PKS 1741-03 | |
---|---|
Observation data (J2000.0 epoch) | |
Constellation | Ophiuchus |
Right ascension | 17h 43m 58.8561s |
Declination | −03° 50′ 04.617″ |
Redshift | 1.054000 |
Heliocentric radial velocity | 315,981 km/s |
Distance | 7.726 Gly |
Apparent magnitude (V) | 20.40 |
Characteristics | |
Type | FSRQ, HPQ, Blazar |
Other designations | |
PKS 1741-038, OHIO T -068, LEDA 2829362, INTREF 817, QSO B1741-038, CGRaBS J1743-0350, 4FGL J1744.2-0353 |
PKS 1741-03 is a blazar [1] located in the constellation of Ophiuchus. This is core-dominated quasar located at a redshift of (z) 1.054, found to be highly polarized. [2] It was first discovered in 1970 as an extragalactic radio source by astronomers [3] and has a radio spectrum appearing to be flat, making it a flat-spectrum source. [4]
PKS 1741-03 is found to undergo a period of extreme scattering event (ESE). [5] [6] This is a dramatic change represented in flux density of radio sources, usually showing a decreasing trend in flux with a duration period of at least several weeks to months. During its ESE period, there was an increase in its angular diameter by 0.7 milliarcsecond. [6] When observed on timescales of few months, PKS 1741-03 exhibited extreme variations at 2.7 GHz but no traces of violent outbursts in its light curve. [7] Variability was also detected in the blazar at 1.49 GHz likely caused by refractive interstellar scintillation. [8]
Radio imaging made by Very Long baseline Interferometry shows PKS 1741-03 to be a simple but compact source, consisting of two components dominated by a central radio core. There is presence of much weaker emission located south of the core which becomes noticed at high frequencies. [9] Imaging made by Very Long Baseline Array shows PKS 1741-03 has a weak component at both epochs. [10] Other VLBI observations at 2 and 8 GHz shows a bright component and a diffused jet structure. [2]
Seven components have been discovered inside the parsec-scale jet of PKS 1741-03. Based on interferometric imaging, the jet components display superluminal motion of various speeds with ranges of between 3.5 and 6.1c. Further evidence also shows they are moving ballistically with the exception of one component displaying signs of bent trajectory. [11]
In 2022, PKS 1741-03 was found to be a candidate source of a neutrino event. IceCube Observatory located at the South Pole detected a high-energy neutrino event, designated as 220205B above 200 TeV and found it to be associated with the blazar. [12] This observation occurred while PKS 1741-03 was undergoing a powerful flare. [13]
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.
4C +71.07 known as S5 0836+71, is a quasar located in the constellation Ursa Major. Based on its high redshift, the object is located 10.7 billion light-years away from Earth and such, classified as a blazar with a flat-spectrum radio source and features a radio jet.
PKS 2215+020, known as PMN J2217+0220, is a quasar located in the Aquarius constellation. Its redshift is 3.57, meaning the object is located 11.6 billion light-years away from Earth. It is classified as a flat spectrum radio source quasar.
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 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.
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.
PKS 0405–385 is a blazar in the constellation of Eridanus. This is a compact radio quasar with a redshift (z) of 1.285, an indicator of its significant distance. The radio spectrum of this source appears flat, making it a flat-spectrum radio quasar (FSRQ).
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.
PKS 0208-512 is a blazar located in the southern constellation of Eridanus. It has a redshift of 1.003 and was first discovered in 1975 by astronomers conducting the Parkes 2700 MHz survey in Australia as a bright astronomical radio source. This object is also classified highly polarized with the radio spectrum appearing to be flat, thus making it a flat-spectrum radio quasar.
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.
PKS 1424-418 is a blazar located in the constellation of Centaurus. It has a redshift of 1.522 and was first discovered in 1971 by astronomer Keith Peter Tritton who identified the object as ultraviolet-excessive. This object is also highly polarized with a compact radio source. The radio spectrum of this source appears flat, making it a flat-spectrum radio quasar.
PKS 0537-441 is a blazar located in the constellation of Pictor. It has a redshift of 0.896 and was discovered in 1973 by an American astronomer named Olin J. Eggen, who noted it as a luminous quasar. This is a BL Lacertae object in literature because of its featureless optical spectra as well as both a possible gravitational microlensing and a gravitationally lensed candidate. Its radio source is found compact and is characterized by a spectral peak in the gigahertz range, making it a gigahertz-peaked spectrum source (GPS).
PKS 0420-014 is a blazar located in the constellation of Eridanus. This is a high polarized quasar with a redshift of (z) 0.915, first discovered as an astronomical radio source by astronomers in 1975. The radio spectrum of this source appears to be flat, making it a flat-spectrum radio quasar (FRSQ).
PKS 1622-297 is a blazar located in the constellation of Scorpius. It is one of the brightest objects of its type in the gamma ray region. It has a redshift of (z) 0.815. This blazar was first discovered as a compact astronomical radio source in 1970 by astronomers who were conducting interferometer observations and identified with an optical counterpart in 1984. In addition, the radio spectrum of the source appears flat, making it a flat-spectrum radio quasar (FRSQ).
PKS 0458-020 also known as PKS 0458-02, is a quasar located in the constellation of Orion. It has a redshift of (z) 2.286 and was first identified as an astronomical radio source during the radio survey conducted by Parkes Observatory in 1966. Subsequently the source was shown to display optical behavior before being classfied as a blazar via an optical polarimetry study in 1985. This source also shows radio spectrum appearing to be flat, hence making it a flat-spectrum radio quasar (FRSQ).
PKS 0454-234 is a blazar located in the constellation of Lepus. It is classified as a highly polarized quasar with a redshift of (z) 1.003. This object was first discovered in 1970 during a 1415 MHz continuum survey conducted by Ohio State University where it was given the designation, OF -292. The radio spectrum of this source is flat, making it a flat-spectrum radio quasar.
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 2255-282 is a blazar located in the constellation of Piscis Austrinus. This is a low-polarized quasar at the redshift of 0.926, first discovered in 1975 by astronomers via a spectroscopic observation. The radio spectrum of this source appears as flat, making it as a flat-spectrum quasar but also a Gigahertz Peaked Spectrum source (GPS) with turnover frequency between 22 and 37 GHz.
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 0528+134 is a distant blazar located in the Galactic anticenter towards the constellation of Orion. This is a compact radio quasar, classified as radio-loud with a redshift of (z) 2.07 yet having low polarization. It was first discovered in 1977 by astronomers as a radio source and contains a radio spectrum that appears as flat making it a flat-spectrum radio quasar. It has an optical brightness of 19.5.