Fast Outflow in the Host Galaxy of the Luminous z $=$ 7.5 Quasar J1007$+$2115 (2409.13189v1)

Abstract: James Webb Space Telescope opens a new window to directly probe luminous quasars powered by billion solar mass black holes in the epoch of reionization and their co-evolution with massive galaxies with unprecedented details. In this paper, we report the first results from the deep NIRSpec integral field spectroscopy study of a quasar at $z = 7.5$. We obtain a bolometric luminosity of $\sim$$1.8\times10^{47}$ erg s$^{-1}$ and a black hole mass of $\sim$0.7--2.5$\times10^{9}$ M${\odot}$ based on H$\beta$ emission line from the quasar spectrum. We discover $\sim$2 kpc scale, highly blueshifted ($\sim$$-$870 km/s) and broad ($\sim$1400 km/s) [O III] line emission after the quasar PSF has been subtracted. Such line emission most likely originates from a fast, quasar-driven outflow, the earliest one on galactic-scale known so far. The dynamical properties of this outflow fall within the typical ranges of quasar-driven outflows at lower redshift, and the outflow may be fast enough to reach the circumgalactic medium. Combining both the extended and nuclear outflow together, the mass outflow rate, $\sim$300 M${\odot}$yr, is $\sim$60%--380% of the star formation rate of the quasar host galaxy, suggesting that the outflow may expel a significant amount of gas from the inner region of the galaxy. The kinetic energy outflow rate, $\sim$3.6$\times10^{44}$ erg s$^{-1}$, is $\sim$0.2% of the quasar bolometric luminosity, which is comparable to the minimum value required for negative feedback based on simulation predictions. The dynamical timescale of the extended outflow is $\sim$1.7 Myr, consistent with the typical quasar lifetime in this era.

• The paper quantifies a fast, 2 kpc outflow at ~2100 km/s, establishing significant quasar feedback at z=7.5.
• The analysis uses deep NIRSpec spectroscopy to derive a bolometric luminosity of ~1.8×10^47 erg/s and SMBH masses of 0.7–2.5×10^9 M⊙.
• The study shows that quasar-driven outflows can exceed star formation rates, influencing host galaxy evolution and cosmic reionization.

Analysis of Fast Outflows in Quasar J1007$+$2115 Using NIRSpec Observations

The paper of high-redshift quasars like J1007$+$2115 at $z = 7.5$ is crucial for understanding the growth and evolution of early supermassive black holes (SMBHs) and their host galaxies. This paper leverages observations from the James Webb Space Telescope (JWST) to investigate a fast, quasar-driven outflow in the host galaxy of the quasar J1007$+$2115, providing new insights into the feedback mechanisms at play during the Epoch of Reionization.

Key Findings

The research presented in the paper conducts a meticulous analysis of the quasar spectrum using deep NIRSpec integral field spectroscopy data. The results yield a bolometric luminosity of $\sim1.8 \times 10^{47}$ erg s$^{-1}$ and an SMBH mass between $\sim0.7$ to $2.5 \times 10^9$ $M_\odot$. These measurements provide a framework for assessing the energetic output of the quasar and its capacity to drive galactic-scale outflows.

Significantly, the paper identifies an extended, fast outflow characterized by a scale of approximately 2 kpc and highly blueshifted line emissions indicative of velocities around 2100 km s$^{-1}$. The mass outflow rate of this outflow is estimated to be $\sim300\, M_\odot$ yr$^{-1}$, which is remarkably high compared to the star formation rate (SFR) of the host galaxy, estimated at $80-520\, M_\odot$ yr$^{-1}$. These results align with the hypothesis that quasar activity could significantly disrupt and expel a substantial portion of the interstellar medium, therefore impacting star formation.

Implications

The findings suggest that quasar-driven outflows at such high redshifts are comparable to those observed at lower redshifts, allowing us to extend models of quasar feedback to much earlier epochs. The detected outflow may influence the circumgalactic medium by injecting energy and enriching it with metals, thus playing a role in cosmic reionization.

Practically, this paper enhances our understanding of quasar feedback mechanisms, demonstrating that early quasar activity contributes significantly to the regulation of star formation in host galaxies. On a theoretical level, it supports models predicting active galactic nuclei (AGNs) as crucial agents in galaxy evolution by limiting the growth of massive galaxies through outflows.

Future Prospects

This research opens avenues for additional studies focused on the multi-phase nature of such outflows, comprising ionized, neutral, and molecular components. Future work should aim to detail these components to paint a comprehensive picture of quasar-driven feedback. With JWST's continuing observations, comparative studies across a variety of quasars at different redshifts will be invaluable for understanding the universality of these mechanisms.

Furthermore, exploring the lifetime and episodic nature of quasar activity through additional observations and advanced simulations will contribute substantially to constraining models of black hole growth and galaxy-quasar co-evolution. By combining the kinematic data from JWST with simulations, one can precisely model the impacts of these energetic processes over cosmic time.

In sum, this paper provides a well-founded picture of the potent effect of early quasar activity and sets a precedent for integrating observational and theoretical frameworks to paper the earliest stages of galaxy evolution.