Constraining the Nuclear Equation of State via Gravitational-wave Radiation of Short Gamma-Ray Burst Remnants

Lin, Li; Lü, Hou-Jun; Rice, Jared; Liang, En‐Wei

doi:10.3847/1538-4357/ab6c64

Cited by 8 publications

(7 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It seems that η should be as low as 0.001 or even smaller to obtain the lower period of magnetar. If this is the case, the rotation energy loss of magnetar is either transformed to kinetic energy of outflow or dominated by GW radiation (Lan et al 2020). present more details for the first situation.…”

Section: The Rotation Energy Loss Of Magnetar Via Gw Radiationmentioning

confidence: 99%

The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

Lü

Yuan

Lin

et al. 2021

Res. Astron. Astrophys.

Self Cite

View full text Add to dashboard Cite

Binary neutron star (NS) mergers may result in remnants of supra-massive or even stable NS, which have been supported indirectly by observed X-ray plateau of some gamma-ray burst (GRB) afterglows. Recently, Xue et al. () discovered an X-ray transient CDF-S XT2 that is powered by a magnetar from merger of double NS via X-ray plateau and following stepper phase. However, the decay slope after the plateau emission is slightly larger than the theoretical value of spin-down in electromagnetic (EM) dominated by losing its rotation energy. In this paper, we assume that the feature of X-ray emission is caused by a supra-massive magnetar central engine for surviving thousands of seconds to collapse into a black hole. Within this scenario, we present the comparisons of the X-ray plateau luminosity, break time, and the parameters of magnetar between CDF-S XT2 and other short GRBs with internal plateau samples. By adopting the collapse time to constrain the equation of state (EOS), we find that three EOSs (GM1, DD2, and DDME2) are consistent with the observational data. On the other hand, if the most released rotation energy of magnetar is dominated by GW radiation, we also constrain the upper limit of ellipticity of NS for given EOS, and its range is [0.32-1.3] × 10−3. Its GW signal cannot be detected by Advanced LIGO or even for more sensitive Einstein Telescope in the future.

show abstract

Section: The Rotation Energy Loss Of Magnetar Via Gw Radiationmentioning

confidence: 99%

The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

Lü

Yuan

Lin

et al. 2021

Res. Astron. Astrophys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Then we consider the GW radiation dominated case, where intensity of GW radiation depends on the NS asymmetries (manifested by the value of ǫ). Here we discuss two mechanisms to induce NS asymmetries: first, the crust of a NS is solid and elastic, where the solid shape is related to the history of neutron star formation and EoS (Haskell et al 2006;Lasky 2015), in which scheme the ǫ value is usually assumed to be a constant during the spin-down process (Corsi & Mészáros 2009;Lasky & Glampedakis 2016;Lü et al 2017;Sarin et al 2018;Lü et al 2019;Lan et al 2020;Sur & Haskell 2021). Second, the NS asymmetry is caused by the distortion of NS magnetic field, in which scheme the ellipticity satisfies ǫ ∝ B 2 p (Bonazzola & Gourgoulhon 1996;Haskell et al 2008;Dall'Osso et al 2009;Gao et al 2017a;Dall'Osso et al 2018;Lander & Jones 2020).…”

Section: Numerical Resultsmentioning

confidence: 99%

The evolution effects of radius and moment of inertia for rapidly rotating neutron stars

Lan,

Gao,

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

A newly born millisecond magnetar is thought to be the central engine of some gamma-ray bursts (GRBs), especially those that present long-lasting X-ray plateau emissions. By solving the field equations, we find that when the rotational speed of the magnetar is approaching the breakup limit, its radius R and moment of inertia I would undergo an obvious evolution as the magnetar spins down. Meanwhile, the values of R and I would sensitively depend on the adoption of neutron star (NS) equation of state (EoS) and the NS baryonic mass. With different EoSs and baryonic masses considered, the magnetic dipole radiation luminosity (L dip ) could be variant within one to two orders of magnitude. We thus suggest that when using the X-ray plateau data of GRBs to diagnose the properties of the nascent NSs, EoS and NS mass information should be invoked as simultaneously constrained parameters. On the other hand, due to the evolution of R and I, the temporal behavior of L dip would become more complicated. For instance, if the spin-down process is dominated by gravitational wave emission due to the NS asymmetry caused by magnetic field distortion (ǫ ∝ B 2 p ), the segment L dip ∝ t 0 could be followed by L dip ∝ t −γ with γ larger than 3. This case could naturally interpret the so-called internal X-ray plateau feature shown in some GRB afterglows, which means the sharp decay following the plateau is unnecessarily corresponding to the NS collapsing. This may explain why some internal X-ray plateaus are followed by late time central engine activity, manifested through flares and second shallow plateaus.

show abstract

“…The late-time steep decay recalls similar behavior in some GRBs. The plateau followed by a steep decay in some GRB X-ray afterglows cannot be explained in the framework of external shock models and usually have to invoke the internal dissipation process of the magnetar wind, while the steep decay may be related to an abrupt cutoff of the center engine (such as the magnetar collapsing into a BH; e.g., Troja et al 2007;Rowlinson et al 2010Rowlinson et al , 2013Lü & Zhang 2014;Lü et al 2015;Chen et al 2017;Lan et al 2020). For the case of AT2018cow, the power off of the center engine immediately ceases the production of high-energy photons from the magnetic dissipation.…”

Section: Late-time Steep Decaymentioning

confidence: 99%

Magnetar as the Central Engine of AT2018cow: Optical, Soft X-Ray, and Hard X-Ray Emission

Li,

Zhong,

Xiao

et al. 2024

ApJL

View full text Add to dashboard Cite

AT2018cow is the most extensively observed and widely studied fast blue optical transient to date; its unique observational properties challenge all existing standard models. In this paper, we model the luminosity evolution of the optical, soft X-ray, and hard X-ray emission, as well as the X-ray spectrum of AT2018cow with a magnetar-centered engine model. We consider a two-zone model with a striped magnetar wind in the interior and an expanding ejecta outside. The soft and hard X-ray emission of AT2018cow can be explained by the leakage of high-energy photons produced by internal gradual magnetic dissipation in the striped magnetar wind, while the luminous thermal UV/optical emission results from the thermalization of the ejecta by the captured photons. The two-component energy spectrum yielded by our model with a quasi-thermal component from the optically thick region of the wind superimposed on an optically thin synchrotron component well reproduces the X-ray spectral shape of AT2018cow. The Markov Chain Monte Carlo fitting results suggest that in order to explain the very short rise time to peak of the thermal optical emission, a low ejecta mass M ej ≈ 0.1 M ⊙ and high ejecta velocity v SN ≈ 0.17 c are required. A millisecond magnetar with P 0 ≈ 3.7 ms and B p ≈ 2.4 × 1014 G is needed to serve as the central engine of AT2018cow.

show abstract

Constraining the Nuclear Equation of State via Gravitational-wave Radiation of Short Gamma-Ray Burst Remnants

Cited by 8 publications

References 70 publications

The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

The evolution effects of radius and moment of inertia for rapidly rotating neutron stars

Magnetar as the Central Engine of AT2018cow: Optical, Soft X-Ray, and Hard X-Ray Emission

Contact Info

Product

Resources

About