Downloads

Downloads:

- Notice_simple.txt

- nahoon.tar.gz [1]

- idl_proc.tar.gz

Links:

Papers referring to these tools:

Chemical databases:

Differential equation solver:

Software:

* Nahoon is the name of a boat which is now a very nice wreck.

[1] Modified the 19 july 2007

Chemical model

To simulate the chemical evolution of a quiescent molecular cloud, you can download the simple gas phase chemical model NAHOON* on this page. Description of the model:
- The model is written in fortran 77 and in double precision.
- The chemical database is osu.2005 but can be modified to read any other list of reactions.
- The solver is dlsode.
- There is an inner option to generate the runs to compute the model uncertainties. Some IDL procedures to compute error bars from these runs are also available on this page.

A notice describing the model and how to use it can be downloaded here:
- Notice for astronomers
- Notice for NON astronomers (this is a simplified version for people that don’t want to know the details of the modeling but just want to test the effect of adding a reaction for instance)

How to install the model:
1) Download the files nahoon.tar.gz.
2) Do: gunzip nahoon.tar.gz
tar -xvf nahoon.tar
3) Read the Notice for the next steps.

Here are some scripts to compile the model:
-linux: G77nahoon_linux.bat
-windows: G77nahoon_win.bat

A series of IDL procedures are also available idl_proc.tar.gz. The IDL language is very similar to fortran. IDL is not a free software but you can install GDL which is the same and is free. We strongly recommend you to look into the IDL procedures yourself and not use them as black boxes, especially the procedures to compute the error bars.
Among the files available, plot_ab.pro plots the abundance of a selected species as a function of time from the one single output file (plot.dat) of the chemical model.
The other files are used for the uncertainties and the details can be found in the Notice previously mentioned.

If you use this model in a publication, please refer to the name of the model and to this web page.
If you have any troubles in using the model, please contact me.

Some figures:

1) First step of the uncertainty calculations: 600 runs of the SO abundance as a function of time. Each line represents the 1 run.

2) Second step of the uncertainty calculation: Error bars (green dashed lines) of the HC7N abundance as a function of time. The blue line is the mean abundance.