The second binary table attached to raw files is the Fibre Table. It relates the fibre buttons on
Ozpoz and the fibre positions in the slits, and also includes lab-measured
fibre transmission values. This table is static and is maintained by the
The columns have the following content:
slit name and plate (Medusa1, Medusa2, IFU1, IFU2, Argus)
Progressive position number of fibre in the slit
Fibre position in the subslit
Serial number of the retractor
Serial number of the button used in the retractor
Serial Number of the Fibre used for the button
Retractor position on the plate. This number corresponds to the fibre number used e.g. in FPOSS (target setup file). All even numbers are Medusa fibres.
Fibre Transmission values as measured in the lab (as percentage). Each column has a different wavelength.
X position of the fibre in the reconstructed image matrix
Y position of the fibre in the reconstructed image matrix
fibre position on the detector; for Medusa and IFU identical to FPS, for Argus the order is reversed.
The ARGUS image reconstruction using the X and Y columns for the table
gives the image in the standard NE orientation on the sky. If the ARGUS
position angle was 0 (ARGPOSAN = 0), N is along the X axis and E along the Y
axis. The position angle is counted N to E.
OBJECT,SimCal data only: differential wavelength shifts, applied for differential correction and obtained by the pipeline from the SimCal fibres
OBJECT,SimCal data only: geocentric correction to be applied (in km/s)
like above, heliocentric correction
like above, barycentric correction
The INDEX counts the pipeline-detected fibres. It will always increment by
one. The FPS represents the physical index of the fibres. As long as it
increments along with INDEX, this means that all fibres (up to the present
INDEX have been allocated and extracted. An increment by more than 1 means
that at least one fibre has given no signal, either because it could not be
allocated (fibre broken), or has not been allocated by the user, or had a
signal too low for the pipeline to detect. The last possibility will actually
not happen since fibre signal localization is always done on flat field data,
and if there a fibre gives too low a signal, it can be considered as not
The number of columns in the product files corresponds to the maximum INDEX.
There are no columns for fibres with no signal.