ISOCAM Interactive Analysis User's Manual Version 5.0 - ISO - ESA

102 CHAPTER 13. DATA CALIBRATION
13.2.5 CVF analysis
Unlike the raster PDS or BS PDS there is no MOSAIC to create in a CVF PDS– the most
interesting information is spectral rather than spatial. Since each EXPOSURE was observed at
a different wavelength, spectra can be obtained directly from EXPOSURE pixels. Since most
observers would like their calibrated spectra to be in janskys CIA provides conv flux to convert
the EXPOSUREs pixels from ADU to mJy.
CIA> conv_flux, cvf_pds, /image
To get a look at the calibrated CVF data use cvf display.
CIA> cvf_display, cvf_pds
By using the mouse to point and click on selected EXPOSURE pixels you can display spectra.
See Section 14.2.1 for more information on cvf display.
13.3 Data calibration with x cia
This section 2 serves as an introduction to the widget interface to CIA, x cia.
13.3.1 Introduction
x cia was designed to help visitors of ‘Centre ISO français du CEA-Saclay’ to become familiar
with ISOCAM data analysis quite rapidly. Once ISOCAM data has been sliced/prepared, a
standard quick look analysis can be performed (Section 13.3.2). ISOCAM data are mainly
affected by the dark current, cosmic ray impacts, transient effects and flat-field errors. Correction
of one of these effects is usually the result of several runs (Section 13.3.3). Note however, that
not all CIA processing steps are available to x cia.
Some advanced functionality is available but should only be used by advanced users of x cia
(Section 23). Guidelines to help the user to choose the most appropriate processing methods
are given in Section 20. These guidelines are based on the joint experiences of all support
astronomers of ‘Centre ISO français du CEA-Saclay’ and they are very likely to evolve as new
methods are available. A general help on x cia is presented in Section 23.2.
13.3.2 Quick Look analysis with x cia
It is strongly advised to read Chapter 8 of the ISOCAM Handbook, in order to inform oneself
about the calibration of ISOCAM images. The final calibrated images are indeed the result of
many attempts. Nevertheless, it is very useful to get a rough idea of what ISOCAM has detected
or to check that saturation has not occurred. In that sense, the following commands can be
considered as the standard quick look analysis:
1. Start a CIA session
2. Type the following on the CIA command line:
CIA> x_cia
2 Taken from Claret A., 1996, ISOCAM Data Analysis with X CIA, v2.2, Sections 1-3.