Monster galaxy lacks a bright core
The giant elliptical galaxy in the centre of this image, taken by the NASA/ESA Hubble Space Telescope, is the most massive and brightest member of the galaxy cluster Abell 2261.
Spanning a little over one million light-years, the galaxy is about 20 times the diameter of our Milky Way galaxy. The bloated galaxy is a member of an unusual class of galaxies with a diffuse core filled with a fog of starlight. Normally, astronomers would expect to see a concentrated peak of light around a central black hole. The Hubble observations revealed that the galaxy's puffy core, measuring about 10 000 light-years, is the largest yet seen.
The observations present a mystery, and studies of this galaxy may provide insight into how black hole behavior may shape the cores of galaxies.
Astronomers used Hubble's Advanced Camera for Surveys and Wide Field Camera 3 to measure the amount of starlight across the galaxy, catalogued as 2MASX J17222717+3207571 but more commonly called A2261-BCG (short for Abell 2261 brightest cluster galaxy). Abell 2261 is located three billion light-years away.
The observations were taken between March and May 2011. The Abell 2261 cluster is part of a multi-wavelength survey called the Cluster Lensing And Supernova survey with Hubble (CLASH).
Credit:
NASA, ESA, M. Postman (Space Telescope Science Institute, USA), T. Lauer (National Optical Astronomy Observatory, USA), and the CLASH team.
About the Image
| Id: | heic1216a |
| Type: | Observation |
| Release date: | 25 October 2012, 19:00 |
| Related releases: | heic1216 |
| Size: | 2641 x 1796 px |
About the Object
| Name: | 2MASX J17222717+3207571, Abell 2261 |
| Type: | • Local Universe : Galaxy : Grouping : Cluster • Early Universe : Galaxy : Type : Elliptical • Galaxies Images/Videos |
| Distance: | 3 billion light years |
Colours & filters
| Band | Wavelength | Telescope |
| Optical B |
475 nm | Hubble Space Telescope ACS |
| Optical B |
435 nm | Hubble Space Telescope ACS |
| Optical R |
606 nm | Hubble Space Telescope ACS |
| Optical R |
625 nm | Hubble Space Telescope ACS |
| Infrared I |
775 nm | Hubble Space Telescope ACS |
| Infrared I |
850 nm | Hubble Space Telescope ACS |
| Infrared Y |
1.05 μm | Hubble Space Telescope WFC3 |
| Infrared Y |
1.1 μm | Hubble Space Telescope WFC3 |
| Infrared J |
1.25 μm | Hubble Space Telescope WFC3 |
| Infrared J |
1.4 μm | Hubble Space Telescope WFC3 |
| Infrared H |
1.6 μm | Hubble Space Telescope WFC3 |
