Improve internal consistency for reporting (previously: Implement separating major events into separate timesteps)

[reinhold-willcox]

As discussed on the compas dev call

[reinhold-willcox]

For future use, here is a grid of systems which all undergo MT leading to a successful CEE (non-merger). But then the donor collapses into a SN and the newborn NS collides with the companion resulting in a merger (collision is determined based on the periapsis of the new, possibly hyperbolic, orbit, so about half of these would actually point away from the companion and survive).

All of this happens in one timestep though. The output is fairly confusing, so I've posted what shows up in BSE_RLOF, BSE_Common_Envelopes, and BSE_Supernovae, with some unrelated parameters cut out for brevity.

The gridfile: grid.txt

BSE_RLOF (masked for events which merge)

SEED	(units)	44474	80929	94843	16135	17536	26338	32515	39649
CEE>MT	Bool	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000
Eccentricity<MT	-	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000
Eccentricity>MT	-	1.981982	0.281605	1.530101	1.758171	1.000767	5.144050	3.503769	7.420938
Mass(1)<MT	Msol	10.239182	10.644315	10.286461	10.326131	10.987537	10.819973	10.430397	10.414658
Mass(1)>MT	Msol	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584
Mass(2)<MT	Msol	5.280300	2.033313	5.289948	1.413487	1.311947	1.477853	2.486255	1.480854
Mass(2)>MT	Msol	5.280300	2.033313	5.289948	1.413487	1.311947	1.477853	2.486255	1.480854
Merger	Bool	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000
RLOF(1)<MT	Bool	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000
RLOF(1)>MT	Bool	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000
RLOF(2)<MT	Bool	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000
RLOF(2)>MT	Bool	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000	0.000000
Radius(1)<MT	Rsol	669.907981	706.225709	675.910473	680.453567	764.315423	771.739234	692.999918	775.562222
Radius(1)>MT	Rsol	0.000014	0.000014	0.000014	0.000014	0.000014	0.000014	0.000014	0.000014
Radius(1)	RL<step	-	1.003207	1.015312	1.007227	1.012826	1.012735	1.010711	1.002218
Radius(1)	RL>step	-	0.000000	0.000013	0.000000	0.000000	0.000000	0.000000	0.000000
Radius(2)<MT	Rsol	2.965933	1.563716	2.966997	1.361929	1.278516	1.395491	1.737141	1.397040
Radius(2)>MT	Rsol	2.965933	1.563716	2.966997	1.361929	1.278516	1.395491	1.737141	1.397040
Radius(2)	RL<step	-	0.006007	0.004745	0.005988	0.004951	0.004389	0.004468	0.004808
Radius(2)	RL>step	-	0.000000	1.177116	0.000000	0.000000	0.000000	0.000000	0.000000
SemiMajorAxis<MT	Rsol	1527.187312	1325.682849	1533.851662	1215.425633	1338.239904	1380.913332	1367.731701	1407.761305
SemiMajorAxis>MT	Rsol	-5.288151	4.405930	-11.811895	-2.468831	-4154.059400	-0.882627	-1.492419	-0.613796
Stellar_Type(1)<MT	-	5.000000	5.000000	5.000000	5.000000	5.000000	5.000000	5.000000	5.000000
Stellar_Type(1)>MT	-	13.000000	13.000000	13.000000	13.000000	13.000000	13.000000	13.000000	13.000000
Stellar_Type(2)<MT	-	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000
Stellar_Type(2)>MT	-	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000	1.000000
Time<MT	Myr	23.809058	22.203436	23.607148	23.451052	20.925556	21.487003	23.030500	22.973963

BSE_Common_Envelopes

SEED	(units)	44474	80929	94843	16135	17536	26338	32515	39649
Eccentricity<CE	-	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00
Eccentricity>CE	-	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00
Immediate_RLOF>CE	Bool	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00
Mass(1)<CE	Msol	1.023918e+01	1.064431e+01	1.028646e+01	1.032613e+01	1.098754e+01	1.081997e+01	1.043040e+01	1.041466e+01
Mass(1)>CE	Msol	1.277584e+00	1.277584e+00	1.277584e+00	1.277584e+00	1.277584e+00	1.277584e+00	1.277584e+00	1.277584e+00
Mass(2)<CE	Msol	5.280300e+00	2.033313e+00	5.289948e+00	1.413487e+00	1.311947e+00	1.477853e+00	2.486255e+00	1.480854e+00
Mass(2)>CE	Msol	5.280300e+00	2.033313e+00	5.289948e+00	1.413487e+00	1.311947e+00	1.477853e+00	2.486255e+00	1.480854e+00
Mass_Env(1)	Msol	6.957756e+00	7.183770e+00	6.983423e+00	7.006420e+00	7.363432e+00	7.269657e+00	7.064993e+00	7.042050e+00
Mass_Env(2)	Msol	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00
Merger	Bool	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00
RLOF(1)	Bool	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00
RLOF(2)	Bool	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00
Radius(1)<CE	Rsol	6.699080e+02	7.062257e+02	6.759105e+02	6.804536e+02	7.643154e+02	7.717392e+02	6.929999e+02	7.755622e+02
Radius(1)>CE	Rsol	1.437401e-05	1.437401e-05	1.437401e-05	1.437401e-05	1.437401e-05	1.437401e-05	1.437401e-05	1.437401e-05
Radius(2)<CE	Rsol	2.965933e+00	1.563716e+00	2.966997e+00	1.361929e+00	1.278516e+00	1.395491e+00	1.737141e+00	1.397040e+00
Radius(2)>CE	Rsol	2.965933e+00	1.563716e+00	2.966997e+00	1.361929e+00	1.278516e+00	1.395491e+00	1.737141e+00	1.397040e+00
RocheLobe(1)<CE	Rsol	6.677667e+02	6.955750e+02	6.710604e+02	6.718367e+02	7.547042e+02	7.635608e+02	6.914660e+02	7.737174e+02
RocheLobe(1)>CE	Rsol	1.769406e+00	1.589537e+00	2.129777e+00	8.547538e-01	1.498572e+00	1.738579e+00	1.635813e+00	1.807852e+00
RocheLobe(2)<CE	Rsol	4.937196e+02	3.295203e+02	4.955286e+02	2.750910e+02	2.912745e+02	3.123519e+02	3.613013e+02	3.220866e+02
RocheLobe(2)>CE	Rsol	2.198493e+00	1.247065e+00	2.640550e+00	5.794074e-01	9.440739e-01	1.166524e+00	1.424553e+00	1.242651e+00
SemiMajorAxis<CE	Rsol	1.527187e+03	1.325683e+03	1.533852e+03	1.215426e+03	1.338240e+03	1.380913e+03	1.367732e+03	1.407761e+03
SemiMajorAxis>CE	Rsol	5.226110e+00	3.734377e+00	6.283215e+00	1.881421e+00	3.196985e+00	3.809939e+00	4.035224e+00	4.003442e+00
Simultaneous_RLOF	Bool	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00	0.000000e+00
Stellar_Type(1)	-	1.300000e+01	1.300000e+01	1.300000e+01	1.300000e+01	1.300000e+01	1.300000e+01	1.300000e+01	1.300000e+01
Stellar_Type(1)<CE	-	5.000000e+00	5.000000e+00	5.000000e+00	5.000000e+00	5.000000e+00	5.000000e+00	5.000000e+00	5.000000e+00
Stellar_Type(2)	-	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00
Stellar_Type(2)<CE	-	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00	1.000000e+00
Time	Myr	2.380906e+01	2.220344e+01	2.360715e+01	2.345105e+01	2.092556e+01	2.148700e+01	2.303050e+01	2.297396e+01
Zeta_Lobe	-	1.423058e+00	7.793581e+00	1.433112e+00	1.188081e+01	1.400061e+01	1.191245e+01	5.755379e+00	1.134133e+01
Zeta_Star	-	1.725106e-01	1.806810e-01	1.736146e-01	1.742852e-01	1.891047e-01	1.860477e-01	1.763418e-01	1.784246e-01

BSE_Supernovae

SEED	(units)	44474	80929	94843	16135	17536	26338	32515	39649
Applied_Kick_Magnitude(SN)	kms^-1	819.415207	148.233199	532.873829	488.730236	333.401327	494.612537	673.26652	594.943335
Eccentricity	-	1.981982	0.281605	1.530101	1.758171	1.000767	5.14405	3.503769	7.420938
Eccentricity<SN	-	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Experienced_RLOF(SN)	Bool	1	1	1	1	1	1	1	1
MT_Donor_Hist(SN)	-	b'5'	b'5'	b'5'	b'5'	b'5'	b'5'	b'5'	b'5'
Mass(CP)	Msol	5.2803	2.033313	5.289948	1.413487	1.311947	1.477853	2.486255	1.480854
Mass(SN)	Msol	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584	1.277584
Mass_CO_Core@CO(SN)	Msol	2.189297	2.328982	2.207144	2.220937	2.47624	2.432836	2.25884	2.318729
Mass_Core@CO(SN)	Msol	2.189297	2.328982	2.207144	2.220937	2.47624	2.432836	2.25884	2.318729
Mass_He_Core@CO(SN)	Msol	3.281426	3.460545	3.303038	3.319711	3.624104	3.550316	3.365404	3.372608
Mass_Total@CO(SN)	Msol	3.281426	3.460545	3.303038	3.319711	3.624104	3.550316	3.365404	3.372608
Orb_Velocity<SN	kms^-1	558.922816	529.651314	510.671374	692.619566	542.600244	501.656423	525.855177	480.805595
SemiMajorAxis	Rsol	-5.288151	4.40593	-11.811895	-2.468831	-4154.0594	-0.882627	-1.492419	-0.613796
SemiMajorAxis<SN	Rsol	5.22611	3.734377	6.283215	1.881421	3.196985	3.809939	4.035224	4.003442
Stellar_Type(CP)	-	1	1	1	1	1	1	1	1
Stellar_Type(SN)	-	13	13	13	13	13	13	13	13
Stellar_Type_Prev(SN)	-	8	8	8	8	8	8	8	8
Supernova_State	Bool	1	1	1	1	1	1	1	1
Time	Myr	23.809058	22.203436	23.607148	23.451052	20.925556	21.487003	23.0305	22.973963
Unbound	Bool	1	0	1	1	1	1	1	1

[reinhold-willcox]

Update: following discussions of this and related improvements, it is probably not possible to split apart events into different timesteps in all cases. An improved solution would be to ensure that the stellar and binary parameters are consistent any time in a timestep that we want to report before and after values (e.g pre/post MT, CE, SN, etc.). This remains a long term fix that we will aim to address in the coming months.

[ilyamandel]

@reinhold-willcox -- does this supplant and incorporate #722 , #539 and #413 -- i.e., can we close those as duplicates and just keep this one?

[reinhold-willcox]

@ilyamandel done

[jeffriley]

@reinhold-willcox is this still an issue? If so, can it be at least ameliorated by using the record-type field and logging records to the RLOF file (and/or other logs files) throughout the timestep? That way the information will be available to users that require it, and other users can just filter those records.

[ilyamandel]

I am convinced that we should only be doing one thing per timestep.

Firstly, we now end up with some weird systems that make analysing data a pain in the neck. For example, I find that among ultra-stripped SNe (SN_Type(SN) == 16), all have the pre-SN mass Mass_Total@CO(SN) equal to the pre-SN CO core mass Mass_CO_Core@CO(SN). But, remarkably, all USSNe have a pre-SN stellar type Stellar_Type_Prev(SN) of 8 -- that's a HeHG star, for which the total mass cannot be equal to the CO core mass since it must have a He envelope! That's because they all experience RLOF from the HeHG star and a SN event on the same timestep, and we update the pre-SN mass but not the pre-SN type...

Secondly, and perhaps more importantly, we really should be using values at the start of the timestep to evolve during that timestep, not intermediate values. I.e., we should evolve the star using the stellar properties at the start of the time step; we should apply tides using the binary and stellar properties at the start of the timestep; we should apply GWs using the binary properties and masses at the start of the timestep; etc. This is the only way for us to be consistent and to pick sensible timesteps.

As for extreme events (SNe, fast case A / case B / case C / CE RLOF), we should check for these at the start of the timestep. If a star is ready to go SN or is in fast case A / case B / case C / CE RLOF, we should undertake that behaviour on a zero-length timestep (*), then return to handling more gradual processes (stellar evolution, tides, GWs, etc.) from the following time step.

We'll have to think a bit further about the corner cases, such as the ordering of SNe and RLOF if both are relevant (hopefully, these will be rare if time steps are sufficiently short, and making SNe happen first in this case would not be an issue).

(*) Zero length timesteps would lead to identical timestamps, which could be problematic for determining the ordering, so perhaps a minimal timestep on which nothing else happens but the timestamp is slightly incremented would be more appropriate.