Discriminating strange star mergers from neutron star mergers by gravitational-wave measurements

Journal Article · Fri Jan 15 00:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.024012· OSTI ID:21409076

Bauswein, A; Oechslin, R; Janka, H -T ^[1]

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1. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

We perform three-dimensional relativistic hydrodynamical simulations of the coalescence of strange stars and explore the possibility to decide on the strange matter hypothesis by means of gravitational-wave measurements. Self-binding of strange quark matter and the generally more compact stars yield features that clearly distinguish strange star from neutron star mergers, e.g. hampering tidal disruption during the plunge of quark stars. Furthermore, instead of forming dilute halo structures around the remnant as in the case of neutron star mergers, the coalescence of strange stars results in a differentially rotating hypermassive object with a sharp surface layer surrounded by a geometrically thin, clumpy high-density strange quark matter disk. We also investigate the importance of including nonzero temperature equations of state in neutron star and strange star merger simulations. In both cases we find a crucial sensitivity of the dynamics and outcome of the coalescence to thermal effects, e.g. the outer remnant structure and the delay time of the dense remnant core to black hole collapse depend on the inclusion of nonzero temperature effects. For comparing and classifying the gravitational-wave signals, we use a number of characteristic quantities like the maximum frequency during inspiral or the dominant frequency of oscillations of the postmerger remnant. In general, these frequencies are higher for strange star mergers. Only for particular choices of the equation of state the frequencies of neutron star and strange star mergers are similar. In such cases additional features of the gravitational-wave luminosity spectrum like the ratio of energy emitted during the inspiral phase to the energy radiated away in the postmerger stage may help to discriminate coalescence events of the different types. If such characteristic quantities could be extracted from gravitational-wave signals, for instance with the upcoming gravitational-wave detectors, a decision on the strange matter hypothesis and the existence of strange stars should be possible.

• OSTI ID: 21409076
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 2; Other Information: DOI: 10.1103/PhysRevD.81.024012; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BLACK HOLES
COALESCENCE
DENSITY
EQUATIONS OF STATE
GRAVITATIONAL WAVE DETECTORS
GRAVITATIONAL WAVES
HYPOTHESIS
LUMINOSITY
NEUTRON STARS
OSCILLATIONS
RELATIVISTIC RANGE
S QUARKS
SENSITIVITY
SIMULATION
SPECTRA
SURFACES
THREE-DIMENSIONAL CALCULATIONS
TIME DELAY
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
FERMIONS
MEASURING INSTRUMENTS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUARKS
RADIATION DETECTORS
STARS
STRANGE PARTICLES