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NRAO 190

NRAO 190 is a blazar located in the constellation of Eridanus. Its redshift is (z) 0.844[1] and it was first discovered as an astronomical radio source via a high-resolution radio interferometry observation in 1968 by astronomers.[2][3] The radio spectrum of the object is considered as flat, leading to it being classified as a flat-spectrum radio source.[4]

Description

NRAO 190 is known to be optically variable at all wavelengths. During an optical study conducted between 1970 and 1992, the source of the object is found to display extreme fluctuations on timescales, with its photographic magnitude reaching around 18.5 to 19.0 magnitude around 1975-1985.[4] It is also said NRAO 190 can be classfied as an optically violently variable quasar (OVV) since its variability is shown to dramatically increase when reaching its active phase.[5][6] During early 1986, it showed a rapid brightening increase of 1.4 magnitude which was soon followed by 1.9 decrease over a period of 34 days.[6]

NRAO 190 displays gamma ray flares. Between August 9 and 20 in 1994, astronomers detected a flare from the direction of it, with the energy range reaching above 100 MeV.[7] Gamma ray outbursts were also detected from the object in May 2009 and June 2013.[1][8] In January 2024, the source showed renewed activity which was detected by the Large Area Telescope (LAT).[9]

The source of NRAO 190 is found to be compact.[10] Images of the radio structure made by Very Long Baseline Array (VLBA) showed it has a single-sided jet with no traces of an extended radio structure located beyond 2 milliarcseocnds from the core region. When imaged with a 22 GHz radio map, the source shows three components; a weak component, a bright yet unresolved core and a bright knot that is moving in a downstream direction.[11] It is indicated NRAO 190 is also a core-dominated source since 40% of its flux mainly originates from the core according to observations made by Very Long Baseline Interferometry.[4][12]

The host galaxy of NRAO 190 is found unresolved through H-band images.[13] A study published in 2024 estimates the object has a supermassive black hole mass of 1.73 x 108 Mʘ with its accretion disk luminosity measured as 1.71 x1046 erg s-1 based on an optical/UV data fit. An Hβ line was also discovered in its optical spectra suggesting a narrow-line Seyfert 1 classification.[14]

References

  1. ^ a b Ciprini, S. (2009-05-01). "Fermi LAT detection of a GeV flare from blazar NRAO 190 (PKS 0440-00)". The Astronomer's Telegram. 2049: 1. Bibcode:2009ATel.2049....1C.
  2. ^ Jauncey, D. L.; Bare, C. C.; Clark, B. G.; Kellermann, K. I.; Cohen, M. H. (April 1970). "High-Resolution Radio Interferometry at 610 MHz". The Astrophysical Journal. 160: 337. Bibcode:1970ApJ...160..337J. doi:10.1086/150432. ISSN 0004-637X.
  3. ^ Kellermann, K. I.; Pauliny-Toth, I. I. K. (1968-01-01). "Variable Radio Sources". Annual Review of Astronomy and Astrophysics. 6: 417–448. Bibcode:1968ARA&A...6..417K. doi:10.1146/annurev.aa.06.090168.002221. ISSN 0066-4146.
  4. ^ a b c McGlynn, Thomas A.; Hartman, Robert C.; Bloom, Steven D.; Aller, Margo; Aller, Hugh; Filippenko, Alexei V.; Barth, Aaron J.; Gear, W. K.; Marscher, Alan P.; Mattox, John R.; Reich, W.; Robson, E. I.; Schramm, Jochen; Stevens, J. A.; Teräsranta, H. (1997-06-01). "A Gamma-Ray Flare in NRAO 190". The Astrophysical Journal. 481 (2): 625. Bibcode:1997ApJ...481..625M. doi:10.1086/304068. ISSN 0004-637X.
  5. ^ Scott, R. L.; Leacock, R. J.; McGimsey, B. Q.; Smith, A. G.; Edwards, P. L.; Hackney, K. R.; Hackney, R. L. (1976-01-01). "Optical behavior of 64 extragalactic radio sources". The Astronomical Journal. 81: 7–19. Bibcode:1976AJ.....81....7S. doi:10.1086/111846. ISSN 0004-6256.
  6. ^ a b Webb, James R.; Smith, Alex G.; Leacock, Robert J.; Fitzgibbons, Gregory L.; Gombola, Paul P.; Shepherd, David W. (1988-02-01). "Optical Observations of 22 Violently Variable Extragalactic Sources: 1968-1986". The Astronomical Journal. 95: 374. Bibcode:1988AJ.....95..374W. doi:10.1086/114641. ISSN 0004-6256.
  7. ^ McGlynn, T. A.; Mattox, J. R.; Vestrand, W. T.; Dingus, B. L.; Bertsch, D. L.; Esposito, J. A.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; von Montigny, C.; Mukherjee, R.; Sreekumar, P.; Thompson, D. J.; Kniffen, D. A.; Lin, Y. C. (1994-08-01). "Gamma-Ray Flare from Direction of NRAO 190". International Astronomical Union Circular (6061): 1. Bibcode:1994IAUC.6061....1M. ISSN 0081-0304.
  8. ^ Buson, S.; Gasparrini, D. (2013-06-01). "Fermi LAT detection of a GeV flare from blazar NRAO 190 (PKS 0440-00)". The Astronomer's Telegram. 5156: 1. Bibcode:2013ATel.5156....1B.
  9. ^ Bernard, Denis (2024-01-01). "Fermi-LAT detection of renewed gamma-ray activity from the FSRQ NRAO 190 (PKS 0440-00)". The Astronomer's Telegram. 16395: 1. Bibcode:2024ATel16395....1B.
  10. ^ Kellermann, K. I.; Jauncey, D. L.; Cohen, M. H.; Shaffer, B. B.; Clark, B. G.; Broderick, J.; Rönnäng, B.; Rydbeck, O. E. H.; Matveyenko, L.; Moiseyev, I.; Vitkevitch, V. V.; Cooper, B. F. C.; Batchelor, R. (1971-10-01). "High-Resolution Observations of Compact Radio Sources at 6 and 18 Centimeters". The Astrophysical Journal. 169: 1. Bibcode:1971ApJ...169....1K. doi:10.1086/151113. ISSN 0004-637X.
  11. ^ Yurchenko, A. V.; Marchenko-Jorstad, S. G.; Marscher, A. P. (2000-06-01). "Parsec-scale jet behavior of NRAO 190 after a gamma -ray outburst in August 1994". Astronomy and Astrophysics. 358: 428–432. Bibcode:2000A&A...358..428Y. ISSN 0004-6361.
  12. ^ Preston, R. A.; Morabito, D. D.; Williams, J. G.; Faulkner, J.; Jauncey, D. L.; Nicolson, G. (1985-09-01). "A VLBI survey at 2.29 GHz". The Astronomical Journal. 90: 1599–1603. Bibcode:1985AJ.....90.1599P. doi:10.1086/113869. ISSN 0004-6256.
  13. ^ Kotilainen, Jari K.; Falomo, Renato; Scarpa, Riccardo (1998-04-01). "Near-infrared imaging of the host galaxies of flat spectrum radio quasars". Astronomy and Astrophysics. 332: 503–513. arXiv:astro-ph/9711065. Bibcode:1998A&A...332..503K. ISSN 0004-6361.
  14. ^ Luna-Cervantes, J; Tramacere, A; Benítez, E (2024-07-18). "Exploring the nature of the jetted hybrid AGNs: PKS 2004-447, 3C 286, and PKS 0440-00 through the SED modeling". Monthly Notices of the Royal Astronomical Society. 532 (4): 3729–3746. arXiv:2407.08197. doi:10.1093/mnras/stae1687. ISSN 0035-8711.