SDSS absolute magnitudes for thin-disc stars based on trigonometric parallaxes


Bilir S. , Karaali S., Ak S. , Coskunoglu K. B. , Yaz E. , Cabrera-Lavers A.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.396, ss.1589-1595, 2009 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 396 Konu: 3
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1111/j.1365-2966.2009.14816.x
  • Dergi Adı: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Sayfa Sayıları: ss.1589-1595

Özet

We present a new luminosity-colour relation based on trigonometric parallaxes for thin-disc main-sequence stars in Sloan Digital Sky Survey (SDSS) photometry. We matched stars from the newly reduced Hipparcos catalogue with the ones taken from Two-Micron All-Sky Survey (2MASS) All-Sky Catalogue of Point Sources, and applied a series of constraints, i.e. relative parallax errors (sigma pi/pi <= 0.05), metallicity (-0.30 <= [M/H] = 0.20 dex), age (0 <= t <= 10 Gyr) and surface gravity (logg > 4), and obtained a sample of thin-disc main-sequence stars. Then, we used our previous transformation equations (Bilir et al. 2008a) between SDSS and 2MASS photometries and calibrated the M(g) absolute magnitudes to the (g - r)(0) and (r - i)(0) colours. The transformation formulae between 2MASS and SDSS photometries along with the absolute magnitude calibration provide space densities for bright stars which saturate the SDSS magnitudes.