A Broker Integrated Algorithm for Gravitational Wave - Electromagnetic Counterpart Searches in O4a and O4b Runs
Universidad de Chile（智利大学）；Data and Artificial Intelligence Initiative (IDIA), Faculty of Physical and Mathematical Sciences, Universidad de Chile（智利大学物理与数学科学学院数据与人工智能倡议(IDIA)）；Centro de Excelencia en Astrofisica y Technologia Afines（天体物理学及相关技术卓越中心）；Millennium Institute of Astrophysics（天体物理学千年研究所）；Center for Mathematical Modeling, Universidad de Chile（智利大学数学建模中心）；Physik-Institut, Universität Zürich（苏黎世大学物理研究所）；Pontificia Universidad Católica de Chile（智利天主教 Pontificia 大学）
Hemanth Bommireddy, Francisco Forster, Isaac McMahon, Manuel Pavez Herrera, Regis Cartier, Felipe Olivares Estay, Lorena Hernández García, Mary Loli Martínez Al… 展开作者
Hemanth Bommireddy, Francisco Forster, Isaac McMahon, Manuel Pavez Herrera, Regis Cartier, Felipe Olivares Estay, Lorena Hernández García, Mary Loli Martínez Aldama, Alejandra Muñoz Arancibia
备注：
16 pages, 17 figures. Revised version submitted to Astronomy & Astrophysics following minor referee corrections
We present an automated framework to search for optical counterparts of LIGO-Virgo-KAGRA (LVK) gravitational wave (GW) superevents using public Zwicky Transient Facility (ZTF) alerts processed through the ALeRCE broker. The goal is to filter and identify optical transients potentially associated with binary black hole (BBH) mergers during the LVK O4a and O4b observing runs. Using the Automatic Learning for the Rapid Classification of Events (ALeRCE) infrastructure, we spatially query ZTF alerts within GW localization regions and apply machine learning classifiers, host-galaxy crossmatching, and temporal cuts within 200 days post-merger to isolate plausible candidates. Our search yielded one candidate in O4a and four in O4b, several consistent with the supernova or tidal disruption event regime. This work demonstrates that public alert brokers can establish a robust baseline for systematic searches for electromagnetic counterparts to GW superevents in current and future observing runs. Our algorithm provides a systematic approach to search for BBH counterparts for all significant LVK GW superevents using survey telescope alerts. The search, together with the accompanying analysis, demonstrates the significance of the counterpart candidates, with one candidate ultimately identified as a transient event consistent with a Bowen fluorescence flare in a now discarded active galactic nucleus (AGN).
Bright in the Black: Searching for Electromagnetic Counterparts to Gravitational-Wave Candidates in LIGO-Virgo-KAGRA Observation Runs with AstroSat-CZTI
