The SDSS-V Black Hole Mapper Reverberation Mapping Project: Unusual Broad-line Variability in a Luminous Quasar

Logan B. Fries*, Jonathan R. Trump, Megan C. Davis, C. J. Grier, Yue Shen, Scott F. Anderson, Tom Dwelly, Michael Eracleous, Y. Homayouni, Keith Horne, Mirko Krumpe, Sean Morrison, Jessie C. Runnoe, Benny Trakhtenbrot, Roberto J. Assef, W. N. Brandt, Joel Brownstein, Collin Dabbieri, Alexander Fix, Gloria Fonseca AlvarezSara Frederick, P. B. Hall, Anton M. Koekemoer, Jennifer I.Hsiu Li, Xin Liu, Mary Loli Martínez-Aldama, Claudio Ricci, Donald P. Schneider, Hugh W. Sharp, Matthew J. Temple, Qian Yang, Grisha Zeltyn, Dmitry Bizyaev

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


We present a high-cadence multiepoch analysis of dramatic variability of three broad emission lines (Mg ii, Hβ, and Hα) in the spectra of the luminous quasar (λ L λ (5100 Å) = 4.7 × 1044 erg s−1) SDSS J141041.25+531849.0 at z = 0.359 with 127 spectroscopic epochs over nine years of monitoring (2013-2022). We observe anticorrelations between the broad emission-line widths and flux in all three emission lines, indicating that all three broad emission lines “breathe” in response to stochastic continuum variations. We also observe dramatic radial velocity shifts in all three broad emission lines, ranging from Δv ∼ 400 km s−1 to ∼800 km s−1, that vary over the course of the monitoring period. Our preferred explanation for the broad-line variability is complex kinematics in the gas in the broad-line region. We suggest a model for the broad-line variability that includes a combination of gas inflow with a radial gradient, an azimuthal asymmetry (e.g., a hot spot), superimposed on the stochastic flux-driven changes to the optimal emission region (“line breathing”). Similar instances of line-profile variability due to complex gas kinematics around quasars are likely to represent an important source of false positives in radial velocity searches for binary black holes, which typically lack the kind of high-cadence data we analyze here. The long-duration, wide-field, and many-epoch spectroscopic monitoring of SDSS-V BHM-RM provides an excellent opportunity for identifying and characterizing broad emission-line variability, and the inferred nature of the inner gas environment, of luminous quasars.

Original languageEnglish
Article number5
JournalAstrophysical Journal
Issue number1
StatePublished - 1 May 2023


FundersFunder number
Fondecyt IniciaciónFB210003, 11190831
Millennium NucleusNCN19058
Millennium Nucleus NCN19
National Science FoundationAST-2009539, AST-2108668, CAREER-1945546
Alfred P. Sloan Foundation
California Department of Fish and GameKR 3338/4-1
Horizon 2020 Framework Programme950533
Heising-Simons Foundation
European Research Council
Fondo Nacional de Desarrollo Científico y Tecnológico1191124
Israel Science FoundationAST-2206499, 1849/19
Agencia Nacional de Investigación y DesarrolloBASAL FB210003


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