Now that your labors have been rewarded with a fully reduced spectrum,
you will want to look at it. This can be done using the
redgspec task by setting the plot flag. This calls the IRAF
splot task which allows interactive viewing and analysis of the
spectrum. Users should consult the help pages for this task for a
full description of its capabilities (type help splot | lpr).
Type a to expand and autoscale the plot to a data range given by
two cursor positions. Type w to window the graph. Type b
to toggle setting the plot baseline to zero rather than autoscaling.
Type c to clear all windowing and redraw the full spectrum.
Type e to measure the equivalent width directly from the data.
Type h to measure the equivalent width assuming a Gaussian
profile. Type k to mark two continuum points and fit a single
Gaussian function. The reported flux is divided by 1000 to convert to
W cm 
. Type d to mark two continuum points and fit
multiple Gaussian functions. Type - to subtract the fit from
the spectrum. Type t to fit a function to the spectrum using
the IRAF icfit task. Type m to compute the mean, RMS, and
signal-to-noise ratio over a region marked by two cursor positions.
Type l to convert from 
to 
units. Type
n to convert from to units. Type
p to define a linear wavelength scale. Type u to adjust the
wavelength scale interactively. Type v to convert to a velocity
scale. Type j to change the data values using the cursor. Type
s to boxcar smooth the spectrum. Type f to do arithmetic
function manipulations. Type i to save any modifications to a
file. Type g to get a new spectrum. Type o to overplot a
spectrum. Type r to redraw the plot. Type :hist yes/no
to enable/disable histogram line type plotting. Type = to make
a hardcopy of the plot. Type q to exit.
The full set of splot cursor commands, and the standard IRAF cursor mode commands that are also available, are listed below.
SPLOT CURSOR COMMANDS
? - This display r - Redraw the current window
/ - Cycle thru short help on stat line s - Smooth (boxcar)
a - Autoexpand between cursors t - Fit continuum (see below)
b - Toggle base plot level to 0.0 u - Adjust coordinate scale
c - Clear and redraw full spectrum v - Velocity scale (toggle)
d - Deblend lines using Gaussians w - Window the graph
e - Equiv. width, integ flux, center x - Connects 2 cursor positions
f - Arithmetic functions: log, sqrt... y - Plot std star flux from calib file
g - Get new image and plot z - Expand x range by factor of 2
h - Equivalent widths (see below) ) - Go to next spectrum in image
i - Write current image as new image ( - Go to previous spectrum in image
j - Fudge a point to Y-cursor value # - Select new line/aperture
k - Gaussian fit to single line % - Select new band
l - Convert to F-lambda $ - Toggle wavelength/pixel scale
m - Mean, RMS, snr in marked region - - Subtract deblended fit
n - Convert to F-nu , - Down slide spectrum
o - Toggle overplot of following plot . - Up slide spectrum
p - Convert to wavelength scale I - Interrupt task immediately
q - Quit and exit <space> - Cursor position and flux
For 'h' key: Measure equivalent widths
a - Left side for width at 1/2 flux l - Left side for continuum = 1
b - Right side for width at 1/2 flux r - Right side for continuum = 1
c - Both sides for width at 1/2 flux k - Both sides for continuum = 1
For 't' key: Fit the continuum with ICFIT and apply to spectrum
/ = normalize by the continuum fit
- = subtract the continuum fit (residuals)
f = replace spectrum by the continuum fit
c = clean spectrum of rejected points
n = do the fitting but leave the spectrum unchanged
q = quit without fitting or modifying spectrum
For 'u' key: Adjust the coordinate scale by marking features
d = apply doppler correction to bring marked feature to
specified coordinate
l = set linear (in wavelength) coordinates based on two marked features
z = apply zero point shift to bring marked feature to
specified coordinate
The colon commands do not allow abbreviations.
:# <comment> - Add comment to log file
:dispaxis <val> - Change summing parameter for 2D images
:log - Enable logging to save_file
:nolog - Disable logging to save_file
:nsum <val> - Change summing parameter for 2D images
:show - Show full output of deblending and equiv. width measurments
:units <value> - Change coordinate units (see below)
:auto [yes|no] - Enable/disable autodraw option
:zero [yes|no] - Enable/disable zero baseline option
:xydraw [yes|no] - Enable/disable xydraw option
:hist [yes|no] - Enable/disable histogram line type option
:nosysid [yes|no] - Enable/disable system ID option
:wreset [yes|no] - Enable/disable window reset for new spectra option
:flip [yes|no] - Enable/disable dispersion coordinate flip
:overplot [yes|no]- Enable/disable permanent overplot mode
UNITS
The units are specified by strings having a unit type from the list below
along with the possible preceding modifiers, "inverse", to select the
inverse of the unit and "log" to select logarithmic units. For example "log
angstroms" to plot the logarithm of wavelength in Angstroms and "inv
microns" to plot inverse microns. The various identifiers may be
abbreviated as words but the syntax is not sophisticated enough to
recognized standard scientific abbreviations such as mm for millimeter.
angstroms - Wavelength in Angstroms
nanometers - Wavelength in nanometers
millimicrons - Wavelength in millimicrons
microns - Wavelength in microns
millimeters - Wavelength in millimeters
centimeter - Wavelength in centimeters
meters - Wavelength in meters
hertz - Frequency in hertz (cycles per second)
kilohertz - Frequency in kilohertz
megahertz - Frequency in megahertz
gigahertz - Frequency in gigahertz
m/s - Velocity in meters per second
km/s - Velocity in kilometers per second
ev - Energy in electron volts
kev - Energy in kilo electron volts
mev - Energy in mega electron volts
z - Redshift
The velocity and redshift units require a trailing value and unit defining the
velocity zero point. For example to plot velocity relative to
a wavelength of 1 micron the unit string would be:
km/s 1 micron
SET GRAPH WINDOW COMMANDS
a Autoscale x and y axes
b Set bottom edge of window
c Center window at cursor position
d Shift window down
e Expand window (mark lower left and upper right of new window)
f Flip x axis
g Flip y axis
j Set left edge of window
k Set right edge of window
l Shift window left
m Autoscale x axis
n Autoscale y axis
p Pan x and y axes about cursor
r Shift window right
t Set top edge of window
u Shift window up
x Zoom x axis about cursor
y Zoom y axis about cursor
z Zoom x and y axes about cursor
STANDARD IRAF CURSOR MODE COMMANDS
Cursor Mode Keystrokes
A draw and label the axes of current viewport
B backup over last instruction in frame buffer
C print the cursor position
D draw a line by marking the endpoints
E expand plot by setting window corners
F set fast cursor (for HJKL)
H step cursor left
J step cursor down
K step cursor up
L step cursor right
M move point under cursor to center of screen
P zoom out (restore previous expansion)
R redraw the screen
T draw a text string
U undo last frame buffer edit
V set slow cursor (for HJKL)
W select WCS at current position of cursor
X zoom in, X only
Y zoom in, Y only
Z zoom in, both X and Y
< set lower limit of plot to the cursor y value
> set upper limit of plot to the cursor y value
\ escape next character
: set cursor mode options
:! send a command to the host system
= shorthand for :.snap (make graphics hardcopy)
0 reset and redraw
1-9 roam
Cursor Mode Commands:
:.axes[+-] draw axes of viewport whenever screen is redrawn
:.case[+-] enable case sensitivity for keystrokes
:.clear clear alpha memory (e.g, this text)
:.cursor n select cursor
:.gflush flush plotter output
:.help print help text for cursor mode
:.init initialize the graphics system
:.markcur[+-] mark cursor position after each cursor read
:.off [keys] disable selected cursor mode keys