Function: Calibrated and extracted spectrum of a fiber.
Syntax: int_nspec image, reference, fibre_n, bundle, bias, spectrum
Parameters:
Description: This task allows us obtain the calibrated (or non-calibrated) spectrum of the a selected fibre.
Firstly, int_nspec defines and traces the apertures (using apall task) of the flat image (reference image). So, a file with the parameters required to extracting is created in the database directory. The syntax of this file is 'ap' followed by the name of the image (in this case, apflat). If this file is already in existence, the operations will not be repeated.
If the apflat no exists, you have to define the apertures interactively. In principle, int_rec marks all the apertures according to the bundle (SB1, SB2 or SB3). One or more intensive cosmic rays (which can be presented along the spatial profile of the fibres taken like reference for defining the apertures) and be marked instead of the fibres (fainter than the cosmic ray/s). In this case, the user has to delete (typing d) the aperture corresponding to the cosmic rays and mark (typing m) near the center of the aperture corresponding to the faint fibre. The broken fibres (in the case of SB1 and SB2 bundles) have to be marked (typing n) too. Probably you have to order the apertures. For do it, type a for select all the apertures and type o for order them. Help is available on these commands by typing ? (see help of apall for more details). You have not to change the aperture widths because these are conveniently selected by int_rec.
After defining of the aperture positions and widths, they are spectrally traced. In principle, the user can do it operation interactively (for some or all the fibres). Although, the tracing parameters (like the order of the polynomial) are conveniently selected and probably you don't need change them.
Once done the defining and tracing of the apertures, these will be extracted.
Obviously, the apobject file wasn't already in existence. So, you need define, trace and extract the apertures of the object. Like the previous operations have been carried out on the flat field image with the same instrument configuration (same central wavelength, grating and bundle), it is safe to assume that the same extraction parameters will apply. The INTEGRAL/WYFFOS system is very stable, and therefore you can use (like good approximation) the same extraction parameters (we principally refer to tracing parameters) for object than those for the flat. This will be unavoidable (and commendable) in the case of very faint objects.
Finally, a calibrated (or non-calibrated) spectrum of the selected fibre is showed on display. The calibration is done according to the object header parameters. Therefore, the calibration is approximative.
Note that an estimation of the bias level is required to int_nspec.