Spiral galaxy NGC 4945

This photograph shows a sky field around the spiral galaxy NGC 4945 . It is assembled from five 15-minute R(ed)-narrowband (shown in red), four 5-minute B(lue)-band (shown in green), and five 1000-second U(ltraviolet)-band (shown in blue) exposures, obtained in January 1999 during the Science Verification phase with the Wide-Field-Imager (WFI) at the MPG/ESO 2.2-m telescope at La Silla. At the recession velocity of NGC 4945, the red filter, centred at 665 nm with an FWHM (full width at half maximum) of only 1.2 nm, does not include the H-alpha emission line of interstellar hydrogen in this galaxy. The original resolution of about 1 arcsec corresponds to roughly 62 light-years at the distance of NGC 4945 (13 million light-years). In addition to NGC 4945 itself, some much more distant galaxies can be recognized as faint, slightly red light patches in the field. The vast majority of the point-like sources are stars in the Milky Way. However, a fair number of those near NGC 4945 are globular clusters belonging to this galaxy. Each frame records 8184 x 8196 = 67,076,064 pixels, and thus the total number of data points (pixels) of the 14 CCD frames used to make this photo is almost 10 9. Their collective information content corresponds to more than 70 x 10 9 photons (not counting those from the Earth's upper atmosphere that were recorded simultaneously). The field covers 32 x 32 arcmin 2. East is to the left and North to the top.

Crédit:

ESO

À propos de l'image

Identification:eso9922a
Type:Observation
Date de publication:26 mars 1999
Communiqués de presse en rapport:eso9922
Taille:2009 x 1980 px

À propos de l'objet

Nom:NGC 4945
Type:Local Universe : Galaxy : Type : Spiral
Distance:12 million années lumière
Constellation:Centaurus
Catégorie:Galaxies

Image Formats

Grand JPEG
907,5 Kio
JPEG taille écran
360,6 Kio

Fonds d'écran

1024x768
288,0 Kio
1280x1024
425,8 Kio
1600x1200
547,1 Kio
1920x1200
593,0 Kio
2048x1536
691,6 Kio

Coordinates

Position (RA):13 5 27.28
Position (Dec):-49° 28' 3.76"
Field of view:31.85 x 31.37 arcminutes
Orientation:North is 0.0° left of vertical

Couleurs & filtres

DomaineLongueur d'ondeTélescope
Ultraviolet
U
336 nmMPG/ESO 2.2-metre telescope
WFI
Visible
B
445 nmMPG/ESO 2.2-metre telescope
WFI
Visible
R
658 nmMPG/ESO 2.2-metre telescope
WFI

 

Voir aussi notre