Cosmic shear in sky field with galaxy cluster

Eso_eso0040a_1024

eso_eso0040a December 1st, 2000

Credit: ESO

The image shows an example of the mapping of the dark mass distribution in one of the 50 sky fields observed with the VLT and FORS1. To the left is the original image, a 36-min exposure in a near-infrared wavelength band. To the right is the reconstructed map of the mass (a "mass photo") in this direction, based on an analysis of the weak shear effect seen in the field; that is, on the measured elongations and directions of the axes of the galaxy images in this field. The brighter areas indicate the directions in which there is most mass along the line of sight. The circle in the left photo surrounds the images of a distant cluster (or group) of galaxies, seen in this direction. Note that there is a corresponding concentration of mass in the "mass photo"; this is obviously the mass of that cluster. The mass reconstruction map shows the (mostly) dark matter responsible for the cosmic shear found on the small scales, now measured with the VLT. Technical information about these photos is available below. Technical information about the photo: The sky photo (left) is reproduced from a 36 min exposure, obtained on 15 June 1999 with VLT ANTU and the multi-mode FORS1 instrument. The optical filter was I (900 nm) and the seeing was 0.53 arcsec. The field measures approx. 6 x 6 arcmin 2. North is up and East is left.

Provider: European Southern Observatory

Image Source: https://www.eso.org/public/images/eso0040a/

Curator: European Southern Observatory, Garching bei München, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

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Image Details

Image Type
Observation
Object Name
Dark Matter Galaxy cluster
Subject - Distant Universe
Galaxy > Grouping > Cluster
Cosmology > Phenomenon > Dark Matter

Color Mapping

  Telescope Spectral Band Wavelength
Grayscale VLT (FORS1) Infrared (I) 900.0 nm
Spectrum_base
Grayscale
Eso_eso0040a_1280
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ID
eso0040a
Subject Category
D.5.5.3   D.6.2.3  
Subject Name
Dark Matter, Galaxy cluster
Credits
ESO
Release Date
2000-12-01T00:00:00
Lightyears
Redshift
Reference Url
https://www.eso.org/public/images/eso0040a/
Type
Observation
Image Quality
Distance Notes
Facility
Very Large Telescope
Instrument
FORS1
Color Assignment
Grayscale
Band
Infrared
Bandpass
I
Central Wavelength
900
Start Time
Integration Time
1160
Dataset ID
Notes
Coordinate Frame
Equinox
Reference Value
Reference Dimension
3000.0, 1479.0
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
eso0040a
Metadata Date
2009-01-20T13:55:46+01:00
Metadata Version
1.1
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Detailed color mapping information coming soon...

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There is no distance meta data in this image.

 

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