Investigating the Colour-Magnitude Relations for White Dwarf Stars in SDSS Photometry

Yıl 2025, Cilt: 3 Sayı: 1, 13 - 20, 24.06.2025

Özcan Çalışkan , Sevinç Gökmen

Öz

In this study, colour-magnitude relations (CMRs) for DA-type white dwarfs in the Sloan Digital Sky Survey (SDSS) photometric system were investigated. For this purpose, the SDSS data for 20,247 white dwarf stars, as provided in the study by Anguiano et al. (2017), were matched with the Gaia third data release (Gaia DR3) catalogue to obtain trigonometric parallax (𝜛) data. The SDSS ugriz magnitudes of the stars were corrected for interstellar extinction using dust maps provided for the Milky Way, and distances from the Sun to the stars were calculated. For the calibration of the stars, 5,516 white dwarf stars were selected with apparent magnitudes brighter than 𝑔0 = 21 mag and relative parallax errors measured to better than 𝜎𝜛/𝜛 = 0.1. Subsequently, three separate CMRs were derived for the absolute magnitudes 𝑀g, 𝑀r , and 𝑀i , each calibrated to two-colour indices. The coefficient of determination (𝑅 2 ) of the obtained CMRs are highly reliable in the range of 0.86 to 0.95. Moreover, the standard deviations of the differences between the absolute magnitudes obtained from the relations and the original ones of the calibration stars range from 0.26 to 0.37 mag.

Anahtar Kelimeler

Techniques , Sloan photometry , Stars , White dwarf , Distance

Kaynakça

• Alam S., et al., 2015, ApJS, 219, 12 google scholar
• Anguiano B., Rebassa-Mansergas A., Garaa-Berro E., Torres S., Free-man K. C., Zwitter T., 2017, MNRAS, 469, 2102 google scholar
• Bahcall J. N., Soneira R. M., 1980, ApJS, 44, 73 google scholar
• Bailer-Jones C. A. L., Rybizki J., Fouesneau M., Demleitner M., An-drae R., 2021, AJ, 161, 147 google scholar
• Bergeron P., Dufour P., Fontaine G., Coutu S., Blouin S., Genest-Beaulieu C., Bedard A., Rolland B., 2019, ApJ, 876, 67 google scholar
• Bilir S., Karaali S., Tunçel S., 2005, Astronomische Nachrichten, 326, 321 google scholar
• Bilir S., Karaali S., Ak S., Yaz E., Cabrera-Lavers A., Coşkunoglu K. B., 2008, MNRAS, 390, 1569 google scholar
• Bilir S., Karaali S., Ak S., Coşkunoglu K. B., Yaz E., Cabrera-Lavers ˇ A., 2009, MNRAS, 396, 1589 google scholar
• Cardelli J. A., Clayton G. C., Mathis J. S., 1989, ApJ, 345, 245 google scholar
• ESA ed. 1997, The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star catalogues derived from the ESA HIPPAR-COS Space Astrometry Mission ESA Special Publication Vol. 1200 google scholar
• Gaia Collaboration et al., 2016, A&A, 595, A1 google scholar
• Gaia Collaboration et al., 2018, A&A, 616, A1 google scholar
• Gaia Collaboration et al., 2023, A&A, 674, A1 google scholar
• Gentile Fusillo N. P., et al., 2019, MNRAS, 482, 4570 google scholar
• Holberg J. B., Bergeron P., 2006, AJ, 132, 1221 google scholar
• Ivezic Z., et al., 2008, ApJ, 684, 287 google scholar
• İyisan S., Bilir S., Önal Taş Ö., Plevne O., 2025, AJ, 169, 138 google scholar
• Juric M., et al., 2008, ApJ, 673, 864 google scholar
• Karaali S., Bilir S., Karataş Y., Ak S. G., 2003, Publ. Astron. Soc. Australia, 20, 165 google scholar
• Karaali S., Bilir S., Ak S., Yaz E., Coşkunoğlu B., 2011, Publ. Astron. Soc. Australia, 28, 95 google scholar
• Kilic M., et al., 2010, ApJS, 190, 77 google scholar
• Kilic M., Munn J. A., Harris H. C., von Hippel T., Liebert J. W., Williams K. A., Jeffery E., DeGennaro S., 2017, ApJ, 837, 162 google scholar
• Kleinman S. J., et al., 2004, ApJ, 607, 426 google scholar
• Koester D., Schulz H., Weidemann V., 1979, A&A, 76, 262 google scholar
• Luri X., et al., 2018, A&A, 616, A9 google scholar
• Marshall D. J., Robin A. C., Reyle C., Schultheis M., Picaud S., 2006, A&A, 453, 635 google scholar
• O’Donnell J. E., 1994, ApJ, 422, 158 google scholar
• Provencal J. L., Shipman H. L., H0g E., Thejll P., 1998, ApJ, 494, 759 google scholar
• Rowell N., Kilic M., 2019, MNRAS, 484, 3544 google scholar
• Schlafly E. F., Finkbeiner D. P., 2011, ApJ, 737, 103 google scholar
• Shipman H. L., 1979, ApJ, 228, 240 google scholar
• Tremblay P. E., et al., 2020, MNRAS, 497, 130 google scholar
• Tremblay P.-E., Bedard A., O’Brien M. W., Munday J., Elms A. K., Gentillo Fusillo N. P., Sahu S., 2024, New Astron. Rev., 99, 101705 google scholar
• Tunçel Güçtekin S., Bilir S., Karaali S., Ak S., Ak T., Bostancı Z. F., 2016, Ap&SS, 361, 186 google scholar
• York D. G., et al., 2000, AJ, 120, 1579 google scholar
• Çelebi M., Bilir S., Ak S., Ak T., Bostancı Z. F., Yontan T., 2019, Ap&SS, 364, 172 google scholar
• van Leeuwen F., 2007, A&A, 474, 653 google scholar