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Basic Information on velmodel
Purpose: Make a model image for a theoretical velocity pattern.
Categories: image analysis
VELMODEL generates a MIRIAD image for a theoretical velocity
pattern specified by model input paramaters. The default option
is to make an image of the line-of-sight velocity corresponding
to a rotating disk model:
velocity = vsys +
The output image can be combined with an intensity
image to make a 3D model using the task VELIMAGE.
Input image name used as template for the output image.
Region of image to be used. The default region is the entire
image. See documentation of region for details. All pixels
within the bounding box are used; pixel masking is ignored.
The rotation center in arcsec from the center pixel, measured
in the directions of RA and DEC. Default=0,0.
Position angle of the major axis in degrees. Default is 0
Inclination angle of the disk in degrees. Default is 0 (face
Sample points along major axis in arcsecs. Need not be evenly
spaced. At least one point must be given.
Rotation curve in the plane of the disk specified by a power
rotation velocity = vrot(1)*(r/radius(1))**vrot(2)
At least one point must be given. For options=sample, vrot
gives the rotation velocity sampled at the radius points above,
and is interpolated between the sample points, with zero
velocity at zero radius, and not extrapolated beyond the last
point. Units are km/s.
Radial velocity in plane of disk specified by a power law:
radial velocity = vrad(1)*(r/radius(1))**vrad(2)
Default=0,0. If only one value given then vrad = vrad(1)
Units are km/s.
Systemic velocity of the disk. Units are km/s. Default=0.
For options=rms, vsys is a constant rms along the line of sight.
Thickness of disk, and power law: z' = z(1)*(r/radius(1))**z(2)
Default=0,0. If only one value given then z' = z(1). The units
of z(1) are the same as arcsec along major axis of disk.
The output image. No default.
rms The output image is the rms calculated from vsys and
the rms velocity along the line of sight, computed by
integrating through the disk thickness given by z.
sample The rotation velocity is specified by values vrot
sampled at the radius values. Default is power law.
Generated by email@example.com on 14 Sep 2016