Constraining neutron star matter from the slope of the mass-radius curves (2025)

Authorization Required

×

×

• 

  Figure 1

  $M(R)$ sequences for nuclear models discussed in the Introduction.

  Reuse & Permissions

• 

  Figure 2

  Sequences $M(R)$ (left) and $M(\mathrm{\Lambda })$ (right) for the set of EOSs satisfying $dM/dR<0$ (top) and $dM/dR\nless 0$ (bottom) with (dark) and without (light) astrophysical constraints (see text for details). Maximum masses vary between $2.01\lesssim M_{\max }/M_{\odot }\lesssim 2.20$ at a 90% CI for $dM/dR<0$ even if astrophysical constraints are imposed, and $2.01\lesssim M_{\max }/M_{\odot }\lesssim 2.43$ ($2.01\lesssim M_{\max }/M_{\odot }\lesssim 2.60$) for $dM/dR\nless 0$, imposing (not imposing) astrophysical constraints. The boundaries of the different regions specify the extremes (minimum/maximum).

  Reuse & Permissions

• 

  Figure 3

  Pressure as a function of baryon density for the set $dM/dR<0$ (blue) and $dM/dR\nless 0$ (red) with (bottom) and without (top) astrophysical constraints. The darker bands represent 90% credible intervals (CI), while the lighter bands show the extremes (minimum/maximum).

  Reuse & Permissions

• 

  Figure 4

  Speed of sound squared as a function of baryon density for the set $dM/dR<0$ (blue) and $dM/dR\nless 0$ (red) with (bottom) and without (top) astrophysical constraints. The lighter bands represent the 90% CI, the darker bands the 50% CI, and the solid lines the median. The vertical bands specify the 65% CI for the central densities ($n_{\max }$) at the $M_{\max }$.

  Reuse & Permissions

• 

  Figure 5

  The normalized matter trace anomaly as a function of baryon density for the set $dM/dR<0$ (blue) and $dM/dR\nless 0$ (red) with (bottom) and without (top) astrophysical constraints. The lighter bands represent the 90% CI, the darker bands the 50% CI, and the solid lines the median. The vertical bands specify the 65% CI for the central densities ($n_{\max }$) at the $M_{\max }$.

  Reuse & Permissions

• 

  Figure 6

  The probability distribution functions for the normalized matter trace anomaly (top) and speed of sound squared (bottom) at the central densities of $M_{\max }$. We display the sets $dM/dR<0$ (blue) and $dM/dR\nless 0$ (red) with (dark) and without (light) astrophysical constraints. The 50% CIs for $\mathrm{\Delta }(n_{\max })$ are $-0.070_{+0.053}^{-0.051}$ ($dM/dR<0$, without restrictions), $-0.057_{+0.049}^{-0.052}$ ($dM/dR<0$, with restrictions), ${0.032}_{+0.073}^{-0.081}$ ($dM/dR\nless 0$, without restrictions), and ${0.008}_{+0.066}^{-0.073}$ ($dM/dR\nless 0$, with restrictions).

  Reuse & Permissions

• 

  Figure 7

  Same plots as in Fig.2, but showing explicitly the $M(R)$ sequences for the EOS with positive $\mathrm{\Delta }(n)$ for $0<n<1.2{\mathrm{fm}}^{-3}$.

  Reuse & Permissions

• 

  Figure 8

  Scatter plot of $dM/dR{|}_{M=1.4M_{\odot }}$ vs $R(2.0M_{\odot })$ (top) and the respective $R(2.0M_{\odot })$ PDF (bottom). The colors indicate the $dM/dR{|}_{M=1.4M_{\odot }}$ value: negative (blue), positive but finite (red), and $\infty$ (black), both with (dark colors) and without (light colors) astrophysical constraints.

  Reuse & Permissions

• 

  Figure 9

  Scatter plot of $dM/dR{|}_{M=1.4M_{\odot }}$ vs $\{M_{\max },R_{\max }\}$ (top panels) and the respective $\{M_{\max },R_{\max }\}$ PDFs (bottom panels). The colors indicate the $dM/dR{|}_{M=1.4M_{\odot }}$ value: negative (blue), positive but finite (red), and $\infty$ (black), both with (dark colors) and without (light colors) astrophysical constraints.

  Reuse & Permissions

• 

  Figure 10

  Scatter plot of $dM/dR{|}_{M=1.4M_{\odot }}$ vs $\mathrm{\Lambda }(1.4M_{\odot })$ (top) and the respective $\mathrm{\Lambda }(1.4M_{\odot })$ PDF (bottom). The colors indicate the $dM/dR{|}_{M=1.4M_{\odot }}$ value: negative (blue), positive but finite (red), and $\infty$ (black), both with (dark colors) and without (light colors) astrophysical constraints.

  Reuse & Permissions

• 

  Figure 11

  The PDFs of the radius of $2.0M_{\odot }$ (left) and the tidal deformability of a $1.4M_{\odot }$ (right), with (bottom) and without (top) astrophysical constraints applied for $dM/dR{|}_{M=1.2M_{\odot }}$ (dark colors) and $dM/dR{|}_{M=1.8M_{\odot }}$ (light colors) values: negative (blue), positive but finite (red), and $\infty$ (black).

  Reuse & Permissions

×