(UV-B) colour index in NGC 1232

This is a computer processed "(U-B) colour-index image" of NGC 1232. This technique allows to show the "difference" between images of the galaxy, as seen in different wavebands. Since different types of objects have different brightness in different colours, this method is very useful to locate objects of a particular type and to obtain an overview of their distribution in the galaxy. The photo is based on two individual images of NGC 1232 obtained by the FORS1 Commissioning Team at the ESO VLT UT1 on 20 September 1998. They were taken in ultraviolet ("U-band") and blue ("B-band") light. The exposure times were 10 min and 6 min, respectively. To obtain this colour-index image, the two images were carefully recentered and then divided numerically. Star formation regions that emit strong ultraviolet light therefore appear as particularly bright areas in this colour-index image. They trace the shock fronts of the gas in the spiral arms. The field measures about 5.5 x 5.5 arcmin 2. North is up and East is left.

Crédit:

ESO

À propos de l'image

Identification:eso9920k
Type:Observation
Date de publication:27 février 1999
Communiqués de presse en rapport:eso9920, eso9916
Taille:1152 x 1281 px

À propos de l'objet

Nom:NGC 1232
Type:Local Universe : Galaxy : Type : Spiral
Distance:60 million années lumière
Constellation:Eridanus
Catégorie:Galaxies

Formats des images

Grand JPEG
1,7 Mio

Fonds d'écran

1024x768
980,3 Kio
1280x1024
1,4 Mio
1600x1200
1,7 Mio
1920x1200
1,7 Mio
2048x1536
2,4 Mio

Coordinates

Position (RA):3 9 47.24
Position (Dec):-20° 34' 28.32"
Field of view:5.37 x 5.97 arcminutes
Orientation:North is 0.1° left of vertical

Couleurs & filtres

DomaineTélescope
Visible
B
Very Large Telescope
FORS1
Ultraviolet
U
Very Large Telescope
FORS1