The candidates were selected primarily based on their lensing properties. They are currently being vetted for other considerations. Comments and suggestions are welcome -- please send to frontierfields@stsci.edu.
- The clusters are known to be massive and highly efficient lenses.
- The clusters have several sets of known multiple image systems confirmed with spectroscopic redshifts.
- Most of the clusters have high-quality magnification maps based on data in hand.
- The clusters were selected based on initial estimates of the number counts of lensed high redshift sources detectable within the WFC3-IR FOV.
- The area enclosed interior to the critical curve for z~4-10 sources can be fully captured within a single pointing of WFC3-IR.
- Clusters with higher redshifts will have less area masked by cluster galaxies, fainter intracluster light, and less contamination in the parallel blank fields.
| Cluster | z | RA | DEC |
|---|---|---|---|
| Abell 370 | 0.37 | 02:39:52.8 | -01:34:36 |
| MACSJ0329.6-0211 | 0.45 | 03:29:40.3 | -02:11:42 |
| MACSJ0416.1-2403 | 0.42 | 04:16:08.4 | -24:04:21 |
| MACSJ0451.0+0006 | 0.429 | 04:51:54.6 | +00:06:17 |
| MACSJ0717.5+3745 | 0.545 | 07:17:35.6 | +37:44:44 |
| MACSJ0744.9+3927 | 0.686 | 07:44:52.8 | +39:27:24 |
| MACSJ1149.5+2223 | 0.543 | 11:49:35.7 | +22:23:55 |
| MACSJ1423.8+2404 | 0.54 | 14:23:48.3 | +24:04:47 |
| Abell 2744 | 0.308 | 00:14:23.4 | -30:23:26 |
| MACSJ0257-2325 | 0.505 | 02:57:08.8 | -23:26:03 |
| MACSJ0520.7-1328 | 0.340 | 05:20:42.0 | -13:28:48 |
In addition to their lensing properties, we are weighing the following additional criteria:
- ecliptic latitude and zodiacal foreground
- accessibility to ground-based observatories, including ALMA
- Galactic latitude, extinction and foreground emission
- scheduling constraints of HST and Spitzer
- JWST follow-up optimization
Other candidates that have been considered but eliminated include the following:
- MACSJ0647.7+7015 (bright stars in field, no ALMA)
- Bullet Cluster (larger than WFC3-FOV)
- Abell 1689 (low redshift, larger than WFC3-FOV)
- Abell 1703 (low redshift, larger than WFC3-FOV)
- Abell 2537 (high zodical background)
- MACSJ1206.2-0747 (high zodical background)
- MACSJ2129.4-0741 (high zodical background)
- MACSJ2214.9-1359 (high zodical background)
- RCS2-2327.4-04 (high zodical background)
- RXJ1347.5-1144 (high zodical background)
- MACSJ0454.1-0300 (moderate zodical background, weaker lenser)
The final two clusters will not be observed with HST until Cycle 23, but need to be observed with Spitzer before the end of its mission (nominally the end of 2014). Our current top contenders for the last two fields are MACS0329.6-2011, MACS0451.0+0006, AbellS1063, MACSJ1149.5+2223, MACSJ1423.8+2404, and MACSJ0257.0-2209. Please feel free to email us at frontierfields@stsci.edu with any additional information.