PIFFLE: Characterizing the Foreground Contributions from 4 Decades in Halo Mass to the FRB20230907D Dispersion Measure
Year: 2026
Type: preprint
Abstract: We characterize the foreground environment of FRB20230907D, localized to a galaxy at $z=0.464$, which has an observed dispersion measure of ${\rm DM}_{\rm obs}=1031~{\rm pc~cm^{-3}}$. At its redshift, FRB20230907D lies above the Macquart relation, the expected relation between cosmological dispersion measure and the source redshift, indicating a substantial excess DM along this line of sight. We use Subaru/PFS and SDSS spectroscopy, published group catalogs, Rubin/LSST imaging, and eROSITA X-ray data to characterize the foreground structures that may account for this excess. A friends-of-friends search identifies a massive foreground system at $z\simeq0.09$ with $M_{200}\simeq5.2\times10^{14}~M_\odot$, while low redshift catalogs reveal an additional group at $z\simeq0.02565$. Assuming that the halo gas follows a modified-NFW halo density profile, we estimate observer frame contributions of $150^{+110}_{-70}~{\rm pc~cm^{-3}}$ and $80^{+60}_{-40}~{\rm pc~cm^{-3}}$ from these systems, respectively. Together with the Milky Way, diffuse intergalactic medium, Virgo cluster, M49 group, and host galaxy contributions, these foreground structures can account for the excess dispersion measure of FRB20230907D within uncertainties. This highlights the importance of dense foreground spectroscopy and multi-wavelength data.
Source: arXiv (Cornell University)
Institutions: Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, Northwestern University, University of Chicago, Pontificia Universidad Católica de Valparaíso, University of Amsterdam, Netherlands Institute for Radio Astronomy, University of Manchester, University of Oxford, The University of Sydney, ARC Centre of Excellence for Gravitational Wave Discovery
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Princeton University, California Institute of Technology, Johns Hopkins University, European Commission, Durham University, Ministry of Education, Culture, Sports, Science and Technology, Academia Sinica, University of Tokyo, Universidade de São Paulo, National Astronomical Observatory of Japan, Agencia Nacional de Investigación y Desarrollo, Max-Planck-Institut für Astrophysik, Office of Science, Jet Propulsion Laboratory, Japan Society for the Promotion of Science, SLAC National Accelerator Laboratory
Awards: G1229526393, NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab): Management and Operations of Vera C. Rubin Observatory, Construction of Vera C. Rubin Observatory under the Major Research Equipment and Facilities Construction (MREFC) Account, Final Design, Construction and Operations of Vera C. Rubin Observatory, G2371548206, G262532246, G303061748, G4235786860, G4264918310, G4654690619, NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab) as a Federally Funded Research and Development Center (FFRDC), G495301720, G498139845, G5570207115, G5622021303, INVESTIGATING THE MAGNETIC FIELDS IN GALACTIC HALOS USING FAST RADIO BURSTS, G8382000481, G8945569637
OpenAlex ID: W7204780279