arXiv subjects

Wen-Qi Ma

Publications and source records attributed to Wen-Qi Ma.

3 recordsLinked to original sources

arXiv2026

Nuclear equation-of-state effects on the two-dimensional post-outburst thermal evolution of magnetized neutron-star crusts

We present a controlled two-dimensional study of nuclear-equation-of-state (EOS) effects on the post-outburst thermal relaxation of magnetized neutron-star crusts. Six EOS models are evolved at a fixed gravitational mass of $1.4 M_{\odot}$ with EOS-specific TOV backgrounds, crust compositions, and transport inputs under identical magnetic-field and heating prescriptions. Our analysis combines self-consistent multi-EOS evolution with a BSk-family factorization that separates structural, microphysical, and interaction contributions, together with an accepted-step energy ledger and a numerical-sensitivity budget. The models show EOS-dependent changes in both the early response and the later redistribution of heat between the surface, crust, and inner boundary; light-curve crossings near $10^2$ days demonstrate that the EOS effect is not a simple luminosity rescaling. By 1000 days the cumulative surface-photon energy fraction differs by less than one percentage point, whereas the internal energy partition differs much more strongly. The updated sensitivity tests show that the late-time luminosity differences and the largest peak contrasts exceed the corresponding BSk24 numerical-sensitivity scales, while the smallest early peak contrast remains less securely resolved. The calculations are intended as a reproducible EOS-sensitivity benchmark rather than an observational fit.

astro-ph.HE↗

arXiv2026

Bayesian Geometrical Modeling of IXPE Polarization Angle Curves of the Magnetars 1E 2259+586 and 1E 1547.0-5408

X-ray polarimetry directly probes the radiation geometry and large-scale magnetic configuration of magnetars. We present a uniform Bayesian comparison between a dipole-dominated classical rotating vector model (CRVM) and a modified rotating vector model (MRVM) including a first-order magnetospheric twist correction. The models are applied to the phase-resolved IXPE polarization position angle (PA) curves of 1E~2259+586 and 1E~1547.0$-$5408. Parameters are inferred with a PA-level likelihood, and the models are compared using $χ^2$, AIC, BIC, and Bayesian evidence. For 1E~1547.0$-$5408, we also test radio-derived geometrical constraints using radio-informed priors and radio-fixed fits. The current IXPE PA data for both sources are consistent with a dipole-dominated geometry and do not require a significant global twist. The MRVM gives only a marginal improvement for 1E~2259+586, with a Bayes factor of $\simeq3.3$, and no meaningful improvement for 1E~1547.0$-$5408, with a Bayes factor of $\simeq1.29$. We confirm that for 1E 1547, the nearly aligned radio geometry is not ruled out, but the radio RVM central geometry is not preferred by the X-ray PA data alone. The two sources show different impact angles, suggesting that magnetar X-ray polarization diversity reflects both viewing geometry and source-dependent emission physics. This work provides a framework for future Stokes-level and multi-epoch polarimetric studies with missions such as eXTP.

astro-ph.HE↗

arXiv2024

A short review of the pulsar magnetic inclination angles (II)

The pulsar magnetic inclination angle is a key parameter for pulsar physics. It influences the observable properties of pulsars, such as the pulse beam width, braking index, polarisation, and emission geometry. In this study, we give a brief overview of the current state of knowledge and research on this parameter and its implications for the internal physics of pulsars. We use the observed pulsar data of magnetic inclination angle and braking index to constrain the star's number of precession cycles, $ξ$, which reflects the interaction between superfluid neutrons and other particles inside a neutron star\,(NS). We apply the method proposed by Cheng et al. (2019) to analyse the data of PSR J2013+3845 and obtain the constraints for $ξ$ ranging from $2.393\times 10^{5}$ to $1.268\times10^{6}$. And further analysis suggests that the internal magnetic field structure of PSR J2013+3845 is likely dominated by toroidal component. This study may help us understand the process of internal viscous dissipation and the related evolution of the inclination angles of pulsars, and may have important implications for the study of continuous gravitational wave emissions from NS.

astro-ph.HE↗