Zooming in on a surprising ring

This Picture of the Week shows the distant galaxy PJ0116-24, a so-called Hyper Luminous Infrared Galaxy (HyLIRG). HyLIRGs are incredibly bright galaxies, lit up by the extremely rapid star formation within them. But what triggers this?

Previous studies suggested that such extreme galaxies must result from galaxy mergers. These galaxy collisions are thought to create dense gas regions in which rapid star formation is triggered. But isolated galaxies could also become HyLIRGs via internal processes alone, if star-forming gas is rapidly funneled towards the galaxy’s centre.

In a new paper led by Daizhong Liu (Max-Planck Institute for Extraterrestrial Physics), observations from ESO’s Very Large Telescope (VLT) and the Atacama Large Millimetre/submillimetre Array (ALMA) were combined to study the motion of gas within PJ0116-24. ALMA traces cold gas, seen here in blue, whereas the VLT, with its new Enhanced Resolution Imager and Spectrograph (ERIS), traces warm gas, shown in red. Thanks to these detailed observations, the team discovered that the gas in this extreme galaxy was rotating in an organised fashion, rather than in the chaotic way expected after a galactic collision –– a surprising result! This shows convincingly that mergers aren’t always needed for a galaxy to become a HyLIRG.

PJ0116-24 is so far away that its light took about 10 billion years to reach us. Luckily, a foreground galaxy (not shown here) acted as a gravitational lens, bending and magnifying the light of PJ0116-24 behind it into the Einstein ring seen here. This precise cosmic alignment allows astronomers to zoom in on very distant objects and see them in a level of detail that would otherwise be very hard to achieve.

Links

Crédit:

ALMA (ESO/NAOJ/NRAO)/ESO/D. Liu et al.

À propos de l'image

Identification:potw2429a
Type:Observation
Date de publication:15 juillet 2024 11:00
Taille:1768 x 1768 px

À propos de l'objet

Nom:PJ0116-24
Type:Early Universe : Galaxy : Activity : Ultraluminous
Distance:10 milliard années lumière
Constellation:Cetus
Catégorie:Galaxies

Image Formats

Grand JPEG
230,4 Kio

Zoomable


Fonds d'écran

1024x768
109,0 Kio
1280x1024
144,5 Kio
1600x1200
186,5 Kio
1920x1200
212,1 Kio
2048x1536
255,5 Kio

Coordinates

Position (RA):1 16 46.80
Position (Dec):-24° 37' 2.00"
Field of view:0.15 x 0.15 arcminutes
Orientation:North is 0.0° left of vertical

Couleurs & filtres

DomaineLongueur d'ondeTélescope
Millimétrique
CO(3-2)
2.7 mmAtacama Large Millimeter/submillimeter Array
Band 3
Infrarouge
H-alpha
2.0 μmVery Large Telescope
ERIS