Hubble Space Telescope's newly repaired Advanced Camera for Surveys (ACS) has peered nearly 5 billion light-years away to resolve intricate details in the galaxy cluster Abell 370.
Abell 370 is one of the very first galaxy clusters where astronomers observed the phenomenon of gravitational lensing, where the warping of space by the cluster's gravitational field distorts the light from galaxies lying far behind it. This is manifested as arcs and streaks in the picture, which are the stretched images of background galaxies.
Gravitational lensing proves a vital tool for astronomers when measuring the dark matter distribution in massive clusters, since the mass distribution can be reconstructed from its gravitational effects.
Ground-based telescopic observations in the mid-1980s of the most prominent arc (near the right-hand side of the picture) allowed astronomers to deduce that the arc was not a structure of some kind within the cluster, but the gravitationally lensed image of an object two times farther away. Hubble resolves unseen new details in the arc that reveal structure in the lensed background galaxy.
Galaxy clusters are the most massive structures of the universe, located at the crossing of the filaments of the cosmic web of dark matter. The most massive clusters can contain up to 1,000 galaxies and intergalactic hot gas, all held together primarily by the gravity of dark matter.
These observations were taken with Hubble's Advanced Camera for Surveys (ACS) in its Wide Field mode on July 16, 2009. The composite image was made using filters that isolate light from green, red, and infrared wavelengths.
These Hubble data are part of the Hubble Servicing Mission 4 Early Release Observations.
Credits
NASA, ESA, the Hubble SM4 ERO Team, and ST-ECF| About The Object | |
|---|---|
| Object Name | Abell 370 |
| Object Description | Cluster of Galaxies |
| R.A. Position | 02h 39m 49.9s |
| Dec. Position | -1° 34' 26.69" |
| Constellation | Cetus |
| Distance | 4.9 billion light-years (1.5 billion parsecs) |
| Dimensions | This image is 2.4 arcminutes (3.4 million light-years or 1 million parsecs) wide. |
| About The Data | |
| Data Description | The Hubble images were created from data from proposal : K. Noll (STScI), M. Chiaberge (STScI/ESA/INAF), M. Mutchler, D. Golimowski, and R. Lucas (STScI), and M. Sirianni (STScI/ESA). Acknowledgments for Abell 370 Observers: K. Noll (STScI), M. Chiaberge (STScI/ESA/INAF), M. Mutchler, D. Golimowski, and R. Lucas (STScI), and M. Sirianni (STScI/ESA) Data Analysis: M. Mutchler (STScI) and R. Hook (ST-ECF) Image Composition: R. Hook, O. Hainaut, A. Bombik, and L. Christensen (ST-ECF), Z. Levay and L. Frattare (STScI) Text: L. Frattare, D. Weaver, and R. Villard (STScI) and C. Sharkey and M. Lombardi (ST-ECF) Illustrations: Z. Levay (STScI) Video: G. Bacon (STScI) Science Consultants: M. Livio and B. Whitmore (STScI) and J.-P. Kneib (Observatoire Midi-Pyrenées) |
| Instrument | HST>ACS/WFC |
| Exposure Dates | July 16, 2009, Exposure Time: 3.5 hours |
| Filters | F475W (G), F625W (R), and F814W (I) |
| About The Image | |
| Color Info | The image is a composite of separate exposures made by the ACS instrument on the Hubble Space Telescope. Three filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Blue: F475W (G) Green: F625W (R) Red: F814W (I) |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
