F型星大気の研究その3 : 原子の励起状態による恒星大気乱流速度の変化について
7
0
0
全文
(2) Journal of Hokkaido University of Education (Section II B) Vol. 28, No. 2 February 1978. »?ttSct±W^ (^2gfSB) ^28^ ^2^- Bg% 53 ^ 2 n. A study of the Atmospheres of F-type Stars III. ^-Independent Micro-turbulent Velocities. Toshio HASEGAWA Earth Science Laboratory, Asahikawa College, Hokkaido University of Education Asahikawa 070. F M^dlWff^ ;e<D 3 , ^y)WW^ ^ ^'I'lM^MSUmjt^te^-c ? ^ Jll ^. WMII(±WW wwm. ^-dependent micro-turbulent velocities in the stellar atmospheres have been adopted by many authors. This paper shows that such dependences are almost due to the systematic errors in. the measurements of old ^-values and equivalent widths. The equivalent widths of y-Cyg (F8 Ib) measured by Zeinalov (1970) and recently revised gf '-values of Fel are used in the curve of growth analysis, and the constant velocity of micro-turbulences are derived from' them. The value is 6.0 km/sec while Zeinalov's values vary from 3.50 to 8.30km/sec.. Introduction In a previous paper1) the author remarked from the curve of growth analysis of F-type. sub-giants (o CMi and 7 Ser) that the ^-dependence of micro-turbulent velocities can be eliminated if one uses the recently revised ^/-values.. The new ^/-values of Fel (e.g. Garz and Kock2>, Wolnik et al.3) and Bridges and Kornblith4') are smaller than the old ones (e.g. Corliss and Warner's compilations5'). The relation between old and new ^/-values are shown in Fig. la, Ib and 1c. In each case, the difference Alog gf= log. ^/(old)-log gf(new) increases with increasing excitation potentials. To compensate such ^dependent errors in old ^/-values, one has to introduce the micro-turbulent velocities (^) which decrease with increasing excitation potentials.. In this paper the case of the F-type super-giant 7 Cyg (F8 Ib) is examined. For this star Zeinalov6) derived strong dependence of ^ on ^ in his paper (See Fig. 4). Method and Result The analysis is made by the same method used in the previous paper1). The initial parameters of the atmosphere are taken from the model atmosphere of super-giants computed by BohmVitense7) as follows T=5300°K To=4550°K Pe = 0.30 dynes/cm2 where T and Pe are the values at r= 0.1 and To is the surface temperature. The atomic para-. meters needed for the curve of growth analysis are taken from the papers of the following authors;. (61).
(3) T. HASEGAWA. (a). & log gf 1-0. h0-5. 3-0^. <. 4-0. 5-0. 6-0. 7'0. eV. -^-^ I I +—+ Xupp. (b ). 4 log gf -I'D. yy. f •-'\. -0-5. \. •\. ^>. /'./. H " •. /•••. \*. •f. *\. s. I'••'"• '. » </\"' .'••. '^'.^ 3-0, ^. +•. 4-0. 5-0. ^. eV. 6-0 +. XUpp. (c). A log gf -1-0 .. ^ \<> :•. \. 4". \. /. '. °5 ''J:. ><\3100-4000. '>•" .y » '« .. >>>.4000-8763. °.s'... f%<'". ^ ^ •. ?. :^f^. ^.:'':. ^-'^ * ° .•' ••. -0-5. / •. ^•:. f'^'/. • "..'.'I''. °. • ^?» • •. I" *•«. f. .. '•••''^. t. fLf". ^. ^3 j0. _..- ". 4:0. 5-.0. 6:0. 7;0 eV Xupp. Fig. 1. Comparison of Corliss-Warner's ^/-values of Fel with ; (a) Galz and. Kock (1969), (b) Wolnik et al (1970.1971), and (c) Bridges and Korn-. blith (1974).. (62).
(4) ^•-Independent Micro-turbulent Velocities. continuous absorption coefficient ........................................................... •Allen8) partition function of Fel ....................................................................... .Bolton9) ^/-values .....................................................................Bridges and Kornblith4'. The equivalent widths are taken from the paper of Zeinalov6) because the aim of this paper is to check his results on turbulent velocities. The values of Wrightlo) are also used for com-. ^ •• ••^»-^'. '- • ..••y:-^""-. •0'5 .. •-".f *<'•. ; ^-y. . • •\^s:.. • •' /' .•.^ ,»'. •. /„. l-o-o'/ • / • / '. I'O. 2-0. J-. _L. logic 3-0. Fig. 2a. Curve of growth of 7 Cyg made of Fel lines measured by Zeinalov6>.. U} •. -15 '\ es. •. -14. \.. ^ es. -13. •. s. -12 1-0. 2-0. J-. J_. 3-0 4-0 eV. J_L. Fig. 2b. Diagram of the curve of growth shifts from Fig. 2a.. (63).
(5) T. HASEGAWi. 0 a. i°g^. /'. 9 ^ • ^-" • 0. ^•-/ ®. ^. e*. a. a - ^ --". •po^.-<"'<?. B. -0-5. ^-. ^9 ®. ° <-<-. •«->^"'°'. 9. '^. s.. y*. V/ a/. /. /. /. ^ 0. a. -o-a / . / / 3 / o. I1-0. 2-0. 1. _L. log no. 3-0 J_. Fig. 3a. Curve of growth of 7 Cyg made of Fel lines measured. by Wright10'.. {A). a. -15 •'. 8. -14. \ a\ •. -13. ^. \. ®. -12 9. 1-0 J_. 2-0 3-0. J_L. 4-0 eV ±. Fig. 3b. Diagram of the curve of growth shifts from Fig. 3a.. parison. Wrubel'sll) theoretical curve of growth for the ME-model and line scattering mechanism. is adopted for fitting, in which the curve for log a =-2.6 and Bo/Bi = 2/3 is selected. The turbulent velocity was determined after some trials as 6. Okm/sec for all the groups of excitation levels. The empirical curve of growth constructed by these parameters are shown in Fig. 2a and Fig.. 3a. Particularly in Fig. 2a, the plotted points are badly scattered because of the unsystematic. (64).
(6) ^-Independent Micro-turbulent Velocities. errors in the measurements of ^/-values and equivalent widths. The systematic errors of these parameters are compensated by a flexible parameter viz. micro-turbulent velocities in the paper of Zeinalov6). Lower velocities are given to the lines of too large ^/-values and somewhat higher. velocities to the lines of largely mesured equivalent widths. The variation of turbulent velocities by Zeinalov are shown in Fig. 4 ; this decreasing curve corresponds to the increasing erros of log gf shown in Fig. 1. Zeinalov's equivalent widths seem to have some systematic errors. They are lar-. km/sec. ger in /U3700-4600A and smaller in /U 46005200A, compared with the values of Wright,. 8-0. and this is one of the reason why the curve. of growth shifts(A) are not in a straight line in Fig. 2b. For example the shift(A) for y = 2.7eV is too large because all the lines. 6-0. included in this excitation group fall in the range /U3700-4600A and plotted higher in the curve of growth. If one gives a higher. velocity to this group the shift(A) is reduced. 4i0. and can get an ordinary position in Fig. 2b.. The swelling part of the turbulent velocity model near 2. 7eV in Fig. 4 seems to be the. 2-0. result of such a process. Another systematic error is the saturation of strong lines, espe-. ci ally in the range A <4000A where strong. 4.0 eV. _L. Fig. 4. Variation of the turbulent velocities with lower excitation potentials derived by Zeinalov6>.. lines are crowded. Even the lines of larger 77. The dashed line represents the constant velocity. cannot reach the damping portion and. derived by the author.. empirical plots cannot be fitted to the theoretical curve by no means, then they are omitted in this analysis.. The excitation temperatures derived from the equivalent widths of Zeinalov and Wright are 5600°K and 5200°K respectively. These values are tolerably coincident with the initial value. Then the unique value of turbulent velocity for all excitations proved to be adequate. The ionization equation yields the abundance of Fe ; log N (Fe) = 18.4 from Fig. 2b and logN(Fe) = 18.9 from Fig. 3b respectively, where N is the number of Fe atoms per gram of stellar material.. The conclusion of this paper is that ^-dependent turbulent velocities hitherto introduced were mostly scope goats for the systematic errors in the measurements of gf '-values and equivalent. widths. The computation for the curves of growth were carried out by FACOM 230-75 at the Hokkaido University Computing Center.. (65).
(7) T. HASEGAWA. References 1 ) T. Hasegawa, Sci. Rep. Tohoku Univ. Ser. I, Vol. 58, 126(1975). 2 ) T. Garz and M. Kock, Astron. and Astrophys. 2,274(1969) 3 ) S. J. Wolnik, R. 0. Berthel and C. W. Wares, Astrophys. J., 162, 1037(1970) and ibid., 166, L3K1971) 4 ) J. M. Bridges and R. L. Kornblith, Astrophys. J., 192, 793(1974) 5 ) C. H. Corliss and B. Warner, Astrophys. J. Supplement Ser., 83, Vol. 8, 395(1964). 6 ) S. K. Zeinalov, Izv. Crimean Astrophys. Obs., 41, 298(1970) 7 ) E. Bohm-Vitense, Molel Stellar Atmospheres and Heavy Element Abundances (Problems in Stellar Atmospheres and Envelopes, Springer-Verlag, p21 (1975), Baschek et al. (ed) 8 ) C. W. Alien, Astrophysical Quantities, The Athlone Press, London (1973), p 100, (converted from G. Bode, Kontinuierliche Abs. van Sternatmospharen, Kiel, 1965) 9 ) C. T. Bolton, Astrophys. J., 161, 1187(1970) 10) K. 0. Wright, Pub. Dom. Astrophys. Obs. Victoria 8, 1(1948) 11) M. H. Wrubel, Astrophys. J., 109, 66(1949). (66).
(8)
図
関連したドキュメント
～農業の景況、新型コロナウイルス感染症拡大による影響
We shall see below how such Lyapunov functions are related to certain convex cones and how to exploit this relationship to derive results on common diagonal Lyapunov function (CDLF)
Then it follows immediately from a suitable version of “Hensel’s Lemma” [cf., e.g., the argument of [4], Lemma 2.1] that S may be obtained, as the notation suggests, as the m A
But in fact we can very quickly bound the axial elbows by the simple center-line method and so, in the vanilla algorithm, we will work only with upper bounds on the axial elbows..
Amount of Remuneration, etc. The Company does not pay to Directors who concurrently serve as Executive Officer the remuneration paid to Directors. Therefore, “Number of Persons”
小学校学習指導要領より 第４学年 Ｂ 生命・地球 （４）月と星
地球温暖化とは，人類の活動によってＧＨＧが大気
大気中の気温の鉛直方向の変化を見ると、通常は地表面から上空に行くに従って気温
