Quark-nova

A quark-nova is the hypothetical violent explosion resulting from the conversion of a neutron star to a quark star. Analogous to a supernova heralding the birth of a neutron star, a quark nova signals the creation of a quark star. The term quark-novae was coined in 2002 by Dr. Rachid Ouyed (currently at the University of Calgary, Canada)[1] and Drs. J. Dey and M. Dey (Calcutta University, India).[2]

The nova process

When a neutron star spins down, it may convert to a quark star through a process known as quark deconfinement. The resultant star would have quark matter in its interior. The process would release immense amounts of energy, perhaps explaining the most energetic explosions in the universe; calculations have estimated that as much as 1046 J could be released from the phase transition inside a neutron star.[3] Quark-novae may be one cause of gamma ray bursts. According to Jaikumar et al.,[4] they may also be involved in producing heavy elements such as platinum through r-process nucleosynthesis.

Candidates

Rapidly spinning neutron stars with masses between 1.5 and 1.8 solar masses are theoretically the best candidates for conversion due to spin down of the star within a Hubble time. This amounts to a small fraction of the projected neutron star population. A conservative estimate based on this, indicates that up to two quark-novae may occur in the observable universe each day.

Theoretically, quark stars would be radio-quiet, so radio-quiet neutron stars may be quark stars.

Observations

Direct evidence for quark-novae is scant; however, recent observations of supernovae SN 2006gy, SN 2005gj and SN 2005ap may point to their existence.[5][6]

See also
  • QCD matter, also known as quark matter – Theorized phases of matter
  • Quark-degenerate matter – Type of dense exotic matter in physics
  • SN 2006gy – 2006 hypernova in constellation Perseus
  • SN 2005gj – Supernova event observed on September 29, 2005

References
  1. "Quark Nova Project". Retrieved 13 Sep 2018.
  2. R. Ouyed; J. Dey; M. Dey (2002). "Quark-Nova". Astronomy and Astrophysics. 390 (3): L39–L42. arXiv:astro-ph/0105109. Bibcode:2002A&A...390L..39O. doi:10.1051/0004-6361:20020982. S2CID 124427846.
  3. "Theories of Quark-novae". Archived from the original on October 7, 2012. Retrieved 11 Feb 2009.{{cite web}}: CS1 maint: unfit URL (link)
  4. Prashanth Jaikumar; Meyer; Kaori Otsuki; Rachid Ouyed (2007). "Nucleosynthesis in neutron-rich ejecta from Quark-Novae". Astronomy and Astrophysics. 471 (1): 227–236. arXiv:nucl-th/0610013. Bibcode:2007A&A...471..227J. doi:10.1051/0004-6361:20066593. S2CID 119093518.
  5. Astronomy Now Online - Second Supernovae Point to Quark Stars
  6. Leahy, Denis; Ouyed, Rachid (2008). "Supernova SN2006gy as a first ever Quark Nova?". Monthly Notices of the Royal Astronomical Society. 387 (3): 1193. arXiv:0708.1787. Bibcode:2008MNRAS.387.1193L. doi:10.1111/j.1365-2966.2008.13312.x. S2CID 15696112.
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