S5 2007+777
| S5 2007+777 | |
|---|---|
 The BL Lacertae object S5 2007+777. | |
| Observation data (J2000.0 epoch) | |
| Constellation | Draco |
| Right ascension | 20h 05m 30.998s |
| Declination | +77° 52′ 43.248″ |
| Redshift | 0.342000 |
| Heliocentric radial velocity | 102,529 km/s |
| Distance | 3.662 Gly |
| Apparent magnitude (V) | 16.5 |
| Characteristics | |
| Type | BL Lac |
| Notable features | Core-dominated source, HYMORS, one of the four BL Lacertae objects displaying an extended kiloparsec-scale X-ray jet |
| Other designations | |
| S5 2007+77, NVSS J200531+775243, 6C 200718+774350, 4FGL J2005.5+7752, 2E 4325, WMAP J2005+7755, 1RXS J200529.2+775240 | |
S5 2007+777 is a classical BL Lacertae object[1] located in the constellation of Draco. This object has a redshift of (z) 0.342[2] and was first discovered in 1981 as a flat-spectrum astronomical radio source.[3] It has characteristics of different Fanaroff-Riley classes on both sides of its active nucleus making it a rare type of Hybrid morphology radio sources (HYMORs).[4] It has an estimated V magnitude of 16.5.[5]
Description
[edit]S5 2007+777 is classified as a blazar[6][7] showing variability across the electromagnetic spectrum with amplitudes rising steadily along with frequency.[8] It is also an Intraday Variable (IDV) source exhibiting variations as a whole as well as in polarized intensity on time scales ranging from 2 to 6 days at centimeter (cm) wavelengths.[9] In dereddened B and I-band light curves during observations conducted in 2001, S5 2007+777 shows a smaller amplitude variation of 10%. Subsequent observations conducted in both 2002 and 2004, shows the object having minimum to maximum variations of order 30-40% on 2-4 day time scales.[10]
Although mostly in a quiescent state, one outburst was detected in S5 2007+777 between 1991 and 1992 with the peak flux of this source reaching 3.69 Jansky at 14.5 GHz.[11] A gamma ray flare was detected in February 2016 during an observation from the Foligno Observatory via a 30 cm telescope.[12]
According to radio imaging of S5 2007+777 made by Very Long Baseline Array, a one-sided core-jet structure is found with one of the components exhibiting proper motion and greater flux density.[13] Imaging by Very Large Array and Very Long Baseline Interferometry, shows the object as a core-dominated source instead, consisting of a bright radio lobe on the eastern side and a long jet on the western side of the nucleus which terminates without a clear hot spot upon reaching at 10 arcseconds from the nucleus.[4][14] This jet is known to show superluminal motion, being aligned 24° to the line of sight with its 4.9 GHz luminosity calculated to be 1032 erg s-1 Hz-1.[4]
The radio emission of the jet in S5 2007+777 shows several unique radio knots with the brightest one located midstream. The jet itself imaged at 1.49 GHz, has an extended structure in linear direction which it bends west at a changed position angle of 20°.[4] An extended X-ray jet was also found by Chandra on kiloparsec-scales, making S5 2007+777 only one of the four BL Lacertae objects to have this feature.[15][16]
References
[edit]- ^ Li, Z. X.; Wu, Z. Z.; Chen, Y. J.; Chen, L.; Gu, M. F.; Mi, L. G. (2019-05-01). "The Radio Properties for BL Lac Object S5 2007+777". Acta Astronomica Sinica. 60 (3): 20. Bibcode:2019AcASn..60...20L. ISSN 0001-5245.
- ^ Peng, B.; Kraus, A.; Krichbaum, T. P.; Witzel, A. (July 2000). "Long-term monitoring of selected radio sources" (PDF). Astronomy and Astrophysics Supplement Series. 145 (1): 1–10. Bibcode:2000A&AS..145....1P. doi:10.1051/aas:2000230. ISSN 0365-0138.
- ^ Biermann, P.; Duerbeck, H.; Eckart, A.; Fricke, K.; Johnston, K. J.; Kuhr, H.; Liebert, J.; Pauliny-Toth, I. I. K.; Schleicher, H.; Stockman, H.; Strittmatter, P. A.; Witzel, A. (July 1981). "Observations of six flat spectrum sources from the 5 GHz survey". The Astrophysical Journal. 247: L53. Bibcode:1981ApJ...247L..53B. doi:10.1086/183588. ISSN 0004-637X.
- ^ a b c d Sambruna, Rita M.; Donato, Davide; Cheung, C. C.; Tavecchio, F.; Maraschi, L. (2008-09-10). "A Kiloparsec-Scale X-Ray Jet in the BL Lac Source S5 2007+777". The Astrophysical Journal. 684 (2): 862–869. Bibcode:2008ApJ...684..862S. doi:10.1086/589918. ISSN 0004-637X.
- ^ Ros, E.; Marcaide, J. M.; Guirado, J. C.; Ratner, M. I.; Shapiro, I. I.; Krichbaum, T. P.; Witzel, A.; Preston, R. A. (1999-08-01). "High precision difference astrometry applied to the triplet of S5 radio sources B1803+784/Q1928+738/B2007+777". Astronomy and Astrophysics. 348: 381–393. arXiv:astro-ph/9905265. Bibcode:1999A&A...348..381R. ISSN 0004-6361.
- ^ Nesci, Roberto (2016-02-01). "Optical follow-up of the blazar S5 2007+77". The Astronomer's Telegram. 8642: 1. Bibcode:2016ATel.8642....1N.
- ^ Carrasco, L.; Miramon, J.; Porras, A.; Recillas, E.; Chavushyan, V.; Carraminana, A. (2015-10-01). "NIR brightening of the Quasar HB89 2007+777". The Astronomer's Telegram. 8187: 1. Bibcode:2015ATel.8187....1C.
- ^ Kraus, A.; Krichbaum, T. P.; Wegner, R.; Witzel, A.; Cimò, G.; Quirrenbach, A.; Britzen, S.; Fuhrmann, L.; Lobanov, A. P.; Naundorf, C. E.; Otterbein, K.; Peng, B.; Risse, M.; Ros, E.; Zensus, J. A. (2003-03-17). "Intraday variability in compact extragalactic radio sources II. Observations with the Effelsberg 100 m radio telescope" (PDF). Astronomy & Astrophysics. 401 (1): 161–172. Bibcode:2003A&A...401..161K. doi:10.1051/0004-6361:20030118. ISSN 0004-6361.
- ^ Gabanyi, K.E.; Krichbaum, T.P.; Kraus, A.; Witzel, A.; Zensus, J.A. (2009). "VSOP Observations of the Blazar S5 2007+77". Approaching Micro-Arcsecond Resolution with VSOP-2: Astrophysics and Technologies ASP Conference Series. 402: 155. arXiv:0802.0540. Bibcode:2009ASPC..402..155G.
- ^ Xilouris, E. M.; Papadakis, I. E.; Boumis, P.; Dapergolas, A.; Alikakos, J.; Papamastorakis, J.; Smith, N.; Goudis, C. D. (2006-02-17). "B and I-band optical micro-variability observations of the BL Lac objects S5 2007+777 and 3C 371". Astronomy & Astrophysics. 448 (1): 143–153. arXiv:astro-ph/0511130. Bibcode:2006A&A...448..143X. doi:10.1051/0004-6361:20054054. ISSN 0004-6361.
- ^ Nieppola, Elina; Hovatta, Talvikki; Tornikoski, Merja; Valtaoja, Esko; Aller, Margo F.; Aller, Hugh D. (2009-05-06). "Long-Term Variability of Radio-Bright Bl Lacertae Objects". The Astronomical Journal. 137 (6): 5022–5036. arXiv:0910.2607. Bibcode:2009AJ....137.5022N. doi:10.1088/0004-6256/137/6/5022. ISSN 0004-6256.
- ^ Nesci, Roberto (2016-02-01). "Optical follow-up of the blazar S5 2007+77". The Astronomer's Telegram. 8642: 1. Bibcode:2016ATel.8642....1N.
- ^ Pérez-Torres, M. A.; Marcaide, J. M.; Guirado, J. C.; Ros, E. (December 2004). "Absolute kinematics of radio source components in the complete S5 polar cap sample II. First and second epoch maps at 15 GHz" (PDF). Astronomy & Astrophysics. 428 (3): 847–866. arXiv:astro-ph/0408581. Bibcode:2004A&A...428..847P. doi:10.1051/0004-6361:20040423. ISSN 0004-6361.
- ^ Gopal-Krishna; Wiita, Paul J. (May 2002). "Hybrid morphology radio sources and the Fanaroff–Riley dichotomy". Astronomy & Astrophysics. 46 (2–7): 357–360. arXiv:astro-ph/0009441. Bibcode:2000A&A...363..507G. doi:10.1016/s1387-6473(01)00208-1. ISSN 1387-6473.
- ^ Wu, ZhongZu; Gu, MinFeng; Chen, YongJun (2010-01-01). "The radio structure of BL Lac object S5 2007+777". Science China Physics, Mechanics and Astronomy. 53 (1): 187–190. Bibcode:2010SCPMA..53S.187W. doi:10.1007/s11433-010-0056-7. ISSN 1862-2844.
- ^ Sambruna, R. M.; Donato, D.; Cheung, C. C. Tavecchio, F.; Maraschi, L. (2008-06-01). "An X-ray Jet in the BL Lac S5 2007+777". Extragalactic Jets: Theory and Observation from Radio to Gamma Ray ASP Conference Series. 386: 94. arXiv:0707.1321. Bibcode:2008ASPC..386...94S.
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External links
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