Probing the Solar Interior with Lensed Gravitational Waves from Known Pulsars

Abstract

When gravitational waves (GWs) from a spinning neutron star arrive from behind the Sun, they are subjected to gravitational lensing that imprints a frequency-dependent modulation on the waveform. This modulation traces the projected solar density and gravitational potential along the path as the Sun passes in front of the neutron star. We calculate how accurately the solar density profile can be extracted from the lensed GWs using a Fisher analysis. For this purpose, we selected three promising candidates (the highly spinning pulsars J1022+1001, J1730−2304, and J1745−23) from the pulsar catalog of the Australia Telescope National Facility. The lensing signature can be measured with 3σ confidence when the signal-to-noise ratio (S/N) of the GW detection reaches 100 (f/300 Hz)−1 over a 1 yr observation period (where f is the GW frequency). The solar density profile can be plotted as a function of radius when the S/N improves to ≳104.

Testing an exact diffraction formula with gravitational wave source lensed by a supermassive black hole in binary systems

“…The sun is nearest massive lens to us. Similar to [23,24], we choose the sun as the lens. In this case, we adopt some typical parameters D L = 1 AU=1.5 × 10 8 km, D LS ∼ D S ≫ D L , source (e.g.…”

“…In this case, we adopt some typical parameters D L = 1 AU=1.5 × 10 8 km, D LS ∼ D S ≫ D L , source (e.g. pulsar [24]) distance D S ∼ 1 kpc=3 × 10 16 km (see pulsar catalog 1 [32]), Schwarzschild radius R S = 3 km for sun, and ξ 0 ≃ √ 2R S D L . We can estimate…”

“…It offers a unique opportunity to measure the propagation speed of GWs [10,11], constrain cosmological models [12], and shed light on the origins of stellar binary black holes (BHs) [13]. Furthermore, it provides a powerful tool to explore the nature of dark matter [14][15][16][17][18][19][20][21][22] and even the internal structure of the sun [23,24]. The potential applications of detecting GL of GWs are vast and promising, paving the way for exciting new discoveries in the field of gravitational physics.…”