ACS UDF Parallels - General Information

UDF parallel observations have been obtained with NICMOS (F110W and F160W), WFPC2 (F300W), STIS (50CCD + MIRROR imaging and 50CCD + G750L slitless spectroscopy), and ACS/HRC (F220W, F555W, F892N, G800L). For more on each of these programs, please click on the link for that instrument.

The deepest part of the NICMOS images should be the deepest near-infrared imaging ever done if the anticipated depths were achieved. The observations were done in two extended observing campaigns or Epochs of about six weeks each between September 2003 and January 2004. A layout of the parallel fields may be seen below, and is also available as a PDF file.

Fields Overlay Diagram: Layout of the ACS UDF and NICMOS UDF with their respective parallels. A more detailed description is available.

By design, the greater part of the observations have been done at one of two ORIENT angles in both of the two observing epochs, but by necessity, in order to accommodate the observations within the same general time frame and to also allow other GO observations to schedule, a smaller number of observations were done at a second ORIENT angle since that allowed for scheduling over a larger number of days within the larger UDF period. In Epoch 1, the largest amount of time was spent at ORIENT 314. In Epoch 2, the largest amount of time was spent at ORIENT 44. The tables below summarize approximate exposure time totals achieved.

The NICMOS parallel observations are intended to be released at the same time as the primary ACS UDF observations. The WFPC2 and STIS UDF parallel observations became public immediately upon their entry into the archive. For more details on data release timing and plans, please see the primary ACS UDF web pages.

Read more background details on the rationale behind UDF parallels design and scheduling here...

Epoch 1:

Observations have now been completed, and approximate exposure time totals are below (summed from Preliminary Observing Timeline Report files except for ACS/HRC, which are totals from the data). NICMOS total exposure times summed from the data are also available and are slightly different from the values below.

Epoch 2:

Observations have now been completed, and approximate exposure time totals are below (summed from Preliminary Observing Timeline Report files except for ACS/HRC, which are totals from the data). NICMOS total exposure times summed from the data are also available and are slightly different from the values below.

Weekly Preliminary Observation Timeline Reports for the UDF showing the Parallels' Association with the ACS Primaries may be seen below.
Note: No parallels were taken with program ID 10086.

Epoch 1:

Some "stray" WFPC2 and STIS parallels:
9980
9981

Epoch 2: