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velmodel

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NAME

velmodel - Make a model image for a theoretical velocity pattern.  

PERSON RESPONSIBLE

mchw  

CATEGORIES

image analysis  

DESCRIPTION

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 +
        (vrot*cos(theta-pa)+vrad*sin(theta-pa))*sin(incline)
The output image can be combined with an intensity image to make a 3D model using the task VELIMAGE.  

PARAMETERS

in
Input image name used as template for the output image.
region
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.
center
The rotation center in arcsec from the center pixel, measured in the directions of RA and DEC. Default=0,0.
pa
Position angle of the major axis in degrees. Default is 0. (north).
incline
Inclination angle of the disk in degrees. Default is 0. (face on).
radius
Sample points along major axis in arcsecs. Need not be evenly spaced. At least one point must be given.
vrot
Rotation curve in the plane of the disk specified by a power law:
        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.
vrad
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.
vsys
Systemic velocity of the disk. Units are km/s. Default=0. For options=rms, vsys is a constant rms along the line of sight.
z
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.
out
The output image. No default.
options
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.


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

This document was created by man2html, using the manual pages.
Time: 18:35:39 GMT, July 05, 2011