Astrophysics with the Laser Interferometer Space Antenna (2203.06016v2)

Abstract: The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it will offer unique opportunities to address many key astrophysical questions in a completely novel way. The synergy with ground-based and space-born instruments in the electromagnetic domain, by enabling multi-messenger observations, will add further to the discovery potential of LISA. The next decade is crucial to prepare the astrophysical community for LISA's first observations. This review outlines the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations that are instrumental for modeling and interpreting the upcoming LISA datastream. To this aim, the current knowledge in three main source classes for LISA is reviewed; ultracompact stellar-mass binaries, massive black hole binaries, and extreme or intermediate mass ratio inspirals. The relevant astrophysical processes and the established modeling techniques are summarized. Likewise, open issues and gaps in our understanding of these sources are highlighted, along with an indication of how LISA could help making progress in the different areas. New research avenues that LISA itself, or its joint exploitation with upcoming studies in the electromagnetic domain, will enable, are also illustrated. Improvements in modeling and analysis approaches, such as the combination of numerical simulations and modern data science techniques, are discussed. This review is intended to be a starting point for using LISA as a new discovery tool for understanding our Universe.

• The paper provides a comprehensive review of LISA's potential to detect and analyze key astrophysical sources, including ultra-compact binaries, massive black hole binaries, and extreme mass ratio inspirals.
• It details the use of theoretical frameworks and numerical simulations to refine predictions and interpret gravitational wave signals across cosmic epochs.
• The study emphasizes multimessenger synergies by integrating LISA observations with electromagnetic data to enhance our understanding of galaxy evolution and strong-field gravity.

Overview of "Astrophysics with the Laser Interferometer Space Antenna"

The Laser Interferometer Space Antenna (LISA) stands poised to redefine our understanding of gravitational wave (GW) astronomy, offering unprecedented insights into a diverse array of astrophysical phenomena. This paper serves as a foundational review, setting the groundwork for the astrological community in preparation for LISA's maiden observations. It provides a comprehensive appraisal of current theoretical frameworks, numerical simulations, and observational strategies pivotal for interpreting the forthcoming LISA data. Three principal classes of sources for LISA are meticulously examined: ultra-compact stellar-mass binaries, massive black hole binaries (MBHBs), and extreme or intermediate mass ratio inspirals (EMRIs/IMRIs).

Key Source Classes and Astrophysical Processes

1. Ultra-Compact Stellar-Mass Binaries: These encompass a vast array of sources including white dwarf + white dwarf (WD+WD) pairs, neutron star binaries, and others. LISA is expected to detect thousands of these binaries, thus revolutionizing our comprehension of their formation processes and the physics governing their evolution.
2. Massive Black Hole Binaries (MBHBs): These systems, formed via galaxy mergers, traverse cosmic epochs shedding light on the growth and assembly of massive black holes. LISA’s ability to detect MBHBs up to high redshifts provides a unique window into their dynamics and collisions, integral to understanding galaxy formation and evolution.
3. Extreme/Intermediate Mass Ratio Inspirals (EMRIs/IMRIs): LISA will potentially unveil populations of compact objects (e.g., stellar-mass black holes or neutron stars) spiraling into massive black holes. These detections will be critical for probing the space-time geometry around black holes and testing general relativity in strong-field regimes.

Synergies and Multimessenger Astronomy

The synergy between LISA and electromagnetically based observatories encapsulates its transformative potential. LISA’s low-frequency observations, when combined with data across various electromagnetic spectra, from radio to gamma-rays, enhance the discovery potential manifold. This multimessenger strategy is pivotal for uncovering electromagnetic counterparts to GW sources, thereby refining our understanding of astrophysical phenomena associated with each.

Anticipated Contributions and Developments

• Theoretical Advancements: The paper underscores the significance of improving current models, particularly in characterizing binary evolution physics, common envelope phases, and gravitational interactions within stellar clusters. Enhanced understanding of these processes will directly refine LISA's ability to parse observational data into meaningful astrophysical inferences.
• Numerical Simulations: The fusion of numerical simulations and cutting-edge data science techniques promises to refine predictions of GW signatures and augment source characterization. These simulations serve as critical benchmarks against which LISA’s empirical observations will be evaluated.
• Astrophysical Implications: LISA’s observations will potentially challenge prevailing astrophysical models, particularly in areas concerning the cosmic distribution of black holes, the conditions conducive to the formation of ultra-compact binaries, and the lifecycle of black holes in various cosmic environments.

Future Prospects

The forthcoming decade is pivotal for the astrophysics community as it aligns its capabilities to fully exploit LISA's debut. The paper encapsulates the collaborative endeavor required across theoretical development, observational readiness, and data analysis methodologies to leverage LISA as a tool for cosmic exploration. As LISA opens a new observational frontier, it promises profound advancements in both fundamental physics and our comprehension of the Universe. The review, therefore, serves as a critical resource, catalyzing further research and collaboration towards an era wherein LISA's contributions will become integral to our astrophysical knowledge base.

In summary, "Astrophysics with the Laser Interferometer Space Antenna" outlines a roadmap for engaging with the rich scientific opportunities LISA embodies, foreshadowing the paradigm shifts its observations will inspire in the landscape of modern astrophysics.