[Mesa-users] irradiated AGB mass loss

Evan Bauer ebauer at physics.ucsb.edu
Wed Mar 14 18:53:02 EDT 2018


Hi Sergei,

It may also be necessary to experiment with the control
	 column_depth_for_irradiation = 1.e0

Try to discern where in the model the irradiation energy gets deposited, and see if that has any correlation with surface resolution?

Cheers,
Evan

> 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
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> mesa-users at lists.mesastar.org
> https://lists.mesastar.org/mailman/listinfo/mesa-users
> 




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