### Abstract

Microlenses with typical stellar masses (a few M_{⊙}) have traditionally been disregarded as potential sources of gravitational lensing effects at LIGO/Virgo frequencies, since the time delays are often much smaller than the inverse of the frequencies probed by LIGO/Virgo, resulting in negligible interference effects at LIGO/Virgo frequencies. While this is true for isolated microlenses in this mass regime, we show how, under certain circumstances and for realistic scenarios, a population of microlenses (for instance stars and remnants from a galaxy halo or from the intracluster medium) embedded in a macromodel potential (galaxy or cluster) can conspire together to produce time delays of order one millisecond, which would produce significant interference distortions in the observed strains. At sufficiently large magnification factors (of several hundred), microlensing effects should be common in gravitationally lensed gravitational waves. We explored the regime where the predicted signal falls in the frequency range probed by LIGO/Virgo. We find that stellar mass microlenses, permeating the lens plane, and near critical curves, can introduce interference distortions in strongly lensed gravitational waves. Lensed events with negative parity, or saddle points (which have never before been studied in the context of gravitational waves), and that take place near caustics of macromodels, are more likely to produce measurable interference effects at LIGO/Virgo frequencies. This is the first study that explores the effect of a realistic population of microlenses, including a macromodel, on strongly lensed gravitational waves.

Original language | English (US) |
---|---|

Article number | A130 |

Journal | Astronomy and Astrophysics |

Volume | 627 |

DOIs | |

State | Published - Jul 1 2019 |

### Fingerprint

### Keywords

- Gravitational lensing: strong
- Gravitational waves

### Cite this

*Astronomy and Astrophysics*,

*627*, [A130]. https://doi.org/10.1051/0004-6361/201935490

**Observational signatures of microlensing in gravitational waves at LIGO/Virgo frequencies.** / DIego, J. M.; Hannuksela, O. A.; Kelly, P. L.; Pagano, G.; Broadhurst, T.; Kim, K.; Li, T. G.F.; Smoot, G. F.

Research output: Contribution to journal › Article

*Astronomy and Astrophysics*, vol. 627, A130. https://doi.org/10.1051/0004-6361/201935490

}

TY - JOUR

T1 - Observational signatures of microlensing in gravitational waves at LIGO/Virgo frequencies

AU - DIego, J. M.

AU - Hannuksela, O. A.

AU - Kelly, P. L.

AU - Pagano, G.

AU - Broadhurst, T.

AU - Kim, K.

AU - Li, T. G.F.

AU - Smoot, G. F.

PY - 2019/7/1

Y1 - 2019/7/1

N2 - Microlenses with typical stellar masses (a few M⊙) have traditionally been disregarded as potential sources of gravitational lensing effects at LIGO/Virgo frequencies, since the time delays are often much smaller than the inverse of the frequencies probed by LIGO/Virgo, resulting in negligible interference effects at LIGO/Virgo frequencies. While this is true for isolated microlenses in this mass regime, we show how, under certain circumstances and for realistic scenarios, a population of microlenses (for instance stars and remnants from a galaxy halo or from the intracluster medium) embedded in a macromodel potential (galaxy or cluster) can conspire together to produce time delays of order one millisecond, which would produce significant interference distortions in the observed strains. At sufficiently large magnification factors (of several hundred), microlensing effects should be common in gravitationally lensed gravitational waves. We explored the regime where the predicted signal falls in the frequency range probed by LIGO/Virgo. We find that stellar mass microlenses, permeating the lens plane, and near critical curves, can introduce interference distortions in strongly lensed gravitational waves. Lensed events with negative parity, or saddle points (which have never before been studied in the context of gravitational waves), and that take place near caustics of macromodels, are more likely to produce measurable interference effects at LIGO/Virgo frequencies. This is the first study that explores the effect of a realistic population of microlenses, including a macromodel, on strongly lensed gravitational waves.

AB - Microlenses with typical stellar masses (a few M⊙) have traditionally been disregarded as potential sources of gravitational lensing effects at LIGO/Virgo frequencies, since the time delays are often much smaller than the inverse of the frequencies probed by LIGO/Virgo, resulting in negligible interference effects at LIGO/Virgo frequencies. While this is true for isolated microlenses in this mass regime, we show how, under certain circumstances and for realistic scenarios, a population of microlenses (for instance stars and remnants from a galaxy halo or from the intracluster medium) embedded in a macromodel potential (galaxy or cluster) can conspire together to produce time delays of order one millisecond, which would produce significant interference distortions in the observed strains. At sufficiently large magnification factors (of several hundred), microlensing effects should be common in gravitationally lensed gravitational waves. We explored the regime where the predicted signal falls in the frequency range probed by LIGO/Virgo. We find that stellar mass microlenses, permeating the lens plane, and near critical curves, can introduce interference distortions in strongly lensed gravitational waves. Lensed events with negative parity, or saddle points (which have never before been studied in the context of gravitational waves), and that take place near caustics of macromodels, are more likely to produce measurable interference effects at LIGO/Virgo frequencies. This is the first study that explores the effect of a realistic population of microlenses, including a macromodel, on strongly lensed gravitational waves.

KW - Gravitational lensing: strong

KW - Gravitational waves

UR - http://www.scopus.com/inward/record.url?scp=85069510002&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85069510002&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201935490

DO - 10.1051/0004-6361/201935490

M3 - Article

AN - SCOPUS:85069510002

VL - 627

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A130

ER -