EZ Stellar Evolution
Contents
• Introduction
• Downloads
• Mailing Lists
• Other Useful Stuff
• Plots and Plotting
• Feedback
EZ to Evolve ZAMS Stars:
A Program Derived from Eggleton's Stellar Evolution Code
The "main sequence" is where stars spend most of their lives while they burn hydrogen in their cores. The zero-age main sequence, "ZAMS", corresponds to stars that are just settling into their careers as hydrogen burners after having formed from a collapsing gas cloud. After a long time spent doing pretty much the same thing, they eventually evolve away from the main sequence and begin burning other elements. Stellar evolution programs simulate this based on the relevant physical information and some simplifying assumptions that hopefully preserve the important features while making the computation tractable.
"Evolve ZAMS'', "EZ'' for short, is derived from Peter Eggleton's stellar evolution program. The core of EZ is a stripped down, rewritten version of a subset of Eggleton's code, specialized to handle single star evolution from the zero-age main sequence until forced to stop by an event such as a helium flash or a crystallizing core. The procedure and data interfaces to the program are designed to be easy to use while still providing a wide range of function.
Downloads
EZ is written in Fortran 95 and can be downloaded using the following links.
• README file for the current release of the stellar evolution simulatorFor optional background info, you can can take a look at
• EZ_3_6_3.tar.gz file with source files and data to build and run EZ yourself
• slides for a talk about EZ
• astro-ph/0405130, a mini-paper introducing EZ
Mailing Lists
There is a mailing list for information about EZ such as new releases and new tools (such as EZ Web).
To subscribe, simply send a blank email, no subject and no title, to EZ-news-on@kitp.ucsb.edu and reply to the email that you get back.There is also a mailing list for comments, questions, and answers concerning the use of EZ.
To unsubscribe, send an email to EZ-news-off@kitp.ucsb.edu and follow the instructions in the email that you get back.
To subscribe, send a blank email to EZ-users-on@kitp.ucsb.edu and then send messages to EZ-users@kitp.ucsb.edu.
To unsubscribe, send an email to EZ-users-off@kitp.ucsb.edu and follow the instructions in the email that you get back.
Other Useful Stuff
EZ Web
Check out EZ Web -- a web interface to EZ provided by Rich Townsend at the University of Delaware. Enter the parameters for the run (mass, metallicity, etc.), click submit, and in a few minutes an email arrives with a link to a 'zip' file with the output of the run.EZbrowser
If you want to poke around inside the EZ implementation, you should try the EZbrowser -- a web browser for the EZ source code provided by Roni Waldman at the Hebrew University of Jerusalem.
Plots and Plotting
I've posted pdf files for lots of stellar structure and evolution plots that I've created from data generated by EZ. In addition to illustrating EZ, you may find that some of the things here are useful on their own. Please feel free to download and use any of them. The bitmap images shown below are only meant to suggest what you'll find in the pdf files by clicking on the link to the library of star plots.
The plots are made from EZ output data, using the Ruby-PDF-TeX based program Tioga (that I created for just this sort of application).
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The pdf files in the library include both history plots and profile plots. The history plots show the progress of certain properties of the star as it evolves. The profile plots show the values of a variety of properties of single state of the star during its evolution. Profiles are given either by mass or by log pressure. The profiles by mass show more details about the interior of the star, while the profiles by log pressure emphasize the outer envelope.