In LIGO's Sight? Vigorous Coherent Gravitational Waves from Cooled Collapsar Disks

Fuente: arXiv
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Main Authors: Gottlieb, Ore, Levinson, Amir, Levin, Yuri
Format: Preprint
Published: 2024
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author Gottlieb, Ore
Levinson, Amir
Levin, Yuri
author_facet Gottlieb, Ore
Levinson, Amir
Levin, Yuri
contents We present the first numerical study of gravitational waves (GWs) from collapsar disks, using state-of-the-art 3D general relativistic magnetohydrodynamic simulations of collapsing stars. These simulations incorporate a fixed Kerr metric for the central black hole (BH) and employ simplified prescriptions for disk cooling. We find that cooled disks with an expected scale height ratio of $H/R\gtrsim0.1$ at $\sim10$ gravitational radii induce Rossby instability in compact, high-density rings. The trapped Rossby vortices generate vigorous coherent emission regardless of disk magnetization and BH spin. For BH mass of $\sim10\,M_\odot$, the GW spectrum peaks at $\sim100\,{\rm Hz}$ with some breadth due to various nonaxisymmetric modes. The spectrum shifts toward lower frequencies as the disk viscously spreads and the circularization radius of the infalling gas increases. Weaker-cooled disks with $H/R\gtrsim0.3$ form a low-density extended structure of spiral arms, resulting in a broader, lower-amplitude spectrum. Assuming an optimistic detection threshold with a matched-filter signal-to-noise ratio of 20 and a rate similar to Type Ib/c supernovae, LIGO-Virgo-KAGRA (LVK) could detect $\lesssim1$ event annually, suggesting that GW events may already be hidden in observed data. Third-generation GW detectors could detect dozens to hundreds of collapsar disks annually, depending on the cooling strength and the disk formation rate. The GW amplitudes from collapsar disks are $\gtrsim100$ times higher with a substantially greater event rate than those from core-collapse supernovae, making them potentially the most promising burst-type GW class for LVK and Cosmic Explorer. This highlights the importance of further exploration and modeling of disk-powered GWs, promising insights into collapsing star physics.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19452
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle In LIGO's Sight? Vigorous Coherent Gravitational Waves from Cooled Collapsar Disks
Gottlieb, Ore
Levinson, Amir
Levin, Yuri
High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
General Relativity and Quantum Cosmology
We present the first numerical study of gravitational waves (GWs) from collapsar disks, using state-of-the-art 3D general relativistic magnetohydrodynamic simulations of collapsing stars. These simulations incorporate a fixed Kerr metric for the central black hole (BH) and employ simplified prescriptions for disk cooling. We find that cooled disks with an expected scale height ratio of $H/R\gtrsim0.1$ at $\sim10$ gravitational radii induce Rossby instability in compact, high-density rings. The trapped Rossby vortices generate vigorous coherent emission regardless of disk magnetization and BH spin. For BH mass of $\sim10\,M_\odot$, the GW spectrum peaks at $\sim100\,{\rm Hz}$ with some breadth due to various nonaxisymmetric modes. The spectrum shifts toward lower frequencies as the disk viscously spreads and the circularization radius of the infalling gas increases. Weaker-cooled disks with $H/R\gtrsim0.3$ form a low-density extended structure of spiral arms, resulting in a broader, lower-amplitude spectrum. Assuming an optimistic detection threshold with a matched-filter signal-to-noise ratio of 20 and a rate similar to Type Ib/c supernovae, LIGO-Virgo-KAGRA (LVK) could detect $\lesssim1$ event annually, suggesting that GW events may already be hidden in observed data. Third-generation GW detectors could detect dozens to hundreds of collapsar disks annually, depending on the cooling strength and the disk formation rate. The GW amplitudes from collapsar disks are $\gtrsim100$ times higher with a substantially greater event rate than those from core-collapse supernovae, making them potentially the most promising burst-type GW class for LVK and Cosmic Explorer. This highlights the importance of further exploration and modeling of disk-powered GWs, promising insights into collapsing star physics.
title In LIGO's Sight? Vigorous Coherent Gravitational Waves from Cooled Collapsar Disks
topic High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2406.19452