[mesa-users] negative age and rotation values in "OSC" file

Juan Carlos Suárez jcsuarez at iaa.es
Thu Feb 16 11:46:32 EST 2017


Hi!
Well, at some point, some years ago, it seemed that glob(14) was the Teff but maybe it changed since.
But I am really not sure about the source of this…

OK so MESA in principle does not provide this information, so that we have to infer it from the 
photometric radius. If I understood correctly glob(2) is the photometric radius, right?

JC


> On 16 Feb 2017, at 16:57, RICHARD H D TOWNSEND <townsend at astro.wisc.edu> wrote:
> 
> Hi Juan Carlos —
> 
> The OSC output routines are based on the description of the OSC file format given in the ESTA project:
> 
> https://www.astro.up.pt/corot/ntools/docs/CoRoT_ESTA_Files.pdf
> 
> According to this document, fields 14 and onwards of glob are not used. Do you have an updated description of the OSC file format which indicates glob(14) should contain Teff?
> 
> cheers,
> 
> Rich
> 
>> On Feb 16, 2017, at 9:54 AM, Juan Carlos Suárez <jcsuarez at iaa.es> wrote:
>> 
>> Dear Richard and all,
>> 
>> Thank you very much for your valuable help. 
>> Now we are able to construct a complete evolutionary track from PMS to TAMS (we are indeed interested in 
>> keeping the PMS models), with around 4K for the number of shells, and using the Eddington atmosphere.
>> Taking a look to the OSC files, it seems that now everything is OK except for the effective temperature (corresponding
>> to glob(14) which is now 0.00000 for all the models in the track).
>> 
>> We have used the inlist attached to this email.
>> 
>> JC
>>> On 11 Feb 2017, at 23:17, RICHARD H D TOWNSEND <townsend at astro.wisc.edu> wrote:
>>> 
>>> Hi Juan Carlos —
>>> 
>>> In your email below, I can spot quite a few different problems you’re running into. In each case I’ll try to explain what’s going on
>>> 
>>>> On Feb 10, 2017, at 12:26 PM, Juan Carlos Suárez <jcsuarez at iaa.es> wrote:
>>>> 
>>>> Dear Richard,
>>>> 
>>>> We have modified a little bit the previous “inlist” in order to include some atmosphere (the default simple atmosphere)
>>>> since we are interested in working with the photosphere radius. So we decided to include the following options in the
>>>> inlist (attached)
>>>> ! if true, write atmosphere to pulse files
>>>> 
>>>> add_atmosphere_to_pulse_info = .TRUE.
>>> 
>>> Although it’s not the main cause of your problems below, I should mention that In MESA 8845 (and previous releases) there is a bug in the atmosphere writing routine. The code should output the same atmosphere as selected by the ‘which_atm_option’ parameter; however, in many cases (including the default ‘simple_photosphere’ atmosphere), the atmosphere written out is actually the ‘Paczynski_grey’ atmosphere. This bug is fixed in the development version of MESA, but only for a restricted set of atmosphere choices:
>>> 
>>> Eddington_grey
>>> Paczynski_grey
>>> solar_Hopf_grey
>>> Krishna_Swamy
>>> grey_and_kap
>>> 
>>> For other atmosphere options the code now halts — because there is insufficient information to construct the atmosphere structure.
>>> 
>>>> ! if true, add point for r=0 to pulse files
>>>> 
>>>> add_center_point_to_pulse_info = .FALSE.
>>> 
>>> In fact, it’s setting this flag to .FALSE. that ‘fixed’ the problem with age and rotation rate being overwritten (as discussed in the previous email) — the central second derivative data only gets calculated when add_center_point_to_pulse_info = .TRUE. (which itself is a bug — again, fixed in the development version)
>>> 
>>>> ! if true, add k=1 cell to pulse files
>>>> 
>>>> keep_surface_point_for_pulse_info = .false.
>>>> ! add double points at discontinuities
>>>> 
>>>> add_double_points_to_pulse_info = .TRUE.
>>> 
>>> This is what’s causing the (approximate) doubling of the number of points in the OSC files. This flag causes MESA to write out a double points when it detects a density discontinuity. The threshold for recognizing density discontinuities is set by the threshold_dlnrho_for_double_point flag. Since this flag defaults to zero, *every* pair of adjacent cells in the model is producing a double point!
>>> 
>>> The fix is to set add_double_points_to_pulse_info = .FALSE., or to specify a non-zero value for threshold_dlnrho_for_double_point — e.g., 10.
>>> 
>>>> 
>>>> Curiously, it seems that now the problem of the negative ages and rotation values is solved, but we
>>>> do not know why. 
>>>> 
>>> 
>>> See above!
>>> 
>>>> On the other hand unfortunately the computation halted with an error 
>>>> 
>>>> failed to open LOGS/profile686.data
>>>> star_finish_step ierr          28
>>>> after_step_loop ierr          28
>>>> 
>>>> That is, it halted at model 686, while without the above options MESA reached the 905 models with no errors.
>>>> 
>>> 
>>> I imagine the program halted because it ran out of disk space. You are writing out a profile *and* an OSC file after each timestep. Each profile file is ~15MB, and each OSC file is ~5MB. After 686 models, you have used up well over 10 GB of disk space.
>>> 
>>> To get around this issue, you should consider the following approaches:
>>> 
>>> *) Don’t set mesh_delta_coeff so small — you use 0.15, which results in very high resolution models (some might say over-resolved). 0.5 might be a better choice for this parameter.
>>> 
>>> *) Only write out every N’th profile/OSC file, rather than all of them. To do this, set profile_interval = N
>>> 
>>> *) Don’t bother writing out the pre-MS models, if you don’t need them. This can be achieved by doing two separate runs — an initial run with no profile/OSC file output, which terminates at the ZAMS. Then, do a restart and write out profiles/OSC files as necessary.
>>> 
>>>> In addition to this, with the above options it seems that MESA has doubled the number
>>>> of mesh points (from 4K to 8K). Is that what we should expect? The 4K additional 
>>>> points are located at the atmosphere?
>>>> 
>>> 
>>> No, as I mentioned above, every single model point is being written as a double point — not what you want!
>>> 
>>> So, to sum up:
>>> 
>>> *) Upgrade to the development version of MESA.
>>> 
>>> *) Set add_atmosphere_to_pulse_data = .FALSE., or set which_atm_option to one of the atmosphere choices listed above.
>>> 
>>> *) Set add_double_points_to_pulse_data = .FALSE., or specify a non-zero value for threshold_dlnrho_for_double_point.
>>> 
>>> *) Adjust mesh_delta_coeff, set_profile_interval to reduce size of files, or run the pre-MS and MS parts separately.
>>> 
>>> (Note also that some of the parameter names have changed, with the phrase ‘pulse_info’ changed to ‘pulse_data’)
>>> 
>>> Hope that helps!
>>> 
>>> cheers,
>>> 
>>> Rich
>>> 
>>> 
>>>> Thanks!
>>>> JC
>>>> 
>>>> 
>>>>> On 9 Feb 2017, at 20:38, Juan Carlos Suárez <jcsuarez at iaa.es> wrote:
>>>>> 
>>>>> Yes here it is!
>>>>> JC
>>>>>> On 9 Feb 2017, at 20:05, RICHARD H D TOWNSEND <townsend at astro.wisc.edu> wrote:
>>>>>> 
>>>>>> Hi Juan —
>>>>>> 
>>>>>> Can you post the inlist file(s) that you’re using?
>>>>>> 
>>>>>> Many thanks,
>>>>>> 
>>>>>> Rich
>>>>>> 
>>>>>>> On Feb 9, 2017, at 12:43 PM, Juan Carlos Suárez <jcsuarez at iaa.es> wrote:
>>>>>>> 
>>>>>>> Dear colleagues
>>>>>>> 
>>>>>>> I am trying to compute a 1.5 Msun evolutionary model (with solar metallicity) from PMS to TAMS approx.
>>>>>>> We have set the options to obtain the .OSC files to be read by our oscillation codes. 
>>>>>>> 
>>>>>>> We found that for all the models the age provided has negative values.
>>>>>>> 
>>>>>>> Moreover, although no option for rotation was included in the inlist (i.e. rotation should be zero)
>>>>>>> we obtain some models with rotation 0 but others with negative non-zero values
>>>>>>> 
>>>>>>> Any idea?
>>>>>>> 
>>>>>>> Thanks in advance!
>>>>>>> 
>>>> 
>>>> --------------------------------------------------------------------------------------------------------------------
>>>> Dr. Juan Carlos Suárez 
>>>>   Ramon y Cajal fellow at Física Teórica y del Cosmos Dept. University of Granada 
>>>>   Facultad de Ciencias. 18071. Granada. Spain
>>>> jcsuarez at ugr.es | +34 958249056 | www.ugr.es/~fqm292/ 
>>>>   Associate researcher at Stellar Physics Dept. IAA-CSIC
>>>> Glorieta de la Astronomia s/n. 18008. Granada. Spain
>>>> jcsuarez at iaa.es | +34 958230619 | www.iaa.es
>>>> --------------------------------------------------------------------------------------------------------------------
>>>> 
>>>> 
>>>> 
>>>> <inlist_project>
>>> 
>> 
>> --------------------------------------------------------------------------------------------------------------------
>> Dr. Juan Carlos Suárez 
>>    Ramon y Cajal fellow at Física Teórica y del Cosmos Dept. University of Granada 
>>    Facultad de Ciencias. 18071. Granada. Spain
>>  jcsuarez at ugr.es | +34 958249056 | www.ugr.es/~fqm292/ 
>>    Associate researcher at Stellar Physics Dept. IAA-CSIC
>>  Glorieta de la Astronomia s/n. 18008. Granada. Spain
>>  jcsuarez at iaa.es | +34 958230619 | www.iaa.es
>> --------------------------------------------------------------------------------------------------------------------
>> <inlist_project>
> 

--------------------------------------------------------------------------------------------------------------------
Dr. Juan Carlos Suárez 
    Ramon y Cajal fellow at Física Teórica y del Cosmos Dept. University of Granada 
    Facultad de Ciencias. 18071. Granada. Spain
	  jcsuarez at ugr.es | +34 958249056 | www.ugr.es/~fqm292/ 
    Associate researcher at Stellar Physics Dept. IAA-CSIC
	  Glorieta de la Astronomia s/n. 18008. Granada. Spain
	  jcsuarez at iaa.es | +34 958230619 | www.iaa.es
--------------------------------------------------------------------------------------------------------------------

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