Stacked Reverberation Mapping of High Redshift Quasars in DESI. I. Feasibility Analysis
Abstract The broad line region of quasars has long been probed by reverberation mapping techniques that measure time lags between continuum and broad emission line variations. Stacked reverberation mapping has been proposed as a less observationally expensive alternative to traditional methods. This ensemble approach also reduces biases from small-number statistics. The Dark Energy Spectroscopic Instrument (DESI) is conducting the most extensive spectroscopic survey of quasars to date. We create mock light curves emulating expected DESI quasar observations at redshifts 1.48 < z < 5.2 and luminosities 44.68 ≤ log λL1350/erg s−1 ≤ 45.99 to test stacked reverberation mapping feasibility using sparse spectroscopic data paired with well-sampled photometric data. The pipeline, using the lag estimation code javelin, successfully recovers the simulated C iv lags within one sigma of the true values using spectroscopic light curves composed of only a few spectral epochs (2-10) with irregular cadences. We investigate how observational factors, including C iv flux error magnitude, number of stacked quasars, and spectral epoch count, affect performance. This work motivates a pathway for future stacked reverberation mapping projects with large scale spectroscopic surveys of quasars having ≥2 spectroscopic observations. Our results suggest an economical alternative for constraining and extending the radius-luminosity relation to higher redshifts and luminosities. Subsequently, this relation can be employed more reliably in single-epoch black hole mass measurements and quasar cosmology in these distant regimes.
Authors
- S. Juneau (ORCID: https://orcid.org/0000-0002-0000-2394)
- Eva-Maria Mueller (ORCID: https://orcid.org/0000-0002-4536-1999)
- S. Nadathur (ORCID: https://orcid.org/0000-0001-9070-3102)
- Andreu Font-Ribera (ORCID: https://orcid.org/0000-0002-3033-7312)
- Victoria A. Fawcett (ORCID: https://orcid.org/0000-0003-1251-532X)
- P. Clark (ORCID: https://orcid.org/0000-0002-6576-7400)
- M. Siudek (ORCID: https://orcid.org/0000-0002-2949-2155)
- Andrei Cuceu (ORCID: https://orcid.org/0000-0002-2169-0595)
- J. E. Forero-Romero (ORCID: https://orcid.org/0000-0002-2890-3725)
- T. M. Davis (ORCID: https://orcid.org/0000-0002-4213-8783)
- T. Shanks (ORCID: https://orcid.org/0000-0003-2612-7926)
- Ragadeepika Pucha (ORCID: https://orcid.org/0000-0002-4940-3009)
- John Moustakas (ORCID: https://orcid.org/0000-0002-2733-4559)
- Wei-Jian Guo (ORCID: https://orcid.org/0000-0001-9457-0589)
- David Alexander (ORCID: https://orcid.org/0000-0003-3168-8680)
- C. Lamman (ORCID: https://orcid.org/0000-0002-6731-9329)
- Paul Martini
- Aaron Meisner
- Todd Claybaugh
- Jessica Aguilar
- Rahma Alfarsy
- Hugh McDougall
- Hu Zou
- Richard Joyce
- Zhiwei Pan
- Davide Bianchi
- Michael Schubnell
- Ramon Miquel
- Nathalie Palanque-Delabrouille
- R E A Canning
- Benjamin Alan Weaver
- David Schlegel
- Gaston Gutierrez
- David Brooks
- David Sprayberry
- Anthony Kremin
- Saisrinivas Dhavala
- Swayamtrupta Panda
- Graziano Rossi
- Axel de la Macorra
- David Kirkby
- Martin Landriau
- Eusebio Sanchez
- Enrique Gaztañaga
- Gregory Tarlé
- Theodore Kisner
- Ignasi Pérez-Ràfols
- Benjamin Floyd
- Laurent Le Guillou
- Steven Ahlen
- Klaus Honscheid
- Francisco Prada
Institutions
- Boston University (US)
- Universidad Complutense de Madrid (ES)
- Centre National de la Recherche Scientifique (FR)
- Fermi National Accelerator Laboratory (US)
- Institute of Space Sciences (ES)
- Lawrence Berkeley National Laboratory (US)
- University of Illinois Urbana-Champaign (US)
- Universidad de Los Andes (CO)
- University of Sussex (GB)
- The University of Queensland (AU)
- Institute for High Energy Physics (ES)
- University of Milan (IT)
- Durham University (GB)
- University of California, Irvine (US)
- University of Utah (US)
- University of Michigan (US)
- Sejong University (KR)
- Sorbonne Université (FR)
- Laboratoire de Physique Nucléaire et de Hautes Énergies (FR)
- Gemini South Observatory (CL)
- Center for Astrophysics Harvard & Smithsonian (US)
- Institut National de Physique Nucléaire et de Physique des Particules (FR)
- Community Science and Data Center (US)
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano (IT)
- NSF NOIRLab (US)
- Instituto de Astrofísica de Andalucía (ES)
- National Astronomical Observatories (CN)
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES)
- University of Southampton (GB)
- University College London (GB)
- The Ohio State University (US)
- University of Portsmouth (GB)
- Newcastle University (GB)
- Universidad Nacional Autónoma de México (MX)
- Siena College (US)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2026-07-27
- DOI
- https://doi.org/10.1093/mnras/stag1418
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00