Optik Bölge Tayf Analizlerinden Manyetik Özellik Göstermeyen geç $B$ -- erken $F$ Türü Yıldızların Kimyasal Element Bollukları

Year 2020, Volume: 1 Issue: 1, 129 - 133, 11.12.2020

Kutluay Yüce

Abstract

Yıldızların ayrıntılı tayf analizleri yapılarak `normal', `civa--mangan (HgMn)' ve `metal ($Am$)' çizgi tayfları veren yıldız tiplerinin ayırt edici tayf çizgilerinden yola çıkılarak, bu yıldızların kimyası irdelendi. Ayrıca He, C, N, O elementleri yanında metallerin ve ağır metallerin yıldız atmosferlerindeki göreli bollukları, gözlemsel olarak türettiğimiz HR diyagramı üzerindeki dağılımları incelendi. Metal çizgili özel yıldızlarda tespit edilen element bolluk dağılımlarındaki değişimin, civa--mangan tipi yıldızlardakine nazaran daha az olduğu belirlendi. Civa--mangan tipinden soğuk yıldızların, metalik türden sıcak yıldızlar ile aynı evrim yolları üzerinde olduğu kanısına ulaşıldı.

Keywords

star: abundances, stars: early-type, spectroscopy

References

• Adelman, S. J.: uvby FCAPT photometry of the metallic-lined stars 60 Tau and HR 1528 and the magnetic CP stars HR 8216 and HR 8770. A&A, (2003), vol.401, 357--360
• Adelman, S. J.: The physical properties of normal A stars. in: J. J. Zverko et al. (eds.), The A Star Puzzle, IAU Symp. 224, UK: Cambridge University Press, (2004), p.1--11
• Adelman, S. J., Unsuree, N.: On chemical abundances of Am and Normal A type stars. Balt. Astron., (2007), vol.16, 183-190
• Adelman, S. J., Yüce, K.: Elemental abundance analyses with Coude Echelle Spectrograms from the TÜBİTAK National Observatory of Turkey: I. The HgMn stars 11 Per, HR 2801, and nu Cnc, Astron. Nachr., (2010), vol.331, 785--793
• Adelman, S. J., Adelman, A. S., & Pintado, O. I.: On the relationship between the mercury-manganese stars and the metallic-lined stars. A&A, (2003), vol.397, 267--273
• Adelman, S. J., Caliskan, H., Kocer, D., Kablan, H., Yüce, K., Engin, S.: Elemental abundance analyses with DAO spectrograms. XXV. The superficially normal B and A stars alpha Draconis, tau Herculis, gamma Lyrae, and HR 7926. A&A, (2001), vol.371, 1078--1083
• Aurière, M. Wade, G. A., Lingières, F., et al.: No detection of large-scale magnetic fields at the surfaces of Am and HgMn stars. A&A, (2010), vol.523, id.A40 p.1--5
• Aurière, M., Wade, G. A. Silvester, J., et al.: Weak magnetic fields in Ap/Bp stars. Evidence for a dipole field lower limit and a tentative interpretation of the magnetic dichotomy. A&A, (2007), vol.475, 1053--1065
• Asplund, M., Grevesse, N., Sauval, A.J., & Scott, P.: The chemical composition of the Sun. ARA&A, (2009), vol.47, 481--522
• Berthet, S.: Which evolution for an Am star? A&A, (1992), vol.253, 451--458
• Conti, P. S.: The early A stars. I. Rotation and metallicism. ApJ., (1965), vol.142, 1594--1603
• Gray, R. O., Garrison, R. F.: The early F-type stars - Refined classification, confrontation with Stromgren photometry, and the effects of rotation. ApJS, (1989), vol.69, 301--321
• Kochukhov, O., Makaganiuk, V., Piskunov, N. et al.: Are there tangled magnetic fields on HgMn stars? A&A, (2013), vol.554, id.A61, pg.1--12
• Kurtz, D. W.: Pulsation of chemically peculiar and pre-main sequence stars in the delta Scuti instability strip. in M. Breger and M. Montgomery (eds.), ASP Conference Series, (San Francisco: ASP) ISBN: 1-58381-041-2, (2000), vol.210, 287--308
• Michaud, G.: Diffusion processes in peculiar A stars. ApJ, (1970), vol.160, 641--658
• Morgan, W.W.: Some evidence for the existence of a peculiar branch of the spectral sequence in the interval B8-F0. ApJ, (1933), vol.77, 330--336
• Petit, P., Lingières, F., Wade, G. A., et al.: The rapid rotation and complex magnetic field geometry of Vega. A&A, (2010), vol.523, A41 p.1--9
• Preston, G. W.: The chemically peculiar stars of the upper main sequence. ARA&A, (1974), vol.12, 257--277
• Talon, S., Richard, O., & Michaud, G.: AmFm stars as a test of rotational mixing model. ApJ, (2006), vol.645, 634--651
• Titus, J., and Morgan, W. W.: On the classifications of the A stars. I. The spectral types of the brighter members of the Hyades Cluster. ApJ, (1940), vol.92, 256--261
• Vauclair, S., Vauclair, G., Schatzman, E., & Michaud, G.: Hydrodynamical instabilities in the envelopes of main-sequence stars - Constraints implied by the lithium, beryllium, and boron observations. ApJ, (1978), vol.223, 567-582
• Wahlgren, G. M.; Ilyin, I., & Kochukhov, O.: Spectrum variability for the HgMn star alpha And. AAS Mtg. 199, (2001), vol.33, p.1506
• Yüce, K., Adelman, S. J.: Elemental abundance analyses with DAO Spectrograms. XXXIV. A three-dimensional graphical examination of the elemental abundances of the mercury-manganese and metallic-line stars. PASP, (2014), vol.126, 345--358
• Yüce, K., Adelman, S. J., & Gulliver, A. F.: Elemental abundance analyses with DAO spectrograms. XXVIII. Comparisons with two series of automated elemental abundance analyses. New Astronomy, (2011a), vol.16, 191--193
• Yüce, K., Castelli, F., & Hubrig, S.: Wavelengths and oscillator strengths of Xe II from the UVES spectra of four HgMn stars. A&A, (2011b), vol.523, id.A37 p.1--16
• Yüce, K., Adelman, S. J., Gulliver, A. F., Hill, G.: Elemental abundance analyses with DAO spectrograms: XXXII. HR 6455 (A3 III), delta Aqr (A3 V), eta Lep (F2 V), and 1 Boo (A1 V). Astron. Nachr., (2011c), vol.332, 681--689