The Intermediate Dispersion Spectrograph (IDS) is a long-slit spectrograph
which sits at the Cassegrain Focal station of the
2.5m Isaac Newton Telescope and is
equipped with a 235-mm focal length camera.
IDS is offered with a set of 16 gratings, and with two CCDs: the blue-sensitive EEV10 CCD (4096×2048 pixels), and the new RED+2 detector
(4096×2048 pixels), more sensitive in the red, which is offered since semester 11A.
Possible grating and CCD combinations
allow dispersions of between 0.24 and 4 Å per pixel. The spatial
scale along the slit is 0.4, and 0.44 arcsec per pixel, respectively for each CCD. The full unvignetted slit length
is 3.3 arcmin.
The SIGNAL program
(S/N calculator) contains reliable updated measurements of the IDS throuhgput
with the two cameras, with an accuracy of some 20%. You can then safely use
it to estimate your exposure times.
Note that IDS will be scheduled in minimum blocks of 4 weeks, as
the ING can only support a small number of instrument changes each
semester. For this reason, we invite the community to present large
programmes to make the best use of the INT (smaller proposals asking no
less than 4 nights are still accepted). IMPORTANT: in
case a long run is going to be covered by several observers, please let us
know well in advance so that student support can be scheduled each time a
new team goes up.
