A Dusty View of Milky Ways Smaller Cousin

Spitzer_sig11-016_1024

spitzer_sig11-016 November 23rd, 2011

Credit: NASA/JPL-Caltech

This spectacular spiral galaxy is known to astronomers as Messier 83. Colloquially, it is also called the Southern Pinwheel due to its similarity to the more northerly Pinwheel galaxy Messier 101. NASAs Spitzer Space Telescope shows us, in spectacular detail, the infrared structure of what many think of as our own Milky Way galaxys smaller cousin.

Living in the middle of the Milky Ways disk, we see our galaxy only from an obstructed vantage point that is both inside-out and edge-on. We see Messier 83 nearly face-on, giving us a chance to really map out its disk in great detail. This information helps astronomers figure out what our own galaxy would look like if we could warp out to a better vantage point.

Like the Milky Way, Messier 83 is classified as a barred spiral galaxy due to the bar-like pattern of stars that run through its center. This bar region is more interesting in the infrared since we can also see the open s shaped curve of dust (green) cutting through the more linear stellar bar (blue).

This arc of inner dust connects up with the more tightly wound spiral arms in the outer disk, seen here as bright green-red ridges. Some of the hottest regions of star formation show up as reddish-white dots along the spiral arms, with the most vigorous star formation happening in the galaxys center. Between the main spiral arms we also see a complex webbing of dust that permeates the entire disk.

While Messier 83 is about 15 million light years away, it is actually one of the closest barred spiral galaxies in the sky. This gives astronomers an excellent chance to study a galaxy that, although half as big, seems very similar in structure to our own Milky Way galaxy.

Infrared light with wavelengths of 3.6 and 4.5 microns is shown as blue/cyan, showing primarily the glow from starlight. 8 micron light is rendered in green, and 24 micron emission is red, tracing the cooler and warmer components of dust, respectively.

Provider: Spitzer Space Telescope

Image Source: http://www.spitzer.caltech.edu/images/4832-sig11-016-A-Dusty-View-of-Milky-Ways-Smaller-Cousin

Curator: Spitzer Space Telescope, Pasadena, CA, USA

Image Use Policy: Public Domain

Image Details

Image Type
Observation
Object Name
Messier 83 M83 NGC 5236 Southern Pinwheel Galaxy
Subject - Local Universe
Galaxy > Type > Spiral
Galaxy > Type > Barred

Distance

Universescale2
14,700,000 light years
Spitzer_sig11-016_128
 

Position Details

Position (ICRS)
RA = 13h 37m 0.5s
DEC = -29° 51’ 57.9”
Orientation
North is 25.0° CW
Field of View
22.5 x 22.5 arcminutes
Constellation
Hydra

Color Mapping

  Telescope Spectral Band Wavelength
Blue Spitzer (IRAC) Infrared (Near-IR) 3.6 µm
Cyan Spitzer (IRAC) Infrared (Near-IR) 4.5 µm
Green Spitzer (IRAC) Infrared (Mid-IR) 8.0 µm
Red Spitzer (MIPS) Infrared (Mid-IR) 24.0 µm
Spectrum_ir1
Blue
Cyan
Green
Red
Spitzer_sig11-016_1280
×
ID
sig11-016
Subject Category
C.5.1.1.   C.5.1.2.  
Subject Name
Messier 83, M83, NGC 5236, Southern Pinwheel Galaxy
Credits
NASA/JPL-Caltech
Release Date
2011-11-23
Lightyears
14,700,000
Redshift
0.001711
Reference Url
http://www.spitzer.caltech.edu/images/4832-sig11-016-A-Dusty-View-of-Milky-Ways-Smaller-Cousin
Type
Observation
Image Quality
Good
Distance Notes
Facility
Spitzer, Spitzer, Spitzer, Spitzer
Instrument
IRAC, IRAC, IRAC, MIPS
Color Assignment
Blue, Cyan, Green, Red
Band
Infrared, Infrared, Infrared, Infrared
Bandpass
Near-IR, Near-IR, Mid-IR, Mid-IR
Central Wavelength
3600, 4500, 8000, 24000
Start Time
2008-03-05T16:21, 2008-03-05T16:21, 2008-03-05T16:21, 2006-02-18T04:09:45
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
204.2521783, -29.8660905
Reference Dimension
1800.0, 1800.0
Reference Pixel
901.0, 901.0
Scale
-0.000208374, 0.00020837411
Rotation
-24.97
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
Spitzer Space Telescope
URL
http://www.spitzer.caltech.edu
Name
Email
Telephone
Address
1200 E. California Blvd.
City
Pasadena
State/Province
CA
Postal Code
91125
Country
USA
Rights
Public Domain
Publisher
Spitzer Science Center
Publisher ID
spitzer
Resource ID
sig11-016.tif
Metadata Date
2011-11-23
Metadata Version
1.2
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Detailed color mapping information coming soon...

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Universescalefull
14,700,000 light years

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