Using the `--black-hole-kicks ZERO` options sets to zero not only the natal kick of BHs, but also of NSs.

[avigna]

To Reproduce Run

`./COMPAS --mode BSE --initial-mass-1 20 --semi-major-axis 10000  -n 1  --logfile-type CSV --random-seed 0 --black-hole-kicks ZERO

then get

0: Unbound binary: (Main_Sequence_>_0.7 -> Black_Hole) + (Main_Sequence_>_0.7 -> Neutron_Star)

and then compare the pertinent columns in the BSE_Supernovae.csv file.

Expected behavior This should affect BHs exclusively, and not NSs, which be reflected in the BSE_Supernovae.csv file.

Versioning

• COMPAS v02.41.01

[jeffriley]

Despite the name of the option, and the name of the function that applies the kick (BaseStar::ApplyBlackHoleKicks()), the kicks are applied for all CCSN events, regardless of the remnant type - no check for stellar type is made (see BaseStar::CalculateSNKickMagnitude()).

If black hole kicks should be applied to black holes only (and this is not just a poorly named option and function), then the function should be implemented in the BH class - not in the base class.

So we need some guidance - is this

(a) just a case of a poorly named option and function, and "black hole kicks" should be applied to all remnants - and so we should rename the option and function, or

(b) a defect in the code, and black hole kicks should only be applied to black holes - in which case we need to fix the code, and likely move the :ApplyBlackHoleKicks() function from the BaseStar class to the BH class

@avigna thinks (b). I tend to agree. @ilyamandel, @reinhold-willcox Thoughts?

[jeffriley]

I never did like the way we differentiate by stellar type in BaseStar::CalculateSNKickMagnitude(), so we might look at making that code more OO as we resolve this issue.

[ilyamandel]

We already have the option of setting all kicks to zero by running with --kick-magnitude-distribution ZERO

I therefore agree with @avigna that --black-hole-kicks ZERO should only apply to black hole kicks.

[jeffriley]

@ilyamandel Just ZERO? What about the other parameters for the --black-hole-kicks option? The question is whether the option applies just to black holes, or all remnants - you're not suggesting we be selective on the value of the option are you?

[ilyamandel]

Indeed, I was just using that as an example, but I agree the --black-hole-kicks option should only apply to BHs.

[ilyamandel]

Fixed in #1109 , closing.