Year: 2023
Type: article
Abstract: We present the serendipitous discovery of eight distant (> 50 pc) late M dwarfs with plausible associated radio emission at 144 MHz. The M-dwarf nature of our sources has been confirmed with optical spectroscopy performed using HET/LRS2 and Subaru/FOCAS, and their radio flux densities are within the range of 0.5−1.0 mJy at 144 MHz. Considering the radio-optical source separation and source densities of the parent catalogues, we suggest that it is statistically probable that the M dwarfs are associated with the radio emission. However, it remains plausible that for some of the sources the radio emission originates from an optically faint and red galaxy hiding behind the M dwarf. The isotropic radio luminosities (∼1017 − 18 erg s−1 Hz−1) of the M dwarfs suggest that if the association is real, the radio emission is likely driven by a coherent emission process produced via plasma or electron-cyclotron maser instability processes, which is potentially caused by binary interaction. Long-term monitoring in the radio and high-resolution radio follow-up observations are necessary to search for any variability and pinpoint the radio emission to determine whether our tentative conclusion that these ultracool dwarfs are radio emitting is correct. If the low-frequency radio emission is conclusively associated with the M dwarfs, this would reveal a new population of optically faint and distant (> 50 pc) radio-emitting M dwarfs.
Source: Astronomy and Astrophysics
Institutions: Leiden University, Leiden Observatory, Netherlands Institute for Radio Astronomy, Royal Observatory, University of Oxford, University College London, Institute for Cosmic Ray Research, The University of Tokyo, McDonald Observatory, The University of Texas at Austin, University of Hertfordshire, University of Colorado Boulder, Laboratory for Atmospheric and Space Physics, Max Planck Institute for Radio Astronomy
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,623
Funders: University of Texas at Austin, University of Hertfordshire, Science Foundation Ireland, Bundesministerium für Bildung und Forschung, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Max-Planck-Gesellschaft, Centre National de la Recherche Scientifique, Université d'Orléans, Ministerium für Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen, Gauss Centre for Supercomputing, Observatoire de Paris, Université de Recherche Paris Sciences et Lettres, Science and Technology Facilities Council, Leibniz-Gemeinschaft, DST-NRF Centre Of Excellence In Tree Health Biotechnology
OpenAlex ID: W4386534786