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.

Créditos:

ESO

Sobre a imagem

Id:eso9922a
Tipo:Observação
Data de divulgação:26 de Março de 1999
Notícias relacionadas:eso9922
Tamanho:2009 x 1980 px

Sobre o objeto

Nome:NGC 4945
Tipo:Local Universe : Galaxy : Type : Spiral
Distância:12 milhão anos-luz
Constellation:Centaurus
Categoria:Galaxies

Formatos de imagens

JPEG grande
907,5 KB

Papéis de parede

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

Coordenadas

Position (RA):13 5 27.28
Position (Dec):-49° 28' 3.76"
Field of view:31.85 x 31.37 arcminutes
Orientação:O norte está a 0.0° à esquerda da vertical

Cores e filtros

BandaComprimento de ondaTelescópio
Ultravioleta
U
336 nmMPG/ESO 2.2-metre telescope
WFI
Óptico
B
445 nmMPG/ESO 2.2-metre telescope
WFI
Óptico
R
658 nmMPG/ESO 2.2-metre telescope
WFI

 

Veja também