Circinus X-1

Circinus X-1
Observationsdata
Epok: J2000.0
StjärnbildCirkelpassaren
Rektascension15t 20m 40,85s[1]
Deklination-57° 10′ 00,1″[1]
Skenbar magnitud ()+21,40 [2]
Stjärntyp
SpektraltypB5 – A0 I[3]
VariabeltypHMXB[4]
Astrometri
Avstånd31 000+2 600-3 300 lå (9 400+800-1 000[5] pc)
Andra beteckningar
2MASS J15204084-5710001, 1RXS J152040.8-571007, SSTGLMC G322.1185+00.0378, V* BR Cir [6][4]

Circinus X-1 är en dubbelstjärna[4] i den norra delen av stjärnbilden Cirkelpassaren. Den har en skenbar magnitud av ca 21,40[2] och kräver ett teleskop för att kunna observeras. I juni 1969 samlade en Aerobee 150-raket, uppskjuten från Natal, Rio Grande do Norte, Brasilien, röntgendata under en skanning av Norma-Lupus-Circinus-regionen som upptäckte en välisolerad källa vid l=321,4±0,9° b=-0,5±2° (galaktisk), RA 15h 14m dec -57° 49′ kallad Circinus XR-1.[7] Avståndet tillCircinus X-1 var inte väl etablerat, med en låg uppskattning på 13 400 ljusår[8] och hög uppskattning på 26 000 ljusår.[9]

I juni 2015 avslöjade en artikel publicerad på NASA:s Chandra X-Ray Observatorys webbplats att ett internationellt team av astronomer hade lyckats bestämma dess avstånd från jorden med mer precision, genom en metod för triangulering av röntgenstrålning som avges av stjärnan, till ca 30 700 ljusår.[10]

Egenskaper

Circinus X-1 är en röntgendubbelstjärna som innehåller en neutronstjärna. Observation av Circinus X-1 i juli 2007 avslöjade närvaron av röntgenstrålning som normalt finns i svarta hål. Den är den första av detta slag som upptäckts och som visar denna likhet med svarta hål. Circinus X-1 kan vara bland de yngsta röntgendubbelstjärnorna som observerats.

Röntgenstrålningsringar från en neutronstjärna in Circinus X-1 (24 June 2015; Chandra X-ray Observatory).

En period hos röntgenstrålningen på 16,6 dygn hittades av Kaluzienski et al.[11] Röntgenkällan antas vara en neutronstjärna, som en del av en röntgendubbelstjärna med låg massa (LMXB), med röntgenutbrott av typ I.[12] Röntgen- och radionebulosorna som omger Circinus X-1 har egenskaper som överensstämmer med en ung supernovarest. Detta sällsynta fall av en röntgendubbelstjärna som uppenbarligen är förbunden med en supernovarest tyder på att dubbelstjärnan är mycket ung på kosmiska tidsskalor, möjligen mindre än 4 600 år gammal.[13] En förening av Circinus X-1 med en annan närliggande supernovarest, G321.9-0.3, har uteslutits.[12]

Den binära naturen hos Circinus X-1 har fastställts.[14] Dubbelstjärnans radiokomponent och en möjlig visuell motsvarighet identifierades av Whelan et al.[15] Dess infraröda motsvarighet lokaliserades och befanns av Glass blossa med en period av 16,6 dygn.[16] En kraftigt rodnande exakt optisk motsvarighet, nu känd som BR Circini, identifierades av Moneti.[17]

Referenser

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, Circinus X-1, 16 november 2021.

Noter

  1. ^ [a b] Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C. S2CID 115529446.
  2. ^ [a b] Liu, Q. Z; Van Paradijs, J; Van Den Heuvel, E. P. J (2007). "A catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)". Astronomy & Astrophysics. 469 (2): 807. arXiv:0707.0544. Bibcode:2007A&A...469..807L. doi:10.1051/0004-6361:20077303. S2CID 14673570.
  3. ^ Jonker, P. G; Nelemans, G; Bassa, C. G (2007). "Detection of the radial velocity curve of the B5-A0 supergiant companion star of Cir X-1?". Monthly Notices of the Royal Astronomical Society. 374 (3): 999–1005. arXiv:astro-ph/0605497. Bibcode:2007MNRAS.374..999J. doi:10.1111/j.1365-2966.2006.11210.x. S2CID 7474465.
  4. ^ [a b c] "V* BR Cir". SIMBAD. Centre de données astronomiques de Strasbourg. Hämtad 22 september 2017.
  5. ^ Heinz, S; Burton, M; Braiding, C; Brandt, W. N; Jonker, P. G; Sell, P; Fender, R. P; Nowak, M. A; Schulz, N. S (2015). "Lord of the Rings: A Kinematic Distance to Circinus X-1 from a Giant X-Ray Light Echo Lord of the Rings: A Kinematic Distance to Circinus X-1 from a Giant X-Ray Light Echo". The Astrophysical Journal. 806 (2): 265. arXiv:1506.06142. Bibcode:2015ApJ...806..265H. doi:10.1088/0004-637X/806/2/265. S2CID 17657655.
  6. ^ V* BR Cir (unistra.fr). Hämtad 2022-07-29.
  7. ^ Margon B; Lampton M; Bowyer S; Cruddace R (October 1971). "A Pulsing X-Ray Source in Circinus". Astrophys. J. 169 (10): L23–5. Bibcode:1971ApJ...169L..23M. doi:10.1086/180806. hdl:2060/19710026671.
  8. ^ R. Iaria; M. Spano; T. DiSalvo; N.R. Robba; et al. (January 2005). "On The Soft Excess In The X-Ray Spectrum Of Circinus X-1: Revisitation Of The Distance To Circinus X-1". The Astrophysical Journal. 619 (1): 503–516. arXiv:astro-ph/0410259. Bibcode:2005ApJ...619..503I. doi:10.1086/426422. S2CID 18973228.
  9. ^ "Circinus X-1: Neutron Stars Join The Black Hole Jet Set". Harvard-Smithsonian Center for Astrophysics. Hämtad 5 december 2013.
  10. ^ "NASA's Chandra Captures X-Ray Echoes Pinpointing Distant Neutron Star". Hämtad 24 juni 2015.
  11. ^ Kaluzienski, L. J.; Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J. (1976). "Evidence for a 16.6 day period from Circinus X-1". Astrophysical Journal. 208: L71–L75. Bibcode:1976ApJ...208L..71K. doi:10.1086/182235.
  12. ^ [a b] Mignani RP; De Luca A; Caraveo PA; Mirabel IF (2002). "HST observations rule out the association between Cir X-1 and SNR G321.9-0.3". Astron. Astrophys. 386 (2): 487–91. arXiv:astro-ph/0202268. Bibcode:2002A&A...386..487M. doi:10.1051/0004-6361:20020224. S2CID 18606269.
  13. ^ S. Heinz; P. Sell; R.P. Fender; P.G. Jonker; et al. (December 2013). "The Youngest Known X-ray Binary: Circinus X-1 and its Natal Supernova Remnant". The Astrophysical Journal. 779 (2): 171. arXiv:1312.0632. Bibcode:2013ApJ...779..171H. doi:10.1088/0004-637X/779/2/171. S2CID 6064052.
  14. ^ Jones C; Tananbaum H; Giacconi R (1973). "UHURU Observations of the Binary Nature of Circinus X-1". 141st Meeting Amer Astron Soc. Tucson, Arizona. 5: 395. Bibcode:1973BAAS....5..395J.
  15. ^ Whelan, J. A. J.; Mayo, S. K.; Wickramasinghe, D. T.; Murdin, P. G.; et al. (1977). "The optical and radio counterpart of Circinus X-1 /3U 1516-56/". Monthly Notices of the Royal Astronomical Society. 181 (2): 259–271. Bibcode:1977MNRAS.181..259W. doi:10.1093/mnras/181.2.259.
  16. ^ Glass, I.S. (1978). "Variations of Circinus X-1 in the infrared". Monthly Notices of the Royal Astronomical Society. 183 (3): 335–340. Bibcode:1978MNRAS.183..335G. doi:10.1093/mnras/183.3.335.
  17. ^ Moneti, A. (1992). "Optical and infrared observations of Circinus X-1". Astronomy and Astrophysics. 260: L7–L10. Bibcode:1992A&A...260L...7M.

Externa länkar

Vidare läsning

Stjärnor i Cirkelpassaren
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Media som används på denna webbplats

Circinus IAU.svg
Författare/Upphovsman: IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), Licens: CC BY 3.0
IAU Circinus chart
Golden star.svg
(c) I, Ssolbergj, CC BY 3.0
Gold-shaded star.
15-137-CircinusX1-XRayLightRings-NeutronStar-Chandra-20150624.jpg
Astronomers using NASA's Chandra X-ray Observatory have discovered the largest and brightest set of rings from X-ray light echoes ever observed. These extraordinary rings, produced by an intense flare from a neutron star, providing astronomers a rare chance to determine how far it is from Earth.

The rings appear as circles around Circinus X-1, a double star system in the plane of the Milky Way containing a neutron star, the dense remnant of a massive star pulverized in a supernova explosion. The neutron star is in orbit with another massive star, and is shrouded by thick clouds of interstellar gas and dust. Circinus X-1 is also the source of a surprisingly powerful jet of high-energy particles.

"It's really hard to get accurate distance measurements in astronomy and we only have a handful of methods,” said Sebastian Heinz of the University of Wisconsin in Madison, who led the study. “But just as bats use sonar to triangulate their location, we can use the X-rays from Circinus X-1 to figure out exactly where it is."

The light echo shows that Circinus X-1 is located about 30,700 light years from Earth, and settles the difference in results published in prior studies. The detection and characterization of the rings required the unique capabilities of Chandra -- the ability to detect fine details combined with sensitivity to faint signals.

Researchers determined that the rings are echoes from a burst of X-rays emitted by Circinus X-1 in late 2013. The burst reflected off intervening clouds of dust, with some reflected X-rays arriving to Earth from different angles at a time delay of about one to three months, creating the observed rings.

By comparing the Chandra data to prior images of dust clouds detected by the Mopra radio telescope in Australia, the researchers determined that each ring was created by the X-ray reflections off a different dust cloud. The radio data provides the distance to the different clouds and the X-ray echo determines the location of Circinus X-1 relative to the clouds. An analysis of the rings with the combined radio data allows researchers to use simple geometry to accurately determine the distance of Circinus X-1 from Earth.

"We like to call this system the 'Lord of the Rings,' but this one has nothing to do with Sauron," said co-author Michael Burton of the University of New South Wales in Sydney, Australia. "The beautiful match between the Chandra X-ray rings and the Mopra radio images of the different clouds is really a first in astronomy."

This new distance estimate means that Circinus X-1 is inherently much brighter in X-rays and other types of light than some scientists previously thought, and indicates that the star system has repeatedly passed a key threshold for brightness where the outward pressure from radiation by the system is balanced by the inward pull of gravity. This behavior is something astronomers generally see more often in systems containing black holes than in systems like Circinus X-1 that contain a neutron star.

The researchers also determined that the speed of the jet of high-energy particles produced by the system is at least 99.9% of the speed of light. This extreme velocity is usually associated with jets produced by a black hole.

"Circinus X-1 acts in some ways like a neutron star and in some like a black hole," said co-author Catherine Braiding, also of the University of New South Wales. "It's extremely unusual to find an object that has such a blend of these properties."

Circinus X-1 is thought to have originally become an X-ray source about 2,500 years ago, as seen from Earth. This makes Circinus X-1 the youngest so-called X-ray binary known. The new Chandra data allows astronomers to make a detailed three-dimensional map of the dust clouds between Circinus X-1 and us, providing a valuable probe of the structure of the galaxy.

These results have been published on June 23 in The Astrophysical Journal and are available online. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for the agency's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.