The host galaxy of a narrow-line Seyfert 1 galaxy RE J1034+396 with X-ray quasi-periodic oscillations

TL;DR

This study models the host galaxy's stellar contribution in a narrow-line Seyfert 1 galaxy, estimates its SMBH mass, and links X-ray QPOs to black hole binaries, revealing insights into galaxy and black hole co-evolution.

Contribution

It provides a new estimation of the SMBH mass in RE J1034+396 using stellar population synthesis and links X-ray QPOs to stellar-mass black hole phenomena.

Findings

SMBH mass estimated at (1-4)×10^6 solar masses

X-ray QPOs scaled to high-frequency QPOs in stellar-mass black holes

Star formation rate and stellar mass characterized in the host galaxy

Abstract

Using simple stellar population synthesis, we model the bulge stellar contribution in the optical spectrum of a narrow-line Seyfert 1 galaxy RE J1034+396. We find that its bulge stellar velocity dispersion is $67.7\pm 8$ \kms. The supermassive black hole (SMBH) mass is about $(1-4)\times 10^6 \msun$ if it follows the well-known $\mbh-\sigma_*$ relation found in quiescent galaxies. We also derive the SMBH mass from the H$\beta$ second moment, which is consistent with that from its bulge stellar velocity dispersion. The SMBH mass of $(1-4)\times 10^6 \msun$ implies that the X-ray quasi-periodic oscillation (QPO) of RE J1034+396 can be scaled to a high-frequency QPO at 27-108 Hz found in Galactic black hole binaries with a 10 $\msun$ black hole. With the mass distribution in different age stellar populations, we find that the mean specific star formation rate (SSFR) over past 0.1 Gyr is $0.0163\pm 0.0011$ $\rm Gyr^{-1}$, the stellar mass in the logarithm is $10.155\pm 0.06$ in units of solar mass, and the current star formation rate is $0.23\pm 0.016 \msun \rm yr^{-1}$. RE J1034+396 does not follow the relation between the Eddington ratio and the SSFR suggested by Chen et al., although a larger scatter in their relation. We also suggest that about 7.0% of the total \ha luminosity and 50% of the total \oii luminosity come from the star formation process.