ALMA’s hole in the Universe

The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by observing the oldest light in the Universe. As it was created nearly 14 billion years ago, this light — which exists now as weak microwave radiation and is thus named the cosmic microwave background (CMB) — has now expanded to permeate the entire cosmos, filling it with detectable photons.

The CMB can be used to probe the cosmos via something known as the Sunyaev-Zel’dovich (SZ) effect, which was first observed over 30 years ago. We detect the CMB here on Earth when its constituent microwave photons travel to us through space. On their journey to us, they can pass through galaxy clusters that contain high-energy electrons. These electrons give the photons a tiny boost of energy. Detecting these boosted photons through our telescopes is challenging but important — they can help astronomers to understand some of the fundamental properties of the Universe, such as the location and distribution of dense galaxy clusters.

This image shows the first measurements of the thermal Sunyaev-Zel’dovich effect from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile (in blue). Astronomers combined data from ALMA’s 7- and 12-metre antennas to produce the sharpest possible image. The target was one of the most massive known galaxy clusters, RX J1347.5–1145, the centre of which shows up here in the dark “hole” in the ALMA observations. The energy distribution of the CMB photons shifts and appears as a temperature decrease at the wavelength observed by ALMA, hence a dark patch is observed in this image at the location of the cluster.

Links

Crédit:

ALMA (ESO/NAOJ/NRAO)/T. Kitayama (Toho University, Japan)/ESA/Hubble & NASA

À propos de l'image

Identification:potw1708a
Type:Observation
Date de publication:20 février 2017 06:00
Taille:3816 x 3559 px

À propos de l'objet

Type:Early Universe : Cosmology
Constellation:Virgo
Catégorie:Galaxy Clusters

Formats des images

Grand JPEG
2,7 Mio
JPEG taille écran
177,0 Kio

Zoomable


Fonds d'écran

1024x768
195,4 Kio
1280x1024
294,6 Kio
1600x1200
423,4 Kio
1920x1200
524,2 Kio
2048x1536
679,4 Kio

Coordinates

Position (RA):13 47 30.65
Position (Dec):-11° 45' 18.95"
Field of view:1.91 x 1.78 arcminutes
Orientation:North is 130.7° right of vertical

Couleurs & filtres

DomaineLongueur d'ondeTélescope
Millimétrique
92 GHz
3.258613 mmAtacama Large Millimeter/submillimeter Array
Band 3
Visible
g
475 nmHubble Space Telescope
ACS
Visible
B
435 nmHubble Space Telescope
ACS
Visible
V
606 nmHubble Space Telescope
ACS
Visible
r
625 nmHubble Space Telescope
ACS
Visible
i
775 nmHubble Space Telescope
ACS
Visible
z
850 nmHubble Space Telescope
ACS
Infrarouge
J
1.1 μmHubble Space Telescope
WFC3
Infrarouge
H short
1.6 μmHubble Space Telescope
WFC3
Visible
I
814 nmHubble Space Telescope
ACS
Infrarouge
J
1.1 μmHubble Space Telescope
WFC3

 

Voir aussi notre