A first look at quasar-galaxy clustering at $zsimeq7.3$
Jan-Torge Schindler, Joseph F. Hennawi, Frederick B. Davies, Sarah E. I. Bosman, Feige Wang, Jinyi Yang, Anna-Christina Eilers, Xiaohui Fan, Koki Kakiichi, Elia Pizzati, Riccardo Nanni
arXiv:2510.08455v2 Announce Type: replace
Abstract: We present JWST observations of the environments surrounding two high-redshift quasars — J0252$-$0503 at $z = 7.0$ and J1007$+$2115 at $z = 7.5$ — which enable the first constraints on quasar-galaxy clustering at $z sim 7.3$. Galaxies in the vicinity of the quasars are selected through ground-based and JWST/NIRCam imaging and then spectroscopically confirmed with JWST/NIRSpec using the multi-shutter assembly (MSA). Over both fields, we identify 51 $z>5$ galaxies, of which eight are found within a $Delta v_{textrm{LOS}}=pm1500 rm{km} rm{s}^{-1}$ line-of-sight velocity window from the quasars and another eight in the background. The galaxy J0252_8713, located just $7,rm{pkpc}$ and $Delta v_{textrm{LOS}} approx 360,rm{km},rm{s}^{-1}$ from quasar J0252$-$0503, emerges as a compelling candidate for one of the most distant quasar-galaxy mergers. Combining the galaxy discoveries over the two fields, we measure the quasar-galaxy cross-correlation and obtain a correlation length of $r_0^{rm{QG}}approx7.6_{-1.6}^{+1.7},h^{-1},rm{cMpc}$, based on a power-law model with a fixed slope of $gamma_{rm{QG}} = 2.0$. Under the assumption that quasars and galaxies trace the same underlying dark matter density fluctuations, we infer a minimum dark matter halo mass for $zsimeq7.3$ quasars of $log_{10}(M_{textrm{halo, min}}/textrm{M}_{odot})= 11.6pm0.6$ in a halo model framework. Compared to measurements from EIGER at $langle z rangle = 6.25$ and ASPIRE at $langle z rangle = 6.7$ (where $log_{10}(M_{textrm{halo, min}}/textrm{M}_{odot}) gtrsim 12.3$), our clustering results provide tentative evidence for a non-monotonic redshift evolution of quasar clustering properties. We further estimate a quasar duty cycle of $f_{rm{duty}}approx0.1%$, consistent with constraints from quasar proximity zones and IGM damping wings. (abridged)arXiv:2510.08455v2 Announce Type: replace
Abstract: We present JWST observations of the environments surrounding two high-redshift quasars — J0252$-$0503 at $z = 7.0$ and J1007$+$2115 at $z = 7.5$ — which enable the first constraints on quasar-galaxy clustering at $z sim 7.3$. Galaxies in the vicinity of the quasars are selected through ground-based and JWST/NIRCam imaging and then spectroscopically confirmed with JWST/NIRSpec using the multi-shutter assembly (MSA). Over both fields, we identify 51 $z>5$ galaxies, of which eight are found within a $Delta v_{textrm{LOS}}=pm1500 rm{km} rm{s}^{-1}$ line-of-sight velocity window from the quasars and another eight in the background. The galaxy J0252_8713, located just $7,rm{pkpc}$ and $Delta v_{textrm{LOS}} approx 360,rm{km},rm{s}^{-1}$ from quasar J0252$-$0503, emerges as a compelling candidate for one of the most distant quasar-galaxy mergers. Combining the galaxy discoveries over the two fields, we measure the quasar-galaxy cross-correlation and obtain a correlation length of $r_0^{rm{QG}}approx7.6_{-1.6}^{+1.7},h^{-1},rm{cMpc}$, based on a power-law model with a fixed slope of $gamma_{rm{QG}} = 2.0$. Under the assumption that quasars and galaxies trace the same underlying dark matter density fluctuations, we infer a minimum dark matter halo mass for $zsimeq7.3$ quasars of $log_{10}(M_{textrm{halo, min}}/textrm{M}_{odot})= 11.6pm0.6$ in a halo model framework. Compared to measurements from EIGER at $langle z rangle = 6.25$ and ASPIRE at $langle z rangle = 6.7$ (where $log_{10}(M_{textrm{halo, min}}/textrm{M}_{odot}) gtrsim 12.3$), our clustering results provide tentative evidence for a non-monotonic redshift evolution of quasar clustering properties. We further estimate a quasar duty cycle of $f_{rm{duty}}approx0.1%$, consistent with constraints from quasar proximity zones and IGM damping wings. (abridged)