Ringdown Waveforms¶

Minke is capable of producing signals which are based on waveforms based on Binary Black Hole (BBH) ringdowns.

Ringdown-like signals, with a sudden rise, and exponential decay in amplitude are expected in the post-merger signal of CBC systems, and in some models of neutron star model excitation [2004PhRvD..70l4015B].

These take the form

\[h(t) = \exp (-t / \tau) \sin( 2 \pi f t)\]

for a strain \(h\) at time \(t\), given a decay time \(\tau\) and frequency \(f\).

BBHRingdown¶

The BBH Ringdown class in the sources module follows a similar style to other source classes within minke. To produce a single ringdown waveform:

>>> import minke.sources
>>> bbh = minke.sources.BBHRingdown(100.23, 1e-22, np.rad2deg(.1), 10., 0.97, 0.01, 1.0,45.)

then the waveforms themselves can be produced by running

>>> hp, hx, _, _ = bbh._generate()

The waveform will be generated at the LIGO sampling rate (16384 Hz) by default, but this can be changed by specifying a rate keyword. The waveforms are also generated for the (2,2) mode by default, but by adding l and m keywords to the _generate() method this can also be changed.