LAMOST DR1 ve WASP'ta ki düşük metal bolluklu zonklayan yıldızlar

Yıl 2018, , 938 - 944, 01.06.2018

Filiz Kahraman Aliçavuş

https://doi.org/10.16984/saufenbilder.341828

Öz

 Bu çalışmada “LAMOST Data Release 1 (DR1)” tayfsal veri
tabanında yer alan düşük metal bolluklu zonklayan yıldızların incelemesi
sunulmuştur. Çalışmada kullanılan sistemler LAMOST DR1 katalogunda yer alan ve
metal bolluğu -2.4 ile -0.5 dex, etkin sıcaklığı 6500 ile 8600 K ve yüzey çekim
ivmesi log g = 3.8 – 4.5 aralığında
bulunan yıldızlardan seçilmiştir. Seçilen yıldızların fotometrik verileri ise
WASP katalogundan alınmıştır. Fotometrik veriler kullanılarak ışık değişimi
gösteren yıldızlar belirlenmiş ve değişim frekansları elde edilmiştir. Sonuç
olarak analiz edilen sistemlerden beşi kesin, ikisi aday RR Lyrae ve üçü de
aday SX Phoenix  yıldızı olarak tanımlanmıştır.
Ayrıca, yıldızların tayf türleri, etkin sıcaklık değerleri ve dönme hızlarıda
tayfsal verilerin analizi ile elde edilmiştir.

Anahtar Kelimeler

Zonklayan yıldızlar, tayf analizi

Low-metallicity pulsating stars in the LAMOST DR1 and WASP

Öz

In this study,
the results of a research about low-metallicity pulsating stars are presented.
The stars having metallicity from -2.4 to -0.5 dex were selected from the
LAMOST DR1 catalogue considering the ranges of 6500-8600 K, 3.8-4.5 cgs of
effective temperature and surface gravity, respectively. Photometric data of
the selected stars were taken from the WASP. The stars showing light variation
were determined and  variability
frequencies of the stars were derived. As a result, five confirmed, two
candidate RR Lyrae stars and three suspect SX Phoenix variables were found. Additionally, spectral types,
effective temperatures, and projected rotational velocities of the stars were
derived.

Anahtar Kelimeler

Pulsating stars, Spectroscopic analysis, Atmospheric parameters

Kaynakça

• A. McWilliam, G. W. Preston, C. Sneden, L. Searle, “Spectroscopic Analysis of 33 of the Most Metal Poor Stars. II,” Astronomical Journal, vol. 109, no. 6, pp. 2757–2799, 1995.
• J. E. Norris, S. G. Ryan and T. C. Beers, “Extremely Metal-poor Stars. I. Spectroscopic Data,” Astrophysical Journal Supplement, vol. 107, pp. 391–402, 1996.
• C. T. Beers and N. Christlieb, “The Discovery and Analysis of Very Metal-Poor Stars in the Galaxy,” Annual Review of Astronomy & Astrophysics, vol. 43, no. 1, pp. 531–580, 2005.
• C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, “Asteroseismology,” Astronomy and Astrophysics Library ISBN 978-1-4020-5178-4. Springer Science+Business Media B.V., 2010.
• R. Smolec, P. Moskalik, J. Kałużny, W. Pych, M. Różyczka, I. B. Thompson, “RR Lyrae stars in NGC 6362,” Monthly Notices of the Royal Astronomical Society, vol. 467, no. 2, pp. 2349–2366, 2017.
• M. A. T. Groenewegen and M. I. Jurkovic, “The period-luminosity and period-radius relations of Type II and anomalous Cepheids in the Large and Small Magellanic Clouds,” Astronomy & Astrophysics, vol. 604, no. 29, pp. 8–22, 2017.
• A.-Li Luo, Y.-Heng Zhao, G. Zhao, Li-Cai Deng, X.-Wei Liu, Y.-Peng Jing, G. Wang, H.-T. Zhang, J.-R. Shi, X.-Q. Cui, and 135 coauthors, “The first data release (DR1) of the LAMOST regular survey,” Research in Astronomy and Astrophysics, vol. 15, no.8, pp. 1095–1137, 2015.
• D. L. Pollacco, I. Skillen, A. Collier Cameron, D. J. Christian, C. Hellier, J. Irwin, T. A. Lister, R. A. Street, R.G. West, D.R. Anderson, and 18 coauthors, “The WASP Project and the SuperWASP Cameras,” The Publications of the Astronomical Society of the Pacific, vol. 118, no.848, pp. 1407–1418, 2006.
• X.-Q. Cui, Y.-H. Zhao, Y.-Q. Chu, G.-P. Li, Q. Li, L.-P. Zhang, H.-J: Su, Z.-Q. Yao,Y.-N. Wang, X.-Z. Xing, and 67 coauthors, “The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST),” Research in Astronomy and Astrophysics, vol. 12, no. 9, pp. 1197–1242, 2012.
• C. A. Navin, L. S. Martell and D. B. Zucker, “New Halo Stars of the Galactic Globular Clusters M3 and M13 in the LAMOST DR1 Catalog,” The Astrophysical Journal, vol. 829, no. 2, pp. 123–137, 2016.
• P. Lenz and M. Breger, “Period04 User Guide, ”Communications in Asteroseismology, vol. 146, no. 2, pp. 53–136, 2005.
• P. Wils, C. Lloyd and K. Bernhard, “A catalogue of RR Lyrae stars from the Northern Sky Variability Survey,” Monthly Notices of the Royal Astronomical Society, vol. 368, no. 4, pp. 1757–1763, 2006.
• M. A. Abbas, E. K. Grebel, N. F. Martin, W. S. Burgett, H. Flewelling, R. J. Wainscoat, “Newly discovered RR Lyrae stars in the SDSS-Pan-STARRS1-Catalina footprint,” Monthly Notices of the Royal Astronomical Society, vol. 441, no. 2, pp. 1230–1242, 2014.
• A.J. Drake, M. Catelan, S. G. Djorgovski, G. Torrealba, M. J. Graham, V. Belokurov, S. E. Koposov, A. Mahabal, J. L. Prieto, C. Donalek, and 4 coauthors, “Probing the Outer Galactic Halo with RR Lyrae from the Catalina Surveys,” The Astrophysical Journal, vol. 763, no. 1, pp. 32–52, 2013.
• E. Kemper, “A spectroscopic study of the c-type RR Lyraes,” Astronomical Journal, vol. 87, no. 1, pp. 1395-1408, 1982.
• V. P. Tsesevich and O. E. Mandel, “On the Blazhko effect of V421 Herculis.,” Perem. Zvezdy, Byull., vol. 22, no. 2, pp. 237–244, 1985.
• R. O. Gray, C. J. Corbally, R. F. Garrison, M. T. McFadden, P. E. Robinson, “Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I.,” The Astronomical Journal, vol. 126, no. 4, pp. 2048–2059, 2003.
• J.-C. Mermilliod, M. Mermilliod, B. Hauck, “The General Catalogue of Photometric Data (GCPD). II.,” A & A Supplement series, vol. 127, p. 349-352, 1997.
• R. M. Cutri, M. F. Skrutskie, S. van Dyk, C. A. Beichman, J. M. Carpenter, T. Chester, L. Cambresy, T. Evans, J. Fowler, J. Gizis, and 15 coauthors, “2MASS All Sky Catalog of point sources,” The IRSA 2MASS All-Sky Point Source Catalog, NASA/IPAC Infrared Science Archive , 2006.
• E. B. Amôres and J. R. D. Lépine, “Models for Interstellar Extinction in the Galaxy,” The Astronomical Journal, vol. 130, no. 2, pp. 659–673, 2005.
• R. Kurucz, “ATLAS9 Stellar Atmosphere Programs and 2 km/s grid,” ATLAS9 Stellar Atmosphere Programs and 2 km/s grid. Kurucz CD-ROM No. 13. Cambridge, Mass.: Smithsonian Astrophysical Observatory, 1993.
• R. L. Kurucz and E. H. Avrett, “Solar Spectrum Synthesis. I. A Sample Atlas from 224 to 300 nm,” SAO Special Report, vol. 391, 1981.
• B. Smalley, R. B. Gardiner, F. Kupka, M. S. Bessell, “On the anomaly of Balmer line profiles of A-type stars. Fundamental binary systems,” Astronomy and Astrophysics, vol. 395, pp. 601–609, 2002.
• O. W. Butters, R. G. West, D. R. Anderson, A. Collier Cameron, W. I. Clarkson, B. Enoch, C. A: Haswell, C. Hellier, K. Horne, Y. Joshi, and 10 coauthors, “The first WASP public data release,” Astronomy and Astrophysics, vol. 520, no. 10, pp. 1–4, 2010.