3C 356 | |
---|---|
![]() The radio galaxy 3C 356. | |
Observation data (J2000.0 epoch) | |
Constellation | Draco |
Right ascension | 17h 24m 19.041s |
Declination | +50° 57′ 40.14″ |
Redshift | 1.079000 |
Heliocentric radial velocity | 323,476 km/s |
Distance | 7.817 Gly |
Apparent magnitude (V) | 21.5 |
Apparent magnitude (B) | 21.5 |
Characteristics | |
Type | NLRG |
Other designations | |
LHE 425, 4C 51.36, OHIO T 538, NRAO 526, NVSS J172420+505714, WB 1723+5100, LEDA 2817697 |
3C 356 is a distant radio galaxy [1] [2] located in the constellation of Draco, hosted by a merging pair of elliptical galaxies located at redshift (z) 1.079 [3] with two radio cores having a separation gap of 5 arcseconds. [4] [5] It was first discovered as an astronomical radio source by P. Veron from a 3C revised catalogue in 1966 [6] and such, shows an alignment effect at both wavelengths. [7] The X-ray source luminosity for this galaxy is estimated to be 2.5 x 1044 erg s−1. [2]
3C 356 contains a double compact source with a 170° position angle. The source is found weakly depolarized in south-east direction closer to the central region. There is a presence of a northern object displaying a more ionized emission line spectrum likely the source's origin. In additional, the northern component is more compact but has an extension directly south by 3 arcseconds. [8] According to Hubble Space Telescope (HST) imaging of a northwest component, this shows a high surface brightness conelike structure with a much fainter extension. [9]
The radio structure of 3C 356 is complex. Its radio core position is unresolved with a diffused region peaking 5 arcseconds away at a position angle of 150° and a radio axis of 162°. [10] There are two radio lobes in 3C 356 are located 15 arcseconds and 30 arcseconds in both directions. [3] According to Very Large Array radio mapping, both northwestern and southeastern lobes are shown enlarged and overlaid polarized. In the southeastern lobe, there are three compact structures of equal brightness. The northwestern lobe on the other hand, contains a defined hot spot and more extended emission. [11]
According to deep near-infrared imaging taken via Subaru Telescope, 3C 356 is found connected with a poor cluster of galaxies. [12] A stellar mass of 4 x 1011 Mʘ has also been calculated for the spectral energy distribution of the galaxy as well, with the supermassive black hole mass being 8.74 ± 0.42 Mʘ. [13]
3C 109 is a Seyfert galaxy located in the constellation Taurus. It is also a broad-line radio galaxy, classified as one of the most active polarized galaxies apart from blazars with quasar-like properties. The black hole in 3C 109 is said to have an estimated mass of 9.3 x 108M☉.
3C 171 is a Seyfert galaxy located in the constellation Lynx, classfied as a radio galaxy, containing an extended emission-line region. It is also a relatively isolated galaxy, not belonging to any other rich galaxy clusters.
3C 249.1 is a Seyfert galaxy located in the constellation Draco. It hosts a powerful radio source and is located at redshift 0.3115, with a peculiar radio structure. One of its radio lobes is classified as having a Fanaroff-Riley classification Type II, while the other lobe has no features nor containing hotspots.
3C 433 is a Seyfert galaxy located in the constellation Vulpecula. It has a redshift of z =0.1016, and is classified as a peculiar radio galaxy with high luminosity other than its complex shell-type. Apart from that, it has a young stellar population and a radio structure mainly made up of knot and jet structures. Using mid-infrared wavelengths from Spitzer Observations, 3C 433 hosts a hidden quasar.
Hercules A is a bright astronomical radio source in the constellation Hercules corresponding to the galaxy 3C 348.
NGC 708 is an elliptical galaxy located 240 million light-years away in the constellation Andromeda and was discovered by astronomer William Herschel on September 21, 1786. It is classified as a cD galaxy and is the brightest member of Abell 262. NGC 708 is a weak FR I radio galaxy and is also classified as a type 2 Seyfert galaxy.
An extended emission-line region (EELR) is a giant interstellar cloud ionized by the radiation of an active galactic nucleus (AGN) inside a galaxy or photons produced by the shocks associated with the radio jets. An EELR can appear as a resolved cloud in relative nearby galaxies and as narrow emission lines in more distant galaxies.
4C+55.16 is an elliptical galaxy, classified type E, located in Ursa Major. The galaxy lies about 2.84 billion light-years from Earth, which means given its apparent dimensions, 4C+55.16 is approximately 445,000 light-years across making it a type-cD galaxy. It is the brightest cluster galaxy (BCG) in a cluster of the same name.
PKS 0438-436, also known as PKS J0440-4333, is a quasar located in constellation Caelum. With a high redshift of 2.86, the object is located 11.2 billion light-years from Earth and is classified as a blazar due to its flat-spectrum radio source, (in terms of the flux density as with α < 0.5 and its optical polarization.
TXS 1545-234 known as NVSS J154817-233701, is a radio galaxy located in the constellation Scorpius. It has a redshift of 2.755.
PKS 1345+125 known as PKS 1345+12 and 4C +12.50, is an ultraluminous infrared galaxy (ULIG) with an active galactic nucleus, located in the constellation Boötes. With a redshift of 0.121740, the galaxy is located 1.7 billion light-years from Earth.
Abell 1942 BCG, also known as PGC 1256558, is a massive elliptical galaxy of type-cD residing as the brightest cluster galaxy of the Abell 1942 galaxy cluster, located in the constellation Virgo. With a redshift of 0.224, the galaxy is located nearly 2.7 billion light-years away from Earth.
PKS 1402+044 is a quasar located in the constellation of Virgo. It has a redshift of 3.207, estimating the object to be located 11.3 billion light-years away from Earth.
4C +26.42 is an elliptical galaxy located in the constellation of Boötes. It has a redshift of 0.063, estimating the galaxy to be located 863 million light-years from Earth. It has an active galactic nucleus and is the brightest cluster galaxy (BCG) in Abell 1795, an X-ray luminous rich cluster (LX 1045 ergs s−1), with an estimated cooling-flow rate of 300 M yr−1.
3C 459 known as IRAS 23140+0348, is a radio galaxy located in the constellation Pisces. It is located 2.74 billion light years from Earth and is classified as a Seyfert 2 and LINER galaxy.
3C 138 is a quasar located in the constellation of Taurus. It has a redshift of (z) 0.76. The radio spectrum of this source appears both compact and steep, making it a compact steep-spectrum radio quasar. It is also one of the few 3C objects showing a defined and turn-over in its electromagnetic spectrum at low frequencies.
3C 309.1 is a quasar located in the constellation of Ursa Minor. It has a redshift (z) of 0.90 and was first identified as an astronomical radio source from the Third Cambridge Catalogue of Radio Sources by in 1966. This object contains a compact steep spectrum (CSS) source, and is classified as one of the brightest and largest of its kind.
3C 196.1 is a low-excitation radio galaxy located in the constellation of Hydra. It has a redshift of 0.198 and was first discovered as an astronomical radio source in 1965. This object resides as the brightest cluster galaxy (BCG) of a cool core galaxy cluster CIZA J0815.4-0308 located at the same redshift, with its source being best described as a HyMOR.
3C 382 is a nearby broad-line radio galaxy located in the constellation of Lyra, located at a redshift of (z) 0.058. First discovered as an astronomical radio source in 1963 and identified with its optical counterpart in 1973, the galaxy is classified as a Fanaroff-Riley class II radio galaxy. Its X-ray luminosity is estimated to be 7×1044 erg/s in the 0.2–2.4 keV band.
GB 1508+5714 is an extremely distant blazar located in the constellation of Draco. It has a redshift of (z) 4.30 and is classified as a radio-loud quasar, first discovered in 1995 by astronomers. The radio spectrum of the source appears as flat, making it a flat-spectrum source but also a bright X-ray source.