Deep WFC and CIRSI observations of ELAIS XMM
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From this page we will summarize the observations carried out to observe the ELAIS XMM N1 and N2 regions using the WFC and CIRSI cameras. Also we will have updated information on the reduction procedures and status.
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(color image of a ~1'x1' region in N1)
ELAIS XMM areas
Below the coordinates of the two deep XMM pointings in N1 and N2. These are also coincident with the Chandra observations. Region XMM N2 is also partly covered with SCUBA. No plans to observe XMM N1 with SCUBA.
XMM N2 -- 16:36:48.48 +41:01:45.9 XMM N1 -- 16:09:51.12 +54:33:21.6
Next pictures show the position of these areas in the ELAIS fields. The blue mosaic correspond to the WFC data, the red square to the CIRSI observations and the pink circle to the XMM area. Dotted circles show the radio coverage. [ELAIS N1] [ELAIS N2]
Deep WFC Observations: June 30th to July 2nd
The coverage of the WFC in each of the N1 and N2 XMM regions is shown in next plots, for N1 and N2. The dashed square shows the region covered by the Chandra observation. Since the rotation angle of this field is dependent of the actual time of observation, the inner circle encloses the Chandra region independent of this rotation angle. The outer circle shows the region that will be covered by the deep XMM observations.
The observing strategy was to do a 9 point dither on each of the fields. The first night and half of the second we used a dither pattern of 5 arcsec saparation between each dither. Some technical problems with the dither script ended with a irregular dither pattern (see problems below). After that we changed to a 20 arcsec separation between dither, although some problems remained (see below). The final dither script, with all problems solved I hope, is here. We used the three broad band filters g', r' and i' and tryed to get at least 1.5 hours in each.
The last two hours of every night the ELAIS fields were below airmass 1.5 so we decided to observe the SIRTF First Look Survey (Verification Survey) in all the tree bands.
Next table summarizes the WFC deep observations carried out in the ELAIS XMM regions. Click on the dates to have a table summarizing the status of the reductions done.
|Date||XMM N1||XMM N2||FLS VS||logfiles|
|20000630||-||-||-||-||60 min||90 min||-||-||30 min||log|
|20000701||-||90 min||-||50 min||50 min||-||50 min||-||-||log|
|20000702||60 min||-||130 min (1)||50 min||-||-||-||50 min||-||log|
|(1) Includes 30 minutes observing at 5' from the central position (do not why).|
|Date||g' band||r' band||i' band|
Known problems known while observing
- First half of observations have a dither pattern of 5 arcsec separation between dithers. We are not sure about how many different pointings have been completed since it happened that after giving the command to move the telescope, it returned to the original position.
- Expusures tipically started 20 seconds after the telescope moved to the new pointing in the dither. After looking at the images, we realized that there is an object nearby every bright star due to a telescope jump while beginnig autoguiding. To solve this we increase the time between moving the telescope and begining of a new exposure to 1 minute. This was only solved tha last few hours of the last day so this problem is expected to happen in almost all frames.
Aids for reductions
- MSCRED guide
- Stacking images (from MSCRED guide)
- Mosaic Photometry (from Phil Massey)
- WFS Pipeline Processing
- IRAF IMSURFIT
- IRAF MSCIMAGE
- IRAF PARAPREDRIZ
- IRAF DRIZZLE
- Images of all science frames after pipeline processing.
- Defringing i' band images.
- Stacking images: N2 XMM g' band
- Final Mosaiced Images
Deep CIRSI Observations: June 12th to June 15th
The strategy is to observe both ELAIS XMM fields in the H band (with N2 as higher priority than N1) for at least 60 minutes and then in the J band if possible. To cover a 30'x30' area we need 4 CIRSI pointings. For each of these pointings we used a dither pattern of 5 positions separated by 15 arcsec. These dither positions consist in 4 readouts of 30 secons each. Then, we observed 4x30=120 secons per dither and 120x5=600 seconds (10 minutes) per pointing. Then we moved to the next pointing until we cover 10 minutes in all the 30'x30' area. After that we go for another 10 minutes mosaic.
- June 12th. We started the run with good weather. After some tests, we began obtaining exposures for the 9166 standard star in Jc, Jd and H. Then moved stright to ELAIS N2. We did 40 minutes in this field (one pointing, position D has only 30 minutes) in the H band. After some reductions of this data we decided to change the gain and readout speed of the detector for the next nights, since some saturation problems appeared in the frames. Despite this, we expect to be able to coadd these data with the ones obtained the next night.
- June 13th. We concentrated again in ELAIS N2 in the H band and observed 50 minutes in this field.
- June 14th. We moved to N1. We completed at least 30 minutes of good data in H band. Some clouds appeared that covered the sky later on. We need to check how much of the data after these 30 minutes is usable (possible about 10 minutes more).
- June 15th. Cloudy during the day but again clear weather during the night. We observed 20 minutes in N1 and then moved to N2 to observe 20 minutes in the Jg band.
In summary, the weather was very good, except for the few last hours of the third night. Instrument performance was ok. We observed a total of 90 min in ELAIS N2 and about 60 min in N1 in the H band. We also observed 20 minutes in N2 in the J band.
|Date||XMM N1||XMM N2||XMM N2 J-band|
- XMM N2 poinitg, dither 5. [full] [detail1] [detail2]
- XMM N2 poinitg, dither 6. [full]
- XMM N2 pointing. Combined 50 minutes image. [detail] [WFC 10min]
See the user guide from Chris Sabbey.
Shallow CIRSI Observations: May 16th to 20th
The aim of this shallow survey was to cover as much area as possible in the H band with integrations of 10 minutes. Table below sumarizes the poinitings done each night.
|Date||XMM N1||XMM N2|
|20000516||12, 13, 14|
|20000519||15, 21, 9|
|20000520||9, 16, 14|
The coordinates of these pointings are:
© Eduardo A. Gonzalez Solares. firstname.lastname@example.org Last modified: Tue May 22 14:20:35 2001