Hello friends, this NASA Hubble Space

Telescope image features a galaxy

cluster called CL0016

+ 1609 or MACS J0018.5

+ 1626

that is very bright at x-ray wavelengths

and is one of the most extensively

studied cluster at x-ray and radio

wavelengths.

The x-ray observation of this cluster

revealed that it is two clusters merging

along our line of sight. Researchers

requested time to observe

with Hubble's

advanced camera for survey because that

data would help them accurately measure

the cluster's dark matter distribution,

which helps them study the merger and

the role of CL0016 + 1609 in the

large-scale structure of the universe.

Hubble cannot directly see dark matter,

but its infrared and visible light

observation can detect dark matter's

gravitational lensing effect on the

normal matter Hubble observed. The data

in this image also includes observation

with Hubble's Wide Field Camera 3 taken

as part of observing program that

obtained the first Hubble infrared image

of 46 massive galaxy cluster and looked

for distant galaxies gravitationally

lensed by these clusters called RELICS,

that is reionization lensing cluster

survey. The survey found some 300 high

redshift candidate

galaxies lensed by these clusters.

You can see the faint vertical arc of

one of these distant galaxies in the

image above. Look for it just to the

left of the large elliptical galaxies in

the center of the image. Another

brighter, though shorter, arc is visible

just above to the right of the large

elliptical galaxies in the center of the

image.

>> Mhm.