A cosmic quartet

Eso_potw2130a_1024

eso_potw2130a July 26th, 2021

Credit: ESO/Ragusa, Spavone et al.

Space can be a lonely place. But not so for this quartet of galaxies making up HCG 86 and observed here with ESOs VLT Survey Telescope (VST). The four galaxies located approximately 270 million light years from Earth in the Sagittarius constellation, are seen from Earth as arranged in triangular shape, with three of them on a straight line and one underneath; the bright objects to the right of the elongated galaxy are not part of the quartet. HCG stands for Hickson Compact Group, and is used to describe groups of four to ten galaxies where members are physically very close to each other. Because of their compactness, such groups are ideal environments to study galactic interactions, which can sometimes lead to galaxies merging with each other. This image of HCG 86 was taken by a team of astronomers led by Rossella Ragusa of the Istituto Nazionale di Astrofisica in Italy as part of the VST Early-type Galaxy Survey (VEGAS) programme. With VST we are able to investigate very faint structures in the galaxies' outskirts, which are the relics of past gravitational interactions and merging events, says Ragusa. In particular, by mapping the light distribution in and around the groups galaxies in this study, the team concluded that these faint structures are the leftovers of satellite galaxies gobbled by the group approximately seven billion years ago. Located at ESOs Paranal Observatory in Chile, the VST is one of the worlds largest survey telescopes, devoted to mapping the sky in visible light wavelengths. 2021 marks the anniversary of its first decade of operation, a period during which it has helped to search for planets outside the Solar System and probe the structure of our galaxy and the wider Universe.

Provider: European Southern Observatory

Image Source: https://www.eso.org/public/images/potw2130a/

Curator: European Southern Observatory, Garching bei München, None, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
HCG 86
Subject - Local Universe
Galaxy > Type > Interacting
Eso_potw2130a_128
 

Position Details

Position (ICRS)
RA = 19h 51m 59.3s
DEC = -30° 49’ 32.8”
Orientation
North is up
Field of View
15.6 x 10.8 arcminutes
Constellation
Sagittarius

Color Mapping

  Telescope Spectral Band Wavelength
Blue VST (OmegaCAM) Optical (g) 480.0 nm
Green VST (OmegaCAM) Optical (r) 625.0 nm
Red VST (OmegaCAM) Optical (i) 770.0 nm
Spectrum_base
Blue
Green
Red
Eso_potw2130a_1280
×
ID
potw2130a
Subject Category
C.5.1.7  
Subject Name
HCG 86
Credits
ESO/Ragusa, Spavone et al.
Release Date
2021-07-26T06:00:00
Lightyears
Redshift
Reference Url
https://www.eso.org/public/images/potw2130a/
Type
Observation
Image Quality
Distance Notes
Facility
VLT Survey Telescope, VLT Survey Telescope, VLT Survey Telescope
Instrument
OmegaCAM, OmegaCAM, OmegaCAM
Color Assignment
Blue, Green, Red
Band
Optical, Optical, Optical
Bandpass
g, r, i
Central Wavelength
480, 625, 770
Start Time
Integration Time
Dataset ID
None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
297.997005264, -30.8257774168
Reference Dimension
4691.0, 3229.0
Reference Pixel
2345.0, 1614.5
Scale
-5.55637019554e-05, 5.55637019554e-05
Rotation
-0
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
European Southern Observatory
URL
https://www.eso.org
Name
Email
Telephone
Address
Karl-Schwarzschild-Strasse 2
City
Garching bei München
State/Province
None
Postal Code
D-85748
Country
Germany
Rights
Creative Commons Attribution 4.0 International License
Publisher
European Southern Observatory
Publisher ID
eso
Resource ID
potw2130a
Metadata Date
2021-07-19T13:08:17+02:00
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.