nigel.stanger / Digital_Repository
Transfer to URL with SHA Find file
Newer
Older
Digital_Repository / Misc / Mass downloads / UTas / 2509.html
Nigel Stanger on 7 May 2013 40 KB - Imported Misc directory.
Raw Blame History 
  1. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
  2. "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  3. <html>
  4.   <head>
  5.     <title>UTas ePrints - Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation</title>
  6.     <script type="text/javascript" src="http://eprints.utas.edu.au/javascript/auto.js"><!-- padder --></script>
  7.     <style type="text/css" media="screen">@import url(http://eprints.utas.edu.au/style/auto.css);</style>
  8.     <style type="text/css" media="print">@import url(http://eprints.utas.edu.au/style/print.css);</style>
  9.     <link rel="icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
  10.     <link rel="shortcut icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
  11.     <link rel="Top" href="http://eprints.utas.edu.au/" />
  12.     <link rel="Search" href="http://eprints.utas.edu.au/cgi/search" />
  13.     <meta content="Cole, A.A." name="eprints.creators_name" />
  14. <meta content="Tolstoy, E." name="eprints.creators_name" />
  15. <meta content="Gallagher, J.S." name="eprints.creators_name" />
  16. <meta content="Smecker-Hane, T.A." name="eprints.creators_name" />
  17. <meta content="andrew.cole@utas.edu.au" name="eprints.creators_id" />
  18. <meta content="" name="eprints.creators_id" />
  19. <meta content="" name="eprints.creators_id" />
  20. <meta content="" name="eprints.creators_id" />
  21. <meta content="article" name="eprints.type" />
  22. <meta content="2007-11-28 23:46:23" name="eprints.datestamp" />
  23. <meta content="2008-02-07T02:08:42Z" name="eprints.lastmod" />
  24. <meta content="show" name="eprints.metadata_visibility" />
  25. <meta content="Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation" name="eprints.title" />
  26. <meta content="pub" name="eprints.ispublished" />
  27. <meta content="240101" name="eprints.subjects" />
  28. <meta content="restricted" name="eprints.full_text_status" />
  29. <meta content="Galaxies: Evolution, Galaxies: Stellar Content, Galaxies: Magellanic Clouds" name="eprints.keywords" />
  30. <meta content="http://www.journals.uchicago.edu/AJ/home.html" name="eprints.note" />
  31. <meta content="We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 arcmin2 area at the optical center of the LMC bar. These are the first spectroscopic abundance measurements of intermediate-age and old field stars in the high surface brightness heart of the LMC. The metallicity distribution is sharply peaked at the median value [Fe/H]=-0.40, with a small tail of stars extending down to [Fe/H]<=-2.1 10% of the red giants are observed to have [Fe/H]<=-0.7. The relative lack of metal-poor stars indicates that the LMC has a ``G dwarf'' problem, similar to the Milky Way. The abundance distribution can be closely approximated by two Gaussians containing 89% and 11% of the stars, respectively: the first component is centered at [Fe/H]=-0.37 with σ=0.15, and the second at [Fe/H]=-1.08 with σ=0.46. The dominant population has a metallicity distribution similar to that of the LMC's intermediate-age star clusters. The mean heliocentric radial velocity of the sample is 257 km s-1, corresponding to the same center-of-mass velocity as the disk (measured at larger radii). Because of the central location of our field, kinematic constraints are not strong, but there is no evidence that the bar deviates from the general motion of the LMC disk. The velocity dispersion of the whole sample is σv=24.7+/-0.4 km s-1. When cut by metallicity, the most metal-poor 5% of stars ([Fe/H]<-1.15) show σv=40.8+/-1.7 km s-1, more than twice the value for the most metal-rich 5%; this suggests that an old, thicker disk or halo population is present. The age-metallicity relation (AMR) is almost flat during the period from 5 to 10 Gyr ago, with an apparent scatter of +/-0.15 dex about the mean metallicity for a given age. Comparing this to chemical evolution models from the literature, we find that a burst of star formation 3 Gyr ago does not reproduce the observed AMR more closely than a steadily declining star formation rate. The AMR suggests that the epoch of enhanced star formation, if any, must have commenced earlier, ~6 Gyr ago-the exact time is model dependent. We compare the properties of the LMC and the Milky Way, and discuss our results in the context of models that attempt to use tidal interactions with the Milky Way and Small Magellanic Cloud to explain the star and cluster formation histories of the LMC. " name="eprints.abstract" />
  32. <meta content="2005-03" name="eprints.date" />
  33. <meta content="published" name="eprints.date_type" />
  34. <meta content="The Astronomical Journal" name="eprints.publication" />
  35. <meta content="129" name="eprints.volume" />
  36. <meta content="3" name="eprints.number" />
  37. <meta content="1465-1482" name="eprints.pagerange" />
  38. <meta content="10.1086/428007" name="eprints.id_number" />
  39. <meta content="TRUE" name="eprints.refereed" />
  40. <meta content="0004-6256" name="eprints.issn" />
  41. <meta content="http://dx.doi.org/10.1086/428007" name="eprints.official_url" />
  42. <meta content="Alcock, C., et al. 2004, AJ, 127, 334 First citation in article | Full Text | NASA ADS 
  43. Armandroff, T. E., &amp; Da Costa, G. S. 1991, AJ, 101, 1329 First citation in article | NASA ADS 
  44. Armandroff, T. E., &amp; Zinn, R. 1988, AJ, 96, 92 First citation in article | NASA ADS 
  45. Bekki, K., Couch, W. J., Beasley, M. A., Forbes, D. A., Chiba, M., &amp; Da Costa, G. S. 2004, ApJ, 610, L93 First citation in article | Full Text | NASA ADS 
  46. Bensby, T., Feltzing, S., &amp; Lundström, I. 2004, A&amp;A, 421, 969 First citation in article | NASA ADS | CrossRef 
  47. Bessell, M. S., Castelli, F., &amp; Plez, B. 1998, A&amp;A, 333, 231 First citation in article | NASA ADS 
  48. Bica, E., Claría, J. J., &amp; Dottori, H. 1992, AJ, 103, 1859 First citation in article | NASA ADS 
  49. Binney, J. J., Dehnen, W., &amp; Bertelli, G. 2000, MNRAS, 318, 658 First citation in article | NASA ADS | CrossRef 
  50. Blair, W. P., et al. 2000, ApJ, 537, 667 First citation in article | Full Text | NASA ADS 
  51. Bonatto, C., Bica, E., &amp; Girardi, L. 2004, A&amp;A, 415, 571 First citation in article | NASA ADS | CrossRef 
  52. Bosler, T. L. 2004, Ph.D. thesis, Univ. California, Irvine First citation in article 
  53. Bosler, T. L., Smecker-Hane, T. A., Cole, A. A., &amp; Stetson, P. B. 2004, in Origin and Evolution of the Elements, ed. A. McWilliam &amp; M. Rauch (Pasadena: Carnegie Obs.), 5 First citation in article 
  54. Butcher, H. 1977, ApJ, 216, 372 First citation in article | NASA ADS 
  55. Carretta, E., Cohen, J. G., Gratton, R. G., &amp; Behr, B. B. 2001, AJ, 122, 1469 First citation in article | Full Text | NASA ADS 
  56. Carretta, E., &amp; Gratton, R. G. 1997, A&amp;AS, 121, 95 (CG97) First citation in article | NASA ADS 
  57. Cenarro, A. J., Gorgas, J., Cardiel, N., Vazdekis, A., &amp; Peletier, R. F. 2002, MNRAS, 329, 863 First citation in article | NASA ADS | CrossRef 
  58. Cohen, R. S., Dame, T. M., Garay, G., Montani, J., Rubio, M., &amp; Thaddeus, P. 1988, ApJ, 331, L95 First citation in article | NASA ADS 
  59. Cole, A. A., Smecker-Hane, T. A., &amp; Gallagher, J. S. 2000, AJ, 120, 1808 (Paper I) First citation in article | Full Text | NASA ADS 
  60. Cole, A. A., Smecker-Hane, T. A., &amp; Mandushev, G. 2002, in ASP Conf. Ser. 274, Observed HR Diagrams and Stellar Evolution, ed. T. Lejeune &amp; J. Fernandes (San Francisco: ASP), 497 First citation in article 
  61. Cole, A. A., Smecker-Hane, T. A., Tolstoy, E., Bosler, T. L., &amp; Gallagher, J. S. 2004, MNRAS, 347, 367 (Paper III) First citation in article | NASA ADS 
  62. Cole, A. A., et al. 2005, in preparation First citation in article 
  63. Cutri, R. M. 2003, Explanatory Supplement to the 2MASS All Sky Data Release (Pasadena: IPAC), http://www.ipac.caltech.edu/2mass/releases/allsky/doc/explsup.html First citation in article 
  64. Da Costa, G. S. 1991, in IAU Symp. 148, The Magellanic Clouds, ed. R. Haynes &amp; D. Milne (Dordrecht: Kluwer), 183 First citation in article 
  65. de Vaucouleurs, G., &amp; Freeman, K. C. 1972, Vistas Astron., 14, 163 First citation in article | NASA ADS | CrossRef 
  66. Dopita, M. A., et al. 1997, ApJ, 474, 188 First citation in article | Full Text | NASA ADS 
  67. Dottori, H., Bica, E., Claría, J. J., &amp; Puerari, I. 1996, ApJ, 461, 742 First citation in article | NASA ADS 
  68. Fitzpatrick, E. L., Ribas, I., Guinan, E. F., Maloney, F. P., &amp; Claret, A. 2003, ApJ, 587, 685 First citation in article | Full Text | NASA ADS 
  69. Freedman, W. L., et al. 2001, ApJ, 553, 47 First citation in article | Full Text | NASA ADS 
  70. Freeman, K., &amp; Bland-Hawthorn, J. 2002, ARA&amp;A, 40, 487 First citation in article | NASA ADS 
  71. Freeman, K. C., Illingworth, G., &amp; Oemler, A. Jr. 1983, ApJ, 272, 488 First citation in article | NASA ADS 
  72. Friel, E. D., Janes, K. A., Tavarez, M., Scott, J., Katsanis, R., Lotz, J., Hong, L., &amp; Miller, N. 2002, AJ, 124, 2693 (Paper III) First citation in article | Full Text | NASA ADS 
  73. Gallagher, J. S., III, et al. 1996, ApJ, 466, 732 First citation in article | NASA ADS 
  74. Gardiner, L. T. 1999, in IAU Symp. 190, New Views of the Magellanic Clouds, ed. Y.-H. Chu, et al. (San Francisco: ASP), 480 First citation in article 
  75. Gardiner, L. T., Sawa, T., &amp; Fujimoto, M. 1994, MNRAS, 266, 567 First citation in article | NASA ADS 
  76. Geha, M. C., et al. 1998, AJ, 115, 1045 First citation in article | Full Text | NASA ADS 
  77. Geisler, D., Bica, E., Dottori, H., Clariá, J. J., Piatti, A. E., &amp; Santos, J. F. C., Jr. 1997, AJ, 114, 1920 First citation in article | NASA ADS 
  78. Girardi, L., Bressan, A., Bertelli, G., &amp; Chiosi, C. 2000, A&amp;AS, 141, 371 First citation in article | NASA ADS 
  79. Gratton, R. G., Bragaglia, A., Clementini, G., Carretta, E., Di Fabrizio, L., Maio, M., &amp; Taribello, E. 2004, A&amp;A, 421, 937 First citation in article | NASA ADS | CrossRef 
  80. Hansen, B. M. S., &amp; Liebert, J. 2003, ARA&amp;A, 41, 465 First citation in article | NASA ADS 
  81. Hayashi, C., Hshi, R., &amp; Sugimoto, D. 1962, Prog. Theor. Phys. Supp. 22 First citation in article 
  82. Hill, V., François, P., Spite, M., Primas, F., &amp; Spite, F. 2000, A&amp;A, 364, L19 First citation in article | NASA ADS 
  83. Hill, V., et al. 2005, in preparation First citation in article 
  84. Hodge, P. W. 1972, PASP, 84, 365 First citation in article | NASA ADS 
  85. Hodge, P. W., &amp; Wright, F. W. 1967, The Large Magellanic Cloud (Washington: Smithsonian Press) First citation in article 
  86. Holtzman, J. A., et al. 1999, AJ, 118, 2262 First citation in article | Full Text | NASA ADS 
  87. Hoyle, F., &amp; Schwarzschild, M. 1955, ApJS, 2, 1 First citation in article | NASA ADS 
  88. Hughes, S. M. G., Wood, P. R., &amp; Reid, N. 1991, AJ, 101, 1304 First citation in article | NASA ADS 
  89. Hurley-Keller, D., Mateo, M., &amp; Nemec, J. 1998, AJ, 115, 1840 First citation in article | Full Text | NASA ADS 
  90. Irwin, M., &amp; Tolstoy, E. 2002, MNRAS, 336, 643 First citation in article | NASA ADS | CrossRef 
  91. Johnson, J. A., Bolte, M., Hesser, J. E., Ivans, I. I., &amp; Stetson, P. B. 2004, in Origin and Evolution of the Elements, ed. A. McWilliam &amp; M. Rauch (Pasadena: Carnegie Obs.), 29 First citation in article 
  92. Jørgensen, U. G., Carlsson, M., &amp; Johnson, H. R. 1992, A&amp;A, 254, 258 First citation in article | NASA ADS 
  93. Kauffmann, G., et al. 2003, MNRAS, 341, 54 First citation in article | NASA ADS | CrossRef 
  94. Kim, S., Staveley-Smith, L., Dopita, M. A., Freeman, K. C., Sault, R. J., Kesteven, M. J., &amp; McConnell, D. 1998, ApJ, 503, 674 First citation in article | Full Text | NASA ADS 
  95. Koornneef, J. 1982, A&amp;A, 107, 247 First citation in article | NASA ADS 
  96. Kormendy, J., &amp; Kennicutt, R. C., Jr. 2004, ARA&amp;A, 42, 603 First citation in article | NASA ADS 
  97. Kotoneva, E., Flynn, C., Chiappini, C., &amp; Matteuci, F. 2002, MNRAS, 336, 879 First citation in article | NASA ADS | CrossRef 
  98. Lasker, B. M. 1978, ApJ, 223, 109 First citation in article | NASA ADS 
  99. Leggett, S. K., Ruiz, M. T., &amp; Bergeron, P. 1998, ApJ, 497, 294 First citation in article | Full Text | NASA ADS 
  100. Luck, R. E., Moffett, T. J., Barnes, T. G., III, &amp; Gieren, W. P. 1998, AJ, 115, 605 First citation in article | Full Text | NASA ADS 
  101. Luks, T., &amp; Rohlfs, K. 1992, A&amp;A, 263, 41 First citation in article | NASA ADS 
  102. McWilliam, A. 1990, ApJS, 74, 1075 First citation in article | NASA ADS 
  103. Minniti, D., Borissova, J., Rejkuba, M., Alves, D. R., Cook, K. H., &amp; Freeman, K. C. 2003, Science, 301, 1508 First citation in article | NASA ADS | CrossRef 
  104. Morell, O., Källender, D., &amp; Butcher, H. R. 1992, A&amp;A, 259, 543 First citation in article | NASA ADS 
  105. Murai, T., &amp; Fujimoto, M. 1980, PASJ, 32, 581 First citation in article | NASA ADS 
  106. Nikolaev, S., &amp; Weinberg, M. D. 2000, ApJ, 542, 804 First citation in article | Full Text | NASA ADS 
  107. Olszewski, E. W. 1993, in ASP Conf. Ser. 48, The Globular ClusterGalaxy Connection, ed. G. H. Smith &amp; J. P. Brodie (San Francisco: ASP), 351 First citation in article 
  108. Olszewski, E. W., Schommer, R. A., Suntzeff, N. B., &amp; Harris, H. C. 1991, AJ, 101, 515 (OSSH91) First citation in article | NASA ADS 
  109. Osterbrock, D. E., Fulbright, J. P., Martel, A. R., Keane, M. J., Trager, S. C., &amp; Basri, G. 1996, PASP, 108, 277 First citation in article | NASA ADS 
  110. Osterbrock, D. E., &amp; Martel, A. 1992, PASP, 104, 76 First citation in article | NASA ADS 
  111. Pagel, B. E. J., &amp; Tautvaiien, G. 1998, MNRAS, 299, 535 (PT98) First citation in article | NASA ADS 
  112. Peletier, R. F., &amp; Balcells, M. 1996, AJ, 111, 2238 First citation in article | NASA ADS 
  113. Reid, I. N. 1999, ARA&amp;A, 37, 191 First citation in article | NASA ADS 
  114. Rolleston, W. R. J., Trundle, C., &amp; Dufton, P. L. 2002, A&amp;A, 396, 53 First citation in article | NASA ADS | CrossRef 
  115. Rutledge, G. A., Hesser, J. E., &amp; Stetson, P. B. 1997, PASP, 109, 907 First citation in article | NASA ADS 
  116. Salaris, M., Chieffi, A., &amp; Straniero, O. 1993, ApJ, 414, 580 First citation in article | NASA ADS 
  117. Salaris, M., Weiss, A., &amp; Percival, S. M. 2004, A&amp;A, 414, 163 First citation in article | NASA ADS | CrossRef 
  118. Sanduleak, N. 1970, Contrib. Cerro Tololo Obs., 89 First citation in article 
  119. Scalo, J. M. 1987, in Starbursts and Galaxy Evolution, eds., T. X. Thuan, T. Montmerle, &amp; J. T. Thanh Van (Paris: Editions Frontières), 445 First citation in article 
  120. Schommer, R. A., Olszewski, E. W., Suntzeff, N. B., &amp; Harris, H. C. 1992, AJ, 103, 447 First citation in article | NASA ADS 
  121. Searle, L., Wilkinson, A., &amp; Bagnuolo, W. 1980, ApJ, 239, 803 First citation in article | NASA ADS 
  122. Shen, J., &amp; Sellwood, J. A. 2004, ApJ, 604, 614 First citation in article | Full Text | NASA ADS 
  123. Skillman, E. D., &amp; Gallart, C. 2002, in ASP Conf. Ser. 274, Observed HR Diagrams and Stellar Evolution, ed. T. Lejeune &amp; J. Fernandes (San Francisco: ASP), 535 First citation in article 
  124. Smecker-Hane, T. A., Cole, A. A., Gallagher, J. S., III, &amp; Stetson, P. B. 2002, ApJ, 566, 239 First citation in article | Full Text | NASA ADS 
  125. Smecker-Hane, T. A., Cole, A. A., Mandushev, G. I., Bosler, T., &amp; Gallagher, J. S., III. 2004, ApJ, submitted (Paper II) First citation in article 
  126. Smecker-Hane, T. A., Gallagher, J. S., III, Cole, A. A., Tolstoy, E., &amp; Stetson, P. B. 1999a, in IAU Symp. 190, New Views of the Magellanic Clouds, ed. Y.-H. Chu et al. (San Francisco: ASP), 343 First citation in article 
  127. Smecker-Hane, T. A., Mandushev, G. I., Hesser, J. E., Stetson, P. B., Da Costa, G. S., &amp; Hatzidimitriou, D. 1999b, in ASP Conf. Ser. 192, Spectrophotometric Dating of Stars and Galaxies, ed. I. Hubeny, S. R. Heap, &amp; R. H. Cornett (San Francisco: ASP), 159 First citation in article 
  128. Smith, V. V., et al. 2002, AJ, 124, 3241 First citation in article | Full Text | NASA ADS 
  129. Sparke, L. S., &amp; Sellwood, J. A. 1987, MNRAS, 225, 653 First citation in article | NASA ADS 
  130. Spergel, D. N., et al. 2003, ApJS, 148, 175 First citation in article | Full Text | NASA ADS 
  131. Staveley-Smith, L., Kim, S., Calabretta, M. R., Haynes, R. F., &amp; Kesteven, M. J. 2003, MNRAS, 339, 87 First citation in article | NASA ADS | CrossRef 
  132. Sweigart, A. V., &amp; Gross, P. G. 1978, ApJS, 36, 405 First citation in article | NASA ADS 
  133. Tolstoy, E., Irwin, M. J., Cole, A. A., Pasquini, L., Gilmozzi, R., &amp; Gallagher, J. S., III. 2001, MNRAS, 327, 918 First citation in article | NASA ADS | CrossRef 
  134. Tolstoy, E., Venn, K. A., Shetrone, M., Primas, F., Hill, V., Kaufer, A., &amp; Szeifert, T. 2003, AJ, 125, 707 First citation in article | Full Text | NASA ADS 
  135. Tonry, J., &amp; Davis, M. 1979, AJ, 84, 1511 First citation in article | NASA ADS 
  136. Udalski, A., Szymaski, M., Kubiak, M., Pietrzyski, G., Soszyski, I., Woniak, P., &amp; ebru, K. 2000, Acta Astron., 50, 307 First citation in article | NASA ADS 
  137. VandenBerg, D. A., Richard, O., Michaud, G., &amp; Richer, J. 2002, ApJ, 571, 487 First citation in article | Full Text | NASA ADS 
  138. van der Marel, R. P. 2001, AJ, 122, 1827 First citation in article | Full Text | NASA ADS 
  139. van der Marel, R. P., Alves, D. R., Hardy, E., &amp; Suntzeff, N. B. 2002, AJ, 124, 2639 First citation in article | Full Text | NASA ADS 
  140. Weinberg, M. D. 2000, ApJ, 532, 922 First citation in article | Full Text | NASA ADS 
  141. Westerlund, B. E. 1997, The Magellanic Clouds (Cambridge: Cambridge Univ. Press) First citation in article 
  142. Worthey, G. 1999, in ASP Conf. Ser. 192, Spectrophotometric Dating of Stars and Galaxies, ed. I. Hubeny, S. Heap, &amp; R. Cornett (San Francisco: ASP), 283 First citation in article 
  143. Zaritsky, D. 2004, ApJ, 614, L37 First citation in article | Full Text | NASA ADS 
  144. Zhao, H. S., Ibata, R. A., Lewis, G. F., &amp; Irwin, M. J. 2003, MNRAS, 339, 701 First citation in article | NASA ADS | CrossRef
  145. " name="eprints.referencetext" />
  146. <meta content="Cole, A.A. and Tolstoy, E. and Gallagher, J.S. and Smecker-Hane, T.A. (2005) Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation. The Astronomical Journal, 129 (3). pp. 1465-1482. ISSN 0004-6256" name="eprints.citation" />
  147. <meta content="http://eprints.utas.edu.au/2509/1/204449.web.pdf" name="eprints.document_url" />
  148. <link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" />
  149. <meta content="Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation" name="DC.title" />
  150. <meta content="Cole, A.A." name="DC.creator" />
  151. <meta content="Tolstoy, E." name="DC.creator" />
  152. <meta content="Gallagher, J.S." name="DC.creator" />
  153. <meta content="Smecker-Hane, T.A." name="DC.creator" />
  154. <meta content="240101 Astronomy and Astrophysics" name="DC.subject" />
  155. <meta content="We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 arcmin2 area at the optical center of the LMC bar. These are the first spectroscopic abundance measurements of intermediate-age and old field stars in the high surface brightness heart of the LMC. The metallicity distribution is sharply peaked at the median value [Fe/H]=-0.40, with a small tail of stars extending down to [Fe/H]<=-2.1 10% of the red giants are observed to have [Fe/H]<=-0.7. The relative lack of metal-poor stars indicates that the LMC has a ``G dwarf'' problem, similar to the Milky Way. The abundance distribution can be closely approximated by two Gaussians containing 89% and 11% of the stars, respectively: the first component is centered at [Fe/H]=-0.37 with σ=0.15, and the second at [Fe/H]=-1.08 with σ=0.46. The dominant population has a metallicity distribution similar to that of the LMC's intermediate-age star clusters. The mean heliocentric radial velocity of the sample is 257 km s-1, corresponding to the same center-of-mass velocity as the disk (measured at larger radii). Because of the central location of our field, kinematic constraints are not strong, but there is no evidence that the bar deviates from the general motion of the LMC disk. The velocity dispersion of the whole sample is σv=24.7+/-0.4 km s-1. When cut by metallicity, the most metal-poor 5% of stars ([Fe/H]<-1.15) show σv=40.8+/-1.7 km s-1, more than twice the value for the most metal-rich 5%; this suggests that an old, thicker disk or halo population is present. The age-metallicity relation (AMR) is almost flat during the period from 5 to 10 Gyr ago, with an apparent scatter of +/-0.15 dex about the mean metallicity for a given age. Comparing this to chemical evolution models from the literature, we find that a burst of star formation 3 Gyr ago does not reproduce the observed AMR more closely than a steadily declining star formation rate. The AMR suggests that the epoch of enhanced star formation, if any, must have commenced earlier, ~6 Gyr ago-the exact time is model dependent. We compare the properties of the LMC and the Milky Way, and discuss our results in the context of models that attempt to use tidal interactions with the Milky Way and Small Magellanic Cloud to explain the star and cluster formation histories of the LMC. " name="DC.description" />
  156. <meta content="2005-03" name="DC.date" />
  157. <meta content="Article" name="DC.type" />
  158. <meta content="PeerReviewed" name="DC.type" />
  159. <meta content="application/pdf" name="DC.format" />
  160. <meta content="http://eprints.utas.edu.au/2509/1/204449.web.pdf" name="DC.identifier" />
  161. <meta content="http://dx.doi.org/10.1086/428007" name="DC.relation" />
  162. <meta content="Cole, A.A. and Tolstoy, E. and Gallagher, J.S. and Smecker-Hane, T.A. (2005) Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation. The Astronomical Journal, 129 (3). pp. 1465-1482. ISSN 0004-6256" name="DC.identifier" />
  163. <meta content="http://eprints.utas.edu.au/2509/" name="DC.relation" />
  164. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/BibTeX/epprod-eprint-2509.bib" title="BibTeX" type="text/plain" />
  165. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/ContextObject/epprod-eprint-2509.xml" title="OpenURL ContextObject" type="text/xml" />
  166. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/ContextObject::Dissertation/epprod-eprint-2509.xml" title="OpenURL Dissertation" type="text/xml" />
  167. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/ContextObject::Journal/epprod-eprint-2509.xml" title="OpenURL Journal" type="text/xml" />
  168. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/DC/epprod-eprint-2509.txt" title="Dublin Core" type="text/plain" />
  169. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/DIDL/epprod-eprint-2509.xml" title="DIDL" type="text/xml" />
  170. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/EndNote/epprod-eprint-2509.enw" title="EndNote" type="text/plain" />
  171. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/HTML/epprod-eprint-2509.html" title="HTML Citation" type="text/html; charset=utf-8" />
  172. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/METS/epprod-eprint-2509.xml" title="METS" type="text/xml" />
  173. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/MODS/epprod-eprint-2509.xml" title="MODS" type="text/xml" />
  174. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/RIS/epprod-eprint-2509.ris" title="Reference Manager" type="text/plain" />
  175. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/Refer/epprod-eprint-2509.refer" title="Refer" type="text/plain" />
  176. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/Simple/epprod-eprint-2509text" title="Simple Metadata" type="text/plain" />
  177. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/Text/epprod-eprint-2509.txt" title="ASCII Citation" type="text/plain; charset=utf-8" />
  178. <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2509/XML/epprod-eprint-2509.xml" title="EP3 XML" type="text/xml" />
  179.  
  180.   </head>
  181.   <body bgcolor="#ffffff" text="#000000" onLoad="loadRoutine(); MM_preloadImages('images/eprints/ePrints_banner_r5_c5_f2.gif','images/eprints/ePrints_banner_r5_c7_f2.gif','images/eprints/ePrints_banner_r5_c8_f2.gif','images/eprints/ePrints_banner_r5_c9_f2.gif','images/eprints/ePrints_banner_r5_c10_f2.gif','images/eprints/ePrints_banner_r5_c11_f2.gif','images/eprints/ePrints_banner_r6_c4_f2.gif')">
  182.     
  183.     <div class="ep_noprint"><noscript><style type="text/css">@import url(http://eprints.utas.edu.au/style/nojs.css);</style></noscript></div>
  184.  
  185.  
  186.  
  187.  
  188. <table width="795" border="0" cellspacing="0" cellpadding="0">
  189.   <tr>
  190.     <td><script language="JavaScript1.2">mmLoadMenus();</script>
  191.       <table border="0" cellpadding="0" cellspacing="0" width="795">
  192.         <!-- fwtable fwsrc="eprints_banner_final2.png" fwbase="ePrints_banner.gif" fwstyle="Dreamweaver" fwdocid = "1249563342" fwnested="0" -->
  193.         <tr>
  194.           <td><img src="/images/eprints/spacer.gif" width="32" height="1" border="0" alt="" /></td>
  195.           <td><img src="/images/eprints/spacer.gif" width="104" height="1" border="0" alt="" /></td>
  196.           <td><img src="/images/eprints/spacer.gif" width="44" height="1" border="0" alt="" /></td>
  197.           <td><img src="/images/eprints/spacer.gif" width="105" height="1" border="0" alt="" /></td>
  198.           <td><img src="/images/eprints/spacer.gif" width="41" height="1" border="0" alt="" /></td>
  199.           <td><img src="/images/eprints/spacer.gif" width="16" height="1" border="0" alt="" /></td>
  200.           <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
  201.           <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
  202.           <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
  203.           <td><img src="/images/eprints/spacer.gif" width="82" height="1" border="0" alt="" /></td>
  204.           <td><img src="/images/eprints/spacer.gif" width="69" height="1" border="0" alt="" /></td>
  205.           <td><img src="/images/eprints/spacer.gif" width="98" height="1" border="0" alt="" /></td>
  206.           <td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
  207.         </tr>
  208.         <tr>
  209.           <td colspan="12"><img name="ePrints_banner_r1_c1" src="/images/eprints/ePrints_banner_r1_c1.gif" width="795" height="10" border="0" alt="" /></td>
  210.           <td><img src="/images/eprints/spacer.gif" width="1" height="10" border="0" alt="" /></td>
  211.         </tr>
  212.         <tr>
  213.           <td rowspan="6"><img name="ePrints_banner_r2_c1" src="/images/eprints/ePrints_banner_r2_c1.gif" width="32" height="118" border="0" alt="" /></td>
  214.           <td rowspan="5"><a href="http://www.utas.edu.au/"><img name="ePrints_banner_r2_c2" src="/images/eprints/ePrints_banner_r2_c2.gif" width="104" height="103" border="0" alt="" /></a></td>
  215.           <td colspan="10"><img name="ePrints_banner_r2_c3" src="/images/eprints/ePrints_banner_r2_c3.gif" width="659" height="41" border="0" alt="" /></td>
  216.           <td><img src="/images/eprints/spacer.gif" width="1" height="41" border="0" alt="" /></td>
  217.         </tr>
  218.         <tr>
  219.           <td colspan="3"><a href="http://eprints.utas.edu.au/"><img name="ePrints_banner_r3_c3" src="/images/eprints/ePrints_banner_r3_c3.gif" width="190" height="31" border="0" alt="" /></a></td>
  220.           <td rowspan="2" colspan="7"><img name="ePrints_banner_r3_c6" src="/images/eprints/ePrints_banner_r3_c6.gif" width="469" height="37" border="0" alt="" /></td>
  221.           <td><img src="/images/eprints/spacer.gif" width="1" height="31" border="0" alt="" /></td>
  222.         </tr>
  223.         <tr>
  224.           <td colspan="3"><img name="ePrints_banner_r4_c3" src="/images/eprints/ePrints_banner_r4_c3.gif" width="190" height="6" border="0" alt="" /></td>
  225.           <td><img src="/images/eprints/spacer.gif" width="1" height="6" border="0" alt="" /></td>
  226.         </tr>
  227.         <tr>
  228.           <td colspan="2"><img name="ePrints_banner_r5_c3" src="/images/eprints/ePrints_banner_r5_c3.gif" width="149" height="1" border="0" alt="" /></td>
  229.           <td rowspan="2" colspan="2"><a href="/information.html" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821132634_0,0,25,null,'ePrints_banner_r5_c5');MM_swapImage('ePrints_banner_r5_c5','','/images/eprints/ePrints_banner_r5_c5_f2.gif',1);"><img name="ePrints_banner_r5_c5" src="/images/eprints/ePrints_banner_r5_c5.gif" width="57" height="25" border="0" alt="About" /></a></td>
  230.           <td rowspan="2"><a href="/view/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133021_1,0,25,null,'ePrints_banner_r5_c7');MM_swapImage('ePrints_banner_r5_c7','','/images/eprints/ePrints_banner_r5_c7_f2.gif',1);"><img name="ePrints_banner_r5_c7" src="/images/eprints/ePrints_banner_r5_c7.gif" width="68" height="25" border="0" alt="Browse" /></a></td>
  231.           <td rowspan="2"><a href="/perl/search/simple" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133201_2,0,25,null,'ePrints_banner_r5_c8');MM_swapImage('ePrints_banner_r5_c8','','/images/eprints/ePrints_banner_r5_c8_f2.gif',1);"><img name="ePrints_banner_r5_c8" src="/images/eprints/ePrints_banner_r5_c8.gif" width="68" height="25" border="0" alt="Search" /></a></td>
  232.           <td rowspan="2"><a href="/perl/register" onMouseOut="MM_swapImgRestore();MM_startTimeout();" onMouseOver="MM_showMenu(window.mm_menu_1018171924_3,0,25,null,'ePrints_banner_r5_c9');MM_swapImage('ePrints_banner_r5_c9','','/images/eprints/ePrints_banner_r5_c9_f2.gif',1);"><img name="ePrints_banner_r5_c9" src="/images/eprints/ePrints_banner_r5_c9.gif" width="68" height="25" border="0" alt="register" /></a></td>
  233.           <td rowspan="2"><a href="/perl/users/home" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133422_4,0,25,null,'ePrints_banner_r5_c10');MM_swapImage('ePrints_banner_r5_c10','','/images/eprints/ePrints_banner_r5_c10_f2.gif',1);"><img name="ePrints_banner_r5_c10" src="/images/eprints/ePrints_banner_r5_c10.gif" width="82" height="25" border="0" alt="user area" /></a></td>
  234.           <td rowspan="2"><a href="/help/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133514_5,0,25,null,'ePrints_banner_r5_c11');MM_swapImage('ePrints_banner_r5_c11','','/images/eprints/ePrints_banner_r5_c11_f2.gif',1);"><img name="ePrints_banner_r5_c11" src="/images/eprints/ePrints_banner_r5_c11.gif" width="69" height="25" border="0" alt="Help" /></a></td>
  235.           <td rowspan="3" colspan="4"><img name="ePrints_banner_r5_c12" src="/images/eprints/ePrints_banner_r5_c12.gif" width="98" height="40" border="0" alt="" /></td>
  236.           <td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
  237.         </tr>
  238.         <tr>
  239.           <td rowspan="2"><img name="ePrints_banner_r6_c3" src="/images/eprints/ePrints_banner_r6_c3.gif" width="44" height="39" border="0" alt="ePrints home" /></td>
  240.           <td><a href="/" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('ePrints_banner_r6_c4','','/images/eprints/ePrints_banner_r6_c4_f2.gif',1);"><img name="ePrints_banner_r6_c4" src="/images/eprints/ePrints_banner_r6_c4.gif" width="105" height="24" border="0" alt="ePrints home" /></a></td>
  241.           <td><img src="/images/eprints/spacer.gif" width="1" height="24" border="0" alt="" /></td>
  242.         </tr>
  243.         <tr>
  244.           <td><img name="ePrints_banner_r7_c2" src="/images/eprints/ePrints_banner_r7_c2.gif" width="104" height="15" border="0" alt="" /></td>
  245.           <td colspan="8"><img name="ePrints_banner_r7_c4" src="/images/eprints/ePrints_banner_r7_c4.gif" width="517" height="15" border="0" alt="" /></td>
  246.           <td><img src="/images/eprints/spacer.gif" width="1" height="15" border="0" alt="" /></td>
  247.         </tr>
  248.       </table></td>
  249.   </tr>
  250.     <tr><td><table width="100%" style="font-size: 90%; border: solid 1px #ccc; padding: 3px"><tr>
  251.       <td align="left"><a href="http://eprints.utas.edu.au/cgi/users/home">Login</a> | <a href="http://eprints.utas.edu.au/cgi/register">Create Account</a></td>
  252.       <td align="right" style="white-space: nowrap">
  253.         <form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/search" style="display:inline">
  254.           <input class="ep_tm_searchbarbox" size="20" type="text" name="q" />
  255.           <input class="ep_tm_searchbarbutton" value="Search" type="submit" name="_action_search" />
  256.           <input type="hidden" name="_order" value="bytitle" />
  257.           <input type="hidden" name="basic_srchtype" value="ALL" />
  258.           <input type="hidden" name="_satisfyall" value="ALL" />
  259.         </form>
  260.       </td>
  261.     </tr></table></td></tr>
  262.   <tr>
  263.     <td class="toplinks"><!-- InstanceBeginEditable name="content" -->
  264.  
  265.  
  266. <div align="center">
  267.   
  268.   <table width="720" class="ep_tm_main"><tr><td align="left">
  269.     <h1 class="ep_tm_pagetitle">Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation</h1>
  270.     <p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Cole, A.A.</span> and <span class="person_name">Tolstoy, E.</span> and <span class="person_name">Gallagher, J.S.</span> and <span class="person_name">Smecker-Hane, T.A.</span> (2005) <xhtml:em>Spectroscopy of Red Giants in the Large Magellanic Cloud Bar: Abundances, Kinematics, and the Age-Metallicity Relation.</xhtml:em> The Astronomical Journal, 129 (3). pp. 1465-1482. ISSN 0004-6256</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/2509/1/204449.web.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" border="0" class="ep_doc_icon" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/2509/1/204449.web.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />2444Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input value="3303" name="docid" accept-charset="utf-8" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><p style="margin-bottom: 1em" class="not_ep_block">Official URL: <a href="http://dx.doi.org/10.1086/428007">http://dx.doi.org/10.1086/428007</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 arcmin2 area at the optical center of the LMC bar. These are the first spectroscopic abundance measurements of intermediate-age and old field stars in the high surface brightness heart of the LMC. The metallicity distribution is sharply peaked at the median value [Fe/H]=-0.40, with a small tail of stars extending down to [Fe/H]&lt;=-2.1 10% of the red giants are observed to have [Fe/H]&lt;=-0.7. The relative lack of metal-poor stars indicates that the LMC has a ``G dwarf'' problem, similar to the Milky Way. The abundance distribution can be closely approximated by two Gaussians containing 89% and 11% of the stars, respectively: the first component is centered at [Fe/H]=-0.37 with σ=0.15, and the second at [Fe/H]=-1.08 with σ=0.46. The dominant population has a metallicity distribution similar to that of the LMC's intermediate-age star clusters. The mean heliocentric radial velocity of the sample is 257 km s-1, corresponding to the same center-of-mass velocity as the disk (measured at larger radii). Because of the central location of our field, kinematic constraints are not strong, but there is no evidence that the bar deviates from the general motion of the LMC disk. The velocity dispersion of the whole sample is σv=24.7+/-0.4 km s-1. When cut by metallicity, the most metal-poor 5% of stars ([Fe/H]&lt;-1.15) show σv=40.8+/-1.7 km s-1, more than twice the value for the most metal-rich 5%; this suggests that an old, thicker disk or halo population is present. The age-metallicity relation (AMR) is almost flat during the period from 5 to 10 Gyr ago, with an apparent scatter of +/-0.15 dex about the mean metallicity for a given age. Comparing this to chemical evolution models from the literature, we find that a burst of star formation 3 Gyr ago does not reproduce the observed AMR more closely than a steadily declining star formation rate. The AMR suggests that the epoch of enhanced star formation, if any, must have commenced earlier, ~6 Gyr ago-the exact time is model dependent. We compare the properties of the LMC and the Milky Way, and discuss our results in the context of models that attempt to use tidal interactions with the Milky Way and Small Magellanic Cloud to explain the star and cluster formation histories of the LMC. </p></div><table style="margin-bottom: 1em" border="0" cellpadding="3" class="not_ep_block"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Additional Information:</th><td valign="top" class="ep_row">http://www.journals.uchicago.edu/AJ/home.html</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">Galaxies: Evolution, Galaxies: Stellar Content, Galaxies: Magellanic Clouds</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/240101.html">240000 Physical Sciences &gt; 240100 Astronomical Sciences &gt; 240101 Astronomy and Astrophysics</a></td></tr><tr><th valign="top" class="ep_row">Collections:</th><td valign="top" class="ep_row">UNSPECIFIED</td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">2509</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Dr. A.A. Cole</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">29 Nov 2007 10:46</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">07 Feb 2008 13:08</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=2509;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&amp;eprintid=2509">item control page</a></p>
  271.   </td></tr></table>
  272. </div>
  273.  
  274.  
  275.  
  276.     <!-- InstanceEndEditable --></td>
  277.   </tr>
  278.   <tr>
  279.     <td><!-- #BeginLibraryItem "/Library/footer_eprints.lbi" -->
  280.     <table width="795" border="0" align="left" cellpadding="0" class="footer">
  281.   <tr valign="top">
  282. <td colspan="2"><div align="center"><a href="http://www.utas.edu.au">UTAS home</a> | <a href="http://www.utas.edu.au/library/">Library home</a> | <a href="/">ePrints home</a> | <a href="/contact.html">contact</a> | <a href="/information.html">about</a> | <a href="/view/">browse</a> | <a href="/perl/search/simple">search</a> | <a href="/perl/register">register</a> | <a href="/perl/users/home">user area</a> | <a href="/help/">help</a></div><br /></td>
  283. </tr>
  284. <tr><td colspan="2"><p><img src="/images/eprints/footerline.gif" width="100%" height="4" /></p></td></tr>
  285.       <tr valign="top">
  286.         <td width="68%" class="footer">Authorised by the University Librarian<br />
  287. © University of Tasmania ABN 30 764 374 782<br />
  288.       <a href="http://www.utas.edu.au/cricos/">CRICOS Provider Code 00586B</a> | <a href="http://www.utas.edu.au/copyright/copyright_disclaimers.html">Copyright &amp; Disclaimers</a> | <a href="http://www.utas.edu.au/accessibility/index.html">Accessibility</a> | <a href="http://eprints.utas.edu.au/feedback/">Site Feedback</a>  </td>
  289.         <td width="32%"><div align="right">
  290.             <p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><img src="http://www.utas.edu.au/shared/logos/unioftasstrip.gif" alt="University of Tasmania Home Page" width="260" height="16" border="0" align="right" /></a></p>
  291.             <p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><br />
  292.             </a></p>
  293.         </div></td>
  294.       </tr>
  295.       <tr valign="top">
  296.         <td><p>  </p></td>
  297.         <td><div align="right"><span class="NoPrint"><a href="http://www.eprints.org/software/"><img src="/images/eprintslogo.gif" alt="ePrints logo" width="77" height="29" border="0" align="bottom" /></a></span></div></td>
  298.       </tr>
  299.     </table>
  300.     <!-- #EndLibraryItem -->
  301.     <div align="center"></div></td>
  302.   </tr>
  303. </table>
  304.  
  305.   </body>
  306. </html>