arXiv subjects

Marek Weżgowiec

Publications and source records attributed to Marek Weżgowiec.

3 recordsLinked to original sources

arXiv2026

Origin of the double-peaked narrow emission-lines in the optical spectra of X-shaped Radio Galaxies

We investigate X-shaped radio galaxies (XRGs) with optical double-peaked narrow emission lines (DPNELs) as potential hosts of dual or binary supermassive black holes (SMBHs). Using available optical spectra from the SDSS and DESI surveys, we identify 55 DPNEL sources among a sample of 187 XRGs. We find that the occurrence of [O III] DPNELs in XRGs is $\sim$30 %, which is substantially higher than the $\sim$1 % observed in the general galaxy population. Using optical (involving {[O III]$λ$5007}, H$α$, H$β$, {[N II]$λ$,6584}, and {[S II]$λλ$6716,6731}) and mid-infrared diagnostic diagrams, we found that both components are predominantly AGN-powered, implying a $\sim$95 % probability of hosting dual AGN systems. In comparison, a stellar-mass-, color-, and redshift-matched control sample of non-XRG DPNEL galaxies shows a lower dual AGN fraction, which depends strongly on radio luminosity, rising from ~25 % in radio-undetected to ~54 % in radio-detected galaxies, and reaching ~95 % in radio-bright XRGs and FR-II radio galaxies. Interestingly, more than 30 % of DPNEL XRGs have companion galaxies, supporting a merger-driven origin for these systems. Finally, we analyze parsec-scale radio structure in 7 XRGs using VLBA observations at 1.4, 4.3, and 7.6 GHz, resolving the core in only one source. Nevertheless, flat radio spectral indices, AGN-like emission-line properties, and radio-optical VLBA-Gaia positional offsets found in 5 cases together support the interpretation that XRGs are strong dual/binary AGN candidates.

astro-ph.GA↗

arXiv2025

Multiwavelength investigations of PKS 2300-18: S-shaped radio quasar with precessing jets and double-peaked broad emission-line spectrum

S-shaped radio galaxy jets are prime sources for investigating the dynamic interplay between the central active galactic nucleus, the jets, and the ambient intergalactic medium. These sources are excellent candidates for studying jet precession, as their S-shaped inversion symmetry strongly indicates underlying precession. We present a multiwavelength analysis of the giant inversion-symmetric S-shaped radio galaxy PKS 2300-18, which spans 0.76 Mpc. The host is a quasar at a redshift of 0.128, displaying disturbed optical morphology due to an ongoing merger with a companion galaxy. We conducted a broadband radio spectral study using multifrequency data ranging from 183 MHz to 6 GHz, incorporating dedicated observations with the uGMRT and JVLA alongside archival radio data. A particle injection model was fitted to the spectra of different regions of the source to perform ageing analysis, which was supplemented with a kinematic jet precession model. The ageing analysis revealed a maximum plasma age of ~ 40 Myr, while the jet precession model indicated a precession period of ~ 12 Myr. ROSAT data revealed an X-ray halo of Mpc size, and from Chandra the AGN X-ray spectrum was modelled using thermal and power-law components. The optical spectrum displaying double-peaked broad emission lines was modelled, indicating complex broad-line region kinematics at the centre with the possibility of a binary SMBH. We present the results of our multiwavelength analysis of the source, spanning scales from a few light-days to a few Mpc, and discuss its potential evolutionary path.

astro-ph.GA↗

arXiv2023

Multifrequency analysis of the radio emission from a post-merger galaxy CGCG 292-057

Galaxies exhibiting a specific large-scale extended radio emission, such as X-shaped radio galaxies, belong to a rare class of winged radio galaxies. The morphological evolution of these radio sources is explained using several theoretical models, including galaxy mergers. However, such a direct link between a perturbed radio morphology and a galaxy merger remains observationally sparse. Here we investigate a unique radio galaxy J1159+5820, whose host CGCG 292-057 displays the optical signature of a post-merger system with a distinct tidal tail feature, and an X-shaped radio morphology accompanied by an additional pair of inner lobes. We observed the target on a wide range of radio frequencies ranging from 147 MHz to 4959 MHz, using dedicated GMRT and VLA observations, and supplemented it with publicly available survey data for broadband radio analysis. Particle injection models were fitted to radio spectra of lobes and different parts of the wings. Spectral ageing analysis performed on the lobes and the wings favors a fast jet realignment model with a reorientation timescale of a few million years. We present our results and discuss the possible mechanisms for the formation of the radio morphology.

astro-ph.GA↗