The search for radio emission from exoplanets using LOFAR beam-formed observations: Jupiter as an exoplanet

Jake D. Turner, Jean-Mathias Grießmeier, Philippe Zarka, Iaroslavna Vasylieva
(Submitted on 20 Feb 2018)

Context. The magnetized Solar System planets are strong radio emitters and theoretical studies suggest that the radio emission from nearby exoplanets in close-in orbits could reach intensity levels $10^{3}-10^{6}$ times higher than Jupiter’s decametric emission. Detection of exoplanets in the radio domain would open up a brand new field of research, however, currently there are no confirmed detections at radio frequencies.

Aims. We investigate the radio emission from Jupiter, scaled such that it mimics emission coming from an exoplanet, with low-frequency beam-formed observations using LOFAR. The goals are to define a set of observables that can be used as a guideline in the search for exoplanetary radio emission and to measure effectively the sensitivity limit for LOFAR beam-formed observations.

Methods. We observe “Jupiter as an exoplanet” by dividing a LOFAR observation of Jupiter by a down-scaling factor and adding this observation to beam-formed data of the “sky background”. Then we run this artificial dataset through our processing and post-processing pipeline and determine up to which down-scaling factor Jupiter is still detected in the dataset.

Results. We find that exoplanetary radio bursts can be detected at 5 pc if the flux is $10^6$ times stronger than the typical level of Jupiter’s radio bursts during active emission events ($\sim4\times10^{5}$ Jy). Equivalently, radio bursts up to 20 pc (encompassing the known exoplanets 55 Cnc, Tau Bootis, and Upsilon Andromedae) can be detected assuming the level of emission is $10^{6}$ times stronger than the peak flux of Jupiter’s decametric burst emission ($\sim5\times10^{6}$ Jy).

Comments:    12 pages, 7 figures, 5 tables, Submitted to A&A
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as:    arXiv:1802.07316 [astro-ph.EP] (or arXiv:1802.07316v1 [astro-ph.EP] for this version)
Submission history
From: Jake Turner
[v1] Tue, 20 Feb 2018 20:30:25 GMT (12187kb,D)
https://arxiv.org/abs/1802.07316