A2744-JD
| A2744-JD | |
|---|---|
| Observation data | |
| Constellation | Sculptor |
| Right ascension | 00 h 14 min 21.2 s |
| Declination | -30° 23' 50.1" |
| Redshift | ~9.8 |
| Characteristics | |
| Size | 850 light years |
A2744-JD is an extremely distant galaxy, identified with the Hubble Space Telescope through gravitational lensing, observing the massive galaxy cluster Abell 2744, also known as Pandora's Cluster. Due to the high redshift (z = ~10), a triple red spot image was obtained of a galaxy observed at an epoch when the Universe was about 500 million years after the Big Bang (approximately 3% of its current age) and whose light took more than 13 billion years to reach Earth. The gravitational lensing effect made it possible to enhance the image of such a distant and extremely faint galaxy by increasing its luminosity about 10 times.
A2744 is a small, primordial galaxy; at the time of the image, it is estimated to have a diameter of only 850 light-years, a mass of about 40 million solar masses, and a star formation rate of one star every three years.
The age of A2744-JD places this galaxy in the reionization phase of the Universe's evolution, a period in which extragalactic hydrogen was transitioning from a neutral to an ionized state. It has been hypothesized that these galaxies, formed early in the Universe's history, were one of the causes of the reionization process.
References
^ HubbleSite - NewsCenter - Hubble Finds Extremely Distant Galaxy Through Cosmic Magnifying Glass (10/16/2014) - The full story, at hubblesite.org. URL accessed August 9, 2015.
^ Adi Zitrin, Wei Zheng, and Tom Broadhurst, "A z~10 Candidate with Multiply Geometric Support from the Hubble Frontier Fields Image of Cluster A2744,""A z~10 Candidate with Multiply Geometric Support from the Hubble Frontier Fields Image of Cluster A2744,"-8205/793/1/L12. URL accessed August 9, 2015.
^ P. A. Oesch, R. J. Bouwens, and G. D. Illingworth, First-frontier field constraints on the cosmic star formation rate density at z ~ 10: The impact of lensing shear on the completeness of high-redshift galaxy samples, in the Astrophysical Journal, vol. 808, no. 1, July 20, 2015, p. 104, DOI: 10.1088/0004-637X/808/1/104 . URL accessed August 9, 2015.
^ "Astronomers discover the most distant galaxy", in phys.org. Accessed August 9, 2015