PKS 0426−380
| PKS 0426−380 | |
|---|---|
.png) The blazar PKS 0426−380 | |
| Observation data (J2000.0 epoch) | |
| Constellation | Caelum |
| Right ascension | 04h 28m 40.424s[1] |
| Declination | −37° 56′ 19.580″[1] |
| Redshift | 1.110000[1] |
| Heliocentric radial velocity | 332,770 km/s[1] |
| Distance | 8.300 Gly |
| Apparent magnitude (V) | 19.0 |
| Apparent magnitude (B) | 18.96 |
| Characteristics | |
| Type | FSRQ BL LAC[1] |
| Other designations | |
| 2MASS J04284041−3756195, LEDA 2823953, PKS J0428−3756, NVSS J042840−375619, RX J0428.6−3756, AT20G J042840.37−375619.3, SUMSS J042840−375619, WISEA J042840.41−375619.6, PMN J0428−3756, VSOP J0428−3756[1] | |
PKS 0426−380 is a blazar[2] located in the southern constellation of Caelum. The redshift of the object is (z) 1.110, meaning it is 8.3 billion light-years away from Earth[1] and it was first discovered as a strong radio source in 1981 by astronomers conducting the Very Large Array (VLA) survey.[3] The radio spectrum of the object is classified flat making it a flat-spectrum radio quasar but also referred to as a BL Lacerate object in literature.[4][5]
Description
PKS 0426−380 has been described having broad emission lines shown visible but in an low-emission state.[4] The object is also noted to be variable on the electromagnetic spectrum, undergoing several flaring episodes with its flux rising by orders of magnitude.[6] It has two gamma-ray flares, detected by Fermi Gamma-ray Space Telescope on January 4, 2010 and 17 December 2012.[7][8]
The host galaxy of PKS 0426−380 is described as a luminous elliptical galaxy with a magnitude of -26.65, and referred to as a microlensing candidate based on a detection of an absorbing galaxy at the redshift of (z) 0.559.[9] It is also said to be a low-polarized quasar since its optical polarization is less than 3%.[10]
The object has a compact radio structure. Observations made by the VLA have found it has a compact core with an extension by 2.7 arcseconds with a position angle of -24°. This core also has a temperature brightness of 7 x 1011 Kelvin.[10] The jet structure of the object is also compact, with a short jet pointing northwest based on high resolution imaging.[11][12]
PKS 0426−380 is known to be a very-high-energy emitter. According to observations by the Fermi Gamma-ray Space Telescope, which detected it in an active flaring phase, it is known to emit several gamma-ray photons at high energies of 134 and 122 GeV, one of them being associated with the object making it the most distant of its kind observed. It was also noted no GeV flux increased on the day of the very-high-energy detection although its spectral index was found hardening significantly.[13] Observations also found most of the flare emitting regions are located within the area between the supermassive black hole and torus.[14]
PKS 0426−380 is an astrophysical neutrino candidate. Dubbed IceCube 190504A, the event was found within the 90% error ellipse from the object and was shown to have an average flux measuring 1.97 ± 0.41 x 10−7 ph cm−2. This occurred while PKS 0426−380 was in a faint gamma-ray state.[15]
In 2017, PKS 0426−380 was found to display a possible quasi-periodicity signal.[4] A further study in 2023, confirmed the signal was caused by quasi-perodic oscillations with a period 12.2 years based on evaluation of its power spectrum signal from its source with the red-noise background. These detections of quasi-perodic oscillations suggests PKS 0426−380 might have a binary supermassive black hole in its center with a mass of 3 x 108 Mʘ and a separation gap of 0.0029 parsecs.[16]
References
- ^ a b c d e f g "NED search results for PKS 0426-380". NASA/IPAC Extragalactic Database. Retrieved 2025-08-02.
- ^ Benkhali, F. Ait; Hofmann, W.; Rieger, F. M.; Chakraborty, N. (2019-01-29), "Evaluating quasi-periodic variations in the γ -ray light curves of Fermi -LAT blazars", Astronomy & Astrophysics, 634: A120, arXiv:1901.10246, doi:10.1051/0004-6361/201935117, retrieved 2025-08-02
- ^ Ulvestad, J.; Johnston, K.; Perley, R.; Fomalont, E. (July 1981). "A VLA survey of strong radio sources". The Astronomical Journal. 86: 1010–1035. Bibcode:1981AJ.....86.1010U. doi:10.1086/112977. ISSN 0004-6256.
- ^ a b c Zhang, Peng-fei; Yan, Da-hai; Liao, Neng-hui; Zeng, Wei; Wang, Jian-cheng; Cao, Li-Jia (2017-06-07). "Possible Quasi-periodic Modulation in the z = 1.1 Gamma-Ray Blazar PKS 0426–380". The Astrophysical Journal. 842 (1): 10. arXiv:1701.00899. Bibcode:2017ApJ...842...10Z. doi:10.3847/1538-4357/aa7465. ISSN 0004-637X.
- ^ Armstrong, Thomas; Brown, Anthony M.; Chadwick, Paula M. (2017-05-29). "Fermi-LAT high-z active galactic nuclei and the extragalactic background light". Monthly Notices of the Royal Astronomical Society. 470 (4): 4089–4098. arXiv:1705.11185. doi:10.1093/mnras/stx1309. ISSN 0035-8711.
- ^ Neronov, A.; Semikoz, D.; Taylor, A. M.; Vovk, Ie (2015-03-01). "Very high-energy γ-ray emission from high-redshift blazars". Astronomy & Astrophysics. 575: A21. arXiv:1207.1962. Bibcode:2015A&A...575A..21N. doi:10.1051/0004-6361/201219970. ISSN 0004-6361.
- ^ "Fermi LAT detection of a GeV flare from PKS 0426-380". The Astronomer's Telegram. Retrieved 2025-08-02.
- ^ "Fermi LAT detection of renewed GeV flaring activity from PKS 0426-380". The Astronomer's Telegram. Retrieved 2025-08-02.
- ^ Heidt, J.; Tröller, M.; Nilsson, K.; Jäger, K.; Takalo, L.; Rekola, R.; Sillanpää, A. (2004-05-01). "Evolution of BL Lacertae host galaxies" (PDF). Astronomy & Astrophysics. 418 (3): 813–825. Bibcode:2004A&A...418..813H. doi:10.1051/0004-6361:20034467. ISSN 0004-6361.
- ^ a b Shen, Z.-Q.; Wan, T.-S.; Moran, J. M.; Jauncey, D. L.; Reynolds, J. E.; Tzioumis, A. K.; Gough, R. G.; Ferris, R. H.; Sinclair, M. W.; Jiang, D.-R.; Hong, X.-Y.; Liang, S.-G.; Edwards, P. G.; Costa, M. E.; Tingay, S. J. (April 1998). "A 5 GHz Southern Hemisphere VLBI Survey of Compact Radio Sources. II". The Astronomical Journal. 115 (4): 1357–1370. arXiv:astro-ph/9803104. Bibcode:1998AJ....115.1357S. doi:10.1086/300284. ISSN 0004-6256.
- ^ Müller, C.; Kadler, M.; Ojha, R.; Schulz, R.; Trüstedt, J.; Edwards, P. G.; Ros, E.; Carpenter, B.; Angioni, R.; Blanchard, J.; Böck, M.; Burd, P. R.; Dörr, M.; Dutka, M. S.; Eberl, T. (2018-02-01). "TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry - II. Additional sources". Astronomy & Astrophysics. 610: A1. arXiv:1709.03091. Bibcode:2018A&A...610A...1M. doi:10.1051/0004-6361/201731455. ISSN 0004-6361.
- ^ Cassaro, P.; Stanghellini, C.; Bondi, M.; Dallacasa, D.; della Ceca, R.; Zappalà, R. A. (November 1999). "Extended radio emission in BL Lac objects. I. The images". Astronomy and Astrophysics Supplement Series. 139 (3): 601–616. arXiv:astro-ph/9910209. Bibcode:1999A&AS..139..601C. doi:10.1051/aas:1999511. ISSN 0365-0138.
- ^ Tanaka, Y. T.; Cheung, C. C.; Inoue, Y.; Stawarz, Ł.; Ajello, M.; Dermer, C. D.; Wood, D. L.; Chekhtman, A.; Fukazawa, Y.; Mizuno, T.; Ohno, M.; Paneque, D.; Thompson, D. J. (2013-10-18). "Fermi LARGE AREA TELESCOPE DETECTION OF TWO VERY-HIGH-ENERGY ( E > 100 GeV) γ-RAY PHOTONS FROM THE z = 1.1 BLAZAR PKS 0426–380". The Astrophysical Journal. 777 (1): L18. arXiv:1308.0595. doi:10.1088/2041-8205/777/1/l18. ISSN 2041-8205.
- ^ Kundu, Maitreya; Bala, Arit; Barat, Saugata; Chatterjee, Ritaban (2025-05-07). "Location of a sample of GeV and optical outbursts in the jets of blazars". Monthly Notices of the Royal Astronomical Society. 540 (2): 1379–1393. doi:10.1093/mnras/staf744. ISSN 0035-8711.
- ^ Kun, E.; Bartos, I.; Tjus, J. Becker; Biermann, P. L.; Franckowiak, A.; Halzen, F.; Mező, Gy (2023-11-01). "Searching for temporary gamma-ray dark blazars associated with IceCube neutrinos". Astronomy & Astrophysics. 679: A46. arXiv:2305.06729. Bibcode:2023A&A...679A..46K. doi:10.1051/0004-6361/202346710. ISSN 0004-6361.
- ^ Hashad, M. A.; EL-Zant, Amr A.; Abdou, Y. (2023-10-15). "Quasi-periodic variability in the γ-Ray blazar PKS 0426–380". Advances in Space Research. 72 (8): 3538–3549. Bibcode:2023AdSpR..72.3538H. doi:10.1016/j.asr.2023.06.042. ISSN 0273-1177.
