Quark-nova remnants

Abstract

XTE J1810−197 and 1E 1547.0−5408 are two transient anomalous X-rays pulsars (AXPs) exhibiting radio emission with unusual properties. In addition, their spin down rates during outburst show opposite trends, which so far has no explanation. Here, we extend our quark-nova model for AXPs to include transient AXPs, in which the outbursts are caused by transient accretion events from a Keplerian (iron-rich) degenerate ring. For a ring with inner and outer radii of 23.5 km and 26.5 km, respectively, our model gives a good fit to the observed X-ray outburst from XTE J1810−197 and the behavior of temperature, luminosity, and area of the two X-ray blackbodies with time. The two blackbodies in our model are related to a heat front (i.e. Bohm diffusion front) propagating along the ring's surface and an accretion hot spot on the quark star surface. Radio pulsations in our model are caused by dissipation at the light cylinder of magnetic bubbles, produced near the ring during the X-ray outburst. The delay between X-ray peak emission and radio emission in our model is related to the propagation time of these bubbles to the light cylinder and scale with the period as t prop. ∝ P 7 2 − α 2 /Ṗ 1/2 where α defines the radial dependence of matter density in the magnetosphere (∝r −α ); for an equatorial wind, α = 1, we predict a ∼1 year and ∼1 month delay for XTE J1810−197 and 1E 1547.0−5408, respectively. The observed flat spectrum, erratic pulse profile, and the pulse duration are all explained in our model as a result of X-point reconnection events induced by the dissipation of the bubbles at the light cylinder. The spin down rate of the central quark star can either increase or decrease depending on how the radial drift velocity of the magnetic islands changes with distance from the central star. We suggest an evolutionary connection between transient AXPs and typical AXPs in our model.

Quark-nova compact remnants: Observational signatures in astronomical data and implications to compact stars

“…Dissipation of magnetic bubbles generated at the ring during these outburst provides a source of transient radio emission which has been associated with some AXPs following bursting periods. 13 When these accretion events happen the inner ring of the disk will be heated by radiation from the surface of the quark star. During quiescent phases, the quark star-ring system should have two emission spectra (X-ray and black body).…”

Strange quark matter and quark stars with the Dyson-Schwinger quark model

“…As a last application, we consider the formation of a SQS from a pure metastable NS, which might occur once and if an initial seed of SQM has been formed in one of several hypothetical ways [11,88,89,90], for example in a two-step phase transition of nuclear matter to 2QM to SQM [91,92], or in the combustion of hot nuclear matter [93,94,95,96,97,98]. This transition is accompanied by a huge energy release, which could be associated with the long gammaray bursts [99,100,101] or the two-neutrino-burst scenario supernovas [102].…”

Quark nova imprint in the extreme supernova explosion SN 2006gy

“…2). Follow‐up studies of neutrino and photon emission processes during the QN (Vogt, Rapp & Ouyed 2004; Ouyed et al 2009b) have shown that these outermost layers (10 −4 to 10 −3 M ⊙ ) can be ejected with up to 10 53 erg in kinetic energy. Nucleosynthesis simulations of the evolution of the neutron‐rich QNE was found to produce primarily heavy elements with mass number, A > 130 (Jaikumar et al 2007).…”