Cluster Lensing and Supernova survey with Hubble

The Cluster Lensing And Supernova survey with Hubble (CLASH) was a program on the Hubble Space Telescope to observe 25 massive galaxy clusters. CLASH was one of three programs selected (along with CANDELS and PHAT) in the first class of Hubble multi-cycle treasury programs, which were designed to tackle large questions unanswerable through normal observations.^[1] Observations for CLASH were conducted between November 2010 and July 2013.^[2] CLASH was led by principal investigator Marc Postman, and had a science team of over 40 researchers.^[2]

Cluster Lensing And Supernova survey with Hubble

Alternative names	CLASH
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This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACS J1206. This is one of 25 clusters being studied as part of the CLASH (Cluster Lensing and Supernova survey with Hubble) programme, a major project to build a library of scientific data on lensing clusters.

Primary observations for CLASH were conducted on the Hubble Space Telescope with the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3). Images were taken in 16 filters, which were selected to maximize the ability to detect distant galaxies behind each cluster.^[3] Twenty of the observed clusters were selected due to their relaxed morphology in X-ray observations, while the other five were chosen due to their strength as gravitational lenses.

History

CLASH Survey Brightest Cluster Galaxies and Simulations.^[4]

As of November 2012, the CLASH has surveyed 20 clusters out of the 25. One of the galaxy clusters, MACS J0647+7015 was found to have gravitationally lensed the most distant galaxy (MACS0647-JD) then ever imaged, in 2012.^[5][6]

In 2013, one study utilizing CLASH data found that RX J1347.5-1145 had intense gravitational bending of light such that 8 images of the same object were detected.^[7] (See Gravitational lensing)

Clusters under observation

List of clusters is:^[8]

Galaxy cluster	Right Ascension	Declination	Redshift	Notes
Abell 209 (ACO 209)	01:31:52.57	-13:36:38.8	0.206
Abell 383 (ACO 383)	02:48:03.36	-03:31:44.7	0.187
MACS0329.7-0211	03:29:41.68	-02:11:47.7	0.450
MACS0429.6-0253	04:29:36.10	-02:53:08.0	0.399
MACS0744.9+3927	07:44:52.80	+39:27:24.4	0.686
Abell 611 (ACO 611)	08:00:56.83	+36:03:24.1	0.288
MACS1115.9+0129	11:15:52.05	+01:29:56.6	0.352
Abell 1423 (ACO 1423)	11:57:17.26	+33:36:37.4	0.213
MACS1206.2-0847	12:06:12.28	-08:48:02.4	0.440
CLJ1226.9+3332 (ClG J1226.9+3332)	12:26:58.37	+33:32:47.4	0.890
MACS1311.0-0310	13:11:01.67	-03:10:39.5	0.494
RX J1347.5-1145	13:47:30.59	-11:45:10.1	0.451	[Notes 1]
MACS1423.8+2404	14:23:47.76	+24:04:40.5	0.545
RXJ1532.9+3021	15:32:53.78	+30:20:58.7	0.345
MACS1720.3+3536	17:20:16.95	+35:36:23.6	0.391
Abell 2261 (ACO 2261)	17:22:27.25	+32:07:58.6	0.224
MACS1931.8-2635	19:31:49.66	-26:34:34.0	0.352
RXJ2129.7+0005	21:29:39.94	+00:05:18.8	0.234
MS2137-2353	21:40:15.18	-23:39:40.7	0.313
RXJ2248.7-4431 (Abell 1063S / ACO 1063S)	22:48:44.29	-44:31:48.4	0.348
MACS0416.1-2403	04:16:09.39	-24:04:03.9	0.42
MACS0647.8+7015	06:47:50.03	+70:14:49.7	0.584
MACS0717.5+3745	07:17:31.65	+37:45:18.5	0.548
MACS1149.6+2223	11:49:35.86	+22:23:55.0	0.544
MACS2129.4-0741	21:29:26.06	-07:41:28.8	0.570

Notes

1. One of the most X-ray luminous and most massive cluster known, with an X-ray luminosity in excess of 10^45^erg/s. Magellan Spectroscopy of the Galaxy Cluster RX J1347.5-1145: Redshift Estimates for the Gravitationally Lensed Arcs