Browse > Article
http://dx.doi.org/10.5467/JKESS.2017.38.6.405

Spectroscopic Observation of AG Peg and Efficiency Changes of Bowen Fluorescence Mechanism  

Hyung, Siek (Department of Earth Science Education, Chungbuk National University)
Lee, Seong-Jae (Department of Earth Science Education, Chungbuk National University)
Lee, Kang Hwan (Department of Earth Science Education, Chungbuk National University)
Publication Information
Journal of the Korean earth science society / v.38, no.6, 2017 , pp. 405-420 More about this Journal
Abstract
We investigated the H I, He II and O III emission lines of the symbiotic star AG Peg, using the spectroscopic data secured at different phases in three periods at the Lick Observatory. We measured FWHM and the intensity of six O III Bowen lines and studied the efficiency of fluorescence mechanism. The mean FWHM of O III normal and Bowen lines observed during three time periods did not make much difference, while Bowen line intensities are about 4.0 times higher than the normal lines. Comparing the predicted and the observed ratios, we found that the observed intensities are higher than predicted intensities, except for O III ${\lambda}$ 3759.87. The O III ${\lambda}$ 3791.26 and 3754.67 intensity ratios observed only in 2001 are in good agreement with the predictions by Saraph and Seaton (1980). We obtained the Bowen efficiency parameter (R)=0.47 for 2002, but we could not find R for the other two periods of time. Because of this, based on the 2002 efficiency result, we calculated the intensity ratio of O III normal and Bowen lines relative to He II ${\lambda}$ 4685.68 and derive the efficiency variation with time period. The result showed that the efficiency is the highest in 1998 and the lowest in 2001. We conclude that the efficiencies with phase are caused by the electron temperature changes in the ionized gas. The efficiencies of AG Peg are likely to increase along with electron temperature. Our analysis results may be useful in understanding the physical conditions of the ionized shell in symbiotic star and the intensity ratio and efficiency variation.
Keywords
symbiotic nova AG Peg; line profile; Bowen line; spectroscopic observation;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
연도 인용수 순위
1 Belczyski, K., Mikolajewska, J., Munari, U., Ivison, R.J., and Friedjung, M., 2000, A catalogue of symbiotic stars. Astronomy and Astrophysics Supplement, 146, 407-435.   DOI
2 Berman, L., 1932, The Spectrum and Temperature of T Coronae (Nova 1866). Publications of the Astronomical Society of the Pacific, 44, 318-323.   DOI
3 Froese-Fischer, C., 1994, Allowed transitions and intercombination lines in C III and C II. Physica Scripta, 49, 323.   DOI
4 Grandi, S.A., 1980, On I 8446 A emission in Seyfert 1 galaxies. Astrophysical Journal, 238, 10-16.   DOI
5 Harrington, J.P., 1972, The Bowen Fluorescence Mechanism in Planetary Nebulae. Astrophysical Journal, 176, 127-137.   DOI
6 Hyung, S., 2014, Spectroscopic Study of the Symbiotic Star CI Cyg. Journal of Korean Earth Science Society, 35, 313-323.   DOI
7 Hyung, S. and Aller, L.H., 1995, The optical spectrum of NGC 7009-II. A high-excitation bright ring region on the minor axis. Monthly Notices of the Royal Astronomical Society, 273, 973-991.   DOI
8 Iben, I.J. and Tutokov, A.V., 1996, On the evolution of symbiotic stars and other binaries with accreting degenerate dwarfs. Astrophysical Journal, 105, 145-180.   DOI
9 Kallman, T. and McCray, R., 1980, Efficiency of the Bowen fluorescence mechanism in static nebulae. Astrophysical Journal, 242, 615-627.   DOI
10 Kastner, S.O. and Bhatia, A.K., 1984, On Bowen enhancement of the N III spectrum under solar and nebular conditions. Astrophysical Journal, 287, 945-951.   DOI
11 Kastner, S.O. and Bhatia, A.K., 1996, The Bowen fluorescence lines: overview and re-analysis of the observations. Monthly Notices of the Royal Astronomical Society, 279, 1137-1156.   DOI
12 Kenny, H.T., 1995, Symbiotic Stars: the Geometry of the Radio Emitting Regions. PhD dissertation. University of Calgary, Alberta, Canada, 292.
13 Kenyon, S.J., 1986, The symbiotic stars. PhD dissertation. Harvard University, Boston, Cambridge University Press, 295.
14 Kenyon, S.J., Proga, D., and Keyes, C.D., 2001, The Continuing Slow Decline of AG Pegasi. The Astronomical Journal, 122, 349-359.   DOI
15 Kim, H. and Hyung, S., 2008, Chemical abundances of the symbiotic nova AG Pegasi. Journal of the Korean Astronomical Society, 41, 23-37.   DOI
16 Lee, K.H., Lee, S.J., and Hyung, S., 2017, An Analysis of the H Emission Line Profiles of the Symbiotic Star AG Peg, Journal of Korean Earth Science Society, 38, 1-10. (in Korean)   DOI
17 Lee, S.J., Hyung, S., and Lee, K.H., 2012, An analysis of the symbiotic star Z And line profile. Journal of Korean Earth Science Society, 33, 608-617. (in Korean)   DOI
18 Liu, X.W. and Danziger, J., 1993, Observations of the Bowen fluorescence mechanism and charge transfer in planetary $nebulae^{\circ}(C)I$. Monthly Notices of the Royal Astronomical Society, 261, 465-495.   DOI
19 Liu, X., Danziger, J., and Murdin, P., 1993, Observations of the Bowen fluorescence mechanism and charge transfer in planetary nebulae. Monthly Notices of the Royal Astronomical Society, 262, 699-710.   DOI
20 McKenna, F.C., Keenan, F.P., Hambly, N.C., Prieto, C.A., Rolleston, W.R.J., Aller, L.H., and Feibelman, W.A., 1997, The Optical Spectral Line List of RR Telescopii. The Astrophysical Journal Supplement Series, 109, 225-239.   DOI
21 Pereira, C.B., de Araujo, F.X., and Landaberry, S.J.C., 1999, Bowen fluorescence lines in symbiotic stars-I. Observational data, line ratios and efficiency. MNRAS, 309, 1074-1084   DOI
22 Saraph, H.E. and Seaton, M.J. 1980, Oscillator strength for O III and Bowen fluorescent mechanism. Monthly Notices of the Royal Astronomical Society, 193, 617-629.   DOI
23 Proga, D., Kenyon, Scott J., and Raymond, J.C., 1998, Illumination in Symbiotic Binary Stars: Non-LTE Photoionization Models. II. WIND Case. The Astrophysical Journal, 501, 339-356.   DOI
24 Raymond, J.C., 1978, Bowen fluorescence in the solar transition region. Astrophysical Journal, 224, 259-264.   DOI
25 Sabbadin, F., Turatto, M., Ragazzoni, R., Cappellaro, E., and Benetti, S., 2006, The structure of planetary nebulae: theory vs. practice. Astronomy and Astrophysics, 451, 937-949.   DOI
26 Seaton, M.J., 1979, Interstellar extinction in the UV. Monthly Notices of the Royal Astronomical Society, 187P, 73-76.
27 Likkel, L. and Aller, L.H., 1986, Observations of the Bowen fluoresecent mechanism in planetary nebulae. Astrophysical Journal, 301, 825-833.   DOI
28 Selvelli, P., Danziger, J., and Bonifacio, P., 2007, The HeII Fowler lines and the OIII and NIII Bowen fluorescence lines in the symbiotic nova RR Telescopii. Astronomy and Astrophysics, 464, 715-734.   DOI
29 Storey, P.J. and Hummer, D.G., 1995, Recombination line intensities for hydrogenic ions-IV. Total recombination coefficients and machine-readable tables for Z=1 to 8, Monthly Notices of the Royal Astronomical Society, 272, 41-48.   DOI
30 Vogel, M. and Nussbaumer, H., 1994, The hot wind in the symbiotic nova AG Pegasi. Astronomy and Astrophysics, 284, 145-155.
31 Wallerstein G., Schachter J., Garnavich P. M., and Oke J. B., 1991, Observation of Bowen fluorescence and other phenomena in five symbiotic stars. Publications of the Astronomical Society of the Pacific, 103, 185-193.   DOI
32 Contini, M., 1997, The Evolving Structure of AG Pegasi, Emerging from the Interpretation of the Emission Spectra at Different Phases. The Astrophysical Journal, 483, 887-898.   DOI
33 Weymann, R.J. and Williams, R.E., 1969, The Bowen Fluorescence Mechanism in Planetary Nebulae and the Nuclei of Seyfert Galaxies. Astrophysical Journal, 157, 1201-1213.   DOI
34 Bowen, I.S., 1934, The Excitation of the Permitted O III Nebular Lines. Publications of the Astronomical Society of the Pacific, 46, 146-148.   DOI
35 Bhatia, A.K. and Kastner, S.O., 1993, Collision Strengths and Transition Rates for O III. Atomic Data and Nuclear Data Tables, 54, 133-164.   DOI
36 Bhatia, A.K., Kastner, S.O., and Behring, W.E., 1982, The solar O III spectrum. I-Photoexcitation of EUV lines by He II Lyman-alpha. Astrophysical Journal, 257, 887-895.   DOI
37 Bowen, I.S., 1935, The Spectrum and Composition of the Gaseous Nebulae. Astrophysical Journal, 81, 1-16.   DOI
38 Boyarchuk, A.A., 1969, SYMBIOTIC STARS. Non-Periodic Phenomena in Varoable Stars of IAU Colloquium, 65, 395.
39 Burgess, A. and Seaton, M.J., 1960, The Abundance of Oxygen in the Planetary Nebula NGC 7027. Monthly Notices of the Royal Astronomical Society, 121, 76-96.   DOI
40 Dalgarno, A. and Sternberg, A., 1982, The excitation of the triplet lines of $O^{2+}$ in nebulae. Monthly Notices of the Royal Astronomical Society, 200, 77-80.   DOI
41 Deguchi, S., 1985, Bowen fluorescence mechanism in Xray binaries. Astrophysical Journal, 291, 492-504.   DOI
42 Eriksson, M., Johansson, S., Wahlgren, G.M., Veenhuizen, H., Munari, U., and Siviero, A., 2005, Bowen excitation of N III lines in symbiotic stars. Astronomy and Astrophysics, 434, 397-404.   DOI
43 Fang, X. and Liu, X.W., Very deep spectroscopy of the bright Saturn nebula NGC 7009-I. Observations and plasma diagnostics. Monthly Notices of the Royal Astronomical Society, 415, 181-198.
44 Aller, L.H., 1984, Physics of thermal gaseous nebulae. Astrophysics and Space Science Library. 112, 360.