A Galactic Embrace

Two galaxies, about 50 million light-years away, are locked in a galactic embrace — literally. The Seyfert galaxy NGC 1097, in the constellation of Fornax (The Furnace), is seen in this image taken with the VIMOS instrument on ESO’s Very Large Telescope (VLT). A comparatively tiny elliptical companion galaxy, NGC 1097A, is also visible in the top left. There is evidence that NGC 1097 and NGC 1097A have been interacting in the recent past.

Although NGC 1097 seems to be wrapping its companion in its spiral arms, this is no gentle motherly giant. The larger galaxy also has four faint jets — too extended and faint to be seen in this image — that emerge from its centre, forming an X-shaped pattern, and which are the longest visible-wavelength jets of any known galaxy. The jets are thought to be the remnants of a dwarf galaxy that was disrupted and cannibalised by the much larger NGC 1097 up to a few billion years ago.

These unusual jets are not the galaxy’s only intriguing feature. As previously mentioned, NGC 1097 is a Seyfert galaxy, meaning that it contains a supermassive black hole in its centre. However, the core of NGC 1097 is relatively faint, suggesting that the central black hole is not currently swallowing large quantities of gas and stars. Instead, the most striking feature of the galaxy’s centre is the ring of bright knots surrounding the nucleus. These knots are thought to be large bubbles of glowing hydrogen gas about 750–2500 light-years across, ionised by the intense ultraviolet light of young stars, and they indicate that the ring is a site of vigorous star formation

With this distinctive central star-forming ring, and the addition of numerous bluish clusters of hot, young stars dotted through its spiral arms, NGC 1097 makes a stunning visual object.

The data were originally taken in 2004 (see eso0438) with the VIMOS instrument on the VLT, and additional colour information from an image taken by amateur astronomer Robert Gendler has been superimposed. The VLT data were taken through three visible-light filters: R (at a wavelength of 652 nanometres, and shown here in red), V (a wavelength of 540 nanometres, shown in green), and B (456 nanometres, shown in blue). The image covers a region of approximately 7.7 x 6.6 arcminutes on the sky.

Credit:

ESO/R. Gendler

About the Image

Id:potw1128a
Type:Observation
Release date:11 July 2011, 10:00
Size:2296 x 2592 px

About the Object

Name:NGC 1097
Type:• Local Universe : Galaxy : Type : Spiral
• Local Universe : Galaxy : Type : Interacting
• X - Galaxies
Distance:50 million light years
Constellation:Fornax

Image Formats

Large JPEG
1.8 MB
Screensize JPEG
317.8 KB

Zoomable


Wallpapers

1024x768
263.1 KB
1280x1024
420.7 KB
1600x1200
598.9 KB
1920x1200
702.3 KB
2048x1536
958.2 KB

Coordinates

Position (RA):2 46 19.13
Position (Dec):-30° 16' 30.93"
Field of view:7.13 x 8.04 arcminutes
Orientation:North is 1.2° left of vertical

Colours & filters

BandWavelengthTelescope
Optical
B
456 nmVery Large Telescope
VIMOS
Optical
V
540 nmVery Large Telescope
VIMOS
Optical
R
652 nmVery Large Telescope
VIMOS

 

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