QSO B2005+403
| QSO B2005+403 | |
|---|---|
 SDSS image of QSO B2005+403. | |
| Observation data (J2000.0 epoch) | |
| Constellation | Cygnus |
| Right ascension | 20h 07m 44.94s |
| Declination | +40° 29′ 48.60″ |
| Redshift | 1.736000 |
| Heliocentric radial velocity | 520,440 km/s |
| Distance | 9.677 Gly |
| Apparent magnitude (V) | 19.00 |
| Apparent magnitude (B) | 18.5 |
| Characteristics | |
| Type | Opt.var. LPQ RLQ |
| Other designations | |
| TXS 2005+403, NVSS J200744+402948, IERS B2005+403, VERA B2005+403, ZOAG G076.82+04.30, JVAS J2007+4029, MASIV J2007+4029 | |
QSO B2005+403 is a quasar located in the constellation of Cygnus. The redshift of the object is (z) 1.736[1] and was discovered as a variable astronomical radio source in 1972 by astronomers located near Cygnus A, later identified with a quasi-stellar object in 1976.[2][3] The radio spectrum of the source is flat, thus it is classfied as a flat-spectrum radio quasar.[4][5]
Description
[edit]QSO B2005+403 is described as variable. Observations in November 1972, noted the object's radio spectrum is slightly inverted, with it reaching 1.7 ± 0.1 Jy at 11.1 centimeters and 2.2 ± 0.2 Jy at 3.7 centimeters. It is also found the flux density of the source reached the highest level of 6.3 Jy on June 18 and 19 in 1973, before deceasing to 4.9 Jy and slightly increased 5.3 Jy in September, suggestive of an outburst.[2] It was shown brightening in November 1973, increasing to 18.5 magnitude.[3]
The source of QSO B2005+403 is compact. Imaging observations above 8 GHz with Very Long Baseline Interferometry, have showed the source has a core-jet structure orientating in east to west. In the central region of 1 milliarcsecond, lies three components namely C1, C2 and C3 which displays a relative alignment seeming to vary, with a slight bend towards north. There is also a faint partially resolved diffused radio emission region. It is found there is a jet in QSO B2005+402, displaying a noticeable bend about 2 milliarcseconds from the nucleus with a bright feature moving closer by 0.1 milliarcsecond over a three year period observation, interpreted as new emerging component.[6] The jet components are moving on a non-ballistic trajectory reaching velocities ranging from 6.3-16.8 c,[7] with the inner part of the jet exhibiting south of east direction based on 15 GHz radio mapping.[8]
The quasar shows a parsec-scale rotation measure. Observations have shown the core has a rotation measurement of 668 ± 58 rad m-2 while the jet on the other hand, has a rotation measurement of -200 ± 57 rad m-2. The radio core itself is inverted with the location fit of the rotation measurement by 1.5 milliarcseconds east of it, also displays an inverted spectrum but however, is optically thin at 15 GHz frequency.[9]
QSO B2005+403 has evidence of anisotropic scattering making it the second known quasar to have it after QSO 2023+335, on lower frequencies. It is showed the scattering patterns caused by imaging of its core, are extended along the 40° position angle at various frequencies and epochs, corresponding to a Galactic latitude line. The core of the quasar also shows an angular separation between itself and a secondary image, following a wavelength squared dependence, hinting scattering of the interstellar medium. In the light curve data presented for the quasar, it is found to undergo a distinctive extreme scattering event with detected flux variations of 10 percent, lasting for a duration of six months.[10]
References
[edit]- ^ "NED search results for QSO B2005+403". NASA/IPAC Extragalactic Database. Retrieved 2025-07-06.
- ^ a b Adgie, R. L.; Palmer, H. P.; Penston, M. V. (1975-01-01). "A New Variable Radio Source in Cygnus". Monthly Notices of the Royal Astronomical Society. 170 (1): 31P – 34P. doi:10.1093/mnras/170.1.31P. ISSN 0035-8711.
- ^ a b A., Boksenberg; A., Briggs, S.; F., Carswell, R.; M., Schmidt; D., Walsh (1976). "2005+403 - a QSO near the galactic plane". Monthly Notices of the Royal Astronomical Society. 177. doi:10.1093/mnra (inactive 6 July 2025). ISSN 0035-8711. Archived from the original on 2022-07-27.
{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link) CS1 maint: multiple names: authors list (link) - ^ Lister, M. L.; Homan, D. C. (October 2005). "MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. I. First-Epoch 15 GHz Linear Polarization Images". The Astronomical Journal. 130 (4): 1389–1417. arXiv:astro-ph/0503152. Bibcode:2005AJ....130.1389L. doi:10.1086/432969. ISSN 0004-6256.
- ^ Desai, K. M.; Fey, A. L. (April 2001). "Anisotropic Interstellar Scattering toward the Cygnus Region". The Astrophysical Journal Supplement Series. 133 (2): 395–411. Bibcode:2001ApJS..133..395D. doi:10.1086/320349. ISSN 0067-0049.
- ^ Lister, M. L.; Cohen, M. H.; Homan, D. C.; Kadler, M.; Kellermann, K. I.; Kovalev, Y. Y.; Ros, E.; Savolainen, T.; Zensus, J. A. (December 2009). "MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VI. Kinematics Analysis of a Complete Sample of Blazar Jets". The Astronomical Journal. 151 (5): 132. doi:10.3847/0004-6256/151/5/132. ISSN 0004-6256.
- ^ Gabányi, K. É; Krichbaum, T. P.; Britzen, S.; Bach, U.; Ros, E.; Witzel, A.; Zensus, J. A. (2006-05-01). "High frequency VLBI observations of the scatter-broadened quasar B 2005+403" (PDF). Astronomy & Astrophysics. 451 (1): 85–98. arXiv:astro-ph/0601362. Bibcode:2006A&A...451...85G. doi:10.1051/0004-6361:20054017. ISSN 0004-6361.
- ^ Gabuzda, D. C.; Roche, N.; Kirwan, A.; Knuettel, S.; Nagle, M.; Houston, C. (2017-08-17). "Parsec scale Faraday-rotation structure across the jets of nine active galactic nuclei". Monthly Notices of the Royal Astronomical Society. 472 (2): 1792–1801. doi:10.1093/mnras/stx2127. ISSN 0035-8711.
- ^ Zavala, R. T.; Taylor, G. B. (2003-05-20). "A View through Faraday's Fog: Parsec-Scale Rotation Measures in Active Galactic Nuclei". The Astrophysical Journal. 589 (1): 126–146. arXiv:astro-ph/0302367. Bibcode:2003ApJ...589..126Z. doi:10.1086/374619. ISSN 0004-637X.
- ^ Koryukova, T A; Pushkarev, A B; Kiehlmann, S; Readhead, A C S (2023-10-06). "Multiple imaging of the quasar 2005 + 403 formed by anisotropic scattering". Monthly Notices of the Royal Astronomical Society. 526 (4): 5932–5948. doi:10.1093/mnras/stad3052. ISSN 0035-8711.