This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars.
Dark matter is an invisible form of matter that accounts for most of the universe's mass. Hubble cannot see the dark matter directly. Astronomers inferred its location by analyzing the effect of gravitational lensing, where light from galaxies behind Abell 1689 is distorted by intervening matter within the cluster.
Researchers used the observed positions of 135 lensed images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue, on an image of the cluster taken by Hubble's Advanced Camera for Surveys. If the cluster's gravity came only from the visible galaxies, the lensing distortions would be much weaker. The map reveals that the densest concentration of dark matter is in the cluster's core.
Abell 1689 resides 2.2 billion light-years from Earth. The image was taken in June 2002.
Credits
NASA, ESA, D. Coe (NASA Jet Propulsion Laboratory/California Institute of Technology, and Space Telescope Science Institute), N. Benitez (Institute of Astrophysics of Andalusia, Spain), T. Broadhurst (University of the Basque Country, Spain), and H. Ford (Johns Hopkins University)| About The Object | |
|---|---|
| Object Name | Abell 1689 |
| Object Description | Galaxy Cluster |
| R.A. Position | 13h 11m 29.5s |
| Dec. Position | -1° 20' 17.01" |
| Constellation | Virgo |
| Distance | The distance to the lensing cluster is 2.2 billion light-years (675 megaparsecs). The distances to the lensed galaxies are between 7 and 12 billion light-years. |
| About The Data | |
| Data Description | ACS/WFC data of Abell 1689 were observed with the HST proposal : H. Ford and N. Benitez (Johns Hopkins University), and T. Broadhurst (Tel Aviv University). The science team includes: D. Coe (NASA JPL/Caltech and STScI), N. Benitez (Institute of Astrophysics of Andalusia, Spain), T. Broadhurst (University of the Basque Country, Spain), and H. Ford (Johns Hopkins University). |
| Instrument | HST>ACS/WFC |
| Exposure Dates | June 2002, Exposure Time: 13 hours |
| Filters | F475W (g), F625W (r), F775W (i), and F850LP (z) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the ACS instrument on the Hubble Space Telescope (HST). Several filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan: Dark Matter Map Blue: F475W (g) Green: F625W (r) Red: F775W (i) + F850LP (z) |
| 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. |
