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.

• "Hubble Finds Extremely Distant Galaxy through Cosmic Magnifying Glass". NASA Science. 16 October 2014.
• Zitrin, Adi; Zheng, Wei; Broadhurst, Tom; Moustakas, John; Lam, Daniel; Shu, Xinwen; Huang, Xingxing; Diego, Jose M.; Ford, Holland; Lim, Jeremy; Bauer, Franz E.; Infante, Leopoldo; Kelson, Daniel D.; Molino, Alberto (September 2014). "A Geometrically Supported z ~ 10 Candidate Multiply Imaged by the Hubble Frontier Fields Cluster A2744". The Astrophysical Journal. 793 (1): L12. arXiv:1407.3769. Bibcode:2014ApJ...793L..12Z. doi:10.1088/2041-8205/793/1/L12. ISSN 2041-8213.
• Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Franx, M.; Ammons, S. M.; Dokkum, P. G. van; Trenti, M.; Labbé, I. (2015-07-23). "First Frontier Field Constraints on the Cosmic Star Formation Rate Density at z ∼ 10—The Impact of Lensing Shear on Completeness of High-redshift Galaxy Samples". The Astrophysical Journal. 808 (1): 104. arXiv:1409.1228. Bibcode:2015ApJ...808..104O. doi:10.1088/0004-637X/808/1/104. ISSN 1538-4357.
• "Astronomers unveil the farthest galaxy". phys.org. May 5, 2015.