MAssive Cluster Survey

The MAssive Cluster Survey (MACS)^[1][2] compiled and characterized a sample of very X-ray luminous (and thus, by inference, massive), distant clusters of galaxies. The sample comprises 124 spectroscopically confirmed clusters at 0.3 < z < 0.7. Candidates were selected from the ROSAT All-Sky Survey data.^[3]

MAssive Cluster Survey

Alternative names	MACS
Website	www.ifa.hawaii.edu/~ebeling/clusters/MACS.html
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Cluster candidates that are south of declination -40° cannot be observed from Mauna Kea and fit into the Southern MACS (SMACS) extension. They are also being investigated when facilities are available.^[4]

History

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, by CLASH. The first statistical study of X-ray cavities in distant clusters of galaxies was performed by analyzing the Chandra X-ray observations of MACS. Out of 76 clusters representing a sample of the most luminous X-ray clusters, observers found 13 cut and clear cavities and 7 possible cavities. A new radio halo, as well as a relic applicant, were found in MACS, with the help of the Giant Meterwave Radio Telescope and the Karoo Array Telescope-7. The discovered radio halo has a largest linear scale of about 0.9Mpc. X-ray chosen clusters are almost free of projection effects because they are composed of intrinsically massive, gravitationally collapsed systems.

MACS team

The MACS team consists of:

• Harald Ebeling, University of Hawaii, USA
• Alastair Edge, University of Durham, UK
• J. Patrick Henry, University of Hawaii, USA

Survey notation

Objects are labelled as JHHMM.m+DDMM where HHMM+DDMM are the coordinates in the J2000 system. Here H, D, and M refer to hours, degrees, and minutes, respectively, and m refers to tenths of minutes of time.

• HH Hours of right ascension
• MM.m Minutes of right ascension or declination
• DD.d Degrees in declination

Southern MAssive Cluster Survey

The Southern MAssive Cluster Survey (SMACS) involved the Hubble Space Telescope.

Notable surveyed objects

Survey object	Right ascension	Declination	Notes
MACS J0025.4-1222	00h 25.4m	−12° 22′
MACS J0358.8-2955	03h 58.8m	−29.5°	Part of Abell 3192[5]
MACS J0416.1-2403	04h 16m 9.9s	−24° 03′ 58″
MACS J0647+7015	06h 47m	+70° 15′
MACS J0717.5+3745	07h 17.5m	+37° 45′
SMACS J0723.3–7327	07h 23m	−73° 27′	Subject of first JWST deep field
MACS J1149 Lensed Star 1	11h 49m 35.59s	22° 23′ 47.4″	Blue supergiant star observed through a gravitational lens
MACS 1423-z7p64	14h 23m	24° 04′	Most distant galaxy known as of April 2017
MACS 2129-1	21h 29m	−1°