WISE Beholds a Pair of Dancing Galaxies

Wise_wise2011-002_500

WISE_WISE2011-002 January 13th, 2011

Credit: NASA/JPL-Caltech/UCLA

This image from NASAs Wide-Field Infrared Survey Explorer, or WISE, features two stunning galaxies engaged in an intergalactic dance. The galaxies, Messier 81 and Messier 82, swept by each other a few hundred million years ago, and will likely continue to twirl around each multiple times before eventually merging into a single galaxy. The relatively recent encounter triggered a spectacular burst of star formation visible in both galaxies.

Messier 81 (bottom of image) is a prototypical grand design spiral galaxy with its pronounced and well-defined arms spiraling into its core. At the wavelengths WISE sees, these beautiful arms show areas of compressed interstellar gas and dust, which go hand-in-hand with areas of increased star formation. The spiral density waves that create this compression and star formation have been enhanced by the close gravitational interaction with its partner galaxy, Messier 82, causing the arms to appear more prominent than in a similarly isolated spiral galaxy.

Messier 82 (top of image) is also a spiral galaxy, however it is seen edge-on from our point of view. It was originally classified as an irregular galaxy, until 2005, when astronomers were able to tease out spiral structure in near-infrared images (similar to wavelengths that WISE sees). Viewed in visible wavelengths, this galaxy appears to have a long thin bar shape, hence its common name the Cigar Galaxy.

Messier 82 is also a starburst galaxy, meaning it is currently undergoing a period of exceptionally high rates of star formation. This huge burst of activity was caused by its close encounter with Messier 81, whose gravitational influence caused gas near the center of Messier 82 to rapidly compress. This compression triggered an explosion of star formation concentrated near the core. The intense radiation from all of the newly formed massive stars creates a galactic superwind that is blowing massive amounts of gas and dust out perpendicular to the plane of the galaxy. This ejected material (seen as the orange/yellow areas extending up and down) is made mostly of polycyclic aromatic hydrocarbons, which are common products of combustion here on Earth. It can literally be thought of as the smoke from the cigar.

A third, smaller galaxy, NGC 3077, can be seen at lower left. This spiral galaxy belongs to the same group as Messier 81 and Messier 82 -- a group that includes at least a dozen gravitationally linked galaxies. NGC 3077 is also experiencing a burst of new star birth, likely triggered by its interaction with Messier 81.

Messier 81 and Messier 82 are both very bright galaxies and can be seen on a clear, dark night with binoculars in the northern constellation Ursa Major, which contains the Big Dipper. In visible light Messier 81 is one of the brightest galaxies that can be seen. Messier 82 is not as bright at visible wavelengths, but in infrared light it is by far the brightest galaxy in the entire night sky.

This image was made from observations by all four infrared detectors aboard WISE. Blue and cyan (blue-green) represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily light from stars. Green and red represent light at 12 and 22 microns, which is primarily emission from warm dust.

Image Source: /image/WISE/WISE2011-002

Curator: Wide-field Infrared Survey Explorer, Berkeley, CA, USA

Image Use Policy: Pulic Domain

Image Details

Image Type
Observation
Object Name
Messier 81 M81 Bode's Galaxy NGC 3031 Messier 82 M82 Cigar Galaxy NGC 3034 NGC 3077
Subject - Local Universe
Galaxy » Type » Spiral
Galaxy » Type » Irregular
Galaxy » Type » Interacting
Galaxy » Grouping » Cluster
Galaxy » Grouping » Multiple

Distance

Universescale2
12,000,000 light years
Wise_wise2011-002_128
 

Position Details

Position (ICRS)
RA = 9h 55m 44.0s
DEC = 69° 22’ 0.0”
Orientation
North is up
Field of View
1.5 x 1.5 degrees
Constellation
Ursa Major

Color Mapping

  Telescope Spectral Band Wavelength
Arrow_left_blue WISE Infrared (Near-IR) 3.4 µm
Arrow_left_cyan WISE Infrared (Near-IR) 4.6 µm
Arrow_left_green WISE Infrared (Mid-IR) 12.0 µm
Arrow_left_red WISE Infrared (Mid-IR) 22.0 µm
Spectrum_ir1
Arrow_top_blue
Arrow_top_cyan
Arrow_top_green
Arrow_top_red
Wise_wise2011-002_1280
×
ID
WISE2011-002
Subject Category
C.5.1.1.   C.5.1.6.   C.5.1.7.   C.5.5.3.   C.5.5.2.  
Subject Name
Messier 81, M81, Bode's Galaxy, NGC 3031, Messier 82, M82, Cigar Galaxy, NGC 3034, NGC 3077
Credits
NASA/JPL-Caltech/UCLA
Lightyears
12,000,000
Redshift
-
Reference Url
/image/WISE/WISE2011-002
Type
Observation
Image Quality
Good
Distance Notes
Approximate distance to group
Facility
WISE, WISE, WISE, WISE
Instrument
Color Assignment
Blue, Cyan, Green, Red
Band
Infrared, Infrared, Infrared, Infrared
Bandpass
Near-IR, Near-IR, Mid-IR, Mid-IR
Central Wavelength
3400, 4600, 12000, 22000
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
148.933330, 69.366670
Reference Dimension
8000, 8000
Reference Pixel
4000.5, 3990.5
Scale
-1.90972219570500e-04, 1.90972219570500e-04
Rotation
0
Coordinate System Projection:
SIN
Quality
Full
FITS Header
Notes
Creator (Curator)
Wide-field Infrared Survey Explorer
URL
http://wise.astro.ucla.edu
Name
Email
outreach@ssl.berkeley.edu
Telephone
Address
7 Gauss Way
City
Berkeley
State/Province
CA
Postal Code
94720
Country
USA
Rights
Pulic Domain
Publisher
Publisher ID
WISE
Resource ID
Resource URL
/image/WISE/WISE2011-002
Related Resources
Metadata Date
2011-08-05
Metadata Version
1.2
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Detailed color mapping information coming soon...

 

×
Universescalefull
12,000,000 light years