 . Using a synthetic sample of 100 localized FRBs, the constraint on the fluctuation parameter is improved by a factor of ∼2. Comparing our F measurement to simulated predictions from cosmological simulation (IllustrisTNG), we find agreement between redshifts 0.4 < z and z < 2.0. However, at z < 0.4, the simulations underpredict F, which we attribute to the rapidly changing extragalactic DM excess distribution at low redshift.
AB - The Macquart relation describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and the redshift z of their host galaxies. The scatter of the Macquart relation is sensitive to the distribution of baryons in the intergalactic medium including those ejected from galactic halos through feedback processes. The variance of the distribution in DMs from the cosmic web (DMcosmic) is parameterized by a fluctuation parameter F. In this work, we present a new measurement of F using 78 FRBs of which 21 have been localized to host galaxies. Our analysis simultaneously fits for the Hubble constant H0 and the DM distribution due to the FRB host galaxy. We find that the fluctuation parameter is degenerate with these parameters, most notably H0, and use a uniform prior on H0 to measure log10F > −0.86 at the 3σ confidence interval and a new constraint on the Hubble constant H0 = 85.3−8.1+9.4kms−1Mpc−1 . Using a synthetic sample of 100 localized FRBs, the constraint on the fluctuation parameter is improved by a factor of ∼2. Comparing our F measurement to simulated predictions from cosmological simulation (IllustrisTNG), we find agreement between redshifts 0.4 < z and z < 2.0. However, at z < 0.4, the simulations underpredict F, which we attribute to the rapidly changing extragalactic DM excess distribution at low redshift.
UR - http://www.scopus.com/inward/record.url?scp=85189973974&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ad2705
DO - 10.3847/1538-4357/ad2705
M3 - Article
AN - SCOPUS:85189973974
SN - 0004-637X
VL - 965
SP - 1
EP - 11
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 57
ER -