Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves
Extreme-mass-ratio inspirals (EMRIs) are promising gravitational-wave (GW) sources for space-based GW detectors. EMRI signals typically have long durations, ranging from several months to several years, necessitating highly accurate GW signal templates for detection. In most waveform models, compact...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Universe |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-1997/11/1/18 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832587367724089344 |
|---|---|
| author | Lujia Xu Shucheng Yang Wenbiao Han Xingyu Zhong Rundong Tang Yuanhao Zhang |
| author_facet | Lujia Xu Shucheng Yang Wenbiao Han Xingyu Zhong Rundong Tang Yuanhao Zhang |
| author_sort | Lujia Xu |
| collection | DOAJ |
| description | Extreme-mass-ratio inspirals (EMRIs) are promising gravitational-wave (GW) sources for space-based GW detectors. EMRI signals typically have long durations, ranging from several months to several years, necessitating highly accurate GW signal templates for detection. In most waveform models, compact objects in EMRIs are treated as test particles without accounting for their spin, mass quadrupole, or tidal deformation. In this study, we simulate GW signals from EMRIs by incorporating the spin and mass quadrupole moments of the compact objects. We evaluate the accuracy of parameter estimation for these simulated waveforms using the Fisher Information Matrix (FIM) and find that the spin, tidal-induced quadruple, and spin-induced quadruple can all be measured with precision ranging from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>, particularly for a mass ratio of ∼<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></semantics></math></inline-formula>. Assuming the “true” GW signals originate from an extended body inspiraling into a supermassive black hole, we compute the signal-to-noise ratio (SNR) and Bayes factors between a test-particle waveform template and our model, which includes the spin and quadrupole of the compact object. Our results show that the spin of compact objects can produce detectable deviations in the waveforms across all object types, while tidal-induced quadrupoles are only significant for white dwarfs, especially in cases approaching an intermediate-mass ratio. Spin-induced quadrupoles, however, have negligible effects on the waveforms. Therefore, our findings suggest that it is possible to distinguish primordial black holes from white dwarfs, and, under certain conditions, neutron stars can also be differentiated from primordial black holes. |
| format | Article |
| id | doaj-art-871eebdc744d441389e103346c36b937 |
| institution | Kabale University |
| issn | 2218-1997 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj-art-871eebdc744d441389e103346c36b9372025-01-24T13:51:30ZengMDPI AGUniverse2218-19972025-01-011111810.3390/universe11010018Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational WavesLujia Xu0Shucheng Yang1Wenbiao Han2Xingyu Zhong3Rundong Tang4Yuanhao Zhang5School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UKShanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, ChinaShanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, ChinaHangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310124, ChinaShanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, ChinaHangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310124, ChinaExtreme-mass-ratio inspirals (EMRIs) are promising gravitational-wave (GW) sources for space-based GW detectors. EMRI signals typically have long durations, ranging from several months to several years, necessitating highly accurate GW signal templates for detection. In most waveform models, compact objects in EMRIs are treated as test particles without accounting for their spin, mass quadrupole, or tidal deformation. In this study, we simulate GW signals from EMRIs by incorporating the spin and mass quadrupole moments of the compact objects. We evaluate the accuracy of parameter estimation for these simulated waveforms using the Fisher Information Matrix (FIM) and find that the spin, tidal-induced quadruple, and spin-induced quadruple can all be measured with precision ranging from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>, particularly for a mass ratio of ∼<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></semantics></math></inline-formula>. Assuming the “true” GW signals originate from an extended body inspiraling into a supermassive black hole, we compute the signal-to-noise ratio (SNR) and Bayes factors between a test-particle waveform template and our model, which includes the spin and quadrupole of the compact object. Our results show that the spin of compact objects can produce detectable deviations in the waveforms across all object types, while tidal-induced quadrupoles are only significant for white dwarfs, especially in cases approaching an intermediate-mass ratio. Spin-induced quadrupoles, however, have negligible effects on the waveforms. Therefore, our findings suggest that it is possible to distinguish primordial black holes from white dwarfs, and, under certain conditions, neutron stars can also be differentiated from primordial black holes.https://www.mdpi.com/2218-1997/11/1/18gravitational wavesextreme-mass-ratio inspiralscompact object |
| spellingShingle | Lujia Xu Shucheng Yang Wenbiao Han Xingyu Zhong Rundong Tang Yuanhao Zhang Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves Universe gravitational waves extreme-mass-ratio inspirals compact object |
| title | Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves |
| title_full | Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves |
| title_fullStr | Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves |
| title_full_unstemmed | Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves |
| title_short | Distinguishing Compact Objects in Extreme-Mass-Ratio Inspirals by Gravitational Waves |
| title_sort | distinguishing compact objects in extreme mass ratio inspirals by gravitational waves |
| topic | gravitational waves extreme-mass-ratio inspirals compact object |
| url | https://www.mdpi.com/2218-1997/11/1/18 |
| work_keys_str_mv | AT lujiaxu distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves AT shuchengyang distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves AT wenbiaohan distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves AT xingyuzhong distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves AT rundongtang distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves AT yuanhaozhang distinguishingcompactobjectsinextrememassratioinspiralsbygravitationalwaves |