Photometric prioritization of neutron star merger candidates
Creators
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1.
Weizmann Institute of Science
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2.
Tel Aviv University
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3.
California Institute of Technology
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4.
Infrared Processing and Analysis Center
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5.
University of Minnesota
Abstract
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, $\dot{g}$, and $\dot{r}$. 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 $\vert\dot{g}\vert>0.7$ mag d−1, are cataclysmic variables or active galactic nuclei with radio counterparts.
Copyright and License
Acknowledgement
We thank an anonymous referee for constructive comments. EOO is grateful for the support of grants from the Benozio Center, Willner Family Leadership Institute, Ilan Gluzman (Secaucus NJ), Madame Olga Klein – Astrachan, Minerva Foundation, Israel Science Foundation, BSF-NSF, Israel Ministry of Science, Weizmann-MIT, and the Rosa and Emilio Segre Research Award. NLS is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via the Walter Benjamin programme – 461903330.
Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grants no. AST-1440341andAST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute of Science, Oskar Klein Center at Stockholm University, University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, France, University of Warwick, University of Bochum, and Northwestern University. Operations are conducted by COO, IPAC, and UW.
The SED Machine is based on work supported by the National Science Foundation under grant no. 1106171.
Data Availability
The data presented in this paper is available in the electronic tables, while the code is accessible via GitHub.
Supplemental Material
Table 2. BTS transients, magnitudes, and magnitude derivatives after Galactic extinction correction. δ symbols indicate uncertainties.
Files
10.1093_mnras_stad3380.pdf
Additional details
Related works
- Is new version of
- Discussion Paper: arXiv:2311.04863 (arXiv)
- Is supplemented by
- Software: https://github.com/EranOfek/AstroPack (URL)
Funding
- Minerva Stiftung
- Israel Science Foundation
- United States-Israel Binational Science Foundation
- Weizmann Institute of Science
- Massachusetts Institute of Technology
- Deutsche Forschungsgemeinschaft
- 461903330
- National Science Foundation
- AST-1440341
- National Science Foundation
- AST-2034437
- National Science Foundation
- 1106171
Dates
- Available
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2023-11-14Published
Caltech Custom Metadata
- Caltech groups
- Astronomy Department , Palomar Observatory , Infrared Processing and Analysis Center (IPAC) , Zwicky Transient Facility , Division of Physics, Mathematics and Astronomy (PMA)
- Publication Status
- Published