Supernova from main sequence merger product not recorded in BSE_Supernovae

[SimonStevenson]

Describe the bug
When using --evolve-main-sequence-merger TRUE to evolve main sequence merger products, I am finding that even if the merger product subsequently undergoes a supernova and forms a NS/BH, that event is not recorded in BSE_Supernovae

Label the issue
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severity_moderate - This is a minor bug with minimal impact

To Reproduce
For example, a single binary that merges can be run with

./COMPAS -n 1 --initial-mass-1 7.0 --initial-mass-2 1.5 --orbital-period 1.0 --evolve-main-sequence-merger TRUE --detailed-output TRUE

Expected behavior
An entry in BSE_Supernovae should be generated for the merger product/all supernovae that occur.

Versioning (please complete the following information):

• OS: MacOS v12.4
• COMPAS v03.10.04

[EDITED TO REMOVE OTHER SYSTEM]

[jeffriley]

I believe the problem is that we flag a stellar merger in BaseBinaryStar::ResolveCommonEnvelopeEvent(), and because --evolve-main-sequence-merger TRUE was specified we continue to evolve the binary, but in BaseBinaryStar::EvaluateBinary() where we call BaseBinaryStar::EvaluateSupernovae() (two places) we first check if there was a stellar merger flagged, and if there was we bypass the call(s) to BaseBinaryStar::EvaluateSupernovae(). That would be the correct behaviour if --evolve-main-sequence-merger was not set TRUE.

@ilyamandel can you take a look? It's probably a fairly simple fix, but since you implemented --evolve-main-sequence-merger you are more familiar with the expected code path.

EDIT: It might be as simple as not flagging the stellar merger if we're evolving merger products.
EDIT Or not... mass transfer tracker history is also set if there was a merger...

@SimonStevenson if I run this:

./COMPAS -n 1 --initial-mass-1 15.0 --initial-mass-2 1.5 --orbital-period 100.0 --evolve-main-sequence-merger FALSE --detailed-output FALSE --logfile-type 'CSV'

using COMPAS v03.10.04 I get:

Stars merged: (Main_Sequence_>_0.7 -> Core_Helium_Burning) + (Main_Sequence_>_0.7 -> Main_Sequence_>_0.7)

I don't see a SN event, so no reason to put an entry in the SN file. Is that not the result you get?

[SimonStevenson]

Hi @jeffriley you're right about the other system, I just double checked it, I think I must have had a mistake in the way I was checking systems. The main issue is with the merger product.

[jeffriley]

@ilyamandel stand down for a bit - I'll be pushing a fix for this in the next hour or so, but it will have some questions for you...

[jeffriley]

Fixed in #1320