[Mesa-users] EOS/opacity (?) issues in proto-WDs

Wed Apr 10 13:12:08 EDT 2019

Hi everyone,

Using MESA-r11554, I have the following problem: I am trying to follow the evolution of a mass losing He-rich star (initial mass 1.0 Msun) in a binary down to a mass of 0.1 Msun (below the mass limit for helium burning). However, once the model reaches between 0.32 and 0.29 Msun, the code runs into convergence issues and crashes with the following error and backtrace:

get_surf_PT: L_surf <= 0        3101   -1.9452885788738120D+32

                                    L u kap logT logRho           1   -1.9452885788738120D+32                       NaN    7.0362623532835888D-01    4.0495086738376775D+00   -5.0086142130207394D+00
                                    L u kap logT logRho           2   -1.8889367050152320D+32                       NaN    4.6888668272319689D-01    4.0091836407479775D+00   -5.0192456415635389D+00
                                    L u kap logT logRho           3   -1.8059551207355153D+32                       NaN    2.8151702244064775D-01    3.9584024748335755D+00   -4.9293263060039179D+00
                                    L u kap logT logRho           4   -1.6775802756995363D+32                       NaN    1.3119664418262897D-01    3.9015665950252587D+00   -4.7667726811442810D+00
                                    L u kap logT logRho           5   -1.4994868526987713D+32                       NaN    9.3921074678169597D-02    3.8510174515718290D+00   -4.5847388422864057D+00
                                    L u kap logT logRho           6   -1.2936231230392295D+32                       NaN    1.1204973157540775D-01    3.8400372871190571D+00   -4.4850509611066780D+00
                                    L u kap logT logRho           7   -1.1193008043810795D+32                       NaN    8.5857002056263204D-02    3.8636664419891473D+00   -4.4909859600597848D+00
                                    L u kap logT logRho           8   -1.0212568108683585D+32                       NaN    8.5964276322603408D-02    3.8621801446661350D+00   -4.4756981402355818D+00
                                    L u kap logT logRho           9   -9.4955104950687273D+31                       NaN    1.4036385419077119D-01    3.8213026619507611D+00   -4.4176272353450017D+00
                                    L u kap logT logRho          10   -8.8811180208086254D+31                       NaN    6.3974290520336111D-02    3.7259415267112881D+00   -4.4247962698408703D+00

                                                 logT =    4.0495086738376775D+00
                                               logRho =   -5.0086142130207394D+00
                                                    x =    2.5797528950722257D-61
                                                    z =    1.7019582018497958D-02
                                                 abar =    4.0521678090748869D+00
                                                 zbar =    2.0260839045374435D+00

 s% use_compression_outer_BC F
 s% use_T_Paczynski_outer_BC F
 s% use_T_black_body_outer_BC F
 s% use_fixed_L_for_BB_outer_BC F
                                        s% tau_for_L_BB   -1.0000000000000000D+00

File: ../private/hydro_vars.f90, Line: 1342
ERROR STOP 1

Error termination. Backtrace:
#0  0x14745007d
#1  0x147450d15
#2  0x147451c67
#3  0x10f3f18a5
#4  0x10ee5f0c3
#5  0x10ee60a74
#6  0x10ef3f480
#7  0x10ef40e51
#8  0x10ef572bd
#9  0x10f0d401d
#10  0x10f0e0ef3
#11  0x10f0e2a7a
#12  0x10f0e4c3b
#13  0x10f0e5d5d
#14  0x10f0f8db1
#15  0x10f1457dd
#16  0x10ed3499d
#17  0x10ed0bb3d
#18  0x10ed0bb50
#19  0x10ed0bb89

My best guess is that this has to do either with the eos, opacity tables or convection controls, but trying different combinations didn’t seem to have an effect (still resulting in the same outcome, albeit at slightly different masses). I also compared my models with the lgR and lgT parameter spaces for the eos and opacities provided in the most recent instrument paper they do not seem to run into any problematic areas. I can’t help but think that the solution ought to be reasonably simple and I’m just not seeing it, but it has eluded me so far. I’d be grateful for any ideas.

See below for the minimum inlists needed to reproduce the problem (note that varcontrol = 1d-3 in order to get to the problematic phase in a reasonable time, the result will be the same with lower values). I can provide the initial helium star model too if required.

Best regards

Patrick

Minimum inlists to reproduce the problem:

! inlist1

&star_job

      load_saved_model = .true.                                                  
      saved_model_name = 'He-star.mod'     
      save_model_when_terminate = .true.
      save_model_filename = 'final.mod'
      change_initial_net = .true.      
      new_net_name = 'pp_extras.net'
      eos_file_prefix = 'mesa'
      kappa_file_prefix = 'gs98'
      change_v_flag = .true.
      new_v_flag = .true.
      set_initial_dt = .true.
      years_for_initial_dt = 1d-10
      pgstar_flag = .true.

/ ! end of star_job namelist

&controls

      max_number_backups = 100
      varcontrol_target = 1d-3
      use_eosDT2 = .true.
      use_eosELM = .true.
      MLT_option = 'Henyey'
      report_ierr = .true.
      photo_interval = 100
      profile_interval = 50
      history_interval = 1
      terminal_interval = 10
      write_header_frequency = 10      
      max_age = 10.1d9
      min_timestep_limit = -1

/ ! end of controls namelist

! inlist2

&star_job

      show_log_description_at_start = .false.

/ ! end of star_job namelist

&controls

         max_number_backups = 10
         max_number_retries = 80

      extra_terminal_output_file = 'log2' 
      photo_directory = 'photos2'
      log_directory = 'LOGS2'

      varcontrol_target = 1d-3

/ ! end of controls namelist

! binary inlist

 &binary_job                                                             

     inlist_names(1) = 'inlist1'                                         
     inlist_names(2) = 'inlist2'                                         

     evolve_both_stars = .false.                                         

     / ! end of binary_job namelist                                      

 &binary_controls                                                        

     m2 = 1.7 ! companion mass in Msun                                
     initial_period_in_days = -1                                        
     initial_separation_in_Rsuns = 0.848074                                        
     limit_retention_by_mdot_edd = .true.                                
     mass_transfer_beta = 1.0         
     report_rlo_solver_progress = .true.                                     
     mdot_scheme = 'Ritter'                                              
     implicit_scheme_tolerance = 1e-3                                                                   
     max_tries_to_achieve = 10

 / ! end of binary_controls namelist    
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