[Mesa-users] STELLA Fe II Velocities

Wed May 1 18:44:18 EDT 2019

> On May 1, 2019, at 3:37 PM, Wilson Ricks <wilson.ricks at gmail.com> wrote:
> 
> Having done several new STELLA runs, I can say that the new early time results are definitely wonky (falling off sharply before 20 days before increasing again as we approach the explosion time). I know this domain hasn't been tested, but can you offer any insight into why early times give apparently unphysical results?

nope.  that’s way out of my area.

do you have any basis for expecting the Fe velocities to be significantly different that the photosphere velocities at the early time?   if not, then don’t push the code into places it wasn’t meant to cover.

-b

> 
> On Wed, May 1, 2019, 12:44 PM Wilson Ricks <wilson.ricks at gmail.com <mailto:wilson.ricks at gmail.com>> wrote:
> Thanks for the heads up. I'll definitely do a sanity check on what comes out.
> 
> On Wed, May 1, 2019, 12:33 PM Bill Paxton <paxton at kitp.ucsb.edu <mailto:paxton at kitp.ucsb.edu>> wrote:
> 
>> On May 1, 2019, at 7:02 AM, Wilson Ricks <wilson.ricks at gmail.com <mailto:wilson.ricks at gmail.com>> wrote:
>> 
>> Hi Bill,
>> 
>> This solves it - thanks for the help.
>> 
>> Best,
>> Wilson
> 
> Glad that produces the output you want.
> 
> But use those results with caution since you are going beyond the usual range where the approximations for the Fe velocity have been used and tested.  That doesn’t mean they are bad, but it does mean you need to be careful to ensure you haven’t just driven your Maserati over a cliff expecting it to fly.   If the results in the new domain look crazy, they don’t use them.
> 
> -Bill
> 
> 
>> 
>> On Tue, Apr 30, 2019, 8:50 PM Bill Paxton <paxton at kitp.ucsb.edu <mailto:paxton at kitp.ucsb.edu>> wrote:
>> 
>>> On Apr 30, 2019, at 5:19 PM, Wilson Ricks <wilson.ricks at gmail.com <mailto:wilson.ricks at gmail.com>> wrote:
>>> 
>>> Hi Bill,
>>> 
>>> I did another run and I think the method you referred to only adds "mesa.dayxxx_post_Lbol_max.data" files, while I'm looking to control output times in "mesa.vel_fell".  This file is still only giving data points starting around 25-30 days, and I'm interested in getting earlier ones.
>> 
>> Ahh.  
>> 
>> Search in stella_extras.f90 for ‘.vel_feII’.   you’ll find this
>> 
>>    fname = trim(filestr)//'.vel_feII'
>>    open(24,file=fname, status='unknown')
>> 
>> Then search from that location for ‘write(24’.   first you find where it writes the header info.   then you’ll find this
>> 
>>             if (k > k_phot - 10) &
>>                write(24,'(i5,99(1pe18.4,x))') k,time-t0, &
>>                   v_sob_lo_tau*1d3, v_sob_med_tau*1d3, v_sob_hi_tau*1d3, &
>>                   10**logRho, 10**logT, eta, &
>>                   m_sob_lo_tau, r_sob_lo_tau, &
>>                   m_sob_med_tau, r_sob_med_tau, &
>>                   m_sob_hi_tau, r_sob_hi_tau
>> 
>> Try commenting out the line "if (k > k_phot - 10) &” so that the write is always done.
>> 
>> -Bill
>> 
>> 
>> 
>> 
>>> 
>>> Thanks,
>>> Wilson
>>> 
>>> On Tue, Apr 30, 2019, 5:27 PM Wilson Ricks <wilson.ricks at gmail.com <mailto:wilson.ricks at gmail.com>> wrote:
>>> Alright, thank you very much for the help. I'll see if I can get things working.
>>> 
>>> Best,
>>> Wilson
>>> 
>>> On Tue, Apr 30, 2019, 4:42 PM Bill Paxton <paxton at kitp.ucsb.edu <mailto:paxton at kitp.ucsb.edu>> wrote:
>>> 
>>>> On Apr 30, 2019, at 1:26 PM, Wilson Ricks <wilson.ricks at gmail.com <mailto:wilson.ricks at gmail.com>> wrote:
>>>> 
>>>> Hi Bill,
>>>> 
>>>> Do you mind explaining how output times can be adjusted using this file? I think the relevant section is between lines 185 and 200, but I'm having trouble interpreting the code.
>>> 
>>> times in the stella code itself use t=0 at start of run.
>>> but the output from stella_extras are at times since Lbol max.
>>> typically there is no stella output for the times since breakout when we want to see results.
>>> so the code has to interpolate between the available stella data snapshots.
>>> the output times are determined by the calls on save_day_post_Lbol_max starting at line 458.
>>> for example, if you want to get interpolated results for 33.7 days post Lbol max, then insert a new line between the ones for output at 30 days and at 40 days.  the final arg to save_day_post_Lbol_max is a string that goes in the filename - you need to change that as well.
>>> 
>>> good luck,
>>> bill
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> 
>>>> Thanks,
>>>> Wilson
>>>> 
>>>> On Tue, Apr 30, 2019, 3:29 PM Bill Paxton <paxton at kitp.ucsb.edu <mailto:paxton at kitp.ucsb.edu>> wrote:
>>>> The Fe II 5169 velocities are calculated during the post-processing done by stella_extras.f90 which lives in stella/res.
>>>> 
>>>> So they are actually derived from STELLA data rather than being output directly by STELLA.
>>>> 
>>>> -Bill
>>>> 
>>>> 
>>>> 
>>>> > On Apr 30, 2019, at 12:24 PM, Wilson Ricks via Mesa-users <mesa-users at lists.mesastar.org <mailto:mesa-users at lists.mesastar.org>> wrote:
>>>> > 
>>>> > Hi all,
>>>> > 
>>>> > I'm currently having trouble controlling when STELLA outputs Fe II 5169 velocities.  The "stella/strad/run/mesa.dat" file which controls all the other STELLA outputs does not seem to affect these, and whatever the default is gives fairly sparse data at early times. Is there another file which can be used to control the Fe II velocity outputs?
>>>> > 
>>>> > Thanks,
>>>> > Wilson Ricks
>>>> > _______________________________________________
>>>> > mesa-users at lists.mesastar.org <mailto:mesa-users at lists.mesastar.org>
>>>> > https://lists.mesastar.org/mailman/listinfo/mesa-users <https://lists.mesastar.org/mailman/listinfo/mesa-users>
>>>> > 
>>>> 
>>> 
>> 
> 

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