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arXiv · 2604.22347

A Morphological Identification and Study of Radio Galaxies from LoTSS DR2. I. The "Winged'' Radio Galaxies

Soumen Kumar Bera·Taotao Fang·Tapan K. Sasmal·M. Kunert-Bajraszewska·Xuelei Chen·Soumen Mondal
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Abstract

We conducted an extensive identification and analysis of various morphological classes and subclasses of radio galaxies using the latest high-resolution data from the second data release of the LOFAR Two-Metre Sky Survey (LoTSS DR2). This paper presents the first results of our large-scale investigation: a new catalog of ``winged" radio galaxies (WRGs). These objects represent a fascinating class of irregular radio galaxies, characterized by a pair of secondary radio lobes (``wings") in addition to the primary active lobes. We identified and cataloged 621 new WRGs and 403 additional candidates. Among the confirmed winged sources, 382 are classified as ``X"-shaped radio galaxies (XRGs), while the remaining 239 are ``Z"-shaped radio galaxies (ZRGs). We also estimated several basic parameters for these winged sources and performed a Fanaroff-Riley (FR) classification. Our results show that the majority of the sources ($\sim$88\%) exhibit edge-brightened radio lobes and high average radio power ($\rm log_{10}[P_{144MHz} / W Hz^{-1}]$ = 26.25), consistent with an FR-II classification. The average spectral index between 144 MHz and 1.4 GHz is --0.84, which is steeper than that found for previously identified winged sources based on higher-frequency data from the VLA Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. This indicates that our study is capable of detecting fainter sources. The median linear size of the winged sources, 498 kpc, confirms that these are large-scale structures, with approximately 16\% having sizes exceeding 0.7 Mpc, making them potential candidates for giant radio galaxies.

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Soumen Kumar Bera, Taotao Fang, Tapan K. Sasmal, M. Kunert-Bajraszewska, Xuelei Chen, Soumen Mondal. 2026-04-24. A Morphological Identification and Study of Radio Galaxies from LoTSS DR2. I. The "Winged'' Radio Galaxies. https://doi.org/10.3847/1538-4365%2Fadc67f

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