[Mesa-users] irradiated AGB mass loss

Wed Mar 14 15:52:44 EDT 2018

hi sergei,

i'm going to guess that the outer layers of the model may not be resolved enough.
try adding the following mesh controls and see what you get.

! mass resolution
      max_dq = 0.001   ! 1/max_dq is the minimum number of cells
      log_tau_function_weight = 100
      log_kap_function_weight = 100

http://mesa.sourceforge.net/controls_defaults.html#max_dq
http://mesa.sourceforge.net/controls_defaults.html#log_tau_function_weight
http://mesa.sourceforge.net/controls_defaults.html#log_kap_function_weight

the test suite examples are a great place to get started on a problem,
but for a specific enough problem the inlist(s) usually need to be be refined. 

fxt

> On Mar 14, 2018, at 7:32 AM, Sergei Nayakshin via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Dear all,
> 
> I’m investigating how mass loss from AGB stars might respond to a very strong irradiation, and I came across some very strange results.
> 
> I would assume that resolving the atmosphere better (to smaller tau) is a good idea in this problem, so I set 
> 
> relax_to_this_tau_factor = 1d-3
> 
> However, with this setting I get the mass loss rate *decreasing* with increasing irradiation flux! That surely should not be the case, and indeed with the default atmosphere depth (relax_to_this_tau_factor = 1), I get an increasing Mdot as the irradiation flux increases. 
> 
> I would really appreciate any ideas on why this is happening. Is there a contradiction in using the ‘Blocker’ mass loss prescription and resolving atmosphere to smaller depths?
> 
> The detail of my inlist are given below.
> 
> Thanks in advance,
> Sergei.
> 
> ——————————————————-
> 
> I am using the ‘agb’ problem from the test_suite of mesa-r10108, and the most relevant lines that I added to the inlist_agb are
> 
> &star_job
> 
> relax_to_this_tau_factor = 1d-3
> dlogtau_factor = 0.1
> relax_initial_tau_factor = .true.
> relax_tau_factor = .true.
> 
> &controls
> 
> column_depth_for_irradiation = 1e0
> irradiation_flux = 1.d10
> 
> 
> 
> —————— Full inlist just in case it’s needed: —————————————
> 
> ! inlist_agb
> 
> 
> &star_job
>      show_log_description_at_start = .false.
>      !list_net_reactions = .true.
> 
>      load_saved_model = .true.
>      saved_model_name = '2m_z1m2_agb.mod'
> 
>      save_model_when_terminate = .true.
>      save_model_filename = 'final.mod'
> 
>      write_profile_when_terminate = .true.
>      filename_for_profile_when_terminate = 'final_profile.data'
> 
>      change_initial_net = .true.      
>      new_net_name = 'o18_and_ne22.net'  ! 10 species
>      !new_net_name = 'agb.net' ! 18 species
>      !new_net_name = 'sagb_NeNa.net' ! 24 species
>      !new_net_name = 'sagb_NeNa_MgAl.net' ! 29 species
> 
>      relax_to_this_tau_factor = 1d-3
>      dlogtau_factor = 0.1
>      relax_initial_tau_factor = .true.
>      relax_tau_factor = .true.
> 
>      set_initial_dt = .true.
>      years_for_initial_dt = 1d-1
> 
>      pgstar_flag = .true.
> 
> 
> / ! end of star_job namelist
> 
> &controls
> 
> 
>      !okay_to_reduce_gradT_excess = .false.
>      !mixing_length_alpha= 1.89
>      varcontrol_target = 1.d-3
> 
> 
>      ! check for retries and backups as part of test_suite
>      ! you can/should delete this for use outside of test_suite
>         max_number_backups = 10
>         max_number_retries = 80
> 
>      max_model_number = 9000
> 
>      initial_mass = 2.0
>      initial_z = 0.01d0
> 
>      ! surface heating
>      column_depth_for_irradiation = 1.e0
>      irradiation_flux = 1.d11     ! day side flux!!! Bill puts in 1/4 by hand
> 
>      star_mass_min_limit = 1.4
> 
>      !xa_surface_upper_limit_species(1) = 'c12'
>      !xa_surface_upper_limit(1) = 0.0013
> 
>      cool_wind_RGB_scheme = 'Reimers'
>      Reimers_scaling_factor = 0.5
>      cool_wind_AGB_scheme = 'Blocker'
>      Blocker_scaling_factor = 0.5
>      RGB_to_AGB_wind_switch = 1d-4
> 
>   !  only use the cool_wind_scheme
>      !cool_wind_full_on_T = 1d8    !K
>      !cool_wind_full_off_T = 1.1d8 !K
>      hot_wind_scheme = ''
> 
>      photo_interval = 50
>      profile_interval = 50
>      history_interval = 1
>      terminal_interval = 10
>      write_header_frequency = 10
> 
> 
>      mesh_dlog_pp_dlogP_extra = 0.25
>      mesh_dlog_cno_dlogP_extra = 0.25
> 
>      mesh_dlog_3alf_dlogP_extra = 0.225
>      mesh_dlog_burn_c_dlogP_extra = 0.225
>      mesh_dlog_burn_n_dlogP_extra = 0.225
>      mesh_dlog_burn_o_dlogP_extra = 0.225
> 
> 
>      mesh_logX_species(1) = 'h1'
>      mesh_logX_min_for_extra(1) = -6
>      mesh_dlogX_dlogP_extra(1) = 0.25
> 
>      mesh_logX_species(1) = 'he4'
>      mesh_logX_min_for_extra(1) = -6
>      mesh_dlogX_dlogP_extra(1) = 0.25
> 
>      xtra_coef_os_above_nonburn = 0.5
>      xtra_coef_os_below_nonburn = 0.25
> 
>      xtra_coef_os_above_burn_h = 0.25
>      xtra_coef_os_below_burn_h = 0.15
> 
>      xtra_coef_os_above_burn_he = 0.25
>      xtra_coef_os_below_burn_he = 0.25
> 
>      xtra_coef_os_above_burn_z = 0.25
>      xtra_coef_os_below_burn_z = 0.25
> 
>      xtra_dist_os_above_nonburn = 0.1
>      xtra_dist_os_below_nonburn = 0.2
> 
>      xtra_dist_os_above_burn_h = 0.2
>      xtra_dist_os_below_burn_h = 0.2
> 
>      xtra_dist_os_above_burn_he = 0.2
>      xtra_dist_os_below_burn_he = 0.2
> 
>      xtra_dist_os_above_burn_z = 0.2
>      xtra_dist_os_below_burn_z = 0.2
> 
>      overshoot_f_above_nonburn_core = 0.014
>      overshoot_f_above_nonburn_shell = 0.014
>      overshoot_f_below_nonburn_shell = 0.014
>      overshoot_f_above_burn_h_core = 0.014
>      overshoot_f_above_burn_h_shell = 0.014
>      overshoot_f_below_burn_h_shell = 0.014
>      overshoot_f_above_burn_he_core = 0.014
>      overshoot_f_above_burn_he_shell = 0.014
>      overshoot_f_below_burn_he_shell = 0.014
>      overshoot_f_above_burn_z_core = 0.014
>      overshoot_f_above_burn_z_shell = 0.014
>      overshoot_f_below_burn_z_shell = 0.014
> 
>      overshoot_f0_above_nonburn_core = 0.004
>      overshoot_f0_above_nonburn_shell = 0.004
>      overshoot_f0_below_nonburn_shell = 0.004
>      overshoot_f0_above_burn_h_core = 0.004
>      overshoot_f0_above_burn_h_shell = 0.004
>      overshoot_f0_below_burn_h_shell = 0.004
>      overshoot_f0_above_burn_he_core = 0.004
>      overshoot_f0_above_burn_he_shell = 0.004
>      overshoot_f0_below_burn_he_shell = 0.004
>      overshoot_f0_above_burn_z_core = 0.004
>      overshoot_f0_above_burn_z_shell = 0.004
>      overshoot_f0_below_burn_z_shell = 0.004
> 
>      overshoot_below_noburn_shell_factor = 10
> 
>      use_Type2_opacities = .true.
>      Zbase = 0.01d0
> 
>      T_mix_limit = 1d4
> 
>      ! FOR DEBUGGING
> 
>      !report_hydro_solver_progress = .true. ! set true to see info about newton iterations
>      !report_ierr = .true. ! if true, produce terminal output when have some internal error
>      !hydro_show_correction_info = .true.
> 
>      !max_years_for_timestep = 3.67628942044319d-05
> 
> 
> 
> / ! end of controls namelist
> 
> 
> 
> &pgstar
> 
>      Grid4_win_flag = .true.
>      Kipp_mass_min = 0.565 ! (Msun units) negative means use default
>      Kipp_mass_max = 0.575 ! (Msun units) negative means use default
>      ! set window size (aspect_ratio = height/width)
>      TRho_Profile_win_width = 8
>      TRho_Profile_win_aspect_ratio = 0.75
> 
> / ! end of pgstar namelist
> 
> 
> 
> 
> 
> 
> 
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> 