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himap - Construct galactic XY/TR (Z) MAP from an LV(B) diagram


himap [parameter=value]


himap converts a galactic position-velocity map into a 2D galactic (top-view) surface density map or density cube. The gridding is done in a polar (THETA-RADIUS) or cartesian (X-Y) grid, and if choosen, Z in the vertical dimension. Coordinates are always normalized to the solar radius, which is one of the user definable parameters.

In both a polar (THETA-RADIUS) and cartesian (X-Y) grid the sun is located at (0,1). The sense of galactic rotation is clockwise in the cartesian X-Y, or in increasing THETA in the polar grid.


The following parameters are recognized in any order if the keyword is also given:
Input VL(B) image. This must be an image(5NEMO) file. No default.
Optional output image, will be in image(5NEMO) format. If no name supplied, no output image is generated. Default: none.
Input rotation curve in (ascii) table(5NEMO) format, with radius (in kpc) in column 1, and velocity (in km/s) in column 2. Note that the table will internally be normalized to (r0,v0). No default.
Grid coordinates in image X coordinates, using a nemoinp(3NEMO) list expression. They are either normalized X or THETA, depending on the gridding mode (see below).
Grid coordinates in image Y coordinates, using a nemoinp(3NEMO) list expression. They are either normalized Y or normalized RADIUS, depending on the gridding mode (see below).
Grid coordinates in image Z coordinates, using a nemoinp(3NEMO) list expression. They are normalized with the solar radius (r0, see below). By default only one plane (z=0) is gridded, all emission is averaged in Z (or b for that matter).
Solar Radius in kpc. [Default: 8].
LSR velocity in km/s. [Default: 220].
Output mode: polar (theta,r) or cartesian (x,y). [Default: polar].
Allow pixels to assume the value of the nearest edge, in case they are found outside the VL/LV map? [Default: false].
Optional output table of {theta,radius,l,v,l_grid,v_grid,surden,vrot}. Default: none.

See Also

hispectrum(1NEMO) , image(3NEMO) , fitsccd(1NEMO) , hispectrum(1NEMO) , fitshicube(1NEMO)


Peter Teuben

Update History

19-Feb-93    V0.1 Created        PJT
7-oct-94    V1.1b added near=, more messages    PJT
10-oct-95    V1.2 added zrange= and 3D support    PJT

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