Blazar in the constellation Centaurus
PKS 1424-418 is a blazar [ 1] located in the constellation of Centaurus . It has a redshift of 1.522[ 2] [ 3] and was first discovered in 1971 by astronomer Keith Peter Tritton who identified the object as ultraviolet -excessive.[ 4] This object is also highly polarized with a compact radio source.[ 5] The radio spectrum of this source appears flat, making it a flat-spectrum radio quasar.[ 6]
PKS 1424-418 is found optically variable on the electromagnetic spectrum .[ 7] It is a strong source of gamma rays .[ 8] [ 9] Between 2008 and 2011, PKS 1424-418 showed four phases of bright flares at GeV energies. The flares have a high correlation between the energy ranges with the exception of one flare that occurred at the same time it showed low gamma activity.[ 10] In April 2013, it underwent a major gamma ray outburst with its peak flux reaching values of F(> 100 MeV ) > 3 x 10−6 ph cm−2 s−1 . According to Large Area Telescope observations, this emission originated beyond its broad-line region.[ 11] A near-infrared flare was witnessed in PKS 1424–418 in January 2018.[ 12] In August 2022, it once again displayed an episode of rapid flaring activity in both gamma ray and optical bands .[ 13]
PKS 1424-418 contains a radio structure, comprising a strong radio core and a weaker component with a position angle of 260°.[ 5] Further observations also showed the core has a size of 0.4 mas with extended emission at both the core's position and northwest.[ 14] In addition, the core has a flat spectral index of -0.04.[ 5] A jet is seen extending west from the core before becoming diffused.[ 15]
Between May 2009 and September 2019, the gamma ray emission from PKS 1424-418 was found to undergo a quasi-periodic oscillation with a 353-day flux oscillation period.[ 16] [ 17] A 355-day period with high significance level is also confirmed by adopting time domain methods.[ 18] This might be explained by orbital motion of a binary supermassive black hole system with the mass of a primary black hole being M ~ 3.5 x 108 - 5.5 x 109 Mʘ .[ 19]
^ Abhir, J.; Joseph, J.; Patel, S. R.; Bose, D. (2021-02-01). "Multi-frequency temporal and spectral variability study of blazar PKS 1424-418" . Monthly Notices of the Royal Astronomical Society . 501 (2): 2504–2511. arXiv :2009.08220 . Bibcode :2021MNRAS.501.2504A . doi :10.1093/mnras/staa3639 . ISSN 0035-8711 .
^ Yang, Jianping; Cao, Gang; Zhou, Bing; Qin, Longhua (2021-01-26). "Quasi-periodic Oscillation of Blazar PKS 1424–418 in γ-Ray Band" . Publications of the Astronomical Society of the Pacific . 133 (1020): 024101. Bibcode :2021PASP..133b4101Y . doi :10.1088/1538-3873/abd152 . ISSN 0004-6280 .
^ White, Graeme L.; Jauncey, David L.; Wright, Alan E.; Batty, Michael J.; Savage, Ann; Peterson, Bruce A.; Gulkis, Sam (April 1988). "Redshifts of southern radio sources. VII" . The Astrophysical Journal . 327 : 561. Bibcode :1988ApJ...327..561W . doi :10.1086/166216 . ISSN 0004-637X .
^ Tritton, K. P. (1971-12-01). "Spectroscopy and Photography of Southern Hemisphere Quasar Identifications" . Monthly Notices of the Royal Astronomical Society . 155 (1): 1P–2P. doi :10.1093/mnras/155.1.1p . ISSN 0035-8711 .
^ a b c 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. (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 .
^ Ciprini, Stefano; Cutini, Sara (2013-01-01). "Swift detection of increased X-ray activity from gamma-ray flaring blazar PKS 1424-41" . The Astronomer's Telegram . 4770 : 1. Bibcode :2013ATel.4770....1C .
^ Shun, Zhang; Tingfeng, Yi; Zhiyuan, Pu; Na, Wang; Zhihui, Chen; Junping, Chen; Li, Ma (2023-07-15). "Study on Optical Variability of Blazar PKS 1424-41 in Multiband" . Astronomical Techniques and Instruments . 20 (4): 275–282. doi :10.14005/j.cnki.issn1672-7673.20230428.003 . ISSN 2097-3675 .
^ Verrecchia, F.; Pittori, C.; Piano, G.; Tavani, M.; Panebianco, G.; Bulgarelli, A.; Fioretti, V.; Parmiggiani, N.; Addis, A.; Baroncelli, L.; Di Piano, A.; Lucarelli, F.; Vercellone, S.; Cardillo, M.; Ursi, A. (2022-12-01). "AGILE detection of increasing gamma-ray activity of blazar PKS 1424-418" . The Astronomer's Telegram . 15818 : 1. Bibcode :2022ATel15818....1V .
^ D'Ammando, F.; Orienti, M.; Longo, F.; Jankowsky, F.; Schwemmer, S.; Wagn, S. (2013-01-01). "Detection of a strong optical and gamma-ray flare from blazar PKS 1424-41" . The Astronomer's Telegram . 4714 : 1. Bibcode :2013ATel.4714....1D .
^
^ Tavecchio, F.; Pacciani, L.; Donnarumma, I.; Stamerra, A.; Isler, J.; MacPherson, E.; Urry, C. M. (2013-07-22). "The far emission region of the γ-ray blazar PKS B1424–418" . Monthly Notices of the Royal Astronomical Society: Letters . 435 (1): L24–L28. arXiv :1306.0734 . doi :10.1093/mnrasl/slt087 . ISSN 1745-3933 .
^ Nesci, R.; Ojha, R.; Kadler, M. (2018-01-01). "Exceptional NIR flare in gamma-ray loud FSRQ PKS B1424-418" . The Astronomer's Telegram . 11235 : 1. Bibcode :2018ATel11235....1N .
^ Kadler, Matthias; Stevens, Jamie; Ojha, Roopesh; Edwards, Philip G.; Roesch, Florian (2022-08-01). "ATCA finds a long-term radio outburst of PKS1424-418 coincident with optical/gamma-ray flaring activity" . The Astronomer's Telegram . 15536 : 1. Bibcode :2022ATel15536....1K .
^ Dodson, R.; Fomalont, E. B.; Wiik, K.; Horiuchi, S.; Hirabayashi, H.; Edwards, P. G.; Murata, Y.; Asaki, Y.; Moellenbrock, G. A.; Scott, W. K.; Taylor, A. R.; Gurvits, L. I.; Paragi, Z.; Frey, S.; Shen, Z.-Q. (April 2008). "The VSOP 5 GHz Active Galactic Nucleus Survey. V. Imaging Results for the Remaining 140 Sources" . The Astrophysical Journal Supplement Series . 175 (2): 314–355. arXiv :0710.5707 . Bibcode :2008ApJS..175..314D . doi :10.1086/525025 . ISSN 0067-0049 .
^ Marshall, H. L.; Schwartz, D. A.; Lovell, J. E. J.; Murphy, D. W.; Worrall, D. M.; Birkinshaw, M.; Gelbord, J. M.; Perlman, E. S.; Jauncey, D. L. (January 2005). "A Chandra Survey of Quasar Jets: First Results" . The Astrophysical Journal Supplement Series . 156 (1): 13–33. arXiv :astro-ph/0409566 . Bibcode :2005ApJS..156...13M . doi :10.1086/425578 . ISSN 0067-0049 .
^ Bhatta, Gopal; Dhital, Niraj (March 2020). "The Nature of γ-Ray Variability in Blazars" . The Astrophysical Journal . 891 (2): 120. arXiv :1911.08198 . Bibcode :2020ApJ...891..120B . doi :10.3847/1538-4357/ab7455 . ISSN 0004-637X .
^ Bhatta, Gopal; Dhital, Niraj (March 2020). "The Nature of γ-Ray Variability in Blazars" . The Astronomical Journal . 891 (2): 120. arXiv :1911.08198 . Bibcode :2020ApJ...891..120B . doi :10.3847/1538-4357/ab7455 .
^ Chen, Junping; Yu, Jinjie; Huang, Weitian; Ding, Nan (2024-02-08). "Transient quasi-periodic oscillations in the gamma-ray light curves of bright blazars" . Monthly Notices of the Royal Astronomical Society . 528 (4): 6807–6822. arXiv :2401.10658 . doi :10.1093/mnras/stae416 . ISSN 0035-8711 .
^ Yang, Jianping; Cao, Gang; Zhou, Bing; Qin, Longhua (2021-01-26). "Quasi-periodic Oscillation of Blazar PKS 1424–418 in γ-Ray Band" . Publications of the Astronomical Society of the Pacific . 133 (1020): 024101. Bibcode :2021PASP..133b4101Y . doi :10.1088/1538-3873/abd152 . ISSN 0004-6280 .