Statistical association between the candidate repeating FRB 20200320A and a galaxy group

• Published in: arXiv.org 2024-02
• Main Authors: Rafiei-Ravandi, Masoud, Smith, Kendrick M, Michilli, D, Pleunis, Ziggy, Bhardwaj, Mohit, Dobbs, Matt, Eadie, Gwendolyn M, Fonseca, Emmanuel, Gaensler, B M, Kaczmarek, Jane, Kaspi, Victoria M, Leung, Calvin, Li, Dongzi, Masui, Kiyoshi W, Pandhi, Ayush, Pearlman, Aaron B, Petroff, Emily, Rahman, Mubdi, Scholz, Paul, Stenning, David C
• Format: Article
• Language: English
• Subjects: Cross correlation; Dark matter; Free electrons; Galaxies; Red shift; Repeaters; Stars & galaxies
• ISSN: 2331-8422

We present results from angular cross-correlations between select samples of CHIME/FRB repeaters and galaxies in three photometric galaxy surveys, which have shown correlations with the first CHIME/FRB catalog containing repeating and nonrepeating sources: WISE\(\times\)SCOS, DESI-BGS, and DESI-LRG. We find a statistically significant correlation (\(p\)-value \(395\) pc cm\(^{-3}\) and WISE\(\times\)SCOS galaxies with redshift \(z>0.275\). We demonstrate that the correlation arises surprisingly because of a statistical association between FRB 20200320A (extragalactic DM \(\approx550\) pc cm\(^{-3}\)) and a galaxy group in the same dark matter halo at redshift \(z\approx0.32\). We estimate that the host halo, along with an intervening halo at redshift \(z\approx0.12\), accounts for at least $\sim$$30\%\( of the extragalactic DM. Our results strongly motivate incorporating galaxy group and cluster catalogs into direct host association pipelines for FRBs with \)\lesssim$$1'\( localization precision, effectively utilizing the two-point information to constrain FRB properties such as their redshift and DM distributions. In addition, we find marginal evidence for a negative correlation at 99.4% CL between a sample of repeating FRBs with baseband data (median extragalactic DM \)=354\( pc cm\)^{-3}\() and DESI-LRG galaxies with redshift \)0.3\le z