Tech time tasks for NOTCam
JHKs zeropoint monitoring (WF)
On every NOTCam technical night which is clear/photometric, observe one of
the below suggested standard fields at three different air masses in the
range [1,2]. NOTCam imaging is done with the WF camera and the three
filters JHKs. The instrument is setup correctly from the scripts,
and target is acquired. You have to verify that autoguiding is achieved,
and the rest is automatic. A finding chart should pop up on the screen,
but no pointing adjustment should be needed in normal cases.
The standard fields are found in the TCS catalogue
/catalogue/notcamstd.cat but you don't need to load it,
since the script will add and goto target.
Use the sequencer scripts whose names are given in the table. The scripts
make a 5-point (dice) dither for each of the three filters Ks, J, and H,
and adjusts the telescope focus accordingly per filter. The total time
refers to the total time spent doing all three filters.
The designation FS stands for the UKIRT Faint Standards (see Leggett et al. 2006,
MNRAS 373, 781-792 for references and JHK magnitudes.)
Finding charts are obtained by clicking on the field name in the
table. These K-band charts have North up and East left, the FOV is
about 4' x 4', and they are taken from
Hunt et al., 1998, AJ 115, 2594, except for Ser-EC68,EC84 which is a NOTCam image.
The field Ser-std contains the new red standards EC68 and EC84 (see Leggett et al. 2006,
MNRAS 373, 781-792 with J-K colours from 3.57 to 3.99 magnitudes.
The visibility plot of today:
Minimum observing altitude when lower hatch closed: 35 degrees.
To calculate the visibility plot for any date you can cut and paste the following
table into the Staralt program.
as05 02 30 17.5 +05 16 20
as16 07 24 15.4 -00 32 47
as19 08 51 20.2 +11 52 43
as26 13 41 45.4 +28 29 50
as33 18 27 13.6 +04 03 10
ser 18 29 55.4 +01 13 11
as40 23 58 50.2 +61 10 02
Illumination correction data
A model of the illumination correction for the H-band has already been made
by Joachim Janz and is published in Janz et al. 2013, submitted. We still
need to take data in photometric conditions to map the J band.
Do as follows:
- Point to a field in the catalogue "notcamstd.cat" at airmass < 1.5.
Use preferrably AS16, AS26 or AS33. Only if fwhm > 1.2'' can you use AS40.
- Use the guide area called NOTCam-Be-NS (see Cookbook for how-to).
- In directory ~/scripts/staff/amanda/ use the script "fov.script"
which does a 5x5 dither with two exposures per position, each with the
command ''frame 3.6 2''. The script takes ~ 1000s to run. Offset ~ 5''
randomly and repeat. Repeat as many times you can. We need about 15 times
per filter, which can be distributed over several nights.
For the Ks band we have a total of 4 + 2 + 7 + 2 = 15 scans.
For the J band we have a total of 5 + 4 + 3 = 12 scans.
Vignetting of narrow-band filters
Check vignetting of narrow-band filters because of the fact that they
are mounted tilted and in the parallel beam. Find a star with a strong
emission line in e.g. Brackett gamma, for instance:
X-Per RA=03:55:23 DEC=31:02:45 (J2000) V=6.1mag
and scan the star across the FOV using the Br gamma narrow band filter
(#209). Use a 5x5 dither. A script is found in ~scripts/staff/amanda/ and it
is called fov.script, but you may have to adjust to a shorter exposure
time than the "frame 4 8".
Check the calibration and performance of the focus pyramid by running the
where exptime is the suitable exposure time for the focus star you
have selected high in the sky (with no pyramid in the beam). For a typical
exptime of 10 seconds, the whole script takes about 30 minutes.
Alternating images are taken with the focus pyramid in and out scanning
the focus range of +-150 units around initial guess-focus. The exptime is
multiplied by 4 for the images taken through the focus pyramid. Make sure
the instrument setup is correct before starting. Use Ks filter. Set the
tcs.focus-position to your initial guess and tcs.focus-delta to zero.