Photometric prioritization of neutron star merger candidates

Eran O. Ofek*, Nora L. Strotjohann, Iair Arcavi, Avishay Gal-Yam, Doron Kushnir, Eli Waxman, Mansi M. Kasliwal, Andrew Drake, Matthew Graham, Josiah Purdum, Ben Rusholme, Yashvi Sharma, Roger Smith, Avery Wold, Brian F. Healy

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Rapid identification of the optical counterparts of neutron star (NS) merger events discovered by gravitational wave detectors may require observing a large error region and sifting through a large number of transients to identify the object of interest. Given the expense of spectroscopic observations, a question arises: How can we utilize photometric observations for candidate prioritization, and what kinds of photometric observations are needed to achieve this goal? NS merger kilonova exhibits low ejecta mass (∼5 × 10-2 M) and a rapidly evolving photospheric radius (with a velocity ∼0.2c). As a consequence, these sources display rapid optical-flux evolution. Indeed, selection based on fast flux variations is commonly used for young supernovae and NS mergers. In this study, we leverage the best currently available flux-limited transient survey-The Zwicky Transient Facility Bright Transient Survey-To extend and quantify this approach. We focus on selecting transients detected in a 3-day cadence survey and observed at a one-day cadence. We explore their distribution in the phase space defined by g-r,, and. Our analysis demonstrates that for a significant portion of the time during the first week, the kilonova AT 2017gfo stands out in this phase space. It is important to note that this investigation is subject to various biases and challenges; nevertheless, it suggests that certain photometric observations can be leveraged to identify transients with the highest probability of being fast-evolving events. We also find that a large fraction (≈75 per cent) of the transient candidates with 0.7$]]> mag d-1, are cataclysmic variables or active galactic nuclei with radio counterparts.

Original languageEnglish
Pages (from-to)3741-3748
Number of pages8
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - 1 Jan 2024


FundersFunder number
Benozio Center
Israel Ministry of Science
University of Bochum
University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University
Willner Family Leadership Institute
National Science FoundationAST-1440341andAST-2034437, 1106171
National Science Foundation
Lawrence Livermore National Laboratory
University of Wisconsin-Milwaukee
California Institute of Technology
Northwestern University
Los Alamos National Laboratory
Trinity College Dublin
Minerva Foundation
Deutsche Forschungsgemeinschaft461903330
Deutsche Forschungsgemeinschaft
Weizmann Institute of Science
Israel Science Foundation
Institut National de Physique Nucléaire et de Physique des Particules


    • gravitational waves
    • methods: data analysis
    • methods: observational
    • methods: statistical
    • software: data analysis
    • stars: neutron
    • supernovae: general


    Dive into the research topics of 'Photometric prioritization of neutron star merger candidates'. Together they form a unique fingerprint.

    Cite this