3C 380 | |
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![]() The quasar 3C 380. | |
Observation data (J2000.0 epoch) | |
Constellation | Draco |
Right ascension | 18h 29m 31.7809s |
Declination | +48° 44′ 46.161″ |
Redshift | 0.6920000 |
Heliocentric radial velocity | 207,456 km/s |
Distance | 6.074 Gly |
Apparent magnitude (V) | 16.81 |
Apparent magnitude (B) | 17.05 |
Characteristics | |
Type | Opt. var, Sy 1.5, LPQ |
Other designations | |
CTA 79, NRAO 565, LEDA 2817708, QSO B1828+4842, 4C +48.46, S4 1828+487, WK 396, WMAP 46, |
3C 380 is a radio-loud quasar located in the constellation of Draco. [1] [2] First discovered in 1965 and identified with a starlike object, [3] [4] it is one of the luminous and powerful radio sources in Third Cambridge Catalogue, with a redshift of (z) 0.692 and a compact steep spectrum (CSS) source. [5] [6] [7]
3C 380 contains a complex radio structure. Radio images produced by the very long baseline interferometry (VLBI) at 5 GHz, showed the source is mainly extended, containing several components including a compact radio core and a ridge of extended radio emission. [8] [9] In additional, the quasar also has a diffused halo with a spectral index of 1.0 ± 0.2 which represents a common feature of the radio lobes in Fanaroff-Riley class II quasars. [6] An extended radio lobe was also discovered in 3C 380, having a low spectral index when compared to those at decimeter wavelengths. [10] There are also two hotpots located in northwest direction. [11]
The radio jet of 3C 380 on parsec-scales is known to be bent. Based on VLBI observations, it is shown to be resolved when travelling in a transverse direction, however it also shows signs of rapid brightness variations unlike other nuclear jets indicating phase effects play a role in causing these changes. Apart from that, the jet shows superluminal motion [12] and a Faraday rotation gradient measuring 70-200 parsecs in width across it. [13] Radio imaging Very Long Baseline Array (VLBA) also finds the jet is extending in a northwest direction. [14]
According to Hubble Space Telescope (HST) and VLBA, the jet has two knots. These knots are respectively named as knot 1, located 0.73 arcseconds from the core and knot 2 which is located 0.4 arcseconds away from the former. Together, these knots are found laid over lobelike emission which in turn, is stretched out in both east and northeast directions. [15]
Multifrequency polarization have also been found in 3C 380. Based on observations, both the core and jet contains polarization by 6 percent, while the other component has 16 percent polarization. [16] Enhanced flux density at 24 GHz from the object was also detected in September 2020. [17]
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.
3C 286, also known by its position as 1328+307 or 1331+305, is a quasar at redshift 0.8493 with a radial velocity of 164,137 km/s. It is part of the Third Cambridge Catalogue of Radio Sources.
NGC 3862 is an elliptical galaxy located 300 million light-years away in the constellation Leo. Discovered by astronomer William Herschel on April 27, 1785, NGC 3862 is an outlying member of the Leo Cluster.
PKS 0637-752 is a quasar located six billion light years in the constellation of Mensa. It is noted for having a bright and largest astrophysical jet at redshift of z = 0.651. Discovered by Einstein Observatory in 1980 through X-rays, PKS 0637-752 was the first celestial object to be observed by Chandra X-ray Observatory upon its commissioning in July 23, 1999.
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.
PKS 1144-379 also known as PKS B1144-379, is a quasar located in the constellation of Centaurus. At the redshift of 1.048, the object is located nearly 8 billion light-years from Earth.
PKS 0805-07 also known as PMN J0808-0751 and 4FGL J0808.2-0751, is a quasar located in the constellation of Monoceros. With a redshift of 1.83, light has taken at least 10 billion light-years to reach Earth.
3C 346 is an elliptical galaxy located in the constellation Hercules. It is located nearly 2.5 billion light years away from Earth and classified a Seyfert galaxy and a compact steep-spectrum source (CSS), although later studies confirm it as a Fanaroff-Riley class II source.
NRAO 530 or PKS 1730-13 is a flat-spectrum radio quasar located in the southern constellation of Serpens. It has a redshift of 0.902. and was first discovered by two astronomers, W.J. Welch and Hyron Spinrad in 1973. It is classified as a blazar because of its optical variability across the electromagnetic spectrum in radio, gamma ray and X-ray bands. This quasar is also further categorized an OVV quasar.
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.
DA 193 is a blazar located in the constellation of Auriga. It has a high redshift of 2.365. It was first discovered as an unknown astronomical radio source in 1971 by D.G. MacDonell and A.H. Bridle. This is a low polarized quasar containing a classic homogeneous synchrotron self-absorption spectrum. The radio spectrum of this source shows a turnover frequency at 5 GHz and this object has also been referred to as a gigahertz-peak spectrum source.
S5 1803+784 is a BL Lacertae object located in the far northern constellation of Draco. It has an estimated redshift of (z) 0.68 and was first discovered as an astronomical radio source in 1981 by a team of astronomers. This object is also classified as a blazar because of its extreme variability on the electromagnetic spectrum and a source of gamma ray activity. According to preliminary analysis in May 2011, the source of S5 1803+784 has a gamma ray flux of electron−6 photon cm−2 s−1.
OQ 172 is a quasar located in the constellation of Boötes. It has a redshift of (z) 3.544, making it one of the most distant quasars at the time of its discovery by astronomers in 1973. This object was the record holder for almost a decade, before being surpassed by PKS 2000-330 in 1982 located at the redshift of (z) 3.78.
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.
4C +28.07 is a blazar located in the constellation of Aries. It has a redshift of 1.213 and was first discovered in 1970 as a compact astronomical radio source during an interferometer observation and designated as CTD 20. The radio spectrum of the source is considered flat, making it a flat-spectrum radio quasar. It is one of the brightest blazars observed in the gamma ray energy band.
PKS 1127-145 is a radio-loud quasar located in the constellation of Crater. This is a Gigahertz Peaked Spectrum object with a redshift of (z) 1.187, first discovered by astronomers in 1966. Its radio spectrum appears to be flat making it a flat-spectrum radio quasar, or an FRSQ in short.
PKS 1741-03 is a blazar located in the constellation of Ophiuchus. This is core-dominated quasar located at a redshift of (z) 1.054, found to be highly polarized. It was first discovered in 1970 as an extragalactic radio source by astronomers and has a radio spectrum appearing to be flat, making it a flat-spectrum source.
NRAO 140 is a quasar located in the constellation of Perseus, noted for its low frequency variability. It has a redshift of (z) 1.258, first discovered in 1973 by Duncan Agnew and Halton Arp as an astronomical radio source, whom they catalogued it as 4C 32.14.
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.
PKS 1335-127 is a blazar located in the constellation of Virgo with a redshift of (z) 0.539. This is a compact BL Lac object containing a radio source of extragalactic origins; discovered in 1970 during the continuum survey conducted by astronomers from Ohio State University. The object shows a radio spectrum appearing as flat, thus making it a flat-spectrum radio quasar (FRSQ), but also classified as a gigahertz-peaked source (GPS) with high polarization.