TY - BOOK

T1 - Unveiling the cosmos

T2 - Advanced gravitational wave searches for eccentric and precessing binary mergers and their astrophysical implications

AU - Dhurkunde, Rahul

PY - 2024/7/8

Y1 - 2024/7/8

N2 - Gravitational-wave (GW) astronomy has ushered in a new era of scientific exploration, providing us with unprecedented insights into compact binary coalescing sources, such as binary black holes and neutron star binaries. GW detectors like Advanced LIGO and Virgo have observed almost a hundred merging binaries, but their origins remain unsolved. The presence of significant orbital eccentricity or orbital precession are signatures for binaries formed in dense environments or with multi-body interactions during their evolution. If such binaries are detected they would indicate the presence of a dynamical formation channel. Detection of these systems could also provide insights into long standing uncertain astrophysical and physical processes such as common envelope evolution, supernovae natal kicks and the dynamics of dense environments. Typically, searches are performed for binaries with quasi-circular orbits, spins aligned to the orbital angular momentum and capture only the dominant mode of the gravitational radiation. Relaxing any one of these search assumptions requires up to $100\times$ larger computational power than an equivalent non-eccentric, non-precessing search. In this thesis we push the boundaries of existing search pipelines to search for novel binaries. We tackle this problem in three different avenues. First, by extending current search methods to look for eccentric systems -- we performed the first search for spinning eccentric neutron star binaries in the public data of Advanced LIGO and Virgo observatories. Using our search results we put state-of-art observational constraints on various astrophysical models and predict eccentric observations for the future observatories. Second, we investigate how many precessing sources may have been missed by existing searches, and identify regions of parameter space crucial for targeted precessing searches. Finally, we address a common issue for searching either of the two novel types of binaries -- increased computational costs. We demonstrate a new matched filtering technique that may save up to $10\times$ the computational costs without losing sensitivity and can be applied to any modeled search schemes.

AB - Gravitational-wave (GW) astronomy has ushered in a new era of scientific exploration, providing us with unprecedented insights into compact binary coalescing sources, such as binary black holes and neutron star binaries. GW detectors like Advanced LIGO and Virgo have observed almost a hundred merging binaries, but their origins remain unsolved. The presence of significant orbital eccentricity or orbital precession are signatures for binaries formed in dense environments or with multi-body interactions during their evolution. If such binaries are detected they would indicate the presence of a dynamical formation channel. Detection of these systems could also provide insights into long standing uncertain astrophysical and physical processes such as common envelope evolution, supernovae natal kicks and the dynamics of dense environments. Typically, searches are performed for binaries with quasi-circular orbits, spins aligned to the orbital angular momentum and capture only the dominant mode of the gravitational radiation. Relaxing any one of these search assumptions requires up to $100\times$ larger computational power than an equivalent non-eccentric, non-precessing search. In this thesis we push the boundaries of existing search pipelines to search for novel binaries. We tackle this problem in three different avenues. First, by extending current search methods to look for eccentric systems -- we performed the first search for spinning eccentric neutron star binaries in the public data of Advanced LIGO and Virgo observatories. Using our search results we put state-of-art observational constraints on various astrophysical models and predict eccentric observations for the future observatories. Second, we investigate how many precessing sources may have been missed by existing searches, and identify regions of parameter space crucial for targeted precessing searches. Finally, we address a common issue for searching either of the two novel types of binaries -- increased computational costs. We demonstrate a new matched filtering technique that may save up to $10\times$ the computational costs without losing sensitivity and can be applied to any modeled search schemes.

U2 - 10.15488/17646

DO - 10.15488/17646

M3 - Doctoral thesis

CY - Hannover

ER -