MIKE – Calibrations
Here we provide some reference numbers for calibrations with MIKE
Note: Be aware that every time MIKE is installed the position of the quartz lamp might change slightly leading to 10% fluctuation of the counts. If the counts are a lot less than what reported in the tables below, it means that the lamp is not aligned with the slit. In such case please inform the daytime crew.
Flats: Internal Quartz lamps – binning 2×2 – speed fast (updated July 2018)
Milky flats: same configuration as above but with the diffuser inserted (updated July 2018)
Sky flats: to be done in daytime with louvres open at
50% and flat screen in. The following exposure times give between 35000
and 45000counts at peak (2×2 binning, speed fast). This results to
~600counts above background on the less efficient part of the blue side
and ~1500counts for the red side.
Blue flats: The internal incandescent lamp is fine on the red side of MIKE, but it does not supply much light for the blue side. For that reason, we STRONGLY suggest that you take some milky flats during twilight using an O or B star. It is a good idea to take half of the flats with the star at one end of the slit, and half with the star at the other end of the slit. The best stars for this purpose are stars with high rotational velocities – high v*sin(i). There is a catalog of such stars with the Telescope Operators (“high_vsini_obscat.cat”). A star with V=4-5 mag gives very good flats in about 25 sec per exposure. For more details please consult the manual.