QSO B1422+202

QSO B1422+202
SDSS image of QSO B1422+202.
Observation data (J2000.0 epoch)
ConstellationBoötes
Right ascension14h 24m 56.88s[1]
Declination+20° 00′ 22.63″[1]
Redshift0.871000[1]
Heliocentric radial velocity261,119 km/s[1]
Distance7.370 Gly
Apparent magnitude (V)17.65
Apparent magnitude (B)18.09
Characteristics
TypeAGN
Other designations
4C 20.33, PKS 1422+20, LEDA 2819642, 7C 1422+2013, RX J1424.9+2000, NVSS J142456+200022, OQ +235, DA 367, CoNFIG 193, Cul 1422+202[1]

QSO B1422+202 is a quasar located in the constellation of Boötes. The redshift of the object is (z) 0.871.[1][2] It was first discovered by astronomers in 1966 through spectroscopic observations[3] and is designated as 4C 20.33 in the Fourth Cambridge Survey.[4]

Description

QSO B1422+202 has a compact steep spectrum source (CSS). When viewed with Very Large Array (VLA) polarimetry imaging, it has a radio core with low polarization and with a lengthy one-sided jet to the south, displaying a large amount of polarized radio emission in its jet components, estimated between 30% and 60%.[5][6] The jet also shown to be curved as well despite VLA describing it as straight.[7] The structure appears to be bent at its southern end.[8]

A radio lobe on the counter-jet side is present in the structure, described as less polarized too with diffused emission located near its nucleus.[5] VLA radio mapping also described the structure of the source as elongated with a faint off-axis region. Additionally, a compact component marked as the beginning of the jet, was found to display an inverted spectral index.[9] Observations made by Very Long Baseline Interferometry (VLBI) at 92 centimeters described the source as diffused instead with emission being concentrated in a 400 milliarcseconds area.[10]

More detailed radio imaging made by both VLA and VLBI shows the quasar displaying radio emission blobs in its elongated structure in a north to south direction. There is the same lengthy jet from the previous observations present, pointing towards the direction of south but there is possibly helical shaped based on the components placed along the major axis position angle. Two hotspot features, mainly a weak hotspot and a bright hotspot located in the jet end on opposite side of another component were discovered. The core contains a gigahertz peaked radio spectrum with emission peaking at 4 GHz.[11]

The quasar is surrounded by extended ionized emission-line gas according to observations made by William Herschel Telescope (WHT) using a faint object spectrograph. When observed, the gas density is estimated to be 55 cm-3 with a separation gap of 24 kiloparsecs. The oxygen line ratios are similar to the quasar 3C 48 at a low redshift, suggesting it has a high amount of gas density.[12]

References

  1. ^ a b c d e f "NED Search results for QSO B1422+202". NASA/IPAC Extragalactic Database. Retrieved 2025-09-06.
  2. ^ Crawford, C. S.; Fabian, A. C. (1989-07-01). "Spectroscopy of extended emission-line gas around quasars at 0.5 > z >1". Monthly Notices of the Royal Astronomical Society. 239 (1): 219–245. doi:10.1093/mnras/239.1.219. ISSN 0035-8711.
  3. ^ Lynds, C. R.; Hill, S. J.; Heere, Karen; Stockton, A. N. (June 1966). "New Spectroscopic Observations of Fourteen Quasi-Stellar Sources". The Astrophysical Journal. 144: 1244. Bibcode:1966ApJ...144.1244L. doi:10.1086/148730. ISSN 0004-637X.
  4. ^ Long, R. J.; Smith, M. A.; Stewart, P.; Williams, P. J. S. (1966-12-01). "The Radio Spectra of Sources in the Fourth Cambridge Catalogue". Monthly Notices of the Royal Astronomical Society. 134 (4): 371–388. doi:10.1093/mnras/134.4.371. ISSN 0035-8711.
  5. ^ a b Mantovani, F.; Junor, W.; Fanti, R.; Padrielli, L.; Saikia, D. J. (November 1997). "VLA polarimetry of compact steep spectrum sources" (PDF). Astronomy and Astrophysics Supplement Series. 125 (3): 573–580. Bibcode:1997A&AS..125..573M. doi:10.1051/aas:1997244. ISSN 0365-0138.
  6. ^ Márquez, I.; Durret, F.; Petitjean, P. (February 1999). "Near infrared observations of quasars with extended ionized envelopes". Astronomy and Astrophysics Supplement Series. 135: 83–101. arXiv:astro-ph/9810012. Bibcode:1999A&AS..135...83M. doi:10.1051/aas:1999163. ISSN 0365-0138.
  7. ^ Bååth, L. B. (1994). "AGN variability and VLBI". Multi-Wavelength Continuum Emission of AGN. 159: 181–186. Bibcode:1994IAUS..159..181B. ISSN 1743-9221.
  8. ^ Kapahi, V. K. (March 1995). "The radio structure of 45 quasars at z < 1.5". Journal of Astrophysics and Astronomy. 16 (1): 1–36. Bibcode:1995JApA...16....1K. doi:10.1007/BF02702483. ISSN 0250-6335.
  9. ^ Mantovani, F.; Junor, W.; Fanti, R.; Padrielli, L.; Browne, I. W. A.; Muxlow, T. W. B. (1992-07-15). "Observations at arcsecond resolution of steep-spectrum sources which vary at low frequencies". Monthly Notices of the Royal Astronomical Society. 257 (2): 353–367. doi:10.1093/mnras/257.2.353. ISSN 0035-8711.
  10. ^ Altschuler, D. R.; Gurvits, L. I.; Alef, W.; Dennison, B.; Graham, D.; Trotter, A. S.; Carson, J. E. (December 1995). "The centi-arcsecond structure of 16 low-frequency variable sources at 92 cm". Astronomy and Astrophysics Supplement Series. 114: 197. Bibcode:1995A&AS..114..197A. ISSN 0365-0138.
  11. ^ Baath, L. B.; Mantovani, F.; Rantakyro, F. T. (November 1997). "High resolution interferometry of the QSO 1422+202" (PDF). Astronomy and Astrophysics Supplement Series. 125 (3): 453–458. Bibcode:1997A&AS..125..453B. doi:10.1051/aas:1997234. ISSN 0365-0138.
  12. ^ Fabian, A. C.; Crawford, C. S.; Johnstone, R. M.; Allington-Smith, J. R.; Hewett, P. C. (December 1988). "WHT spectroscopy of emission-line gas around two separate quasars at z=0.87". Monthly Notices of the Royal Astronomical Society. 235: 13P–18. doi:10.1093/mnras/235.1.13P. ISSN 0035-8711.
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.