# High-Resolution Radio Observations of Five Optically Selected Type 2 [PERSON]
## 5 Discussion  
### VLBI Structure of the Target Sources  
From the five targeted LLAGN sources, only SDSS J\(1026-0042\) was firmly detected with the EVN. One source component was found at both observing frequencies, 1.7 and 5 GHz. The VLBI positions (the coordinates corresponding to the origin of the maps in Figure 1) agree with each other within the uncertainty of about 1 mas. At both frequencies, the component is seen as a compact source. We calculated the minimum resolvable angular size with the interferometer using Equation (2) of [37]. The single detected component in SDSS J\(1026-0042\) is resolved at both frequencies as the fitted circular Gaussian diameters, 0.79 \(\pm\) 0.06 mas and 0.065 \(\pm\) 0.007 mas (FWHM) at 1.7 and 5 GHz, respectively, are larger than the minimum resolvable sizes. The size uncertainties were calculated following Fomalont [38]. Using the AIPS task MAXFIT, the peak position of the 5-GHz image is at right ascension \(\alpha_{\rm EVN}=10^{\rm h}26^{\rm m}40.4381^{\rm s}\) and declination \(\delta_{\rm EVN}=-00^{\circ}42^{\prime}06.496^{\prime\prime}\). In comparison, the most accurate optical position taken from the _Gaia_ Data Release 2 [28; 29] database ([[https://gea.esac.esa.int/archive/](https://gea.esac.esa.int/archive/)]([https://gea.esac.esa.int/archive/](https://gea.esac.esa.int/archive/))) is \(\alpha_{\rm Gaia}=10^{\rm h}26^{\rm m}40.4371^{\rm s}\pm 0.0003^{\rm s}\) \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multicolumn{1}{c}{**ID**} & \multicolumn{1}{c}{\(\rm S_{\rm 14.GHz}\)} & \(\rm S_{\rm 17.GHz}\) & \(\rm S_{\rm 27.GHz}\) & \(\rm S_{\rm 5 GHz}\) & \(\rm S_{\rm 84.GHz}\) & \(\rm S_{\rm 14.4}\) \\  & **mJy** & **mJy** & **mJy** & **mJy** & **mJy** & **mJy** & **mJy** & **mJy** \\ \hline SDSS J\(0741+3020\) & \(1.12\pm 0.16\) & \(0.28\pm 0.03\) & \(0.79\pm 0.12\) & \(<\)0.08 & 2.97 \(\pm\) 0.01 & \(-0.53\)\(\pm\) 0.04 \\ SDSS J\(0956+5735\) & \(0.88\pm 0.15\) & \(0.71\pm 0.07\) & \(0.47\pm 0.07\) & \(<\)0.08 & 2.88 \(\pm\) 0.01 & \(-0.95\)\(\pm\) 0.03 \\ SDSS J\(1014+0244\) & \(2.02\pm 0.13\) & \(1.70\pm 0.17\) & \(1.20\pm 0.18\) & \(<\)0.11 & 4.53 \(\pm\) 0.02 & \(-0.80\)\(\pm\) 0.07 \\ SDSS J\(1026-0042\) & \(1.85\pm 0.15\) & \(1.24\pm 0.12\) & \(1.63\pm 0.24\) & \(0.20\pm 0.02\) & 3.68 \(\pm\) 0.02 & \(-0.20\)\(\pm\) 0.09 \\ SDSS J\(1447+0211\) & \(0.76\pm 0.15\) & \(0.23\pm 0.02\) & \(0.55\pm 0.08\) & \(<\)0.08 & 2.76 \(\pm\) 0.01 & \(-0.49\)\(\pm\) 0.08 \\ \hline \hline \end{tabular}  
* Notes: Column 2, VLA [11; 31]: Column 3, EVN (this paper); Column 4, VLA [15]: Column 5, EVN (this paper); Column 6, VLA [11]: Column 7, two-point spectral index calculated from the arcsec-scale VLA (1.4-GHz FIRST and 2.7-GHz VLA85) measurements [15; 31].  
\end{table} 
Table 2: Flux densities with their associated uncertainties and the derived \(a_{14}^{27}\) spectral indices of the target sources. \(\delta_{\rm Gaia}=-00^{\circ}42^{\prime}06.4843^{\prime\prime}\pm 0.0081^{\prime\prime}\). There is a radio-optical positional difference of \(\sim 15\) mas in right ascension and \(\sim 10\) mas in declination (Figure 1). Given that the EVN positions are accurate to within 1 mas, and for the optical position the uncertainties are \(\Delta\alpha\approx 5\) mas and \(\Delta\delta\approx 8\) mas, the difference is significant. At \(z=0.364\), this corresponds to (\(\sim\)90 \(\pm\) 40) pc projected linear distance between the _Gaia_ optical and the VLBI radio position. According to [PERSON] et al. [39], at least 20-50 pc projected difference between the VLBI and _Gaia_ positions is quite common in bright AGNs. They also found that in 80% of Seyfert 2 galaxies, the associated _Gaia_ position related to the jet is located farther away from the nucleus than the VLBI core. This offset could be explained by the presence of a bright extended optical jet which shifts the _Gaia_ centroid [40,41].