Identification of field dwarfs and giants in the second Radial Velocity Experiment Data Release
Küçük Resim Yok
Tarih
2011
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Wiley-Blackwell
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
The second Radial Velocity Experiment (RAVE) Data Release (DR2) derives log g values. However, we present a simpler and cleaner method of identifying dwarfs and giants by using only magnitudes, which does not require spectroscopic analysis. We confirm the method presented in an earlier paper, with which we estimate the number of dwarfs and giants using their positions in the JV two-magnitude diagram, by applying it to RAVE DR2. It is effective in estimating the number of dwarfs and giants at JH > 0.4 compared to RAVEs log g values. For JH= 0.4, where dwarfs and subgiants show a continuous transition in the J magnitude histogram, we used the Besancon Galaxy model predictions to statistically isolate giants. The percentages of giants for red stars and for the whole sample are 85 and 34 per cent, respectively. If we add the subgiants, the percentage of evolved stars for the whole sample increases to 59 per cent. For the first time in the literature, we have analysed the effect of CHISQ on RAVEs log g values (CHISQ is the penalized 2 from RAVEs technique of finding an optimal match between the observed spectrum and synthetic spectra to derive stellar parameters). Neither the CHISQ values nor the signal-to-noise ratio bias the RAVE log g values. Therefore, the method of identifying dwarfs and giants using the two-magnitude diagram has been verified against an unbiased data set.
Açıklama
Anahtar Kelimeler
techniques: photometric, catalogues, surveys
Kaynak
Monthly Notices Of The Royal Astronomical Society
WoS Q Değeri
Q1
Scopus Q Değeri
N/A
Cilt
418
Sayı
1
