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A Matched Survey for the Enigmatic Low Radio Frequency Transient ILT J225347+862146

Huang, Yuping and Anderson, Marin M. and Hallinan, Gregg and Lazio, T. Joseph W. and Price, Danny C. and Sharma, Yashvi (2022) A Matched Survey for the Enigmatic Low Radio Frequency Transient ILT J225347+862146. Astrophysical Journal, 925 (2). Art. No. 171. ISSN 0004-637X. doi:10.3847/1538-4357/ac4048.

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Discovered in 2011 with LOFAR, the 15 Jy low-frequency radio transient ILT J225347+862146 heralds a potentially prolific population of radio transients at <100 MHz. However, subsequent transient searches in similar parameter space yielded no detections. We test the hypothesis that these surveys at comparable sensitivity have missed the population due to mismatched survey parameters. In particular, the LOFAR survey used only 195 kHz of bandwidth at 60 MHz, while other surveys were at higher frequencies or had wider bandwidth. Using 137 hr of all-sky images from the Owens Valley Radio Observatory Long Wavelength Array, we conduct a narrowband transient search at ∼10 Jy sensitivity with timescales from 10 minutes to 1 day and a bandwidth of 722 kHz at 60 MHz. To model the remaining survey selection effects, we introduce a flexible Bayesian approach for inferring transient rates. We do not detect any transient and find compelling evidence that our nondetection is inconsistent with the detection of ILT J225347+862146. Under the assumption that the transient is astrophysical, we propose two hypotheses that may explain our nondetection. First, the transient population associated with ILT J225347+862146 may have a low all-sky density and display strong temporal clustering. Second, ILT J225347+862146 may be an extreme instance of the fluence distribution, of which we revise the surface density estimate at 15 Jy to 1.1 × 10⁻⁷ deg⁻² with a 95% credible interval of (3.5 × 10⁻¹², 3.4 × 10⁻⁷) deg⁻². Finally, we find a previously identified object coincident with ILT J225347+862146 to be an M dwarf at 420 pc.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Huang, Yuping0000-0003-4267-6108
Anderson, Marin M.0000-0003-2238-2698
Hallinan, Gregg0000-0002-7083-4049
Lazio, T. Joseph W.0000-0002-3873-5497
Price, Danny C.0000-0003-2783-1608
Sharma, Yashvi0000-0003-4531-1745
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 October 21; revised 2021 November 19; accepted 2021 December 4; published 2022 February 3. We thank the anonymous referee for a thoughtful report that improved the quality of the manuscript. We thank Casey Law for a thorough reading of the manuscript. We are indebted to Viraj Karambelkar, Mansi Kasliwal, Andy Tzanidakis, Yuhan Yao, and the ZTF team for the DBSP observation and data reduction. We thank Barak Zackay, Yuhan Yao, Sarah Blunt, and Ryan Rubenzahl for helpful discussions. This material is based in part upon work supported by the National Science Foundation under grant Nos. AST-1654815, AST-1212226, and AST-1828784. This work was supported by a grant from the Simons Foundation (668346, JPG). We are grateful to Schmidt Futures for supporting the Radio Camera Initiative, under which part of this work was carried out. The OVRO-LWA project was initiated through the kind donation of Deborah Castleman and Harold Rosen. Y.H. thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining grant No. 1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. G.H. acknowledges the support of the Alfred P. Sloan Foundation and the Research Corporation for Science Advancement. This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC; Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research has made use of the NASA/IPAC Extragalactic Database, which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. Facilities: Hale (DBSP) - , Gaia. - Software: astropy (Astropy Collaboration et al. 2018), TTCal (Eastwood 2016), WSClean (Offringa et al. 2014), CASA (McMullin et al. 2007), CASA 6 (Raba et al. 2020), seaborn (Waskom 2021), Jupyter (Kluyver et al. 2016), Matplotlib (Hunter 2007), pymc3 (Salvatier et al. 2016), arviz (Kumar et al. 2019), lightkurve (Lightkurve Collaboration et al. 2018), pyraf-dbsp (Bellm & Sesar 2016), and SciPy (Virtanen et al.2020).
Group:Astronomy Department
Funding AgencyGrant Number
Simons Foundation668346
Schmidt Futures ProgramUNSPECIFIED
Deborah Castleman and Harold RosenUNSPECIFIED
Large Synoptic Survey Telescope CorporationUNSPECIFIED
Brinson FoundationUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Research CorporationUNSPECIFIED
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:Radio transient sources; Radio interferometry; Non-thermal radiation sources; Bayesian statistics; M dwarf stars
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Radio transient sources (2008); Radio interferometry (1346); Non-thermal radiation sources (1119); Bayesian statistics (1900); M dwarf stars (982)
Record Number:CaltechAUTHORS:20220125-215144189
Persistent URL:
Official Citation:Yuping Huang et al 2022 ApJ 925 171
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113106
Deposited By: George Porter
Deposited On:26 Jan 2022 15:22
Last Modified:08 Feb 2022 23:46

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