Structural and spectral properties of Galactic plane variable radio sources

In the time domain, radio sky in particular along Galactic plane direction may vary significantly because of various energetic activities associated with stars, stellar and supermassive black holes. Using multi-epoch Very Large Array surveys at 5.0 GHz, Becker et al. (2010) presented a catalogue 39 variable sources flux density range 1-70 mJy. To probe their structures spectra, we observed 17 very-long-baseline interferometric (VLBI) imaging technique collected additional multi-frequency data from literature. We detected all 5 GHz Westerbork Synthesis Radio Telescope, but only G23.6644-0.0372 European VLBI Network (EVN). Together its decadal variability spectrum, interpret it as an extragalactic peaked-spectrum source size <~10 pc. The remaining were resolved out by long baselines EVN either strong scatter broadening latitude <1 deg or intrinsically very extended on centi-arcsec scales. According to spectral structural properties, find that sample has diverse nature. notice two young H II regions spot star candidate planetary nebula. rest are likely active galactic nuclei (AGN). Two them also displays arcsec-scale faint jet activity. study indicates AGN commonplace even among plane.