Quark Nova

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A quark nova is a hypothetical type of supernova in which a neutron star is converted into a quark star .

Neutron stars are a possible end point of stellar evolution , at which the Fermi pressure prevents further gravitational collapse . Neutron stars have been detected in radio pulsars , X-ray pulsars and X-ray binary stars and are assumed to be in other star classes such as soft gamma repeaters . The upper limit of the mass of a neutron star, the Tolman-Oppenheimer-Volkoff limit , is not exactly known. According to studies on various pulsars, it should be at least two solar masses .

A quark star is a hypothetical star with a higher binding energy and correspondingly a smaller radius than a neutron star. A quark star would consist almost entirely of a quark-gluon plasma . The equations of state of highly compressed matter are not experimentally accessible and therefore it is not known whether quark stars really exist.

QN as a working hypothesis for various observations

Quark novae are used as working hypotheses for a number of properties of astronomical objects :

  • Double-humped supernovae show two maxima in their light curves , which are referred to as double humps . While the first maximum is interpreted as a normal supernova explosion with the formation of a neutron star, the second could be interpreted as an energy release by a quark nova. After that, the neutron star accreted matter that was not accelerated beyond its escape speed and collapsed into a quark star. Candidates for these double explosions are SN 2009ip, SN 2010mc and SN 2006gy. Alternative models for these supernovae: In the case of SN 2009ip it could be a supernova impostor and SN 2006gy a hypernova , the great luminosity of which was caused by a pair instability supernova and by interaction with circumstellar matter.
  • Some unusual X-ray pulsars show anti- glitches in which the rotation period of the stars briefly decreases . This is partially interpreted as an accretion of matter from a retrograde accretion disk onto a quark star.
    Alternatively, the observed behavior can also be explained by assuming a massive white dwarf with a strong magnetic field instead of a quark star formed in a quark nova .
  • Quark novae in early Population III stars are responsible for the cosmic lithium problem . This was caused by the constant abundance of lithium in white dwarfs regardless of the metallicity and the temperature of the compact stars in the galactic halo . This frequency is well below the values predicted by the Standard Model of the Big Bang . The highly depleted matter released back into the interstellar matter by quark novae could be the cause.
  • The accelerated expansion of the universe has been discovered on the basis of the Phillips relationship of type Ia supernovae , which describes a connection between the absolute brightness and the speed of the decrease in brightness . The cause of thermonuclear supernovae is suspected to be a crossing of the Chandrasekhar limit of the mass of a white dwarf with a CO nucleus that accretes mass from a companion . The weakness of this model lies in the problem of simulating the explosion and observing the precursor systems of the Ia supernova. An alternative model suspects the cause of these supernovae in a close binary system of a neutron star and a white dwarf. After an accretion of matter from the white dwarf, a quark nova occurs when the neutron star collapses, and this explosion ignites a carbon burn on the white dwarf as in the traditional model . The energy released during the event is therefore dependent on the quark nova and the mass of the white dwarf. The mass of a white dwarf, however, depends on the mass of the predecessor star (the greater the mass of the predecessor, the more massive the white dwarf). If one follows the Quarknova hypothesis for the thermonuclear supernovae, the accelerated expansion of the universe is not real, but rather a consequence of the higher mean mass of the white dwarfs shortly after the first starburst generation compared to today.

Individual evidence

  1. ↑ Marcio GB de Avellar, Jorge E. Horvath: Entropy, Disequilibrium and Complexity in Compact Stars: An information theory approach to understand their composition . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1308.1033v2 .
  2. ↑ Rachid Ouyed, Nico Koning, Denis Leahy: SN 2009ip and SN 2010mc as dual-shock Quark-Novae . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1308.3927v2 .
  3. ↑ a b Rachid Ouyed, Mathew Kostka, Nico Koning, Denis Leahy, Wolfgang Steffen: Quark nova imprint in the extreme supernova explosion SN 2006gy: the advent of the Quark Star . In: Astrophysics. Solar and Stellar Astrophysics . 2010, arxiv : 1010.5530v1 .
  4. ↑ E. Chatzopoulos, JC Wheeler, J. Vinko, ZL Horvath, A. Nagy: Analytical Light Curve Models of Super-Luminous Supernovae: χ²-Minimizations of Parameter Fits . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1306.3447v3 .
  5. ↑ Rachid Ouyed, Denis Leahy, Nico Koning: “Anti-glitches” in the Quark-Nova model for AXPs . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1307.1386v1 .
  6. ↑ H. Tong, RX Xu: Is magnetar a fact or fiction to us? In: Astrophysics. Solar and Stellar Astrophysics . 2012, arxiv : 1210.4680v1 .
  7. ↑ Rachid Ouyed: A resolution of the cosmic lithium trouble . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1304.3715v1 .
  8. ^ Nico Koning, Denis Leahy, Jan E. Staff, Daniel T. Cassidy: Quark-Novae Ia in the Hubble diagram: Implications For Dark Energy . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1310.4535v1 .