A DOUBLE MAIN SEQUENCE IN THE GLOBULAR CLUSTER NGC 6397

被引:90
|
作者
Milone, A. P. [1 ,2 ]
Marino, A. F. [3 ]
Piotto, G. [4 ,5 ]
Bedin, L. R. [6 ]
Anderson, J. [6 ]
Aparicio, A. [1 ,2 ]
Cassisi, S. [7 ]
Rich, R. M. [8 ]
机构
[1] Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain
[2] Univ La Laguna, Dept Astrophys, E-38200 San Cristobal la Laguna, Tenerife, Spain
[3] Max Planck Inst Astrophys, D-85741 Garching, Germany
[4] Univ Padua, Dipartimento Astron, I-35122 Padua, Italy
[5] INAF Osservatorio Astron Padova, I-35122 Padua, Italy
[6] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[7] INAF Osservatorio Astron Collurania, I-64100 Teramo, Italy
[8] Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA
关键词
globular clusters: individual (NGC 6397); stars: Population II; MULTIPLE STELLAR POPULATIONS; ADVANCED CAMERA; OMEGA-CENTAURI; GIANT STARS; ACS SURVEY; ABUNDANCES; NGC-6397; BRANCH; ASTROMETRY; NGC-2808;
D O I
10.1088/0004-637X/745/1/27
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
High-precision multi-band Hubble Space Telescope (HST) photometry reveals that the main sequence of the globular cluster NGC 6397 splits into two components, containing similar to 30% and similar to 70% of the stars. This double sequence is consistent with the idea that the cluster hosts two stellar populations: (1) a primordial population that has a composition similar to field stars, containing similar to 30% of the stars, and (2) a second generation with enhanced sodium and nitrogen, depleted carbon and oxygen, and a slightly enhanced helium abundance (Delta Y similar to 0.01). We examine the color difference between the two sequences across a variety of color baselines and find that the second sequence is anomalously faint in m(F336W). Theoretical isochrones indicate that this could be due to NH depletion.
引用
收藏
页数:10
相关论文
共 50 条
  • [31] A theoretical approach to globular cluster low main sequence stars
    Alexander, DR
    Brocato, E
    Cassisi, S
    Castellani, V
    Ciacio, F
    Degl'Innocenti, S
    ASTRONOMY & ASTROPHYSICS, 1997, 317 (01) : 90 - 98
  • [32] The globular cluster NGC 6642: evidence for a depleted mass function in a very old cluster
    Balbinot, E.
    Santiago, B. X.
    Bica, E.
    Bonatto, C.
    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2009, 396 (03) : 1596 - 1602
  • [33] Searching for globular cluster chemical anomalies on the main sequence of a young massive cluster
    Cabrera-Ziri, I.
    Speagle, J. S.
    Dalessandro, E.
    Usher, C.
    Bastian, N.
    Salaris, M.
    Martocchia, S.
    Kozhurina-Platais, V.
    Niederhofer, F.
    Lardo, C.
    Larsen, S. S.
    Saracino, S.
    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2020, 495 (01) : 375 - 382
  • [34] MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397
    Kamann, S.
    Husser, T. -O.
    Brinchmann, J.
    Emsellem, E.
    Weilbacher, P. M.
    Wisotzki, L.
    Wendt, M.
    Krajnovic, D.
    Roth, M. M.
    Bacon, R.
    Dreizler, S.
    ASTRONOMY & ASTROPHYSICS, 2016, 588
  • [35] The Age of the Old Metal-poor Globular Cluster NGC 6397 Using WFC3/IR Photometry
    Correnti, Matteo
    Gennaro, Mario
    Kalirai, Jason S.
    Cohen, Roger E.
    Browns, Thomas M.
    ASTROPHYSICAL JOURNAL, 2018, 864 (02)
  • [36] JWST imaging of the closest globular clusters-I. Possible infrared excess among white dwarfs in NGC 6397
    Bedin, L. R.
    Nardiello, D.
    Salaris, M.
    Libralato, M.
    Bergeron, P.
    Burgasser, A. J.
    Apai, D.
    Griggio, M.
    Scalco, M.
    Anderson, J.
    Gerasimov, R.
    Bellini, A.
    ASTRONOMISCHE NACHRICHTEN, 2024, 345 (6-7)
  • [37] Spectroscopic analysis of the two subgiant branches of the globular cluster NGC 1851
    Gratton, R. G.
    Villanova, S.
    Lucatello, S.
    Sollima, A.
    Geisler, D.
    Carretta, E.
    Cassisi, S.
    Bragaglia, A.
    ASTRONOMY & ASTROPHYSICS, 2012, 544
  • [38] NGC 362: another globular cluster with a split red giant branch
    Carretta, E.
    Bragaglia, A.
    Gratton, R. G.
    Lucatello, S.
    D'Orazi, V.
    Bellazzini, M.
    Catanzaro, G.
    Leone, F.
    Momany, Y.
    Sollima, A.
    ASTRONOMY & ASTROPHYSICS, 2013, 557
  • [39] Globular cluster candidates in NGC 891
    Harris, W. E.
    Mouhcine, M.
    Rejkuba, M.
    Ibata, R.
    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2009, 395 (01) : 436 - 442
  • [40] EVIDENCE FOR ENRICHMENT BY SUPERNOVAE IN THE GLOBULAR CLUSTER NGC 6273
    Han, Sang-Il
    Lim, Dongwook
    Seo, Hyunju
    Lee, Young-Wook
    ASTROPHYSICAL JOURNAL LETTERS, 2015, 813 (02)