|
UDFy-38135539 (also known as "HUDF.YD3") is the Hubble Ultra Deep Field (UDF) identifier for a galaxy which was calculated to have a light travel time of 13.1 billion years〔 with a present proper distance of around 30 billion light-years. It was discovered by three teams in September 2009 in sensitive infrared Hubble Space Telescope images and identified by these as source UDF-38135539 (R Bouwens ''et al''.,) source HUDF.YD3 (A Bunker ''et al''.) and source 1721 (R McLure ''et al''.), and additionally reported in the ''Astrophysical Journal'', and the ''Monthly Notices of the Royal Astronomical Society''. All teams independently identified the source likely an extremely distant galaxy because there were no measurable light at visible wavelengths (caused by absorption of hydrogen gas along the line of sight). Following the discovery of this candidate distant galaxy, another team targeted this object with ground-based spectroscopy to confirm the distance, reporting a redshift z=8.6. However, attempts to replicate this observation strongly suggest the original claim was in error, meaning that at the present time the galaxy only has a photometric redshift estimate. 〔VLT/XSHOOTER & Subaru/MOIRCS Spectroscopy of HUDF-YD3: No Evidence for Lyman-alpha Emission at z=8.55〕 == Detection == Its first known imaging was in Hubble telescope's Hubble Ultra Deep Field, the most detailed deep space picture at that time.〔 The galaxy was observed in August and September 2009.〔(【引用サイトリンク】title=Dim galaxy is most distant object yet found )〕 The image data was released to the scientific community, which led to the galaxy's detection by the teams of Bouwens,〔 Bunker〔 and McLure,〔 and subsequent spectroscopic campaign by the team of Lehnert and colleagues. Just on Hubble data, the galaxy could be an object intrinsically red and relatively close to Earth,〔 therefore, confirmation using suitably sensitive spectroscopic equipment was needed.〔 This was attempted using the European Southern Observatory's SINFONI-equipped Very Large Telescope unit Yepun, located atop Cerro Paranal in Chile's Atacama Desert.〔〔 Lehnert's team observed the galaxy for 16 hours, and then analysed their results over 2 months,〔 and published their findings in ''Nature'', in October 2010.〔 Since then, more sensitive measurements have failed to replicate the result, suggesting the spectroscopic claim was in error. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「UDFy-38135539」の詳細全文を読む スポンサード リンク
|