VLT map of gas within NGC 7252’s minispiral

This unusual image reveals the aftermath of a catastrophic collision between two galaxies, which happened about one billion years ago. The result? A single, very oddly shaped galaxy named NGC 7252, and curiously nicknamed the Atoms for Peace galaxy.

At the heart of this merger remnant lies a fascinating “minispiral” — a rotating disc of glowing gas, bursting with star formation. Using the VIsible Multi-Object Spectrograph (VIMOS) instrument on ESO’s Very Large Telescope, astronomers were able to measure the movement of the gas within this disc, allowing them to map its rotation. Red regions indicate gas moving away from us, and blue regions towards us. Together, these colours reveal the galaxy's steadily rotating centre, as well as highlighting two flowing streams of hot gas north-west and south-east of the central region. Past studies suggested that the central spiral was rotating counter to the rest of the galaxy, but by comparing the movement of stars around the galaxy with the gas ionised by newly formed stars in the minispiral, we now know that they are in fact rotating in the same direction.

Such a detailed map is possible due to the Integral Field Unit (IFU) on VIMOS, allowing astronomers to study the gas in NGC 7252 with a comprehensive "mosaic" view. Much like the way a fly observes the world, an IFU divides its subject into many cells, or pixels, generating a spectrum for every single one. The resulting information is arranged into a 3D data cube, which is particularly useful in studying extended objects in just one shot.

Kilde:

ESO/ESA/Hubble & NASA/J. Weaver et al.

Om bildet

ID:potw1806b
Type:Observasjon
Publiseringsdato:5. februar 2018 06:00
Størrelse:2461 x 1614 px

Om objektet

Navn:NGC 7252
Type:Local Universe : Galaxy : Type : Interacting
Avstand:200 million lysår
Constellation:Aquarius
Kategori:Galaxies

Bildeformater

Stor JPEG
1,3 MB
Medium JPEG
195,1 KB

Zoombart


Skrivebordsbakgrunner

1024x768
323,4 KB
1280x1024
552,9 KB
1600x1200
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2048x1536
1,2 MB

Koordinater

Position (RA):22 20 44.69
Position (Dec):-24° 40' 42.33"
Field of view:1.63 x 1.07 arcminutes
Orientering:Nord er 0.1° til venstre for vertikalen

Farger og filtre

BåndBølgelengdeTeleskop
OptiskVery Large Telescope
VIMOS
Optisk
u
336 nmHubble Space Telescope
WFC3
Optisk
g
475 nmHubble Space Telescope
WFC3
OptiskVery Large Telescope
VIMOS
Infrarødt
J
1.1 μmHubble Space Telescope
WFC3