Aug 2-3 2016, Dan Stark’s run; Ramesh was the observer.
Traci made masks for 2211, A2537 (two masks). Dan et al. made masks for El Gordo and whl0137.
Night 1
Ramesh had a successful night on LDSS. The conditions were good throughout the night with seeing ~0.6-0.8”. We started with a non-RELICS cluster from Adi and then observed 3 RELICS clusters in the remainder of the night.
1. RXC2211: 1 hour of integration. Emission lines are visible in two arcs (multiple image of same source). The position of emission line confirms the source to be multiply imaged. Few other sources show traces of continuum.
2. A2537a: 1.5 hour of integration on the cluster. Emission line visible in two separate arcs. Continuum detection in few other sources.
3. El gordo: 2 hr at the end of the night. Emission line detection in one small arc. Nothing visible from a prominent giant arc in the cluster. Few other sources showing continuum traces.
Our plan at the moment is to observe the remaining three masks (MACS1447, WHL0137 and A2537b) tonight. We may also obtain deeper data on RXC2211, since there was only 1 hr when this cluster is visible.
Night 2
We lost ~ 40 min due to a mechanical issue. The seeing improved over the night and remained mostly between 0.7" and 1.0". I managed to observe three RELICS clusters (in addition to a source from Adi at the beginning of the night) which are as follows:
1. rxc2211: I observed 1 hr on this cluster making total integration of 2 hr (1 hr from the other night). Emission lines are detected in two multiple images of a single source. Few other arcs have continuum traces detection.
2. a2537b: This is the second mask on a2537 cluster. We detected emission lines from two different sources last night using a2537a mask. Tonight we detected another emission line from an arc with 1.5 hr of integration. There are also emission lines detection from a couple of "Jelly fish" galaxies that Keren/Traci put into the mask.
3. whl0137: I observed the cluster towards the end of the night with total integration of 2 hr and 10 min. Although continuum traces are visible in few arcs, I couldn't see any emission line yet.
We want to share the results from August 2-3 LDSS3 observations of four relics clusters (abell2537, rxc2211, whl0137, el-gordo). The observations were made with 5 masks (2 for a2537 cluster). Fortunately, the weather conditions were pretty good throughout the observations with average seeing ranging 0.6-0.9 arcsec.
The data were reduced with the standard COSMOS pipeline. We detect emission lines in 11 sources within the four clusters of which some were used as a mask filler. I hope this will be useful to constrain the mass models. Below I provide the redshifts of the sources estimated from the emission lines, which are calculated either from strong optical lines ([OIII]5007, H-beta, H-alpha) or Lyman alpha. The name of the sources are same as used in the masks (a2537a, a2537b and rxc2211) prepared by Traci.
1. A2537 cluster: 2 masks (a2537a and a2537b)
Object RA DEC Emission lines redshift Notes
C2 08:22.229 -02:11:24.68 Lyman-alpha 3.611 photo-z=3.75, also presence of tentative [OIII]1661,1666.
P1 08:20.165 -02:11:13.27 [OII]3727,3729, [OIII]5007 0.810 photo-z=0.71
Bigarc 08:24.586 -02:12:11.62 [OII], H-beta, [OIII], H-alpha 0.531 photo-z=0.25
ZC 08:20.110 -02:11:18.02 [OII], H-beta, [OIII] 0.810 photo-z=0.81
Jellyfish1 08:19.957 -02:11:43.25 [OII],[OIII],H-beta, H-alpha 0.304 photo-z=0.13
Jellyfish2 08:23.346 -02:10:37.82 [OII],[OIII],H-beta, H-alpha 0.297 photo-z=0.29
2. RXCJ2211:
Object RA DEC Emission lines redshift Notes
Arc1.1 22:11:45.597 -03:49:26.63 [OII], [NeIII]3869, H-beta, [OIII] 1.051 photo-z=0.85
Arc1.2 22:11:43.938 -03:49:43.78 [OII], [NeIII]3869, H-beta, [OIII] 1.051 photo-z=0.94
3. whl0137:
Object RA DEC Emission lines redshift Notes
arc4.2 01:37:27.026 -08:28:19.32 Lyman-alpha 4.871 photo-z=4.99
4. El-gordo:
Object RA DEC Emission lines redshift Notes
g1 01:03:10.469 -49:16:07.81 [OII], H-beta, [OIII] 0.797 Used as a mask filler. Not lensed by the cluster. cluster redshift=0.87.
g2 01:03:04.619 -49:17:04.62 [OII] 1.579 photo-z=0.87. Emission line at 9615.7 angstrom, most likely interpretation is [OII] 3727 at z=1.579. Need to confirm whether it is a lensed candidate.