[Mesa-users] Requesting help Regarding Conservation of Mass during Evolution of LMXB

Pulkit Ojha pulkit.ojha at niser.ac.in
Sat Oct 29 08:01:37 UTC 2022


Dear Dr Evan,

Thank you for your advice. I varied the parameter "mdot_edd_eta = 0" and
setting it to 0 allowed the mass to remain conserved during the evolution.
I'm deeply thankful for your help.

Yours Truly
Pulkit




On Thu, Oct 27, 2022 at 1:45 AM Evan Bauer <evan.bauer.astro at gmail.com>
wrote:

> Hi Pulkit,
>
> It looks like your eval_other_mdot_edd routine is setting mdot_edd_eta =
> 0.5, which is causing the accretor in your model not to retain all of the
> transferred mass even when the accretion rate isn't Eddington limited. See
> the comments here:
> https://docs.mesastar.org/en/release-r22.05.1/reference/binary_controls.html#use-radiation-corrected-transfer-rate
>
>
> You should be able to get rid of this behavior by setting
> limit_retention_by_mdot_edd = .false.
> use_other_mdot_edd = .false.
>
> Hope that helps!
>
> Cheers,
> Evan
>
> On Oct 26, 2022, at 11:22 AM, Francis Timmes via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
> hi pulkit,
>
> the inlist_project and run_star_extras, with its own
> eval_mdot_edd_routine, is relatively complicated.
> my suggestion to help you resolve your issue is to simplify and bisect.
> for example, turn off all the
> binary interaction controls. check that the total mass now remains
> constant. then add the binary interaction
> controls one at a time until you identify the control that is causing the
> issue.
>
> fxt
>
>
>
>
> On Oct 23, 2022, at 4:36 AM, Pulkit Ojha via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
> Dear All,
>
> I'm Pulkit and I'm trying to evolve LMXB containing a main sequence donor
> star of mass 1 Msun and a point mass of 1.35 MSun (specified as NS
> accretor) with an initial period of 1 - 1.5 days. While evolving binary
> systems, I'm facing some problems related to conservation of total mass
> during the evolution of LMXBs. Even if the mass transfer efficiency ( given
> by f_{mt} = 1 - \alpha - \beta - \delta ) is 1 by setting all the three
> parameters alpha, beta and delta to 0, the total mass of donor + NS is lost
> by 21%, i.e.  about 1.855 Msun mass remains finally.
>
> It has also been mentioned on the mesa document that "winds will carry
> specific angular momentum of stars even if the efficiency is 1". Since,
> alpha and beta are defined as "alpha = fraction of the mass lost from the
> vicinity of the donor as fast winds" and similarly beta for the accretor,
> they lead me to the question of what are the other kinds of winds which are
> not being controlled by these parameters.
>
> Hence, I would be really grateful if someone could help me understand the
> reason for mass not remaining conserved while evolving LMXBs.  For your
> reference, I'm attaching a zip file containing relevant inlist files.
>
> Yours Truly
> Pulkit
>
> --
> Pulkit Ojha
> 5th Year Integrated MSc.,
> School of Physical Sciences,
> National Institute of Science Education and Research
> Bhubaneswar, INDIA
>
>
>
> <Pulkit_2022_LMXB.zip>_______________________________________________
> mesa-users at lists.mesastar.org
> https://lists.mesastar.org/mailman/listinfo/mesa-users
>
>
> _______________________________________________
> mesa-users at lists.mesastar.org
> https://lists.mesastar.org/mailman/listinfo/mesa-users
>
>
>

-- 
Pulkit Ojha
5th Year Integrated MSc.,
School of Physical Sciences,
National Institute of Science Education and Research
<https://www.niser.ac.in/>
Bhubaneswar, INDIA
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20221029/82d3b271/attachment.htm>


More information about the Mesa-users mailing list