More than meets the eye

Despite the advances made in past decades, the process of galaxy formation remains an open question in astronomy. Various theories have been suggested, but since galaxies come in all shapes and sizes — including elliptical, spiral, and irregular — no single theory has so far been able to satisfactorily explain the origins of all the galaxies we see throughout the Universe.

To determine which formation model is correct (if any), astronomers hunt for the telltale signs of various physical processes. One example of this is galactic coronas, which are huge, invisible regions of hot gas that surround a galaxy’s visible bulk, forming a spheroidal shape. They are so hot that they can be detected by their X-ray emission, far beyond  the optical radius of the galaxy. Because they are so wispy, these coronas are extremely difficult to detect. In 2013, astronomers highlighted NGC 6753, imaged here by the NASA/ESA Hubble Space Telescope, as one of only two known spiral galaxies that were both massive enough and close enough to permit detailed observations of their coronas. Of course, NGC 6753 is only close in astronomical terms — the galaxy is nearly 150 million light-years from Earth.

NGC 6753 is a whirl of colour in this image — the bursts of blue throughout the spiral arms are regions filled with young stars glowing brightly in ultraviolet light, while redder areas are filled with older stars emitting in the cooler near-infrared.

 

Credit:

ESA/Hubble & NASA
Acknowledgement: Judy Schmidt


 

About the Image

Id:potw1738a
Type:Observation
Release date:18 September 2017, 06:00
Size:1103 x 1101 px

About the Object

Name:NGC 6753
Type:Local Universe : Galaxy : Type : Spiral
Distance:150 million light years
Constellation:Pavo
Category:Galaxies

Image Formats

Large JPEG
467.1 KB
Screensize JPEG
302.8 KB

Zoomable


Wallpapers

1024x768
358.7 KB
1280x1024
470.4 KB
1600x1200
634.7 KB
1920x1200
727.3 KB
2048x1536
929.3 KB

Coordinates

Position (RA):19 11 23.69
Position (Dec):-57° 2' 52.29"
Field of view:1.84 x 1.83 arcminutes
Orientation:North is 18.8° right of vertical

Colours & filters

BandWavelengthTelescope
Optical
U
300 nm Hubble Space Telescope
WFPC2
Optical
U
300 nm Hubble Space Telescope
WFPC2
Optical
I
814 nm Hubble Space Telescope
WFPC2
Optical
I
814 nm Hubble Space Telescope
WFPC2

Also see our


Accelerated by CDN77