Antennae galaxies, side-by-side comparison of ALMA and VLT observations

Eso_eso1137d_500

eso_eso1137d October 3rd, 2011

Credit: ALMA (ESO/NAOJ/NRAO). Visible light image: ESO/Alberto Milani.

The Antennae Galaxies (also known as NGC 4038 and 4039) are a pair of distorted colliding spiral galaxies about 70 million light-years away, in the constellation of Corvus (The Crow). This view shows a comparison of the millimetre and submillimetre light observations (left), made in two different wavelength ranges by ALMA during the observatory's early testing phase, with visible-light observations from the ESO Very Large Telescope.Most of the ALMA test observations used to create this image were made using only twelve antennas working together far fewer than will be used for the first science observations and much closer together as well.Both of these factors make the new image just a taster of what is to come. As the observatory grows, the sharpness, speed, and quality of its observations will increase dramatically as more antennas become available and the array grows in size. Even so, this is the best submillimetre-wavelength image ever taken of the Antennae Galaxies and opens a new window on the submillimetre Universe.While visible light reveals the newborn stars in the galaxies, ALMAs view shows us something that cannot be seen at those wavelengths: the clouds of dense cold gas from which new stars form. The ALMA observations shown here in red, pink and yellow were made at specific wavelengths of millimetre and submillimetre light (ALMA bands 3 and 7), tuned to detect carbon monoxide molecules in the otherwise invisible hydrogen clouds, where new stars are forming.Massive concentrations of gas are found not only in the hearts of the two galaxies, but also in the chaotic region where they are colliding. Here, the total amount of gas is billions of times the mass of our Sun a rich reservoir of material for future generations of stars. Observations like these will be vital in helping us understand how the collision of galaxies can trigger the birth of new stars. This is just one example of how ALMA reveals parts of the Universe that cannot be seen with visible-light and infrared telescopes. The ESO VLT image was produced using observational data found by Alberto Milani, who posted his image in the Your ESO Pictures Flickr group.

Image Source: https://www.eso.org/public/images/eso1137d/

Curator: European Southern Observatory, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
Antennae Galaxies NGC 4038 NGC 4039
Subject - Local Universe
Galaxy » Type » Interacting

Color Mapping

  Telescope Spectral Band Wavelength
Arrow_left_blue Very Large Telescope (FORS1) Optical (B) 435.0 nm
Arrow_left_green Very Large Telescope (FORS1) Optical (V) 550.0 nm
Arrow_left_red Very Large Telescope (FORS1) Infrared (I) 814.0 nm
Arrow_left_magenta Very Large Telescope (FORS1) Optical (H-alpha + Nii) 658.0 nm
Arrow_left_purple Atacama Large Millimeter/submillimeter Array (None) Millimeter (ALMA Band 3) 2.6 mm
Arrow_left_green Atacama Large Millimeter/submillimeter Array (None) Millimeter (ALMA band 7) 870.0 µm
Arrow_left_yellow Atacama Large Millimeter/submillimeter Array (None) Millimeter (ALMA band 7) 870.0 µm
Arrow_left_orange Atacama Large Millimeter/submillimeter Array (None) Millimeter (ALMA band 7) 870.0 µm
Arrow_left_red Atacama Large Millimeter/submillimeter Array (None) Millimeter (ALMA band 3) 2.6 mm
Spectrum_ir1
Arrow_top_blue
Arrow_top_green
Arrow_top_red
Arrow_top_magenta
Arrow_top_purple
Arrow_top_green
Arrow_top_yellow
Arrow_top_orange
Arrow_top_red
Eso_eso1137d_1280
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ID
eso1137d
Subject Category
C.5.1.7  
Subject Name
Antennae Galaxies, NGC 4038, NGC 4039
Credits
ALMA (ESO/NAOJ/NRAO). Visible light image: ESO/Alberto Milani.
Lightyears
Redshift
Reference Url
https://www.eso.org/public/images/eso1137d/
Type
Observation
Image Quality
Distance Notes
Facility
Very Large Telescope, Very Large Telescope, Very Large Telescope, Very Large Telescope, Atacama Large Millimeter/submillimeter Array, Atacama Large Millimeter/submillimeter Array, Atacama Large Millimeter/submillimeter Array, Atacama Large Millimeter/submillimeter Array, Atacama Large Millimeter/submillimeter Array
Instrument
FORS1, FORS1, FORS1, FORS1, None, None, None, None, None
Color Assignment
Blue, Green, Red, Magenta, Purple, Green, Yellow, Orange, Red
Band
Optical, Optical, Infrared, Optical, Millimeter, Millimeter, Millimeter, Millimeter, Millimeter
Bandpass
B, V, I, H-alpha + Nii, ALMA Band 3, ALMA band 7, ALMA band 7, ALMA band 7, ALMA band 3
Central Wavelength
435, 550, 814, 658, 2600000, 870000, 870000, 870000, 2600000
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
Equinox
Reference Value
Reference Dimension
6742.0, 3362.0
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
FITS Header
Notes
Creator (Curator)
European Southern Observatory
URL
http://www.eso.org/
Name
Email
Telephone
Address
Karl-Schwarzschild-Strasse 2
City
Garching bei München
State/Province
Postal Code
D-85748
Country
Germany
Rights
Creative Commons Attribution 4.0 International License
Publisher
European Southern Observatory
Publisher ID
eso
Resource ID
eso1137d
Metadata Date
2011-09-28T10:41:50+02:00
Metadata Version
1.0
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Detailed color mapping information coming soon...

 

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There is no distance meta data in this image.