Supernova Identification (SNID)

New templates-2.0 set available (see Download section below)

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You can also access: manual, Frequently Asked Questions

Contents: Copyright | Download | Installation | Documentation | References | Useful websites | Comic

SNID was originally written by John Tonry to determine redshifts of Type Ia supernovae, using the correlation techniques of Tonry & Davis (1979). I have since then re-written and expanded SNID to include type and age determination, as well as an interactive plotting package.

SNID makes extensive use of the PGPLOT plotting package and the associated BUTTON library.

If you would like to be kept updated on new releases of SNID and associated spectral templates, please send me an email: my


SNID is Copyright (C) 1999-2007 Stéphane Blondin and John L. Tonry, and is available under the GNU General Public License. The full GNU License text is included in the SNID release as separate text file (gpl-3.0.txt).


You can download the current version (5.0) of SNID here: snid-5.0.tar.gz (3.8 Mb)

You can download the latest set of templates here: templates-2.0.tgz (6.2 Mb). A README file is included with installation instructions. If you plan to use SNID beyond 1 micron, you should use different versions of the templates-2.0 set, available here.

Other template sets are available: A set of IDL routines to flatten spectra as in SNID is available here: snid_pro.tgz (this can also be achieved with the logwave program).


SNID is written in Fortran 77 and so requires an appropriate compiler (g77, gfortran, etc.). The interactive plotting package is based on PGPLOT, so make sure you have the corresponding libraries installed. The list of Useful websites below will lead you to the right places to download/install an appropriate fortran compiler for your system and the PGPLOT library. Check out the Frequently Asked Questions if PGPLOT or a fortran compiler are not installed on your computer.

If you have complaints/suggestions on compiler options etc. please contact me: my
email. You can also look at the Frequently Asked Questions.

To install SNID, follow the following steps:

STEP 0. Unpack the tarball snid-5.0.tar.gz in the directory of your choice (hereby referred to as INSTALL_DIR):

	cp snid-5.0.tar.gz INSTALL_DIR
	gunzip snid-5.0.tar.gz
	tar -xvf snid-5.0.tar
This will create a directory named snid-5.0/ . You can then safely remove the snid-5.0.tar file. The snid-5.0/ directory contains the following subdirectories:

bin contains the snid, logwave, and plotlnw executables
button contains the button library used with PGPLOT
doc contains various documentation
examples contains example text and graphical output
source contains most of the fortran source code (*.f)
templates contains the spectral templates (*.lnw)
test contains files for test runs
utils contains further fortran source code (*.f)

It also contains installation instructions (AAREADME), the Makefile, and a copy of the GNU General Public License (gpl-3.0.txt).

STEP 1. cd to the snid-5.0/ directory. Open the file snidmore.f in the source/ subdirectory with your favourite editor, and set the tempdir variable (in the gettempdir subroutine, line 52 in snidmore.f) to point to the directory containing the spectral templates:

NOTE: Make sure you comply with the 72 character line limit! (Read the "IMPORTANT!" note in snidmore.f)

STEP 2. Now you need to edit the Makefile. Open this file up with your favourite editor and uncomment the FC, FFLAGS, XLIBS, and PGLIBS variables corresponding to your operating system (Linux, Solaris, Mac PowerPC, or Mac Intel). For example, on a Linux PC:

	# ------
	# Linux
	# ------
	# NOTE: for 64-bit CPUs, the X11 libraries are located in the lib64/
	# directory:
	#    XLIBS= -L/usr/X11R6/lib64 -lX11
	# OR XLIBS= -L/usr/lib64 -lX11
	# ------
	FC= g77
	XLIBS= -L/usr/X11R6/lib -lX11 
	PGLIBS= -L/usr/local/pgplot -lpgplot
NOTE: the X11 and PGPLOT libraries may not be located at /usr/X11R6/lib/ and /usr/local/pgplot/, respectively. If this is the case, edit the XLIBS and PGLIBS settings accordingly.

NOTE: If you use a compiler different than the one specified for your OS (g77 for Linux; Sun f77/f90 for Solaris; g77 for Mac PPC; g77 for Mac Intel), consult the table below to set the appropriate FFLAGS compiler flags:
	Compiler	OS			FFLAGS 
	g77		Linux			-O -fno-automatic
	gfortran	Linux			-O -fno-automatic
	Intel 		Linux			-O -save
	Sun 		Solaris			-O
	IBM 		IBM AIX, Linux, etc.	-O -qsave
	SGI 		SGI IRIX		-O -static
	Compaq 		Tru64 Unix		-O -static
FOR MAC USERS: Linking the pgplot libraries on a Mac requires to also link the png, z, and aquaterm libraries:
	PGLIBS= (...) -L/sw/lib -lpng -lz -laquaterm (...)
If the libpng.*, libz.* and libaquaterm.* are not in /sw/lib, you will need to edit the PGLIBS setting accordingly. E.g. the libpng.* and libz.* libraries could be in /usr/lib, while the libaquaterm.* library could be in /usr/local/lib. In this case you should set (assuming the libpgplot.* library is in /sw/lib):
	PGLIBS= -Wl,-framework -Wl,Foundation -L/usr/lib -lpng -lz -L/usr/local/lib -laquaterm -L/sw/lib/pgplot -lpgplot

STEP 3. Set the LD_LIBRARY_PATH and PGPLOT_DIR environment variables to point to the PGPLOT installation directory (see the note in the Makefile).

[in (t)csh]
      setenv LD_LIBRARY_PATH /usr/local/pgplot
      setenv PGPLOT_DIR /usr/local/pgplot

[in bash]
      export LD_LIBRARY_PATH="/usr/local/pgplot"
      export PGPLOT_DIR="/usr/local/pgplot"
NOTE: the PGPLOT installation directory may not be /usr/local/pgplot/. If this is the case, edit the LD_LIBRARY_PATH and PGPLOT_DIR settings accordingly.

STEP 4. Now you're ready to compile SNID! Make sure you're in the snid-5.0/ directory (which contains the Makefile) then simply type:

If this doesn't produce any error messages (note that you may get a few "Warnings" depending on which compiler you use, but those are harmless) then type:
	make install
which will simply copy the executable files (snid, logwave, and plotlnw) to the bin/ directory. Remember to add this bin/ directory to your $PATH environment variable if you want to be able to execute SNID from any directory on your system:
	setenv PATH $PATH:INSTALL_DIR/snid-5.0/bin     [in (t)csh]
        export PATH=$PATH:INSTALL_DIR/snid-5.0/bin     [in bash]
NOTE: If you do get error messages after typing "make" then make sure you clean up before attempting to recompile. This is done by typing:
	make realclean ; make
If the compilation then succeeds you can type 'make install' to copy the executable files to the bin/ directory.

STEP 5. For info on how to use SNID, look at the Howto.snid file in the doc/ subdirectory (or at the online manual). In the meantime, you can do a trial run on the spectrum of sn2003jo.dat in the test/ subdirectory [follow the '1.3. Example run' section in Howto.snid]:

	cd test/
	snid sn2003jo.dat
...and follow the prompts. Have fun!


For information on how to use SNID and its companion programs (logwave and plotlnw), please refer to the online manual. There is also a separate webpage with Frequently Asked Questions.

You can view the SNID flowchart here [ps, pdf], as well as information on the SNID spectral templates [ps, pdf].


For a detailed discussion on SNID, please refer to:

Determining the Type, Redshift, and Age of a Supernova Spectrum [ADS, astro-ph]
Blondin, S. & Tonry, J. L. 2007. ApJ, 666, 1024

For the original paper describing the Tonry & Davis cross-correlation techniques, check out:

A survey of galaxy redshifts. I - Data reduction techniques [ADS]
Tonry, J. L. & Davis, M. 1979. AJ, 84, 1511

Useful websites

GCC, the GNU Compiler Collection -- includes fortran compilers
Fink -- Unix software for Mac OS X
High-performance computing for Mac OS X -- g77 and gfortran binaries for Mac
Scisoft OSX -- astronomical data reduction and analysis software for Mac (includes PGPLOT)
X11 for Mac OS X -- Implementation of the X Window System for Mac OS X
The MacPorts Project -- compile, install, and upgrade either command-line, X11 or Aqua based open-source software for Mac OS X
PGPLOT -- PGPLOT graphics library; see also Compiling PGPLOT on Mac OS X
BUTTON -- Graphic buttons with PGPLOT


Michael Woodson has invented a stick figure called "Snid" who is the greatest fighter in the world. I requested Snid to fight a supernova, and this is the result (note that you can access the complete series of "Snid vs." comics here):