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The Korean Astronomical Society (한국천문학회)
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ROTATION AND SURFACE ABUNDANCE PECULIARITIES IN A-TYPE STARS

  • Published : 2008.08.31
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Abstract

In an attempt of clarifying the connection between the photospheric abundance anomalies and the stellar rotation as well as of exploring the nature of "normal A" stars, the abundances of seven elements (C, O, Si, Ca, Ti, Fe, and Ba) and the projected rotational velocity for 46 A-type field stars were determined by applying the spectrum-fitting method to the high-dispersion spectral data obtained with BOES at BOAO. We found that the peculiarities(underabundances of C, O, and Ca; an overabundance of Ba) seen in slow rotators efficiently decrease with an increase of rotation, which almost disappear at $v_esin\;i{\gtrsim}100km\;s^{-1}$. This further suggests that stars with sufficiently large rotational velocity may retain the original composition at the surface without being altered. Considering the subsolar tendency(by several tenths dex below) exhibited by the elemental abundances of such rapidly-rotating (supposedly normal) A stars, we suspect that the gas metallicity may have decreased since our Sun was born, contrary to the common picture of galactic chemical evolution.

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References

  1. Winsor, G. and P. Adams. 1987. Diagnosis of mineral disorders in plants. Vol. 3. Glasshouse crops. Her Majesty's Stationery Office, London
  2. Allende Prieto, C., Barklem, P. S., Lambert, D. L., & Cunha, K., 2004, $S^4N$: A spectroscopic survey of stars in the solar neighborhood. The Nearest 15 pc, A&A, 420, 183
  3. Andrievsky, S. M., et al., 2002, The elemental abundance pattern of twenty lambda Bootis candidate stars, A&A, 396, 641 https://doi.org/10.1051/0004-6361:20021423
  4. Asplund, M., Grevesse, N., Sauval, A. J., Allende Prieto, C., & Kiselman, D., 2004, Line formation in solar granulation. IV. [O I], O I and OH lines and the photospheric O abundance, A&A, 417, 751 https://doi.org/10.1051/0004-6361:20034328
  5. Cayrel de Strobel, G., Soubiran, C., & Ralite, N., 2001, Catalogue of [Fe/H] determinations for FGK stars: 2001 edition, A&A, 373, 159 https://doi.org/10.1051/0004-6361:20010525
  6. Coupry, M. F. & Burkhart, C., 1992, The A and Am- Fm stars. II - Equivalent widths for the Li region, microturbulence, and comments on curious-looking line profiles, A&AS, 95, 41
  7. Dunkin, S. K., Barlow, M. J., & Ryan, S. G., 1997, High-resolution spectroscopy of Vega-like stars - I. Effective temperatures, gravities and photospheric abundances, MNRAS, 286, 604 https://doi.org/10.1093/mnras/286.3.604
  8. Edvardsson, B., Andersen, J., Gustafsson, B., Lambert, D. L., Nissen, P. E., & Tomkin, J., 1993, The Chemical Evolution of the Galactic Disk - Part One - Analysis and Results, A&A, 275, 101
  9. ESA 1997, The Hipparcos and Tycho Catalogues, ESA SP-1200, available from NASA-ADC or CDS in a machine-readable form (file name: hip main.dat)
  10. Flower, P. J., 1996, Transformations from Theoretical Hertzsprung-Russell Diagrams to Color-Magnitude Diagrams: Effective Temperatures, B-V Colors, and Bolometric Corrections, ApJ, 469, 355 https://doi.org/10.1086/177785
  11. Fossati, L., Bagnulo, S., Landstreet, J., Wade, G., Kochukhov, O., Monier, R., Weiss, W., & Gebran, M., 2008, The effect of rotation on the abundances of the chemical elements of the A-type stars in the Praesepe cluster, A&A, 483, 891 https://doi.org/10.1051/0004-6361:200809467
  12. Gebran, M., Monier, R., & Richard, O., 2008, Chemical composition of A and F dwarf members of the Coma Berenices open cluster, A&A, 479, 189 https://doi.org/10.1051/0004-6361:20078807
  13. Gebran, M. & Monier, R., 2007, in Convection in Astrophysics, ed. F. Kupka, I. W. Roxburgh, & K. L. Chan, Proc. IAU Symp. 239 (Cambridge: Cambridge University Press), 160
  14. Gebran, M. & Monier, R., 2008, Chemical composition of A and F dwarfs members of the Pleiades open cluster, A&A, 483, 567 https://doi.org/10.1051/0004-6361:20079271
  15. Gies, D. R. & Lambert, D. L., 1992, Carbon, nitrogen, and oxygen abundances in early B-type stars, ApJ, 387, 673 https://doi.org/10.1086/171116
  16. Girardi, L., Bressan, A., Bertelli, G., & Chiosi, C., 2000, Evolutionary tracks and isochrones for lowand intermediate-mass stars: From 0.15 to 7 $M_{\bigodot}$, and from Z=0.0004 to 0.03, A&AS, 141, 371 https://doi.org/10.1051/aas:2000126
  17. Hauck, B. & Mermilliod, M., 1980, Uvbybeta photoelectric photometric catalogue, A&AS, 40, 1
  18. Kang, D.-I., Park, H.-S., Han, I.-W., Valyavin, G., Lee, B.-C., & Kim, K.-M., 2006, Development Of An Automatic Processing Program for Boes Data II, PKAS, 21, 101 https://doi.org/10.5303/PKAS.2006.21.2.101
  19. Kato, K., & Sadakane, K. 1982, A model atmosphere analysis of Procyon ($[\alpha}$CMi, F5 IV-V), A&A, 113, 135
  20. Kilian, J., 1992, Chemical abundances in early B-type stars. IV - He, CNO, and SI abundances, A&A, 262, 171
  21. Kilian, J., 1994, Chemical abundances in early B-type stars V. Metal abundances and LTE/NLTE comparison, A&A, 282, 867
  22. Kurucz, R. L., 1993, Kurucz CD-ROM, No. 13 (Harvard-Smithsonian Center for Astrophysics)
  23. Kurucz, R. L. & Bell, B., 1995, Kurucz CD-ROM, No. 23 (Harvard-Smithsonian Center for Astrophysics)
  24. Kurucz, R. L., & Peytremann, E., 1975, Smithsonian Astrophys. Obs. Spec. Rept., No. 362
  25. Kurucz, R. L., & Peytremann, E., 1975, Smithsonian Astrophys. Obs. Spec. Rept., No. 362
  26. Lemke, M., 1990, in The Atmospheres of Early- Type Stars, ed. U. Heber & C. S. Jeffery (Berlin: Springer), p.54
  27. Luck, R. E. & Lambert, D. L., 1985, Carbon, nitrogen, and oxygen in intermediate-mass supergiants - Is oxygen underabundant?, ApJ, 298, 782 https://doi.org/10.1086/163660
  28. Moon, T. T., 1985, Commun. Univ. London Obs., No. 78
  29. Napiwotzki, R., Sch¨onberner, D., & Wenske, V., 1993, On the determination of effective temperature and surface gravity of B, A, and F stars using Stromgren UVBY beta photometry, A&A, 268, 653
  30. Niemczura, E., 2003, Metallicities of the SPB stars from the IUE ultraviolet spectra, A&A, 404, 689 https://doi.org/10.1051/0004-6361:20030546
  31. Nissen, P. E., 1993, in Inside the stars, ASP Conf. Ser. 40, eds. W. W. Weiss & A. Baglin, (San Francisco: Astronomical Society of the Pacific), p. 108
  32. Royer, F., Gerbaldi, M., Faraggiana, R., & Gomez, A. E., 2002a, Rotational velocities of A-type stars. I. Measurement of v sin i in the southern hemisphere, A&A, 381, 105 https://doi.org/10.1051/0004-6361:20011422
  33. Royer, F., Grenier, S., Baylac, M.-O., Gomez, A. E., & Zorec, J. 2002b, Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i, A&A, 393, 897 https://doi.org/10.1051/0004-6361:20020943
  34. Sadakane, K., 1990, in Accuracy of element abundances from stellar atmospheres, Lecture Note in Physics, No. 356, ed. R. Wehrse (Berlin and New York: Springer), 57
  35. Sadakane, K. & Okyudo, M. 1989, Abundances of nitrogen and sulfur in A-type stars, PASJ, 41, 1055 https://doi.org/10.1002/app.1990.070410516
  36. Savanov, I. S., 1995a, Abundance anomalies in the atmospheres of rapidly-rotating Am stars, Astron. Rep., 39, 653
  37. Savanov, I. S., 1995b, On the negative correlation between the [C/Fe], [N/Fe], [O/Fe], and Fe abundances in the atmospheres of upper-main-sequence chemically-peculiar stars, Astron. Lett., 21, 684
  38. Steffen, M., 1985, A model atmosphere analysis of the F5 IV-V subgiant Procyon, A&AS, 59, 403
  39. Takeda, Y., 1995, Self-consistent multi-parameter fitting of stellar flux spectra, PASJ, 47, 287
  40. Takeda, Y., 2003, Oxygen line formation in late-F through early-K disk/halo stars. Infrared O I triplet and [O I] lines, A&A, 402, 343 https://doi.org/10.1051/0004-6361:20030217
  41. Takeda, Y., et al., 2005a, High-Dispersion Spectra Collection of Nearby F-K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards, PASJ, 57, 13 https://doi.org/10.1093/pasj/57.1.13
  42. Takeda, Y. & Honda, S., 2005, Photospheric CNO Abundances of Solar-Type Stars, PASJ, 57, 65 https://doi.org/10.1093/pasj/57.1.65
  43. Takeda, Y., Ohkubo, M., Sato, B., Kambe, E., & Sadakane, K., 2005b, Spectroscopic Study on the Atmospheric Parameters of Nearby F-K Dwarfs and Subgiants, PASJ, 57, 27 [Erratum: PASJ, 57, 415] https://doi.org/10.1093/pasj/57.1.27
  44. Takeda, Y. & Sadakane, K., 1997, Oxygen $\lambda$7771-5 Triplet in Hyades A-Type Stars: A Quest for the Key to the AM Phenomenon, PASJ, 49, 367 https://doi.org/10.1093/pasj/49.3.367
  45. Takeda, Y., Sato, B., & Murata, D., 2008, Stellar Parameters and Elemental Abundances of Late-G Giants, PASJ, 60, 781 https://doi.org/10.1093/pasj/60.4.781
  46. Takeda, Y. & Takada-Hidai, M., 1998, Oxygen Abundances in Late-B through F Supergiants, PASJ, 50, 629 https://doi.org/10.1093/pasj/50.6.629
  47. Takeda, Y., Takada-Hidai, M., Jugaku, J., Sakaue, A., & Sadakane, K. 1999, Oxygen 6156-8 Angstroms Triplet in Chemically Peculiar Stars of the Upper Main Sequence: Do HgMn Stars Show an Oxygen Anomaly?, PASJ, 51, 961 https://doi.org/10.1093/pasj/51.6.961
  48. Varenne, O. & Monier, R., 1999, Chemical abundances of A and F-type stars: the Hyades open cluster, A&A, 351, 247
  49. Young, P. R., 2005, The Ne/O abundance ratio in the quiet Sun, A&A, 444, L45 https://doi.org/10.1051/0004-6361:20053647

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