Precision of mass and radius determination for neutron star using the ATHENA mission. (arXiv:1912.01608v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Majczyna_A/0/1/0/all/0/1">A. Majczyna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Madej_J/0/1/0/all/0/1">J. Madej</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nalezyty_M/0/1/0/all/0/1">M. Nalezyty</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rozanska_A/0/1/0/all/0/1">A. Rozanska</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beldycki_B/0/1/0/all/0/1">B. Beldycki</a>
In this paper we show that X-ray spectral observations of the ATHENA mission,
which is planned to launch in 2031, can constrain the equation of state of
superdense matter. We use our well-constrained continuum fitting method for
mass and radius determination of the neutron star. Model spectra of the
emission from a neutron star were calculated using the atmosphere code ATM24.
In the next step, those models were fitted to a simulated spectra of the
neutron star calculated for ATHENA’s WFI detector, using the satellite
calibration files. To simulate the spectra we assumed three different values of
effective temperatures, surface gravities and gravitational redshifts. There
cases are related to the three different neutron star masses and radii. This
analysis allows us to demonstrate the precision of our method and demonstrate
the need for a fast detector onboard of ATHENA. A large grid of theoretical
spectra was calculated with various parameters and a hydrogen-helium-iron
composition of solar proportion. These spectra were fitted to the simulated
spectrum to estimate the precision of mass and radius determination. In each
case, we obtained very precise mass and radius values with errors in the range
3–10% for mass and in the range 2–8% for radius within the 1-sigma confidence
error. We show here that with the ATHENA WFI detector, such a determination
could be used to constrain the equation of state of superdense neutron star
matter.
In this paper we show that X-ray spectral observations of the ATHENA mission,
which is planned to launch in 2031, can constrain the equation of state of
superdense matter. We use our well-constrained continuum fitting method for
mass and radius determination of the neutron star. Model spectra of the
emission from a neutron star were calculated using the atmosphere code ATM24.
In the next step, those models were fitted to a simulated spectra of the
neutron star calculated for ATHENA’s WFI detector, using the satellite
calibration files. To simulate the spectra we assumed three different values of
effective temperatures, surface gravities and gravitational redshifts. There
cases are related to the three different neutron star masses and radii. This
analysis allows us to demonstrate the precision of our method and demonstrate
the need for a fast detector onboard of ATHENA. A large grid of theoretical
spectra was calculated with various parameters and a hydrogen-helium-iron
composition of solar proportion. These spectra were fitted to the simulated
spectrum to estimate the precision of mass and radius determination. In each
case, we obtained very precise mass and radius values with errors in the range
3–10% for mass and in the range 2–8% for radius within the 1-sigma confidence
error. We show here that with the ATHENA WFI detector, such a determination
could be used to constrain the equation of state of superdense neutron star
matter.
http://arxiv.org/icons/sfx.gif
