Neutron Star - White Dwarf Binaries: Probing Formation Pathways and Natal Kicks with LISA

We present supplementary datasets accompanying our publication Neutron Star - White Dwarf Binaries: Probing Formation Pathways and Natal Kicks with LISA. These catalogues reperesent the Galactic population of double white dwarf (DWD) and neutron star  - white dwarf (NSWD) binaries emitting gravitational waves (GWs) in the Laser Interferometer Space Antenna (LISA) frequency band (0.1 mHz - 1 Hz). The catalogues have been constructed based on binary evolution models Toonen et al. 2012 for DWDs and Toonen et al. 2018 for NSWD binaries, obtained using SeBa binary population synthesis code.

Data contents

The dataset consists of 12 catalogues representing Galactic populations of NSWD and/or DWD binaries, which are expected to be the most numerous types of binaries amongt LISA's Galactic sources. Each catalogue is distinguished by its model ID, which specifies the presence of NSWD and/or DWD binaries, the CE model used, CE efficiency values, and the NS natal kick prescription applied (see table below).

Each catalogue is structured to describe a binary systems with the following attributes:

Name*: binary identifier; this consist of a prefix indicating the binary type ('MW_DWD' for a DWD binary, 'MW_NSWD_ecc0' for a circular NSWD bianry, or 'MW_NSWD_ecc1' for an eccentric NSWD binary) followed by a unique ID number. For example, 'MW_DWD 28713637'.

Frequency: present-day GW frequency (Hz).

Frequency Derivative: rate of change of GW frequency over time (Hz^2).

Ecliptic Latitude: in radians (rad).

Ecliptic Longitude: in radians (rad).

Amplitude: GW amplitude (dimensionless).

Inclination: angle between the binary's orbital plane and our line of sight, in radians (rad).

Polarization: Orientation of the GW's polarization, in radians (rad).

Initial Phase: initial phase (rad).

Eccentricity: orbital eccentricity (dimensionless).

*Note that the Name field for eccentric NS+WD binaries (staring with 'MW_NSWD_ecc1') is not unique because these binaries are represented by multiple harmonics sharing the same name ID. The number of harmonics included varies for each binary to ensure that at least 99% of the binary's total GW power is represented. Thus, for each binary, we added harmonics incrementally until this threshold is reached.

Model ID
WD+WD
NS+WD
CE model
CE efficiency
NS natal kick

1_0
Yes
No
αα
αλ=2.00
N/A

1_1
Yes
Yes
αα
αλ=2.00
Verbunt

1_2
Yes
Yes
αα
αλ=2.00
Arzoumanian

1_3
Yes
Yes
αα
αλ=2.00
Hobbs

1_4
Yes
Yes
αα
αλ=2.00
Blaauw

2_0
Yes
No
αα2
αλ=0.25
N/A

2_1
Yes
Yes
αα2
αλ=0.25
Verbunt

2_2
Yes
Yes
αα2
αλ=0.25
Arzoumanian

2_3
Yes
Yes
αα2
αλ=0.25
Hobbs

2_4
Yes
Yes
αα2
αλ=0.25
Blaauw

3_0
Yes
No
αγ
αλ=2.00, γ=1.75
N/A

3_1
Yes
Yes
αγ
αλ=2.00, γ=1.75
Verbunt

Citing the Dataset

When utilising these catalogues in your research, please cite Korol et al. 2024. We also note our companion data-analysis-focused paper Moore et al. 2024.