A general, scale-independent description of the sound speed in neutron stars
- Using more than a million randomly generated equations of state that satisfy theoretical and observational constraints, we construct a novel, scale-independent description of the sound speed in neutron stars, where the latter is expressed in a unit cube spanning the normalized radius, r/R, and the mass normalized to the maximum one, M/MTOV. From this generic representation, a number of interesting and surprising results can be deduced. In particular, we find that light (heavy) stars have stiff (soft) cores and soft (stiff) outer layers, or that the maximum of the sound speed is located at the center of light stars but moves to the outer layers for stars with M/MTOV ≳ 0.7, reaching a constant value of cs = 1 2 2 as M → MTOV. We also show that the sound speed decreases below the conformal limit cs = 1 3 2 at the center of stars with M = MTOV. Finally, we construct an analytic expression that accurately describes the radial dependence of the sound speed as a function of the neutron-star mass, thus providing an estimate of the maximum sound speed expected in a neutron star.
Verfasserangaben: | Christian EckerORCiD, Luciano RezzollaORCiDGND |
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URN: | urn:nbn:de:hebis:30:3-843938 |
DOI: | https://doi.org/10.3847/2041-8213/ac8674 |
ISSN: | 2041-8213 |
Titel des übergeordneten Werkes (Englisch): | The astrophysical journal letters |
Verlagsort: | American Astronomical Society |
Dokumentart: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Datum der Veröffentlichung (online): | 10.11.2022 |
Datum der Erstveröffentlichung: | 10.11.2022 |
Veröffentlichende Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Datum der Freischaltung: | 02.05.2024 |
Jahrgang: | 939 |
Ausgabe / Heft: | 2, L35 |
Aufsatznummer: | L35 |
Seitenzahl: | 8 |
Institute: | Physik |
Wissenschaftliche Zentren und koordinierte Programme / Frankfurt Institute for Advanced Studies (FIAS) | |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Sammlungen: | Universitätspublikationen |
Lizenz (Deutsch): | Creative Commons - CC BY - Namensnennung 4.0 International |