Content-type: text/html Manpage of cotra

cotra

Section: User Commands (1)
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NAME

cotra - Coordinate transformations  

PERSON RESPONSIBLE

pjt  

CATEGORIES

utility  

DESCRIPTION

COTRA is a MIRIAD task to transform between astronomical coordinate systems. The coordinate systems must be one of: equatorial, galactic, ecliptic, super-galactic

For given galactic longitude,latitude, it also shows three conversions for common velocity frames of reference: dVlsr = Vlsr - Vbsr (BSR = Heliocentric) dVgsr = Vgsr - Vlsr dVlgsr = Vlgsr - Vgsr

In addition, several conversions between doppler velocities can be calculated (optical, radio, relativistic)  

PARAMETERS

radec
Input RA/DEC or longitude/latitude. RA is given in hours (or hh:mm:ss), whereas all the others are given in degrees (or dd:mm:ss). There is no default.
type
Input coordinate system. Possible values are "b1950" (the default), "j2000", "galactic", "ecliptic" and "super-galactic". b1950 and j2000 are equatorial coordinates in the B1950 and J2000 frames. All other coordinates are in the B1950 frames.
epoch
Epoch (in standard Miriad time format) of the coordinate. Note that this is distinct from the equinox of the coordinate as given above. Varying epoch changes the coordinate values by less than an arcsecond. The default is b1950.
uvw
Standard Solar motion in right handed UVW coordinate system. The classic value of 20 km/s toward RA,DEC=18h,30d corresponds to uvw=10.3,15.3,7.7 but is using too high a value for V. A bettter, Hipparchos based, value would be uvw=10.0,5.2,7.2 Default: 9,12,7
theta0
LSR speed in km/s. Default: 220 The GSR motion (-62,40,-35) is currently hardcoded.
z
Redshift (unitless) or velocity (km/s). If velocity is given, the optical or radio definition in a 2nd argument needs to be specified. Valid are Default : 0
restfreq
Rest frequency of a spectral line in GHz. Default: 115.271204 (the CO 0-1 transition)


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

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Time: 18:35:38 GMT, July 05, 2011