Abstract
Galactic compact binaries with orbital periods shorter than a few hours emit detectable gravitational waves (GWs) at low frequencies. Their GW signals can be detected with the future Laser Interferometer Space Antenna (LISA). Crucially, they may be useful in the early months of the mission operation in helping to validate LISA's performance in comparison to prelaunch expectations. We present an updated list of 55 candidate LISA-detectable binaries with measured properties, for which we derive distances based on Gaia Data Release 3 astrometry. Based on the known properties from electromagnetic observations, we predict the LISA detectability after 1, 3, 6, and 48 months using Bayesian analysis methods. We distinguish between verification and detectable binaries as being detectable after 3 and 48 months, respectively. We find 18 verification binaries and 22 detectable sources, which triples the number of known LISA binaries over the last few years. These include detached double white dwarfs, AM CVn binaries, one ultracompact X-ray binary, and two hot subdwarf binaries. We find that across this sample the GW amplitude is expected to be measured to ≈10% on average, while the inclination is expected to be determined with ≈15° precision. For detectable binaries, these average errors increase to ≈50% and ≈40°, respectively.
| Original language | English |
|---|---|
| Article number | 100 |
| Number of pages | 14 |
| Journal | The Astrophysical Journal |
| Volume | 963 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 4 Mar 2024 |
Bibliographical note
AcknowledgmentsWhile working on this study, we were deeply saddened by the loss of Professor Tom Marsh, a world-leading expert on compact binary star systems and a visionary in recognizing the potential of the LISA mission for the study of these binaries. Professor Marsh's profound knowledge and pioneering insights were invaluable to this study. His enthusiasm and dedication to the field were not only inspiring but also instrumental in shaping the direction of our work.
T.K. acknowledges support from the National Science Foundation through grant AST No. 2107982, from NASA through grant 80NSSC22K0338 and from STScI through grant HST-GO-16659.002-A. Co-funded by the European Union (ERC, CompactBINARIES, 101078773). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. V.K. acknowledges support from the Netherlands Research Council NWO (Rubicon 019.183EN.015 grant). P.J.G. is partially supported by NRF SARChI grant 111692. Armagh Observatory & Planetarium is core funded by the Northern Ireland Executive through the Dept for Communities. S.S. acknowledges support from the DLR grant No. Förderkennzeichen: 50OQ1801.
This work presents results from the ESA space mission Gaia. Gaia data are being processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions, in particular, the institutions participating in the Gaia MultiLateral Agreement (MLA). The Gaia mission website is https://www.cosmos.esa.int/gaia. The Gaia archive website is at https://archives.esac.esa.int/gaia.
Facility: Gaia - .
Software: Matplotlib (Hunter 2007), Astropy (Astropy Collaboration et al. 2013, 2018), NumPy (Oliphant 2015), LDASOFT (Littenberg et al. 2020).
Keywords
- Compact binary stars
- Gravitational wave sources
- Semi-detached binary stars
- White dwarf stars