Merger and post-merger of binary neutron stars with a quark-hadron crossover equation of state
| Autor: | Huang, Yong-Jia, Baiotti, Luca, Kojo, Toru, Takami, Kentaro, Sotani, Hajime, Togashi, Hajime, Hatsuda, Tetsuo, Nagataki, Shigehiro, Fan, Yi-Zhong |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 129, 181101 (2022) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.129.181101 |
| Popis: | Fully general-relativistic binary-neutron-star (BNS) merger simulations with quark-hadron crossover (QHC) equations of state (EOSs) are studied for the first time. In contrast to EOSs with purely hadronic matter or with a first-order quark-hadron phase transition (1PT), in the transition region QHC EOSs show a peak in sound speed, and thus a stiffening. We study the effects of such stiffening in the merger and post-merger gravitational (GW) signals. Through simulations in the binary-mass range $2.5 < M/M_{\odot} < 2.75$, characteristic differences due to different EOSs appear in the frequency of the main peak of the post-merger GW spectrum ($f_2$), extracted through Bayesian inference. In particular, we found that (i) for lower-mass binaries, since the maximum baryon number density ($n_{\rm max}$) after the merger stays below $3\text{--}4$ times the nuclear-matter density ($n_0$), the characteristic stiffening of the QHC models in that density range results in a lower $f_2$ than that computed for the underlying hadronic EOS and thus also than that for EOSs with a 1PT, (ii) for higher-mass binaries, where $n_{\rm max}$ may exceed $4\text{--}5 n_0$ depending on the EOS model, whether $f_2$ in QHC models is higher or lower than that in the underlying hadronic model depends on the height of the sound-speed peak. Comparing the values of $f_2$ for different EOSs and BNS masses gives important clues on how to discriminate different types of quark dynamics in the high-density end of EOSs and is relevant to future kilohertz GW observations with third-generation GW detectors. Comment: 6+8 pages, 5+6 figures |
| Databáze: | arXiv |
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