This page describes the optical version of the code. To see the
ultraviolet version (HII-CHI-mistry-UV) click here.
HII-CHI-mistry is a python program that
calculates for gaseous nebulae ionized by
massive stars the oxygen abundance in terms of
12+log(O/H), the nitrogen-to-oxygen ratio as
log(N/O) and the ionisation parameter as log U
from a set of emission-line optical intensities,
consistently with the direct method. The
methodology and the results are described in Pérez-Montero
(2014, MNRAS, 441, 2663).
HISTORY AND DOWNLOADS
Each compressed tar.gz file
contains the python file of the code, the
libraries of the models and a file with
- Version 3.0 (2017/09).
The errors of the input intensity lines are now considered in the
calculation of the errors of the derived abundances and log U. To
do so an iterative Monte-Carlo simulation is performed in the
script. In addition, in the interpolated grid of models, this grid
is only used once a first estimation of the results is obtained to
reduce the time of calculation.
- Version 2.2 (2017/02)
(In order to avoid some divergences in the calculation of O/H,
it enhances in the interpolated mode the parameter defined to
fix the number of constrained models once calculated
-ersion 2.0 (2016/01)
uses the library numpy, so asciidata is not anymore required.
the results are now stored in an independent ascii file. Finally
this version lets the user to choose a model grid of better
resolution in O/H and N/O to smooth results around the knots of
the model grid. In addition, the program uses all the
models for the weighted means of the results, not just a subset
of them as in previous versions.)
- Version 1.2
(It fixes a bug for observational sets with
[OIII[ 4363 but without [NII] 6584 for N/O and it expands the
metallicity range from 12+log(O/H) = 6.9).
HOW TO RUN IT
HII-CHI-mistry has been written in python. It
requires the library numpy
(versions previous to v2.0 use the library
asciidata). It also needs the files of the
relative emission line intensities predicted by
the models, assuming a different set of input
In version 2.0 and later the distribution also
has the files with the linear interpolations of
the grid in O/H and N/O. These files have the
same name with and additional "int" at the end.
These files represent the whole set of models,
limiting the values of log U at each Z (left
picture), and limiting also the values of N/O,
respectively (right picture).
All were calculated with Cloudy v.13
and a POPSTAR
SED at an age of 1Myr with an IMF of Chabrier.
To run the program, just type (for v3.0, in
other versions use the name of
thecorresponding python script ):
> python HCm_v3.0.py
For version 2.0 and later the program will ask
about what sets of models must be used (0:
non-interpolated, 1:interpolated) and then will
ask you about your input file
It must be written in text format with five
columns containing in each row the following
information about a gaseous nebula or a postion
all of them reddening corrected. If no
information exists about a certain line it must
typed as zero.
In version 3.0 the file must have ten columns,
including the associated errors. If no error is
considered these columns must be typed as zero.
If the input file is correctly introduced, the
program will calculate the wanted quantities and
their corresponding errors.
The information will be displayed in the screen
for each object, along with the ratio of
completeness of the task. It will be also added
an index saying
what grid was used, where
1: the complete grid is used (only if [OIII]
4363 > 0)
2: the log U limited grid is used (when [OIII]
4363 = 0)
3: the log U and N/O limited grid is used
(if, besides, [NII]/[OII] and [NII]/[SII] cannot
In addition in version 2.0 and later it will
create a file called output.dat with the
columnas of the input emission lines and seven
new columns will be added to the input
file with the
error of 12+log(O/H)
log(N/O) (-10 if grid 3 is used)
error of log(N/O)
error of log(U) (take with care if grid 2 or 3
Last update: 2016, April