PKS 2354−35
Type-cD galaxy in the constellation Sculptor
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PKS 2354−35 also designated as ESO 349-010,[2] is a type-cD galaxy located in the constellation of Sculptor. The redshift of the galaxy is (z) 0.049[1] and it was first discovered as an extragalactic radio source by astronomers in December 1965, whom they identified it with a spherical object surrounded by a diffused envelope.[3] It is classified as a radio galaxy[4] and is the brightest cluster galaxy in Abell 4059.[2]
| PKS 2354−35 | |
|---|---|
PKS 2354−35 taken with DESI Legacy Surveys | |
| Observation data (J2000 epoch) | |
| Constellation | Sculptor |
| Right ascension | 23h 57m 00.72s[1] |
| Declination | −34° 45′ 32.97″[1] |
| Redshift | 0.049051[1] |
| Heliocentric radial velocity | 14,705 km/s[1] |
| Distance | 707.0 ± 49.5 Mly (216.77 ± 15.18 Mpc)[1] |
| Group or cluster | Abell 4059 |
| Apparent magnitude (V) | 14.42[1] |
| Characteristics | |
| Type | cD;E+4;BrClG[1] |
| Size | ~641,600 ly (196.73 kpc) (estimated)[1] |
| Other designations | |
| PGC 73000, ESO 349-G010, G4Jy 1858, ABELL 4059:[AAV2011] BCG, 2MASX J23570068-3445331, 6dF J2357006-344533[1] | |
Description
PKS 2354−35 is a cD galaxy dominating the center of Abell 4059. It has also been categorized as a Type I Fanaroff-Riley class radio galaxy and contains dust absorption features in its center when imaged by Hubble Space Telescope (HST).[5][6] The radial profile of the galaxy is found to display no signs of rotation but the velocity dispersion profile is mainly positive.[7] The optical spectrum of the galaxy contains both doubly ionized oxygen and ionized neon lines.[4]
The radio source of PKS 2354−35 is found to be compact. When observed, it has a radio core component shown to have a size of around 0.4 arcseconds with a flux density of seven mJy. There is a presence of jet structure on both sides of the source. The radio spectrum has been described as extremely steep and the total radio luminosity has been calculated as 1.5 × 1042 erg s−1.[4] Two radio lobes have been detected in the galaxy, depicted as extending along a major axis and positioned perpendicularly towards an X-ray bar feature.[8][9]
HST imaging have also detected the presence of a dust lane in PKS 2354−35. When observed, the dust lane is shown to shown an extension of five arcseconds across with a projection across the central region. Evidence also found the dust lane is mainly twisted with a position angle of between 60° to 70° in relation to the galaxy's own radio axis. This suggested a recent galaxy merger around 108 million years ago.[10] The central supermassive black hole has been estimated as 0.7+1.0-0.4 × 109 M☉ based on a factor adjustment of 0.35, with an Eddington ratio of 1.2+4.6-0.9 × 10−3 Medd.[11] A pair of X-ray cavities have been discovered inside a central region along with X-ray emission ridge that is associated with the galaxy. Evidence also suggested the galaxy's nucleus may be activated through tidal stripping of cold gas from a late-type starburst galaxy based on asymmetries of the interstellar medium.[12]