Additional tips for AIPS
Start AIPS remotely
aips tv=local
Switching the velocity reference system
To define the relationship between frequency axis and radial velocity in one’s favourite reference system one can use the verb
ALTDEF
The required parameters of ALTDEF are displayed by the command INP ALTDEF. Typical inputs for an H Ⅰ data set could be
GETN n
AXTYPE 'RAD LSR'
AXVAL vlsr,0
AXREF refpix
RESTFREQ 1.420E+9,405752
ALTDEF
After having defined the frequency-velocity relationship with ALTDEF one can use the verb
ALTSW
to change the spectral axis type from frequency to velocity (and back again) before computing moment maps of a data cube (but after imaging and deconvolution).
Computing moment maps
Before moment maps of a data cube can be created, the cube has to be transposed to change the order of spatial and velocity axes. This is done by the task
TRANS
where the correct axis order (312) can be specified. After changing the axis order, moment maps can be computed using the task
MOMNT
(Caution: For unknown reasons the developers of AIPS decided to omit the “E” in the name of the task!)
Other useful commands
Clear the read/write status flags of files:
CLRSTAT
Delete tables:
EXTD
Shut down all servers and message windows and exit from AIPS:
KLEENEX