Back ثقب أسود ثنائي Arabic Agujero negro binario Spanish سیاهچاله دوتایی Persian Trou noir binaire French Binarna crna jama Croatian Buco nero binario Italian Podwójna czarna dziura Polish Двойная чёрная дыра Russian Binary black hole SIMPLE இருமக் கருந்துளை Tamil
A binary black hole (BBH), or black hole binary, is a system consisting of two black holes in close orbit around each other. Like black holes themselves, binary black holes are often divided into stellar binary black holes, formed either as remnants of high-mass binary star systems or by dynamic processes and mutual capture; and binary supermassive black holes, believed to be a result of galactic mergers.
For many years, proving the existence of binary black holes was made difficult because of the nature of black holes themselves and the limited means of detection available. However, in the event that a pair of black holes were to merge, an immense amount of energy should be given off as gravitational waves, with distinctive waveforms that can be calculated using general relativity.[2][3][4] Therefore, during the late 20th and early 21st century, binary black holes became of great interest scientifically as a potential source of such waves and a means by which gravitational waves could be proven to exist. Binary black hole mergers would be one of the strongest known sources of gravitational waves in the universe, and thus offer a good chance of directly detecting such waves. As the orbiting black holes give off these waves, the orbit decays, and the orbital period decreases. This stage is called binary black hole inspiral. The black holes will merge once they are close enough. Once merged, the single hole settles down to a stable form, via a stage called ringdown, where any distortion in the shape is dissipated as more gravitational waves.[5] In the final fraction of a second the black holes can reach extremely high velocity, and the gravitational wave amplitude reaches its peak.
The existence of stellar-mass binary black holes (and gravitational waves themselves) was finally confirmed when LIGO detected GW150914 (detected September 2015, announced February 2016), a distinctive gravitational wave signature of two merging stellar-mass black holes of around 30 solar masses each, occurring about 1.3 billion light-years away. In its final 20 ms of spiraling inward and merging, GW150914 released around 3 solar masses as gravitational energy, peaking at a rate of 3.6×1049 watts – more than the combined power of all light radiated by all the stars in the observable universe put together.[6][7][8] Supermassive binary black hole candidates have been found, but not yet categorically proven.[9]
- ^ Credits: SXS (Simulating eXtreme Spacetimes) project.
- ^ Pretorius, Frans (2005). "Evolution of Binary Black-Hole Spacetimes". Physical Review Letters. 95 (12): 121101. arXiv:gr-qc/0507014. Bibcode:2005PhRvL..95l1101P. doi:10.1103/PhysRevLett.95.121101. ISSN 0031-9007. PMID 16197061. S2CID 24225193.
- ^ Campanelli, M.; Lousto, C. O.; Marronetti, P.; Zlochower, Y. (2006). "Accurate Evolutions of Orbiting Black-Hole Binaries without Excision". Physical Review Letters. 96 (11): 111101. arXiv:gr-qc/0511048. Bibcode:2006PhRvL..96k1101C. doi:10.1103/PhysRevLett.96.111101. ISSN 0031-9007. PMID 16605808. S2CID 5954627.
- ^ Baker, John G.; Centrella, Joan; Choi, Dae-Il; Koppitz, Michael; van Meter, James (2006). "Gravitational-Wave Extraction from an Inspiraling Configuration of Merging Black Holes". Physical Review Letters. 96 (11): 111102. arXiv:gr-qc/0511103. Bibcode:2006PhRvL..96k1102B. doi:10.1103/PhysRevLett.96.111102. ISSN 0031-9007. PMID 16605809. S2CID 23409406.
- ^ Abadie, J.; et al. (2011). "Search for gravitational waves from binary black hole inspiral, merger and ringdown". Physical Review D. 83 (12): 122005. arXiv:1102.3781. Bibcode:2011PhRvD..83l2005A. doi:10.1103/PhysRevD.83.122005. S2CID 174250.
- ^ "Observation Of Gravitational Waves From A Binary Black Hole Merger" (PDF). LIGO. 11 February 2016. Archived from the original (PDF) on 16 February 2016. Retrieved 11 February 2016.
- ^ Harwood, W. (11 February 2016). "Einstein was right: Scientists detect gravitational waves in breakthrough". CBS News. Archived from the original on 12 February 2016. Retrieved 12 February 2016.
- ^ Drake, Nadia (11 February 2016). "Found! Gravitational Waves, or a Wrinkle in Spacetime". National Geographic News. Archived from the original on 12 February 2016. Retrieved 12 February 2016.
- ^ Liu, Fukun; Komossa, Stefanie; Schartel, Norbert (22 April 2014). "Unique Pair of Hidden Black Holes Discovered yy XMM-Newton". A milli-parsec supermassive black hole binary candidate in the galaxy SDSS J120136.02+300305.5. Retrieved 23 December 2014.