Quick CRUSH guide for dummies

To reduce GISMO data with crush, first log into your project account:

ssh -X project_number@mrt-lx2.iram.es     

(for project "test" data the project_number is t16. Ask the AoD for the password)

Raw data are stored in the directory ~/observationData/gismo. The scans are stored in a filing hierarchy, organised by source name, then an IRAM scan ID composed of a UT calendar date and a scan number. For example, the scan 113 taken on 2013-04-12 of M33 is stored as:

~/observationData/gismo/M33/2013-04-12.113/M33_2013-04-12.113_gismo.fits

To reduce this scan with crush, type in your terminal:

crush gismo -default -datapath=~/observationData/gismo -object=M33 -date=2013-04-12 113 -outpath=~/crush_reduction -name=M33

Replace -default by one of the following options:

  -deep ! for deep fields when the most agressive filtering of common mode is done
  -extended ! for structures larger than the field-of-view
  -faint ! faint sources (S/N<10) 
  -bright ! bright sources (S/N>1000)

You may also want to use combinations like e.g. "-faint -extended". And don't forget that Attila Kovacs wrote good documentation which is all online on the crush homepage.

It is possible to add several scans:

crush gismo -faint -datapath=~/observationData/gismo -object=M33 -date=2013-04-12 113-116 120 -date=2013-04-13 1-6 -outpath=~/crush_reduction -name=M33_faint_allscans

and also to combine different source-names:

crush gismo -faint -datapath=~/observationData/gismo -object=M33a -date=2013-04-12 113-116 120 -object=M33b -date=2013-04-14 21-23 -outpath=~/crush_reduction -name=M33ab_faint_allscans

For a detailed description of crush's options and capabilities, see the crush documentation.