[{"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","OA_place":"publisher","DOAJ_listed":"1","author":[{"full_name":"Lin, Allison","last_name":"Lin","first_name":"Allison"},{"last_name":"Charisi","first_name":"Maria","full_name":"Charisi, Maria"},{"first_name":"Zoltán","last_name":"Haiman","full_name":"Haiman, Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","orcid":"0000-0003-3633-5403"}],"file":[{"file_size":2619679,"success":1,"checksum":"5162d1539ef7d10927ef73d8b4500017","file_name":"2026_AstrophysicalJour_Lin.pdf","relation":"main_file","access_level":"open_access","date_created":"2026-05-04T10:24:49Z","content_type":"application/pdf","creator":"dernst","file_id":"21789","date_updated":"2026-05-04T10:24:49Z"}],"acknowledgement":"M.C. acknowledges support by the European Union (ERC; MMMonsters, 101117624). This work was also supported in part by NASA grants 80NSSC24K0440 and 80NSSC22K0822. This research used the resources of the Center for Institutional Research Computing at Washington State University.","has_accepted_license":"1","month":"02","status":"public","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"department":[{"_id":"ZoHa"}],"date_created":"2026-04-12T22:01:49Z","citation":{"ieee":"A. Lin, M. Charisi, and Z. Haiman, “Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves,” <i>The Astrophysical Journal</i>, vol. 997, no. 2. IOP Publishing, 2026.","apa":"Lin, A., Charisi, M., &#38; Haiman, Z. (2026). Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ae29a7\">https://doi.org/10.3847/1538-4357/ae29a7</a>","ama":"Lin A, Charisi M, Haiman Z. Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves. <i>The Astrophysical Journal</i>. 2026;997(2). doi:<a href=\"https://doi.org/10.3847/1538-4357/ae29a7\">10.3847/1538-4357/ae29a7</a>","chicago":"Lin, Allison, Maria Charisi, and Zoltán Haiman. “Lomb-Scargle Periodogram Struggles with Non-Sinusoidal Supermassive Black Hole Binary Signatures in Quasar Lightcurves.” <i>The Astrophysical Journal</i>. IOP Publishing, 2026. <a href=\"https://doi.org/10.3847/1538-4357/ae29a7\">https://doi.org/10.3847/1538-4357/ae29a7</a>.","ista":"Lin A, Charisi M, Haiman Z. 2026. Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves. The Astrophysical Journal. 997(2), 316.","short":"A. Lin, M. Charisi, Z. Haiman, The Astrophysical Journal 997 (2026).","mla":"Lin, Allison, et al. “Lomb-Scargle Periodogram Struggles with Non-Sinusoidal Supermassive Black Hole Binary Signatures in Quasar Lightcurves.” <i>The Astrophysical Journal</i>, vol. 997, no. 2, 316, IOP Publishing, 2026, doi:<a href=\"https://doi.org/10.3847/1538-4357/ae29a7\">10.3847/1538-4357/ae29a7</a>."},"publisher":"IOP Publishing","_id":"21712","issue":"2","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"intvolume":"       997","quality_controlled":"1","date_published":"2026-02-01T00:00:00Z","doi":"10.3847/1538-4357/ae29a7","publication_status":"published","file_date_updated":"2026-05-04T10:24:49Z","language":[{"iso":"eng"}],"article_number":"316","abstract":[{"text":"Supermassive black hole binary (SMBHB) systems are expected to form as a consequence of galaxy mergers. At subparsec separations, SMBHBs can be identified as quasars with periodic variability, with previous periodicity searches uncovering significant candidates. However, these searches focused primarily on sinusoidal signals, while theoretical models and hydrodynamical simulations predict that binaries produce more complex non-sinusoidal pulse shapes. Here we examine the efficacy of the Lomb–Scargle periodogram (LSP; one of the most popular tools for periodicity searches in unevenly sampled lightcurves) to detect periodicities with a sawtooth shape mimicking results of hydrodynamical simulations. We simulate idealized well-sampled lightcurves, lightcurves that mimic the data in the Palomar Transient Factory (PTF) analyzed in M. Charisi et al. (2016), and lightcurves that resemble our expectations for single-band data in the upcoming Legacy Survey of Space and Time (LSST) of the Rubin Observatory. We approximate quasar variability with a damped random walk (DRW) model, inject sinusoidal and sawtooth pulse shapes, and assess their statistical significance. We find that in the presence of red noise, the LSP detects a relatively low fraction of the sinusoidal signals (∼45%, ∼24%, and ∼23%, in the PTF-like, idealized, and LSST-like lightcurves, respectively). The fraction is significantly reduced for sawtooth periodicity (with only ∼9% in PTF-like and ∼1% in idealized and LSST-like lightcurves). These low recovery rates imply that previous searches have missed the large majority of binaries. They also have significant implications for the detection of SMBHBs in upcoming LSST necessitating the development of advanced tools that go beyond the simple LSP.","lang":"eng"}],"oa":1,"day":"01","OA_type":"gold","year":"2026","volume":997,"title":"Lomb-scargle periodogram struggles with non-sinusoidal supermassive Black Hole binary signatures in quasar lightcurves","article_processing_charge":"Yes","article_type":"original","scopus_import":"1","ddc":["520"],"publication":"The Astrophysical Journal","type":"journal_article","date_updated":"2026-05-04T10:26:59Z"}]