The SDSS-V Black Hole Mapper Reverberation Mapping Project: Light Echoes of the Coronal-line Region in a Luminous Quasar
Year: 2025
Type: article
Abstract: We present a reverberation mapping (RM) analysis of the coronal line [Ne v ] λ 3427-emitting region of the quasar COS168 (SDSS J095910.30+020732.2). [Ne v ] λ 3427 is known as one of the “coronal lines,” which are a species of emission lines present in active galactic nuclei (AGN) spectra with high ionization potentials (≥ 100 eV) that can serve as tracers for AGN activity. The spatial extent of the coronal line region has been studied with only spatial resolving techniques that are not sensitive to the innermost regions of AGN. Through our RM analysis of [Ne v ] λ 3427, we measure a nominal “optimal emission radius” for [Ne v ] λ 3427 of 381 . 1 − 22 + 16 lt-day (observed frame). We place the coronal line region in context with other AGN regions by comparing it with the characteristic radius of H α , the dust-sublimation radius, and the dusty torus. The coronal line region is located at a larger radius from the black hole than the characteristic radius of the dusty torus, measured using a torus–radius luminosity relationship. The virial product ( v 2 R / G ) of both H α and [Ne v ] λ 3427 is consistent within the uncertainties, implying that the coronal line region, as probed by the [Ne v ] λ 3427 line, may be in a virialized orbit that is dominated by the gravitational potential of the black hole. This plausibly suggests that coronal lines could be an effective method for estimating black hole masses.
Source: The Astrophysical Journal
Authors: Theodore B. Smith, Logan B. Fries, Jonathan R. Trump, Catherine J. Grier, Yue Shen, Scott F. Anderson, W. N. Brandt, Megan C. Davis, Tom Dwelly, P. B. Hall, Keith Horne, Y. Homayouni, J. McKaig, Sean Morrison, Hugh W. Sharp, Roberto J. Assef, Franz E. Bauer, Anton M. Koekemoer, Donald P. Schneider, Benny Trakhtenbrot, Hector Javier Ibarra-Medel, Castalia Alenka Negrete Peñaloza
Institutions: University of Connecticut, University of Wisconsin–Madison, University of Illinois Urbana-Champaign, National Center for Supercomputing Applications, University of Washington, Pennsylvania State University, Max Planck Institute for Extraterrestrial Physics, York University, University of St Andrews, Oak Ridge Associated Universities, Goddard Space Flight Center, Universidad Diego Portales, University of Tarapacá, Space Telescope Science Institute, Tel Aviv University, Universidad Nacional Autónoma de México
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funder: National Science Foundation
OpenAlex ID: W4417386364