papers

Publications (16)

astro-ph.GA2025

The Drivers of the Decline in Supermassive Black Hole Growth at

Zhibo Yu, W. N. Brandt, Fan Zou +4

It is well established that cosmic supermassive black hole (SMBH) growth peaks at , followed by a strong decline of toward the present day, w…

astro-ph.GA2025

The Nature of an Unidentified X-ray Source in the 7 Ms Chandra Deep Field-South Catalog

Quinn P. Sullivan, Zhibo Yu, William N. Brandt +2

In the 7 Ms Chandra Deep Field-South catalog, only one source, XID 912, was highly significantly detected in X-rays but had no formally reported counterparts in the UV, optical, in…

astro-ph.GA2024

A Rapidly Accreting Active Galactic Nucleus Hidden in a Dust-Obscured Galaxy at

Nathan Cristello, Fan Zou, William N. Brandt +3

Dust-obscured galaxies (DOGs) containing central supermassive black holes (SMBHs) that are rapidly accreting (i.e., having high Eddington ratios, ) may represent a…

cs.LG2026

The Routing Plateau: Understanding and Breaking the Accuracy Limits of LLM Routers

Yifan Lu, Qiyue Zhang, Shenrun Zhang +4

LLM routing has become a popular approach to improve the cost-quality trade-off of LLM services by dynamically selecting a model for each query. Recent work has explored a broad ra…

astro-ph.GA2023

Stellar Masses and Star-Formation Rates of Galaxies and AGNs in the eFEDS GAMA09 Field

Zhibo Yu, Fan Zou, William N. Brandt

The eFEDS is a wide 140 deg field that has extensive multiwavelength coverage. To improve the utility of the existing data, we use CIGALE to fit source Spectral Energ…

astro-ph.GA2024

Dust-Obscured Galaxies in the XMM-SERVS Fields: Selection, Multiwavelength Characterization, and Physical Nature

Zhibo Yu, W. N. Brandt, Fan Zou +7

Dust-obscured galaxies (DOGs) are enshrouded by dust, and many are believed to host accreting supermassive black holes (SMBHs), which makes them unique objects for probing the coev…

astro-ph.HE2023

The Low Temperature Corona in ESO 511G030 Revealed by NuSTAR and XMM-Newton

Zuobin Zhang, Jiachen Jiang, Honghui Liu +9

We present the results from a coordinated XMM-Newton NuSTAR observation of the Seyfert 1 Galaxy ESO 511G030. With this joint monitoring programme, we conduct a detailed vari…

astro-ph.GA2024

Investigating the Star-Formation Characteristics of Radio Active Galactic Nuclei

Bojun Zhang, Fan Zou, W. N. Brandt +5

The coevolution of supermassive black holes and their host galaxies represents a fundamental question in astrophysics. One approach to investigating this question involves comparin…

astro-ph.HE2022

Reflection spectra of accretion disks illuminated by disk-like coronae

Shafqat Riaz, Askar B. Abdikamalov, Dimitry Ayzenberg +3

Relativistic reflection features in the X-ray spectra of black hole binaries and AGNs are thought to be produced through illumination of a cold accretion disk by a hot corona. In t…

astro-ph.HE2025

Narrow-Line Seyfert 1 Galaxies Beyond the Local X-ray Universe: An X-ray spectral sample

Jiachen Jiang, Dominic J. Walton, Luigi C. Gallo +8

Narrow-line Seyfert 1 AGNs (NLS1s) represent a unique stage in the black hole growth history, characterised by low black hole masses of approximately - solar masses…

astro-ph.HE2021

Constraining the Konoplya-Rezzolla-Zhidenko deformation parameters II: limits from stellar-mass black hole X-ray data

Zhibo Yu, Qunfeng Jiang, Askar B. Abdikamalov +5

Astrophysical black holes are thought to be the Kerr black holes predicted by general relativity, but macroscopic deviations from the Kerr solution can be expected from a number of…

astro-ph.GA2025

The X-ray Link Between High Eddington Ratio Dust-Obscured Galaxies (DOGs) and Hot DOGs

Fan Zou, W. N. Brandt, Elena Gallo +2

Dust-obscured galaxies (DOGs) with extremely red optical-to-infrared colors are often associated with intense starburst and AGN activity. Studying DOGs can provide insights into th…

astro-ph.HE2024

The Remarkable X-ray Spectra and Variability of the Ultraluminous Weak-Line Quasar SDSS J1521+5202

Shouyi Wang, W. Niel Brandt, Bin Luo +4

We present a focused X-ray and multiwavelength study of the ultraluminous weak-line quasar (WLQ) SDSS J1521+5202, one of the few X-ray weak WLQs that is amenable to basic X-ray spe…

astro-ph.GA2024

Mapping the Growth of Supermassive Black Holes as a Function of Galaxy Stellar Mass and Redshift

Fan Zou, Zhibo Yu, W. N. Brandt +3

The growth of supermassive black holes is strongly linked to their galaxies. It has been shown that the population mean black-hole accretion rate () prima…

astro-ph.GA2024

The Cosmic Evolution of the Supermassive Black Hole Population: A Hybrid Observed Accretion and Simulated Mergers Approach

Fan Zou, W. N. Brandt, Elena Gallo +4

Supermassive black holes (SMBHs) can grow through both accretion and mergers. It is still unclear how SMBHs evolve under these two channels from high redshifts to the SMBH populati…

astro-ph.HE2023

An XMM-Newton Study of Six Narrow-Line Seyfert 1 Galaxies at z = 0.35--0.92

Zhibo Yu, Jiachen Jiang, Cosimo Bambi +5

We report a detailed analysis of the XMM-Newton spectra of six Narrow-Line Seyfert 1 (NLS1) galaxies at redshift z = 0.35--0.92. Compared with the NLS1s at lower redshift in the pr…