Δημοσιεύσεις

Project Acronym: GWAVES
Title:
Affiliation: aristotle university of thessaloniki
Pi: Nikolaos Stergioulas
Research Field: universe sciences

Neutron-star Radius Constraints from GW170817 and Future Detections
by Andreas Bauswein, Oliver Just, Hans-Thomas Janka and Nikolaos Stergioulas
Abstract:
We introduce a new, powerful method to constrain properties of neutron stars (NSs). We show that the total mass of GW170817 provides a reliable constraint on the stellar radius if the merger did not result in a prompt collapse as suggested by the interpretation of associated electromagnetic emission. The radius IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn1.gif] ${R}_{1.6}$ of nonrotating NSs with a mass of1.6 IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn2.gif] ${M}_{\odot }$ can be constrained to be larger than IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn3.gif] ${10.68}_{-0.04}^{+0.15}$ km, and the radius R max of the nonrotating maximum-mass configuration must be larger than IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn4.gif] ${9.60}_{-0.03}^{+0.14}$ km. We point out that detections of future events will further improve these constraints. Moreover, we show that a future event with a signature of a prompt collapse of the merger remnant will establish even stronger constraints on the NS radius from above and the maximum mass M max of NSs from above. These constraints are particularly robust because they only require a measurement of the chirp mass and a distinction between prompt and delayed collapse of the merger remnant, which may be inferred from the electromagnetic signal or even from the presence/absence of a ringdown gravitational-wave (GW) signal. This prospect strengthens the case of our novel method of constraining NS properties, which is directly applicable to future GW events with accompanying electromagnetic counterpart observations. We emphasize that this procedure is a new way of constraining NS radii from GW detections independent of existing efforts to infer radius information from the late inspiral phase or post-merger oscillations, and it does not require particularly loud GW events.
Reference:
Neutron-star Radius Constraints from GW170817 and Future Detections (Andreas Bauswein, Oliver Just, Hans-Thomas Janka and Nikolaos Stergioulas), In The Astrophysical Journal Letters, volume 850, 2017.
Bibtex Entry:
@article{2041-8205-850-2-L34,
 author = {Andreas Bauswein and Oliver Just and Hans-Thomas Janka and Nikolaos Stergioulas},
 title = {Neutron-star Radius Constraints from GW170817 and Future Detections},
 journal = {The Astrophysical Journal Letters},
 volume = {850},
 number = {2},
 pages = {L34},
 url = {http://stacks.iop.org/2041-8205/850/i=2/a=L34},
 doi = {10.3847/2041-8213/aa9994},
 year = {2017},
 bibyear = {2017},
 abstract = {We introduce a new, powerful method to constrain properties of neutron stars (NSs). We show that the total mass of GW170817 provides a reliable constraint on the stellar radius if the merger did not result in a prompt collapse as suggested by the interpretation of associated electromagnetic emission. The radius IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn1.gif] {${R}_{1.6}$} of nonrotating NSs with a mass of1.6 IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn2.gif] {${M}_{\odot }$} can be constrained to be larger than IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn3.gif] {${10.68}_{-0.04}^{+0.15}$} km, and the radius R max of the nonrotating maximum-mass configuration must be larger than IMG [http://ej.iop.org/images/2041-8205/850/2/L34/apjlaa9994ieqn4.gif] {${9.60}_{-0.03}^{+0.14}$} km. We point out that detections of future events will further improve these constraints. Moreover, we show that a future event with a signature of a prompt collapse of the merger remnant will establish even stronger constraints on the NS radius from above and the maximum mass M max of NSs from above. These constraints are particularly robust because they only require a measurement of the chirp mass and a distinction between prompt and delayed collapse of the merger remnant, which may be inferred from the electromagnetic signal or even from the presence/absence of a ringdown gravitational-wave (GW) signal. This prospect strengthens the case of our novel method of constraining NS properties, which is directly applicable to future GW events with accompanying electromagnetic counterpart observations. We emphasize that this procedure is a new way of constraining NS radii from GW detections independent of existing efforts to infer radius information from the late inspiral phase or post-merger oscillations, and it does not require particularly loud GW events.},
}