Useful Intermediate Displays
Continuum and Line Removal
- spectra ""
- List of file names of spectra to analyze.
@filename indicates list should come from file filename.
filename[range] indicates that a range of apertures in a multispec
file should be processed, where range is a comma- and/or
hyphen-separated list of numbers.
- specnum 0
- If this is nonzero and spectra contains
a single file name, this is
a range of spectrum numbers in a multispec file which will be cross-
correlated. Wavelength dispersion information is read from the header
parameter APNUMn, and velocity information is read from APVELn. In a
non-multispec file, radial velocity is read from the VELOCITY header parameter.
- specband 0
- If this is nonzero, it is the band from the multispec file(s) specified by
spectra which will be summed.
Wavelength dispersion information is read from APNUMn, where n
is the aperture specified by specnum or the WCS
keywords. Velocity information is read from APVELn.
(New in version 2.0)
- specdir 0
- Directory containing spectra to analyze.
- fixbad no
- If "yes", remove wavelength-delimited regions listed in the file specfied
by badlines. (added in version 2.0)
- File containing list of starting and stopping wavelengths in Angstroms
for removal of portions of all object spectra if
fixbad is yes. All information after
the second wavelength is a comment field. This file is assumed to be in
the directory linedir unless a complete
pathname starting with "/" is specified. (added in version 2.0)
- linedir "rvsao$lib/"
- Directory containing line list file named by
This parameter is ignored if:
- that filename contains a "/" in the first
column, as it is assumed to be a full pathname,
- if there is a "/" anywhere else in the filename, as it is assumed to
be a path relative to the current working directory, or
- if there is a "$" in the filename, as the part preceding the "$" is
assumed to be an IRAF environment parameter (ending in "/") defining a
- renormin no
- If true, the data spectrum is divided by its mean value before being
processed. Use this on spectra which have unusual data values such
as those produced by flux calibration.
- compobj ""
- Object name for resulting composite spectrum.
- compfile ""
- Output file name for resulting composite spectrum.
- compdir ""
- Directory for output composite spectrum
- nspec 1
- Number of spectra in output file. If =1, the spectra are added together
if a value is given for compobj. If >1, the spectra are stacked in
the output file using the same dispersion function.
- renormout no
- If true, the data spectrum is divided by its mean value after being
rebinned and having its continuum removed. This is useful if it is desired
that all spectra in the sum be treated equally.
- save_names yes
- If true, save the names of the files summed or stacked into the
output file in that files header as HISTORY lines if unshifted or
shifted into the rest frame and as VSKYn keyword values if the spectra
are shifted to the observation frame.
- st_lambda INDEF
- Starting wavelength in angstroms of portion of spectrum to correlate.
If INDEF, use beginning of wavelength overlap between input spectra.
- end_lambda INDEF
- Ending wavelength in angstroms of portion of spectrum to correlate.
If INDEF, use end of wavelength overlap between input spectra.
- ncols 2048
- Number of columns into which to rebin data before transforming. If it is
zero, the wavelength range of the overlap between all of the input spectra
is printed and no output file is written. The velocity coverage of each
individual spectrum is computed after shifting to
velocity, if it is set, or without shifting if
velocity is INDEF).
- complog no
- If yes, rebin into log wavelength; otherwise, rebin into linear wavelength.
- interp_mode "spline3"
- Interpolation mode to use when rebinning spectra, must be
"linear" or "spline3" or "poly3" or "poly5" or "sums".
- normout 0.0
- If 0, do not renormalize the rebinned spectrum or spectra. If nonzero,
normalize the spectrum so the mean is equal to this value.
- spec_plot no
- If yes, plots of the individual spectra are displayed. During this time the
normal IRAF cursor commands are active as well as several more that are
itemized below. If emission lines are chopped, before and after plots
are displayed, as well as the chopped line(s).
- spec_int no
- If yes, pause in cursor mode after
each input spectrum has been plotted.
- comp_plot no
- If yes, a plot of the composite spectrum is displayed after each input
spectrum is added.
Cursor commands are activated, and a portion of the spectrum may be viewed
using the keystroke \fIz\fR at each end of the wavelength region to be viewed.
Hard copies to stdplot may also be made using the \fI@\fR command.
- comp_int no
- If yes, pause in cursor mode after
the composite spectrum has been plotted.
- Set continuum fitting parameters in the
- cont_remove no
- Remove continuum from input spectra if not "no". If "subtract",
subtract continuum. If "divide", divide by continuum. If "zerodiv",
divide by continuum and subtract 1. This last should be used instead
of "divide" if the file is to be cross-correlated. In version 2.0,
"divide" subtracted 1; in version 2.1b15 and later, it doesn't, and
the "zerodiv" option was added.
- reject no
- Chop out emission lines from object spectrum before adding them to the
template if " yes". If EMCHOP in a spectrum file is 1, emission
lines are not removed from that spectrum. If "no", emission lines are not
- abs_reject 100.0
- Input spectrum absorption line rejection in sigma of fit
- em_reject 2.0
- Input spectrum emission line rejection in sigma of fit
- cont_plot yes
- If yes, plots of the continuum-subtracted input spectra are
displayed. This is most useful for determining the appropriateness of
the continuum fitting parameters set above and in
- cont_add 0.0
- Continuum level added to final template spectrum to keep all flux
above zero, for example.
- velcomp INDEF
- Velocity in km/sec to which to shift individual spectra. If both
velcomp and zcomp are set to INDEF, the spectra
are not shifted.
- zcomp INDEF
- Delta lambda / lambda to which to shift individual spectra.
This is useful for making spectra for very distant objects and supercedes
velcomp if it is not INDEF. Wavelength limits are not changed.
- svel_corr "barycentric"
- Spectrum velocity correction to the solar system barycenter. Set to
"none" if spectrum has already been shifted or if this correction is
unnecessary. If "file", BCV is used if present in the file header,
or else HCV. If "hfile", the header parameter HCV is always
used. If neither is found, no correction is made. If svel_corr is not
set to "none", but velcomp and zcomp are INDEF, data is shifted to the
barycentric velocity correction of the first spectrum, if it has one.
- If "heliocentric"
or "barycentric" corrections are chosen, position and time parameters
are read from the spectrum data file header. DATE-OBS (date in
format 'dd-mm-yy') UT (U.T. at end of exposure as 'hh:mm:ss')
and UTOPEN (U.T. at start of exposure as 'hh:mm:ss') or
EXPOSURE (length of exposure in seconds) are used to compute
the midtime of the exposure. RA (right ascension as 'hh:mm:ss.ss'),
DEC (declination as 'dd:mm:ss.ss'), and EPOCH (epoch of
coordinates defaults to 1950.0) give the position of the object whose
spectrum this is. SITELONG (observatory longitude as 'dd:mm:ss.ss'
or degrees), SITELAT (observatory latitude as 'dd:mm:ss.ss' or
degrees), and SITEELEV (observatory altitude in meters) give the
- nsmooth 0
- If >0, the data spectrum is smoothed this many times when it is graphed.
- device stdgraph
- Interactive device on which to display a graphic summary of
- hardcopy yes
- Display graphic summary of results on plotter.
- plotter stdplot
- Second, non-interactive device on which to plot the graphic summary of results.
- logfiles STDOUT,sumspec.log
- All results from SUMTEMP are recorded in these files.
- debug no
- If yes, values of the parameters fit to the selected peak
are recorded in the log files. This is most useful for debugging.
the order of the polynomial chosen to fit the continuum.
- cursor ""
- Graphics cursor input. When null the standard cursor is used otherwise
the specified file is used.
Last updated 23 August 2021 by Jessica Mink