4.2 Target Selection: Massive, Intermediate Redshift, Galaxy Clusters

The first task involves the selection of targets for the observations. There are many low-z clusters with existing multiwavelength observations and spectroscopy. Without attempting to be exhaustive in a target list, let us concentrate on the candidates, listed in Table 4.1.

Table 4.1: The targets for the coordinated IRAC/MIPS deep imaging program.

Target	z	ra	dec	in ROC?
		J2000	J2000
Abell 2218	0.176	16:35:53.99	+66:13:00.2	Yes
ZwCl0024.0+1652	0.4	00:26:36.01	+17:08:36.1	Yes
Abell 665	0.18	08:30:45.19	+65:52:55.3	Yes
Abell 1689	0.18	13:11:34.20	-01:21:55.5	Yes
AC 114	0.31	22:58:52.34	-34:46:54.6	Yes

As with all observations, we need to determine if the targets are already scheduled for observations with the Spitzer Space Telescope. To check for duplicate observations, we use the Leopard search tool.

http://ssc.spitzer.caltech.edu/documents/leopard/.

We find that all of the above targets already do have reserved/scheduled/accepted IRAC mapping programs. To propose to observe the targets in Table 4.1 again, we would need to comply with the Spitzer Observing Rules by, for example, reaching to a sensitivity $\geq 2$ than the observations already proposed. However, for the purpose of this example, we will not worry about violating the duplicate observation rule, and will proceed as if all targets have not been observed already.