Meissner effect and vortex dynamics in quark stars

Ouyed, Rachid; Elgarøy, Ø.; Dahle, H.; Keränen, P.

doi:10.1051/0004-6361:20034180

Cited by 37 publications

(54 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While gravitational effects are expected to dominate photon trajectories outside of magnetars (Heyl & Shaviv 2002;Kim 2012), it is generally believed that plasma effects should also become important deep within magnetar atmospheres (Lai & Ho 2003). A particularly interesting alternative to the magnetar model describes AXP and SGR behaviour in terms of a quark star (Ouyed et al 2004;Leahy & Ouyed 2009). The environments around these objects are expected to be complex, and some models explain magnetar-like behaviour through accretion from fall-back material on to the surface of the object (Ouyed, Leahy & Niebergal 2007).…”

Section: Discussionmentioning

confidence: 99%

Frequency-dependent effects of gravitational lensing within plasma

Rogers

2015

Monthly Notices of the Royal Astronomical Society

132

120

View full text Add to dashboard Cite

The interaction between refraction from a distribution of inhomogeneous plasma and gravitational lensing introduces novel effects to the paths of light rays passing by a massive object. The plasma contributes additional terms to the equations of motion, and the resulting ray trajectories are frequency-dependent. Lensing phenomena and circular orbits are investigated for plasma density distributions N ∝ 1/r h with h ≥ 0 in the Schwarzschild space-time. For rays passing by the mass near the plasma frequency refractive effects can dominate, effectively turning the gravitational lens into a mirror. We obtain the turning points, circular orbit radii, and angular momentum for general h. Previous results have shown that light rays behave like massive particles with an effective mass given by the plasma frequency for a constant density h = 0. We study the behaviour for general h and show that when h = 2 the plasma term acts like an additional contribution to the angular momentum of the passing ray. When h = 3 the potential and radii of circular orbits are analogous to those found in studies of massless scalar fields on the Schwarzschild background. As a physically motivated example we study the pulse profiles of a compact object with antipodal hotspots sheathed in a dense plasma, which shows dramatic frequency-dependent shifts from the behaviour in vacuum. Finally, we consider the potential observability and applications of such frequency-dependent plasma effects in general relativity for several types of neutron star.

show abstract

Section: Discussionmentioning

confidence: 99%

Frequency-dependent effects of gravitational lensing within plasma

Rogers

2015

Monthly Notices of the Royal Astronomical Society

132

120

View full text Add to dashboard Cite

show abstract

“…Despite the accumulated evidence for the magnetar model, there are also alternative hypotheses proposed to explain the observational features of SGRs and AXPs in terms of, e.g., accretion from a fossil disk (Alpar 2001a;Trümper et al 2010), invoking a quark star model (Ouyed et al 2004), or as fast rotating massive white dwarves (Malheiro et al 2012). Therefore, it is imperative at this stage to observationally examine the radiation properties of this group of objects, and understand their radiation properties in a unified way.…”

Section: −1ṗmentioning

confidence: 99%

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

Enoto¹,

Shibata²,

Kitaguchi³

et al. 2017

ApJS

116

View full text Add to dashboard Cite

Studies were made of the 1-70 keV persistent spectra of fifteen magnetars as a complete sample observed with Suzaku from 2006 to 2013. Combined with early NuSTAR observations of four hard X-ray emitters, nine objects showed a hard power-law emission dominating at 10 keV with the 15-60 keV flux of ∼1-11 × 10 −11 ergs s −1 cm −2 . The hard X-ray luminosity L h , relative to that of a soft-thermal surface radiation L s , tends to become higher toward younger and strongly magnetized objects. Updated from the previous study, their hardness ratio, defined as ξ = L h /L s , is correlated with the measured spin-down rateṖ as ξ = 0.62 × (Ṗ /10 −11 s s −1 ) 0.72 , corresponding with positive and negative correlations of the dipole field strength B d (ξ ∝ B d) and the characteristic age τ c (ξ ∝ τ −0.68 c ), respectively. Among our sample, five transients were observed during X-ray outbursts, and the results are compared with their long-term 1-10 keV flux decays monitored with Swift/XRT and RXTE/PCA. Fading curves of three bright outbursts are approximated by an empirical formula used in the seismology, showing a ∼10-40 d plateau phase. Transients show the maximum luminosities of L s ∼1035 erg s −1 , which is comparable to those of the persistently bright ones, and fade back to 10 32 erg s −1 . Spectral properties are discussed in a framework of the magnetar hypothesis.

show abstract

“…Owing to the superconductivity of the CFL state, the star's interior contains a lattice of vortices that confine the magnetic field (Ouyed et al 2004). This interior configuration consequently forces the exterior field to align with the rotation axis Niebergal et al 2006); this is illustrated in Fig.…”

Section: The Quark Star: Magnetically Aligned Rotatormentioning

confidence: 99%

Quark-nova remnants

Ouyed¹,

Leahy²,

Niebergal³

2010

A&A

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Meissner effect and vortex dynamics in quark stars

Cited by 37 publications

References 51 publications

Frequency-dependent effects of gravitational lensing within plasma

Frequency-dependent effects of gravitational lensing within plasma

Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE

Quark-nova remnants

Contact Info

Product

Resources

About