<p>We present a multi-frequency analysis of the candidate double–double radio galaxy (DDRG) J2349−0003, exhibiting a possible lobe misalignment. High-resolution uGMRT observations at Bands 3 and 4 reveal a complex radio morphology featuring a pair of inner and outer lobes, and the radio core, while the Band 5 image detects the core and the compact components. The positioning of both pairs of lobes with the central core supports its classification as a DDRG. Spectral age estimates for the inner and outer lobes indicate two distinct episodes of active galactic nucleus (AGN) activity interspaced by a short quiescent phase. The possible compact steep-spectrum nature of the core, together with its concave spectral curvature, suggests ongoing or recent jet activity, suggesting the possibility that J2349−0003 may be a candidate triple-double radio galaxy. With a projected linear size of 1.08 Mpc, J2349−0003 is classified as a giant radio galaxy (GRG), although its moderate radio power (<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12036_2025_10102_Article_IEq1.gif" Format="GIF" Height="6" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$\sim $</EquationSource> <EquationSource Format="MATHML"><math> <mo>∼</mo> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12036_2025_10102_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="29" /> </InlineMediaObject> <EquationSource Format="TEX">$10^{24}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>10</mn> <mn>24</mn> </msup> </math></EquationSource> </InlineEquation> WHz<InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12036_2025_10102_Article_IEq3.gif" Format="GIF" Height="11" Rendition="HTML" Resolution="72" Type="Linedraw" Width="18" /> </InlineMediaObject> <EquationSource Format="TEX">$^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow /> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </mmultiscripts> </math></EquationSource> </InlineEquation>) suggests a sparse surrounding environment. Arm-length (<InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12036_2025_10102_Article_IEq4.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="22" /> </InlineMediaObject> <EquationSource Format="TEX">$R_\theta $</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>R</mi> <mi>θ</mi> </msub> </math></EquationSource> </InlineEquation>) and flux density ratios (<InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="12036_2025_10102_Article_IEq5.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="24" /> </InlineMediaObject> <EquationSource Format="TEX">$R_S$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>R</mi> <mi>S</mi> </msub> </math></EquationSource> </InlineEquation>) indicate environmental influences on source symmetry. The observed lobe misalignment and the presence of nearby galaxies in the optical image suggest that merger-driven processes may have played a key role in shaping the source’s evolution.</p>

A multi-frequency study of the candidate double–double radio galaxy J2349−0003 with a possible misalignment

期刊论文
发表日期：

2025年10月6日

查看全文

T. P. Sudheesh,
Ruta Kale,
V. Jithesh,
C. H. Ishwara-Chandra,
Joe Jacob

摘要

We present a multi-frequency analysis of the candidate double–double radio galaxy (DDRG) J2349−0003, exhibiting a possible lobe misalignment. High-resolution uGMRT observations at Bands 3 and 4 reveal a complex radio morphology featuring a pair of inner and outer lobes, and the radio core, while the Band 5 image detects the core and the compact components. The positioning of both pairs of lobes with the central core supports its classification as a DDRG. Spectral age estimates for the inner and outer lobes indicate two distinct episodes of active galactic nucleus (AGN) activity interspaced by a short quiescent phase. The possible compact steep-spectrum nature of the core, together with its concave spectral curvature, suggests ongoing or recent jet activity, suggesting the possibility that J2349−0003 may be a candidate triple-double radio galaxy. With a projected linear size of 1.08 Mpc, J2349−0003 is classified as a giant radio galaxy (GRG), although its moderate radio power ( $\sim $ $\sim$ $10^{24}$ $10^{24}$ WHz $^{-1}$ $^{- 1}$ ) suggests a sparse surrounding environment. Arm-length ( $R_\theta $ $R_{θ}$ ) and flux density ratios ( $R_S$ $R_{S}$ ) indicate environmental influences on source symmetry. The observed lobe misalignment and the presence of nearby galaxies in the optical image suggest that merger-driven processes may have played a key role in shaping the source’s evolution.