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Special Calibs |
Last update of this page: Mon Dec 22 15:41:38 2008
Run State: TERMINATED/PO
USD review status:
O.K.!
| Pre-Imaging? | Special-Calibration? | Time-Critical? | ToO/GTO/Large program? | Carry-Over? | |
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Special Remarks:
NO REMARKS
Abstract for MTS:
This run has been completed once, but the data were of inferior quality so the PI
has been granted a re-execution. Several issues were listed in the README and in
the MTS comments (old MTS can be found below this). One thing has changed for this
re-submission. We managed to convince the PI that the OBs did not need to be that
long, but could be executed as a single sequence of 3 OBs. So, all the comments are
still correct, except that rather than a single OB there are now 3 OBs that need
to be executed back-to-back on a single night. PA must be set manually between each
OB.
There are also some STD OBs to be executed as described in the README.
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For info, here I also copy the email from the PI discussing the problems with the
previous data-set:
We have decided to agree to split the OB into three separate OBs and
have now uploaded them via p2pp. I have also ammended the finding chart
as best I can. This new finding chart is attached to all three new
OBs: PKS1549-79_sw1p3-a, PKS1549-79_sw1p3-b, PKS1549-79_sw1p3-c.
We would like to stress again that we believe inserting the parallactic
angle manually is not the source of the fault. The target was acquired
using an R band filter and so if the slit was correctly centred on the
peak of the R band filter, the spectrum should at least be bright in this
region. However, this is not the case and the overall spectrum is weak
AT ALL WAVELENGTHS and all spectra are similar.
We have also looked at the acquisition frames for this object. Looking at
the first frame, the image on the sky
taking a slice across PKS 1549-79 shows a peak count in the nuclear
regions (after a basic background subtraction) of ~6000 counts at ~pix
2312,250. Inspection of the image through the slit
shows a very faint region of emission in the slit at Y positions ~220-240
(slit X position is ~2312-2319) which has a peak flux (again, after a
basic background correction) ~750 counts at the right-edge of the slit
region. This is almost a factor of 10 lower than we expect despite the
same exposure time and set up.
Hence, this is consistent with the target not being correctly centred
in the slit at the time of acquisition rather than to do with manually
setting PAs etc. For the new observations, please align the slit with
the centroid of the emission from PKS 1549-79 to correctly acquire the
nucleus in the slit.
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Old MTS comment (per78)
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I recommend to read the entire README file carefully for this run before starting
to execute it. Note the three issues:
(1) long OBs
(2) sequencing of OBs (science + special calibrations)
(3) observer needs to calculate and manually set the PA of the slit
Two waivers were accepted for this run, one for the long OBs (3 hours 22 mins), and
one for the request to set the slit PA manually. The PI insists that both are
indisputable requirements for success of the project, so I think we need to accept
this and execute the OBs the way it is described in the README. This means a
sequence of a long OB on target, a special calib OB, one (or two) of the three
submitted spectrophot OBs, and another set of spectrophot OBs as per standard
calibration plan. All of this needs to be done on the same night.
Here is the link to the par-ang online calculator:
http://www.sc.eso.org/%7Et2p2web/WebTools/1p54/ParAng/
README of this run:
Web version of approved README readme_78053700.html