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PKS 0805-07 | |
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Observation data (J2000.0 epoch) | |
Constellation | Monoceros |
Right ascension | 08h 08m 15.54s |
Declination | −07° 51′ 09.89″ |
Redshift | 1.837000 |
Heliocentric radial velocity | 550,719 km/s |
Distance | 10.053 Gly (light travel time distance) |
Apparent magnitude (V) | 0.388 |
Apparent magnitude (B) | 0.513 |
Surface brightness | 18.4 |
Characteristics | |
Type | Blazar, FSRQ |
Notable features | Blazar emitting gamma rays |
Other designations | |
WMAP 133, TXS 0805-077, PGC 2825379, PKS B0805-077, NVSS J080815-075109, 3FGL J0808.2-0751, 4FGL J0808.2-0751, PMN J0808-0751, MRC 0805-077, 2MASSi J0808155-075109, Cul 0805-076, IRCF J080815.5-075109 |
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. [1]
Classified a high redshift blazar, [2] [3] a type of powerful radio-loud active galactic nuclei containing a relativistic jet, pointing towards the direction of Earth, [4] PKS 0805-07 shows emitted radiation, mainly detected in gamma-rays (E>~100 MeV) [5] as detected by Large Area Telescope. [6] The quasar is known to have an extreme variability across its entire electromagnetic spectrum. [7] [8] Based on the strength of optical spectral lines, which the equivalent width (EW) of the spectral line is found greater or less than 5 Å, PKS 0805-07 is further classified a flat-spectrum radio quasar (FSRQ) containing strong emission-lines. [9] [10] [11]
Like many other FSRQs, PKS 0805-07 contains characteristics like a high bolometric luminosity, [12] and thermal activity that is related to an accretion disk in the quasar's optical and ultraviolet (UV) spectra. [13] [14] It is also known to have characteristic radio polarization at 1.4 GHz, P1.4 > 1% [15] and a spinning black hole. [16]
As studied by researchers for its emission properties, PKS 0805-07 exhibits lower electron energy (γ p ≲ 1.6 × 103) compared to BL Lacertae objects (BL Lacs) with a separation of Γ = -0.127 log ly + 8.18 in γ-ray luminosity versus photon index plane with a success rate of 88.6\%. [17] It also has a stronger magnetic field (B) with smaller electron-to-magnetic energy ratio (U e/U B) than BL Lacs. [18] Moreover, PKS 0805-07 shows a core-jet morphology with at least five observing epochs at 15 GHz between January 1996, and August 2019, observed by Very Long Baseline Array. [19] The quasar also has a core-dominated source, showing asymmetric features than lobe-dominated sources, which is caused by modest relativistic motion (β ≡ 0.20) within its radio lobes. [20]
Since April 2009, PKS 0805-07 was shown to have high levels of gamma-ray activity when detected by Large Area Telescope. Amongst other quasars, PKS 0805-07 has one of the fastest superluminal motions at that time. [21]
Between 17 and 19, November 2022, an ongoing bright gamma-ray from PKS 0805-07 was observed by AGILE satellite. This source had a flux measured of F( > 100 MeV) = (2.7 +/- 0.8) x 10-6 photons/cm2/s and around 6 sigma. [22]
The Whole Earth Blazar Telescope (WEBT) is an international consortium of astronomers created in 1997, with the aim to study a particular category of Active Galactic Nuclei (AGN) called blazars, which are characterized by strong and fast brightness variability, on time scales down to hours or less.
Georges Meylan is a Swiss astronomer, born on July 31, 1950, in Lausanne, Switzerland. He was the director of the Laboratory of Astrophysics of the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, and now a professor emeritus of astrophysics and cosmology at EPFL. He is still active in both research and teaching.
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AP Librae is a BL Lacertae object located at a distance of 700 million light years in the southern constellation of Libra. In the visual band it is one of the most active blazars known. AP Lib is surrounded by an extended source with a spectrum characteristic of a red-shifted giant elliptical galaxy. The derived visual magnitude of this region is 15.0, and it follows a radially decreasing brightness that is characteristic of an elliptical. Seven fainter galaxies are visible within an angular radius of 9′, suggesting it is the brightest member of a galactic cluster.
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IRAS 09104+4109 is a galaxy located in the constellation Lynx. With a redshift of 0.440797, the light travel time for this galaxy, corresponds to 4.8 billion light-years from Earth. It is the brightest cluster galaxy in MACS J0913.7+4056 galaxy cluster and classified as a hyperluminous infrared galaxy.
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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.
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PKS 1402-012, also known as UM 632, is a quasar located in the constellation of Virgo. With a redshift of 2.51, the object is located 10.7 billion light-years from Earth.
4C +03.10 also known as PKS 0505+03 and OG +008, is a quasar located in the constellation of Orion. At a redshift of 2.46, the object is located 10.6 billion light-years away from Earth.
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