泰爾讓7

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泰爾讓7
Terzan 7 by HST.jpg
哈伯太空望遠鏡拍攝的泰爾讓7,視直徑3.5’。
Credit: NASA、ESA、和A. Sarajedini(佛羅里達大學)。Acknowledgement: Gilles Chapdelaine
觀測數據(J2000 曆元)
星座 人馬座
赤經 19h 17m 43.92s[1]
赤緯 -34° 39′ 27.8″[1]
距離 75.7 kly(23.2 kpc[2]
視星等 (V) 12.0[2]
視直徑(V) 7′.3[2]
物理性質
半徑 160 光年[a]
VHB 17.76[3]
估計年齡 7.5 Gyr[4]
值得注意的特色 young extragalactic globular
其它名稱 Ter 7,[4] GCl 109.1[5]
參見:球狀星團球狀星團表

泰爾讓7是鬆散和年輕的球狀星團,被認為起源於人馬座矮椭球星系(Sag DEG)並與之有物理上的關聯。相較之下它是富金屬,它的金屬量是[Fe/H = -0.6[6],並且估計年齡是75億歲[4]。泰爾讓7有少量的([Ni/Fe]=-0.2),因為有著相似的化學特徵,這支持它是人馬座矮椭球星系的成員[7]。它有豐富的藍掉隊星,並且強烈的朝向中心集中[8]。它的平均亮度分佈在Mv = -5.05.[9]。它的半光度半徑(Rh)= 6.5秒差距[10]

歷史[编辑]

泰爾讓7是法國天文學家阿戈普·泰爾讓英语Agop Terzan在1968年發現的[11]最亮的[12]六個球狀星團之一[12]

年輕的球狀星團[编辑]

幾乎所有的銀河系的银晕的球狀星團是同時形成(12-15 Gyr)。 即使是位於遠處的NGC 2419(距離銀河中心約100 kpc)也有相似的年齡。這種趨勢也適用於大麦哲伦星系Fornax Dwarf(來自銀河中心的約140 kpc)發現的球狀團的年齡。

註解[编辑]

  1. ^ 75.7 kly × tan( 7′.3 / 2 ) = 160 ly. radius

參考資料[编辑]

  1. ^ 1.0 1.1 Goldsbury, Ryan; 等, The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters, The Astronomical Journal, December 2010, 140 (6): 1830–1837, Bibcode:2010AJ....140.1830G, arXiv:1008.2755, doi:10.1088/0004-6256/140/6/1830. 
  2. ^ 2.0 2.1 2.2 Terzan 7 @ seds, (原始内容存档于2002-10-24) 
  3. ^ Wilson, Barbara, Obscure Globulars, July 2, 1995 
  4. ^ 4.0 4.1 4.2 Geisler, Doug; Wallerstein, George; Smith, Verne V.; Casetti-Dinescu, Dana I., Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo, The Publications of the Astronomical Society of the Pacific, September 2007, 119 (859): 939–961, Bibcode:2007PASP..119..939G, arXiv:0708.0570, doi:10.1086/521990 
  5. ^ SIMBAD Astronomical Object Database. Results for Terzan 7. [2008-01-27]. 
  6. ^ Sbordone, L.; Bonifacio, P.; Marconi, G.; Buonanno, R.; Zaggia, S., Family ties: Abundances in Terzan 7, a Sgr dSph globular cluster, Astronomy and Astrophysics, July 3, 2005, 437 (3): 905–910, Bibcode:2005A&A...437..905S, arXiv:astro-ph/0505307, doi:10.1051/0004-6361:20042315 
  7. ^ Sbordone, L.; Bonifacio, P.; Marconi, G.; Buonanno, R., Chemical abundances in Terzan 7, Memorie della Societa Astronomica Italiana, 2004, 75: 396, Bibcode:2004MmSAI..75..396S 
  8. ^ Held, Enrico V.; Rosenberg, Alfred; Saviane, Ivo; Momany, Yazan, 写于Pucon, Chile, Geisler, D.; Grebel, E.K.; Minniti, D., 编, The Globular Cluster Terzan 7 in the Sagittarius Dwarf Spheroidal Galaxy, Astronomical Society of the Pacific (San Francisco), March 12–16, 2001: 165 (2002), Bibcode:2002IAUS..207..165H 
  9. ^ van den Bergh, Sidney, The Luminosity Distribution of Globular Clusters in Dwarf Galaxies, The Astronomical Journal, July 2007, 134 (1): 344–345, Bibcode:2007AJ....134..344V, arXiv:0704.2226, doi:10.1086/518868 
  10. ^ van den Bergh, Sidney, Young Globular Clusters and Dwarf Spheroidals, The Astrophysical Journal, February 2000, 530 (2): 777–782, Bibcode:2000ApJ...530..777V, arXiv:astro-ph/9910243, doi:10.1086/308413 
  11. ^ Terzan, Agop, Six nouveaux amas stellaires (Terzan 3-8) dans la region DU centre de la Voie lactee et les constellations DU Scorpion et DU Sagittaire, C.R. Acad. Sci., 1968, 267 (Ser. B): 1245–1248, Bibcode:1968CRASB.267.1245T 
  12. ^ 12.0 12.1 Gottlieb, Steve, Sky and Telescope, August 1, 2000, 100 (2): 112, ISSN 0037-6604  缺少或|title=为空 (帮助)
天球赤道座標星图 19h 17m 43.5s,−34°39′27″