5.5 Duration

Let's review what we've done so far:

First, for the Abell 2218 field, we designed observations with MIPS 24 and 160 passbands, with the large field size for both wavebands. At 24 microns, we used the 30 second frame time, 1 cycle, and a sky offset of $10^{\prime\prime}$. For 160 microns, we used 4 cycles of the 10 second frame time.

At 70 microns, we covered a $\simeq 5^\prime \times 5^\prime$ FOV by using a Fixed Cluster-offsets target with offsets of $(0^{\prime\prime}, 80^{\prime\prime})$, $(0^{\prime\prime},-80^{\prime\prime})$ in array coordinates observing ``offsets only.'' We chose a frame time of 10 seconds, and requested 5 cycles.

Screen captures of the completed MIPS Photometry/Super Resolution AOT entry dialogs are shown in Figure 5.8 and 5.9.

Figure 5.8: The completed MIPS Photometry/Super Resolution AOT for 24 and 160 micron imaging of Abell 2218.

Figure 5.9: The completed MIPS Photometry/Super Resolution AOT for 70 micron imaging of Abell 2218.

How long do these AORs take to execute? For the 70 micron observations, Spot returns a duration of 1731.3 s, including overheads (545.3 s integration), while the 24 + 160 micron observations take 3039.6 s, including overheads (2 x 375.4 s integration on-source for 24 microns, and 41.9 s at 160 microns).

The (next to) last step we need to do is clone these AORs for the other targets in the target list. We'll get to that in a moment. First we will consider how to constrain these observations so that both the IRAC observations (see §4) and those obtained with MIPS (this chapter) have the same (or similar) position angle.