Astronomy:S5 1803+784

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S5 1803+784
The BL Lac object S5 1803+784.
Observation data (J2000.0 epoch)
ConstellationDraco
Right ascension 18h 00m 45.683s
Declination+78° 28′ 04.018″
Redshift0.691000
Helio radial velocity207,157 km/s
Distance6.419 Gly
Apparent magnitude (V)15.90
Apparent magnitude (B)16.4
Characteristics
TypeFRSQ, BL LAC
Other designations
IRAS 18036+7827, S5 1803+78, NVSS J180045+782805, WMAP 072, 4FGL J1800.6+7828, 6C B180338.9+782745

S5 1803+784 is a BL Lacertae object[1] located in the far northern constellation of Draco. It has an estimated redshift (z) of 0.68[2] and was first discovered as an astronomical radio source in 1981 by a team of astronomers.[3] This object is also classified as a blazar because of its extreme variability on the electromagnetic spectrum[4][5] and a source of gamma ray activity.[6] According to preliminary analysis in May 2011, the source of S5 1803+784 has a gamma ray flux (E >100 MeV) of 1.1 ± 0.2 × 10−6 photon cm−2 s−1.[7]

Description

S5 1803+784 is in a constant flaring state.[8][9] In April 2020, S5 1803+784 had a major outburst followed by more flaring episodes. During this period, S5 1803+784 exhibited highest flux level of 1.1 × 10−6 ph cm−2 s−1 while in pre-flaring region, a low flux was shown below 0.2 × 10−6 ph cm−2 s−1.[10] In August 2020, S5 1803+784 entered a new flaring phase which lasted for 57 days. Its source brightness varied from 13.617 ± 0.009 to 15.888 ± 0.01 in R-bands, which the brightest-ever state for S5 1803+783 was observed on August 25.[11] It is also known to show near-infrared flares.[12]

In an optical light curve, S5 1803+784 showed the overall variation greater than 3 magnitudes with the largest changes observed within three flares through no periodicity was found. However, the radio band variability is found different, showing modest oscillations instead of flares with a maximum amplitude of 30%.[13]

S5 1803+784 shows a peculiar radio structure with a compact radio core.[14] There is a presence of an ejector nozzle, 0.1 parsecs in diameter surrounded by a ring structure with both a diameter of 1.4 parsecs and a width of 0.25 parsecs.[15] Furthermore, it has a weaker secondary component located 45 arcseconds south and slightly to the west side of the core with a faint emission bridge joining them together.[16][17][18]

The jet of S5 1803+784 has a complex morphology. In milliarcsecond-scales, it is described as a bend chain of seven individual jet components with both separation gaps of 0.2 and 3 mas from its core, where new components appear to be emerging from it every two years. Three of the jet components are found to approach a brightest and stationary component (1.4 mas at 8.4 GHz) exhibiting apparent superluminal motion.[19] Further studies showed in the jet's parsec-scale, most of the jet components within the inner core remain constant over a long period of time with the jet's width changing periodically around 8–9 years.[20] Interestingly, the jet is shaped into a cone which the 18-cm emission from the injector region is found to be weaken by a factor of 300.[21]

References

  1. ↑ Strom, R. G.; Biermann, P. L. (1991-02-01). "1803+784 : a BL Lacertae object with remarkable radio properties.". Astronomy and Astrophysics 242: 313. ISSN 0004-6361. Bibcode: 1991A&A...242..313S. https://ui.adsabs.harvard.edu/abs/1991A&A...242..313S/abstract. 
  2. ↑ Nesci, R.; Massaro, E.; Maesano, M.; Montagni, F.; Sclavi, S.; Venturi, T.; Dallacasa, D.; D'Alessio, F. (July 2002). "Optical and Radio Monitoring of S5 1803+784". The Astronomical Journal 124 (1): 53–64. doi:10.1086/341038. ISSN 0004-6256. Bibcode: 2002AJ....124...53N. https://iopscience.iop.org/article/10.1086/341038/pdf. 
  3. ↑ Biermann, P.; Duerbeck, H.; Eckart, A.; Fricke, K.; Johnston, K. J.; Kuhr, H.; Liebert, J.; Pauliny-Toth, I. I. K. et al. (July 1981). "Observations of six flat spectrum sources from the 5 GHz survey". The Astrophysical Journal 247: L53. doi:10.1086/183588. ISSN 0004-637X. Bibcode: 1981ApJ...247L..53B. https://articles.adsabs.harvard.edu//full/1981ApJ...247L..53B/L000053.000.html. 
  4. ↑ Carrasco, L.; Porras, A.; Escobedo, G.; Recillas, E. (2022-07-01). "A New NIR Flare of the Blazar HB89 1803+784". The Astronomer's Telegram 15505: 1. Bibcode: 2022ATel15505....1C. https://ui.adsabs.harvard.edu/abs/2022ATel15505....1C/abstract. 
  5. ↑ Nesci, R.; Maesano, M.; Massaro, E.; Montagni, F.; Trenta, F. (1999-01-01). "BVRI photometry of the blazar S5 1803+78.". Memorie della Societa Astronomica Italiana 70: 233–234. ISSN 0037-8720. Bibcode: 1999MmSAI..70..233N. https://ui.adsabs.harvard.edu/abs/1999MmSAI..70..233N/abstract. 
  6. ↑ Giroletti, M.; Ciprini, S.; La Mura, G. (2022-03-01). "Fermi-LAT detection of highest gamma-ray daily flux from the BL Lac S5 1803+78". The Astronomer's Telegram 15292: 1. Bibcode: 2022ATel15292....1G. https://ui.adsabs.harvard.edu/abs/2022ATel15292....1G/abstract. 
  7. ↑ Reyes, Luis C. (2011-05-01). "Fermi LAT detection of a GeV flare from blazar S5 1803+78". The Astronomer's Telegram 3322: 1. Bibcode: 2011ATel.3322....1R. https://ui.adsabs.harvard.edu/abs/2011ATel.3322....1R/abstract. 
  8. ↑ Nowakowski, Tomasz; Phys.org. "Study investigates flaring activity of blazar S5 1803+78" (in en). https://phys.org/news/2022-04-flaring-blazar-s5.html. 
  9. ↑ Pursimo, Tapio; Ojha, Roopesh; Dahle, Haakon (2020-05-01). "Bright Optical Flare in the flaring gamma-ray BL Lac S5 1803+784". The Astronomer's Telegram 13711: 1. Bibcode: 2020ATel13711....1P. https://ui.adsabs.harvard.edu/abs/2020ATel13711....1P/abstract. 
  10. ↑ Priya, Shruti; Prince, Raj; Agarwal, Aditi; Bose, Debanjan; Özdönmez, Aykut; Ege, Ergün (2022-04-15). "Multiwavelength temporal and spectral analysis of Blazar S5 1803+78". Monthly Notices of the Royal Astronomical Society 513 (2): 2239–2251. doi:10.1093/mnras/stac1009. ISSN 0035-8711. 
  11. ↑ Agarwal, A.; Pandey, Ashwani; Özdönmez, Aykut; Ege, Ergün; Kumar Das, Avik; Karakulak, Volkan (2022-07-01). "Characterizing the Optical Nature of the Blazar S5 1803+784 during Its 2020 Flare". The Astrophysical Journal 933 (1): 42. doi:10.3847/1538-4357/ac6cef. ISSN 0004-637X. 
  12. ↑ Carrasco, L.; Escobedo, G.; Porras, A.; Recillas, E.; Felix, L. (2023-11-01). "A recent NIR Flare and similar amplitude fluctuations near maximum light of the blazar [HB89 1803+784"]. The Astronomer's Telegram 16344: 1. Bibcode: 2023ATel16344....1C. https://ui.adsabs.harvard.edu/abs/2023ATel16344....1C/abstract. 
  13. ↑ Nesci, R.; Massaro, E.; Maesano, M.; Montagni, F.; Sclavi, S.; Venturi, T.; Dallacasa, D.; D'Alessio, F. (2002-07-01). "Optical and Radio Monitoring of S5 1803+784". The Astronomical Journal 124 (1): 53–64. doi:10.1086/341038. ISSN 0004-6256. Bibcode: 2002AJ....124...53N. https://ui.adsabs.harvard.edu/abs/2002AJ....124...53N/abstract. 
  14. ↑ Airapetyan, E.A.; Matveenko, L.I (1997). "The Fine Structure of Compact Radio Sources from Geodetic Data". Astronomy Letters 23 (1): 64–70. https://articles.adsabs.harvard.edu/pdf/1997AstL...23...64A. 
  15. ↑ Matveyenko, L. I.; Sivakon', S. S.; Jorstad, S. G.; Marscher, A. P. (2010-03-01). "Structural peculiarities of the AGN object 1803+784". Astronomy Letters 36 (3): 151–166. doi:10.1134/S1063773710030011. ISSN 0320-0108. Bibcode: 2010AstL...36..151M. https://ui.adsabs.harvard.edu/abs/2010AstL...36..151M/abstract. 
  16. ↑ Gabuzda, D. C.; Cawthorne, T. V. (2000-12-21). "VLBI polarization images of eight compact active galactic nuclei at 𝜆 = 1.3 cm". Monthly Notices of the Royal Astronomical Society 319 (4): 1056–1066. doi:10.1046/j.1365-8711.2000.03881.x. ISSN 0035-8711. https://articles.adsabs.harvard.edu/pdf/2000MNRAS.319.1056G. 
  17. ↑ Britzen, S.; Krichbaum, T. P.; Strom, R. G.; Witzel, A.; Muxlow, T. W. B.; Matveenko, L. I.; Campbell, R. M.; Alef, W. et al. (2005-11-25). "Large-scale motion, oscillations and a possible halo on the counter-jet side in 1803+784". Astronomy & Astrophysics 444 (2): 443–454. doi:10.1051/0004-6361:20041823. ISSN 0004-6361. https://www.aanda.org/articles/aa/full/2005/47/aa1823-04/aa1823-04.html. 
  18. ↑ Cassaro, P.; Stanghellini, C.; Bondi, M.; Dallacasa, D.; Della Ceca, R.; Zappala, R.A. (1999). "Extended radio emission in BL Lac objects. I. The images". Astronomy & Astrophysics Supplement Series 139 (3): 601–616. doi:10.1051/aas:1999511. https://aas.aanda.org/articles/aas/pdf/1999/18/ds1030.pdf. 
  19. ↑ Britzen, S.; Witzel, A.; Krichbaum, T. P.; Beckert, T.; Campbell, R. M.; Schalinski, C.; Campbell, J. (2005-09-21). "The radio structure of S5 1803+784". Monthly Notices of the Royal Astronomical Society 362 (3): 966–974. doi:10.1111/j.1365-2966.2005.09369.x. ISSN 0035-8711. 
  20. ↑ Britzen, S.; Kudryavtseva, N. A.; Witzel, A.; Campbell, R. M.; Ros, E.; Karouzos, M.; Mehta, A.; Aller, M. F. et al. (February 2010). "The kinematics in the pc-scale jets of AGN". Astronomy and Astrophysics 511: A57. doi:10.1051/0004-6361/20079267. ISSN 0004-6361. http://dx.doi.org/10.1051/0004-6361/20079267. 
  21. ↑ Matveenko, L. I.; Witzel, A. I. (1999). "The Jets of Quasars 3C 345 and 1803+784". Symposium - International Astronomical Union 194: 229–234. doi:10.1017/s0074180900162047. ISSN 0074-1809. https://articles.adsabs.harvard.edu/pdf/1999AstL...25..555M. 




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