Xin Liu

About

Professor Xin Liu is a faculty member at the University of Illinois Urbana-Champaign, holding positions in both the Astronomy department and the National Center for Supercomputing Applications (NCSA). She earned her B.S. in Physics from Tsinghua University in 2004 and completed her Ph.D. in Astrophysical Sciences at Princeton University in 2010 under the mentorship of Professor Michael A. Strauss. Prior to joining UIUC in 2015, she was a NASA Einstein Fellow at Harvard and a Hubble Fellow at UCLA. Her research interests lie at the intersection of astronomical survey science, data science, multi-messenger and time-domain astrophysics, and the application of artificial intelligence (AI) to scientific problems. Professor Liu's work addresses the challenges and opportunities presented by the large volumes of data generated by modern astronomical surveys. She focuses on advancing machine learning (ML) methodologies within astronomy, moving beyond the use of pre-packaged models to develop physics-informed learning, statistical learning with probabilistic frameworks that enable uncertainty quantification and generative modeling, and transparent, interpretable ML models that emphasize robustness, accuracy, and comprehensibility. Her research aims to integrate ML as an essential component of principled scientific analysis frameworks, reflecting the maturation of the field as it embraces big data and AI techniques. Her academic contributions are complemented by her teaching roles,…

Research topics

• Computer Science
• Astrophysics
• Astronomy
• Physics
• Chemistry
• Operating system

Selected publications

• The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

  The Astrophysical Journal Supplement Series · 2023 · 249 citations

  Abstract The eighteenth data release (DR18) of the Sloan Digital Sky Survey (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs or “Mappers”: the Milky Way Mapper (MWM), the Black Hole Mapper (BHM), and the Local Volume Mapper. This data release contains extensive targeting information for the two multiobject spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific ob…

  DOI

• Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results

  The Astrophysical Journal · 2024-04-26 · 39 citations

  articleOpen access

  Abstract “Changing-look” active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated spectroscopy of nearly 29,000 previously known active galactic nuclei (AGNs), combined with dedicated follow-up spectroscopy, and publicly available optical light curves, we have identified 116 CL-AGNs where (at least) one broad emission line has essentially (di…

  PublisherDOI

• VODKA-JWST: Synchronized Growth of Two Supermassive Black Holes in a Massive Gas Disk? A 3.8 kpc Separation Dual Quasar at Cosmic Noon with the NIRSpec Integral Field Unit

  The Astrophysical Journal · 2025-03-01 · 8 citations

  articleOpen access

  Abstract The search for dual supermassive black holes (SMBHs) is of immense interest in modern astrophysics. Galaxy mergers may fuel and produce SMBH pairs. Actively accreting SMBH pairs are observed as dual quasars, which are vital probes of SMBH growth. Dual quasars at cosmic noon are not well characterized. Gaia observations have enabled a novel technique to identify dual quasars at kiloparsec scales based on the small jitters of the light centroid as the two quasars vary stochastically. We p…

  PublisherDOI

• Varstrometry for Off-nucleus and Dual Sub-Kpc AGN (VODKA): A Mix of Singles, Lenses, and True Duals at Cosmic Noon

  The Astrophysical Journal · 2025-08-07 · 7 citations

  articleOpen accessCorresponding

  Abstract Dual active galactic nuclei (AGNs), a phase in some galaxy mergers during which both central supermassive black holes (SMBHs) are active, are expected to be a key observable stage leading up to SMBH mergers. Constraining the population of dual AGNs in both the nearby and high- z Universe has proven to be elusive until very recently. We present a multiwavelength follow-up campaign to confirm the nature of a sample of 20 candidate dual AGNs at cosmic noon ( z ∼ 2) from the VODKA sample. T…

  PublisherDOI

• DAVOS: Dwarf Active Galactic Nuclei from Variability for the Origins of Seeds: Properties of Variability-selected Active Galactic Nuclei in the COSMOS Field and Expectations for the Rubin Observatory

  The Astrophysical Journal · 2024-08-01 · 7 citations

  articleOpen access

  Abstract We study the black hole mass–host galaxy stellar mass relation, M BH – M * , of a sample of z < 4 optically variable active galactic nuclei (AGNs) in the COSMOS field. The parent sample of 491 COSMOS AGNs were identified by optical variability from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) program. Using publicly available catalogs and spectra, we consolidate their spectroscopic redshifts and estimate virial black hole masses using broad-line widths and luminosities. W…

  PublisherDOI

Recent grants

• EARS: Utilizing Diverse Spectrum Bands in Cellular Networks - A Unified Information Learning and Decision Making Approach

  NSF · $354k · 2016–2019

• WoU-MMA: Frequency and Abundance of Binary sUpermassive bLack holes from Optical Variability Surveys (FABULOVS)

  NSF · $367k · 2022–2026

• NeTS: Small: Learning-Guided Network Resource Allocation: A Closed-Loop Approach

  NSF · $479k · 2017–2021

Frequent coauthors

• Yue Shen

  209 shared

• Yu-Ching Chen

  Bloomberg (United States)

  65 shared

• Hengxiao Guo

  Shanghai Astronomical Observatory

  63 shared

• Colin J. Burke

  61 shared

• E. Bertin

  Orange (France)

  61 shared

• L. N. da Costa

  Laboratório Interinstitucional de e-Astronomia

  57 shared

• M. A. G. Maia

  Laboratório Interinstitucional de e-Astronomia

  56 shared

• M. Carrasco Kind

  Urbana University

  54 shared

Labs

• Astro-AI GroupPI

  Department of Astronomy, University of Illinois at Urbana-Champaign

Education

• PhD, Astrophysical Sciences

  Princeton University

  2010

• Master of Science, Physics

  Tsinghua University

  2006

• Bachelor of Science, Physics

  Tsinghua University

  2004

Awards & honors

• Norman P. Jones Professorial Scholar (2023-2026)
• Excellent Teacher Ranked by Students (2023)
• NCSA Faculty Fellow (2020 & 2023)

Similar researchers at University of Illinois Urbana-Champaign

• Felipe Menanteauh-101
• Joaquin Vieirah-86