Radio morphology of southern narrow-line Seyfert 1 galaxies with Very Large Array observations

We present the results of new radio observations carried out with the Karl G. Jansky Very Large Array C-configuration at 5.5 GHz for a sample of southern narrow-line Seyfert 1 galaxies (NLS1s). This work increases the number of known radio-detected NLS1s in the Southern hemisphere, and confirms that the radio emission of NLS1s is mainly concentrated in a central region at kpc-scale and only a few sources show diffuse emission. In radio-quiet NLS1s, the radio luminosity tends to be higher in steep-spectrum sources and be lower in flat-spectrum sources, which is opposite to radio-loud NLS1s. This may be because the radio emission of steep NLS1s is dominated by misaligned jets, active galactic nucleus driven outflows, or star formation superposing on a compact core. Instead the radio emission of flat NLS1s may be produced by a central core that has not yet developed radio jets and outflows. We discover new NLS1s harbouring kpc-scale radio jets and confirm that a powerful jet does not require a large-mass black hole to be generated. We also find sources dominated by star formation. These NLS1s could be new candidates in investigating the radio emission of different mechanisms.

Keywords

Galaxies: active, Galaxies: jets, Galaxies: nuclei, Galaxies: Seyfert, Radio continuum: galaxies

DOI

10.1093/mnras/staa2373

Citation

Chen , S , Järvelä , E , Crepaldi , L , Zhou , M , Ciroi , S , Berton , M , Kharb , P , Foschini , L , Gu , M , la Mura , G & Vietri , A 2020 , ' Radio morphology of southern narrow-line Seyfert 1 galaxies with Very Large Array observations ' , Monthly Notices of the Royal Astronomical Society , vol. 498 , no. 1 , pp. 1278-1297 . https://doi.org/10.1093/mnras/staa2373

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-2020123160483

Collections

[article-cris] Sähkötekniikan korkeakoulu / ELEC

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