[Mesa-users] (no subject)

[Wolf, William M]

Hi Zhao,

There’s no simple answer to how high one should set tau_factor. In general, you will run into convergence problems if it’s too low when the WD expands (unless you can find clever ways to make the hydro solver happy).

If your goal is to measure a multiwavelength light curve, I would strongly warn against that unless you are really comfortable using stella or something similar to properly handle the radiative transfer. If you just want to get a bolometric luminosity, you can do that, I and setting tau factor to something modest (in the 100’s) may give you something useful. It is your responsibility to determine if this value makes a difference in the data you are truly interested in, though.

As for getting expansion with larger accretion rates, setting mass change to something larger like 7d-7 and shutting off the super eddington wind (super_eddington_scale_factor = 0d0) gives rapid and problematic expansion on the first flash.

Regards,

Bill

From: Mesa-users <mesa-users-bounces at lists.mesastar.org> on behalf of Rob Farmer via Mesa-users <mesa-users at lists.mesastar.org>
Reply-To: Rob Farmer <r.j.farmer at uva.nl>
Date: Tuesday, December 3, 2019 at 2:19 AM
To: "zhaoweitao at ynao.ac.cn" <zhaoweitao at ynao.ac.cn>
Cc: mesa-users <mesa-users at lists.mesastar.org>
Subject: Re: [Mesa-users] (no subject)

If you keep the replies on list then other people might be able to help or be helped.

Maybe someone who works with white dwarfs can help here?

Rob
On Tue, 3 Dec 2019, 02:35 zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>, <zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>> wrote:
Hi Rob

         I'm happy to receive your reply soon .I tried to tau=300.In Nomoto's steady burn model ,when the rate of accrate material excess this critical value,WD will keep  expanding ,but if this tau=300 and the accration rate more than the critical value,WD won't keep expending.


Zhao


-------- Original message --------
From: Rob Farmer <r.j.farmer at uva.nl<mailto:r.j.farmer at uva.nl>>
Date: Mon, Dec 2, 2019, 11:10 PM
To: zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>, mesa-users <mesa-users at lists.mesastar.org<mailto:mesa-users at lists.mesastar.org>>
Subject: Re: [Mesa-users] (no subject)
Hi,
Please keep all replies on list.

Did you try the value of 300 from the wd2 test case?

Tau is the optical depth for the outer boundary. By making tau large you ignore the outer layers (material at lower tau values), this can help with convergence issues as you don;t have to model this material.

Rob


On Mon, 2 Dec 2019 at 12:04, zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn> <zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>> wrote:
Hello Rob

          I'm sorry for not expressing clearly.
          Now,I am simulating the light curve of supersoft X-ray sources by MESA.  The suite case wd2 was used to simulate the expand and shrink of WD,but I don't know how to set the proper parameters of the set_tau_factor and set_to_this_tau_factor. If I set the parameter too small (such as 1 or 2/3), MESA will appear logQ_min_limit or get_atm_eos_kap_info  and do atm_grey_and_kap.
         So I would like to know the suitable range of parameter to WD, and in MESA,what this tau stand for? What it determines? My settings are in the attachment.
Zhao


-------- Original message --------
From: Rob Farmer <r.j.farmer at uva.nl<mailto:r.j.farmer at uva.nl>>
Date: Mon, Dec 2, 2019, 5:49 PM
To: zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>
Cc: MESA <mesa-users at lists.mesastar.org<mailto:mesa-users at lists.mesastar.org>>
Subject: Re: [Mesa-users] (no subject)
Hi,

Its unclear what you are doing, what parameter are you changing? What result is wrong and why is it wrong? Providing your inlist as well as the parameters you are changing is needed before we can help.

Rob

On Sat, 30 Nov 2019 at 14:28, zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn> <zhaoweitao at ynao.ac.cn<mailto:zhaoweitao at ynao.ac.cn>> wrote:
Hi
     Recently, I'm using MESA to simulate the light curve. In  star_job defaults,I don't know how to set the appropriate parameters of opcital depth. At present, I set the parameter range to 1~30,if the parameter is too large ,the result is not what i want,and the parameter is too small,MESA error when running. so anyone tell me why?
at the same time,i would like to know what  is the specific definition of optical depth in MESA. I only know  that use optical depth to determine the surface boundary condition in the MESA atmosphere model.
      ZHAO Weitao
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