Three New Spiral Galaxies with Active Nuclei Producing Double Radio Lobes

Abstract

Double radio lobes are generally believed to be produced by active nuclei of elliptical galaxies. However, several double-lobed radio sources have been solidly found to be associated with spiral galaxies. By cross-matching ~9 x 10^5 spiral galaxies selected from the SDSS DR8 data with the full 1.4GHz radio source catalogs of NVSS and FIRST, we identify three new spiral galaxies: J0326-0623, J1110+0321 and J1134+3046 that produce double radio lobes, in addition to five double-lobed spirals previously known. By combining the newly discovered and all the other known cases in literature, we find that most of these spiral galaxies are located in a galaxy group or a poor cluster, in which the environment is denser than in the field, and about half of them are the central brightest galaxies in their parent system. We therefore suggest that the environment is one of the key factors for a spiral to produce double radio lobes.

Four Late-type Galaxies with Double Radio Lobes and Properties of Such Galaxies

“…It is pivotal to adopt an optimal radius for optical-radio crossmatching since a small value would miss some large-scale lobes, while a large radius would produce an overwhelming number of fake associations. Based on the experience gained from previous works (Yuan et al 2016;Gao et al 2023), we set the crossmatching radius as 500 kpc. This radius is sufficiently large given that only one case, J2345−0449, is known to host radio lobes with a total length exceeding 1 Mpc.…”

“…Recently, Wu et al (2022) expanded the existing sample by identifying 18 disks associated with radio lobes. In addition, Gao et al (2023) discovered three new cases, J0326−0623, J1110+0321 and J1134+3046, by crossmatching a spiral sample derived by Kuminski & Shamir (2016) with the source catalogs of NRAO VLA Sky Survey (NVSS, Condon et al 1998) and Faint Images of the Radio Sky at Twenty-centimeter (FIRST, Becker et al 1995).…”

“…Wu et al (2022) claimed that the mass of galaxy and then BH is a crucial factor in the formation of radio lobes. Gao et al (2023) found that the surrounding environment may also play an important role because most (12/17) double-lobed spirals are found in galaxy groups or poor clusters.…”

“…To date, only about 30 LaGRLs have been identified (e.g., Wu et al 2022;Gao et al 2023), and most of the previous systematic searches (e.g., Mao et al 2015;Singh et al 2015;Wu et al 2022;Gao et al 2023) relied on optical samples derived from the Sloan Digital Sky Survey (SDSS, York et al 2000). The Dark Energy Spectroscopic Instrument (DESI) imaging surveys (Dey et al 2019), covering a larger sky region and having a deeper exposure than those of the SDSS, are publicly available recently (e.g., Zou et al 2022).…”

Identifying Host Galaxies of Extragalactic Radio Emission Structures using Machine Learning

“…Most of the host galaxies of radio galaxies are large elliptical galaxies (Kuźmicz et al 2019). However, some of the doublelobed radio sources with structures on larger than kiloparsec scales are found to be hosted by disk galaxies (e.g., Ledlow et al 1998Ledlow et al , 2001Croston et al 2008;Hota et al 2011;Tsai et al 2013;Mao 2015;Mulcahy et al 2016;Gao et al 2023). There is not, yet, a consensus model that describes the formation processes of these radio structures and the interaction between the radio emission and their host galaxies.…”