June 2000 Observing Plan
version 0.1 2000-June-14; 02:40am(rgm@int)
Run dates: Mon June 12 to Thur 22 June, 2000
- 12-15 ELAIS CAT(INT/00A/C16: Perez-Fournon)
[ Proposal ]
- 16-22 Survey PATT(INT/00A/P16: McMahon)
[ Proposal ]
Note this ELAIS CIRSI CAT survey proposal is different from the
ELAIS CIRSI ITP survey proposal. In the ITP run in May we did
a shallow survey with an exposure time of 10mins in H whereas
in the June CAT run the goal is to go deep in a single 4-pointing
tile.
How much time do we have available
Each night there is 6.9hrs between astronomical twilight. However we may
be able to get 7.9hrs is we observe between 12degree twilights. We should
aim for this. This means do a snafu on a V=5 star soon after sunset.
Lets assume 7hrs per night and 50% of time is used for science observations.
This gives:
Other useful material:
The first stab at an observing plan for the June PATT run is as follows:
- complete 3x3 CIRSI raster in ELAIS N1 and N2 regions in H to
the same depth as the ITP survey
- ITP time has covered 10 of the 18 tiles
- 3.92 deg^2
- Observing strategy:
- 4 loops of 30sec
- 5 dithers
- 4 macro-steps
- on sky time is 10mins per pointing
- to do 8 tiles requires 32 pointings
- total on sky time needed is 320 minutes
- with overheads this will probably take two nights
In our PATT proposal we proposed to expose for 300seconds. I propose
to use 360seconds as outlined in the next section. This will amount
to 192 minutes
- extend the raster in N1 in H to cover full 3deg x 3deg region
- This is 36 CIRSI tiles or 144pointings
- 9 will be done when we complete the ELAIS-ITP region
- One simple strategy would be to do 4pt dithers with 3 loops of
30seconds per dither
- This would give 360seconds per pointing.
- A tile would then take 1440seconds on sky => 48minutes assuming
50% overheads.
- To cover the 27 tiles would then take 1296minutes
- get some coverage in J. A decision on this needs an assessment
of the J throughput and J background
- Observe some XMM fields in J and H
- 10 53 23.1 +57 32 57 J2000.0:
highest priority is the Lockman-1 field. This field
is a deep XMM pointing that will go public on July 10th. Lots of
PR possible, especially if we do the field properly during the WFC
run.
- aim for 10mins per pointing per night in 3 pointings from the
the full tile
- cycle through the pointings for 2-3 nights in H and then repeat
in J.
- aim for 20mins per band per pointing
- maybe it would be better to do 3 dithers per night and
cover all 4 pointings in a tile
- However please start the second night on the 3rd pointing
of the tile so that when the data is conbined the data is
more uniform
- Get J and H images of 1 Feltzing/Gilmore/Wyse galactic clusters that
were observed in a previous PATT run
- say 5mins per pointing per band in one cluster
- will take an elapsed time of around 1hr per band
- Get J and H raster of WFC field of the z=0.583 galaxy cluster MS 2053.7-0449
- 2240+0000 WFS region; concentrate on region covered in CFHT survey
- go deep in 1deg x 1 deg region in J and H
- shallow scan in WFS region with extant data: 2200 to 2300 will give
15 deg x 0.3deg high => 7.5deg^2
What did we say we would do in our proposal
- we said we would expose for 300second per pointing
- assumed 8.4hrs per night scheduled in mid-May; this
should have said 7.4hrs!
- 40% observing efficiency
- asked for 14nights of 8.4hrs => 117.6hrs
- proposedto cover 25deg^2 in J and H.
- actual allocation was 7 nights of 6.9hrs => 46.2hrs
- i.e. 39.3% of requested amount
How do we get some J coverage
To get some J we have a number of options;
- descope of the H coverage
- reduce the H band exposure times
- reduce the observing overheads
One option would be to cover 1.5degx1.5deg regions in the ELAIS N1
and N2 regions in J for 360secs per pointing. This would give us
around 4.5deg^2 of J data. It would require:
- 72 pointings of 360seconds
- 432minutes on sky
Going shorter than 360seconds with the current CIRSI software is
quite inefficient. I will write more on this when I have analyzed
my timing tests.