3C 411

3C 411 is a high-excitation Fanaroff-Riley class Type 2 radio galaxy (HEG)^[2] located in the constellation of Delphinus. The estimated redshift for this galaxy is (z) 0.467^[1][3] and it was first recorded in the Third Cambridge Catalogue of Radio Sources in 1962.^[4] It was classified as an extragalactic radio source in 1974 by astronomers,^[5] before being identified as an N galaxy, that is described to have a distant redshift based on an observation by Hyron Spinrad.^[6]

3C 411
Pan-STARRS image of 3C 411.
Observation data (J2000.0 epoch)
Constellation	Delphinus
Right ascension	20h 22m 08.43s[1]
Declination	+10° 01′ 11.26″[1]
Redshift	0.467000[1]
Heliocentric radial velocity	140,003 km/s[1]
Distance	4.947 Gly
Apparent magnitude (B)	19.70
Characteristics
Type	N galaxy HEG[1]
Other designations
4C +09.67, PKS 2019+09, LEDA 2817722, PKS B2019+098, NVSS J202208+100110, OW +032, DA 512, NRAO 0627, TXS 2019+098[1]

Description

3C 411 is a broad-line radio galaxy (BLRG).^[7] It is found to contain a double lobed source. When observed through radio mapping, the source is found to contain a radio emission bridge of low surface brightness connecting the components, with a nuclear point source dominating over the optical object.^[6] Imaging by the Very Large Array (VLA) in 1984 showed the source is heavily depolarized with the radio spectrum steepening outside the location of its hotspots. A radio jet is also shown linking with a central component with the hotspot feature that is located in the western radio lobe.^[8] At 15 GHz the source also shows signs of spectra steepening in both of its lobes.^[9]

An observation conducted in 2014 by XMM Newton found 3C 411 is a flat spectrum radio quasar. It is found to have a cold accretion disk around its central supermassive black hole. The estimated mass of the black hole is 3 x 10⁷ M_ʘ, and the object has a total flux density of 2.20 ± 0.16 x 10^-12 erg cm^-2 s^-1. A double power-law component was also found in 3C 411, mainly made up of a hard component and a Seyfert type-like component.^[10]

In March 2019 the object was thought to have a blazar core in its center. However when observed, its jet is shown as straight on a trajectory path with an inclination angle at 50°. Although Very Long Baseline Interferometry (VLBI) observations found the core as compact, it is found to be modelled by multiple jet components instead of a blazar jet, ruling out the possibly of it being classified as a blazar.^[11]