DA 193 | |
---|---|
Observation data (J2000.0 epoch) | |
Constellation | Auriga |
Right ascension | 05h 55m 30.805s |
Declination | +39° 48′ 49.165″ |
Redshift | 2.365000 |
Heliocentric radial velocity | 709,009 km/s |
Distance | 10.545 Gly |
Apparent magnitude (V) | 18.3 |
Characteristics | |
Type | Blazar |
Other designations | |
SWIFT J0555.5+3946, WMAP 100, TXS 0552+398, 2XMM J055530.7+394848 |
DA 193 is a blazar [1] located in the constellation of Auriga. It has a high redshift of 2.365. [2] [3] It was first discovered as an unknown astronomical radio source in 1971 by D.G. MacDonell and A.H. Bridle. [4] This is a low polarized quasar [5] containing a classic homogeneous synchrotron self-absorption spectrum. [6] The radio spectrum of this source shows a turnover frequency at 5 GHz [5] and this object has also been referred to as a gigahertz-peak spectrum source. [7] [8]
DA 193 is found variable on the electromagnetic spectrum. It is bright in X-rays and displays a flat X-ray spectrum that is above 10 keV. During the first week of January 2018, it underwent a giga-electron volt (GeV) flare which was detected by Fermi-LAT. [9] This GeV flare exhibited from DA 193 showed an exceeded binned gamma ray flux (1 x 10-6 ph cm-2 s-1) and was found to be extremely luminous (Lγ = (1.3 ± 0.4) x 1050 erg s-1). When observing its hard gamma-ray spectrum, the flare in DA 193 was confirmed to be a rare sight. In the optical-X-ray energy range, it shows an insignificant flux meaning its source went back to its quiescence state. [10]
DA 193 contains one of the most compact radio sources known on both millisecond and arcsecond scales. [2] In its radio structure, there are four components in the core region with the suggestion of a weak component located 2.3 mas. There is presence of a short jet extending towards the western direction. [11] Furthermore, DA 193 has a simple core-halo structure according to VLBI Observations, with the major axis of the halo having a 110° position angle. This halo's position angle is found alike to the linear polarization position angle. [5]
The central supermassive black hole of DA 193 is estimated to be (5.5 ± 0.9) x 109 Mʘ based on calculations of a single optical spectroscopic emission line information, derived from usage of C IV emission lines and acquiring empirical relations proposed by Yue Shen. Its accretion disk luminosity is estimated as (1.3 ± 0.1) x 1047 erg s-1. [10]
DA 193 has one close companion 2.9" to the north. The companion is found connected to the quasar via tidal interactions. Both objects are situated in a dense compact galaxy group. [8] [12]
TXS 0506+056 is a very high energy blazar – a quasar with a relativistic jet pointing directly towards Earth – of BL Lac-type. With a redshift of 0.3365 ± 0.0010, it has a luminosity distance of about 1.75 gigaparsecs. Its approximate location on the sky is off the left shoulder of the constellation Orion. Discovered as a radio source in 1983, the blazar has since been observed across the entire electromagnetic spectrum.
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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 0537-286, also known as QSO B0537-286, is a quasar located in the constellation Columba. With a redshift of 3.104, the object is located 11.4 billion light years away and belongs to the flat spectrum radio quasar blazar subclass (FSQR). It is one of the most luminous known high-redshift quasars.
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 2215+020, known as PMN J2217+0220, is a quasar located in the Aquarius constellation. Its redshift is 3.570000, meaning the object is located 11.6 billion light-years away from Earth. It is classified as a flat spectrum radio source quasar.
PKS 2126-158, also known as PKS 2126-15, is a quasar located in Capricornus. It has a redshift of 3.268000, which corresponds to the distance of 11.5 billion light years. It is classified as a gigahertz peaked-spectrum quasar (GPS) with a flat-spectrum radio source and a blazar, a type of active galaxy shooting an astrophysical jet towards Earth.
PKS 0226-559 known as PMN J0228-5546 is a quasar located in the constellation Horologium. At the redshift of 2.464, the object is roughly 10.6 billion light-years from Earth.
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 0736+017 is a blazar located in the constellation of Canis Minor. This object is also a highly polarized compact radio quasar. Its source having a radio spectrum, appears to be flat, making it a flat spectrum radio quasar. It has a redshift of (z) 0.189 and is hosted in a large elliptical galaxy with a half light radius measurement of re = 13 kiloparsecs. The black hole mass in PKS 0736+017 is 7.32+0.89-0.91 x 107 Mʘ based on a full width at half maximum (FWHM) scaling factor and virial relation.
H1426+428 also known as 1ES 1426+428, is a high-frequency peaked BL Lacertae object (HBL) located in the constellation of Boötes. It is located at a relatively high redshift of (z) 0.129, and was discovered in 1984 by astronomers who presented a catalogue of X-ray sources taken with the HEAO 1 satellite.
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.
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.
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 2004-447 is a narrow-line Seyfert 1 galaxy located in the constellation of Sagittarius. It has a redshift of (z) 0.24 and is the radio-loudest gamma ray emitting AGN known in the southern hemisphere. It was first identified as an astronomical radio source during a very-long-baseline interferometry survey in 1989. The radio spectrum appears to be powerful and compact, making it a compact steep spectrum source. The X-ray emission for this source is described by a simple power-law in the energy range.
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.