Metallicity and absolute magnitude calibrations for UBV photometry

Karataş, Yüksel; Schuster, W. J.

doi:10.1111/j.1365-2966.2006.10800.x

Cited by 33 publications

(61 citation statements)

References 31 publications

(93 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We applied these calibrations to two sets of data with À1.76 # [Fe/H] # 0.4 dex taken from Karaali et al (2003) and Karatas -& Schuster (2006) and we compared the evaluated metallicities with the original ones for two calibrations. The metallicities of 75 stars in the first set were estimated spectroscopically, whereas those for 469 stars are based on photometry.…”

Section: Application Of the Methodsmentioning

confidence: 99%

“…We derived metallicity calibrations for two sets of guillotine factors using the same procedure and applied them to two different sets of data. The data of the first set were taken from Karaali et al (2003), whereas those of the second set are from Karatas -& Schuster (2006). For the first set, the mean deviations of the residuals for two calibrations are different.…”

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

An Improved Metallicity Calibration with UBV Photometry

Karaali

Bilir

et al. 2011

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

Abstract:We used the data of 701 stars covering the colour index interval 0.32 , B À V # 1.16, with metallicities À1.76 # [Fe/H] # þ0.40 dex. The data were taken from the PASTEL catalogue and estimated metallicity-dependent guillotine factors, which provide a more accurate metallicity calibration. We reduced the metallicities of 11 different authors to the metallicities of Valenti & Fischer (2005), and thus obtained a homogeneous set of data which increased the accuracy of the calibration, i.e. [Fe/H] ¼ À14.316d 0.6 2 À 3.557d 0.6 þ 0.105. Comparison of the metallicity residuals for two sets of data based on the metallicitydependent guillotine factors with the ones obtained via metal-free guillotine factors shows that metallicities estimated by means of the new guillotine factors are more accurate than the other ones. This advantage can be used in the metallicity gradient investigation of the Galactic components, i.e. thin disc, thick disc, and halo.

show abstract

Section: Application Of the Methodsmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

An Improved Metallicity Calibration with UBV Photometry

Karaali

Bilir

et al. 2011

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

show abstract

“…1(a) and (b)) as representative of the mean metal abundances of the cluster has been estimated, and these average values are given in Table 4 Table 1A given by Sandage (1969). Then, the metallicity values, [Fe/H], for the 20 OCs have been derived from the empirical calibration, [Fe/H]-δ(U -B) 0.6 , as given in equation (6) of Karataş & Schuster (2006). These final [Fe/H] values are given for each cluster in Table 6.…”

Section: Interstellar Reddenings and Photometric Metallicitiesmentioning

confidence: 99%

“…To be able to appreciate the photometric metal-abundance determination and the iso-metallicity line (the red curve in Fig. 1 Karataş & Schuster (2006), who also have used the Hyades mean colours as reference. Thus, from the estimated values of (U -B) 0 for (B-V ) 0 ≈ 0.24 − 0.44, the iso-metallicity line which corresponds to Z = +0.013 has been drawn in Fig.…”

Section: Interstellar Reddenings and Photometric Metallicitiesmentioning

confidence: 99%

CCD UBV(RI)C photometry of twenty open clusters

Oralhan¹,

Karataş²,

Schuster³

et al. 2015

New Astronomy

View full text Add to dashboard Cite

Fundamental astrophysical parameters have been derived for 20 open clusters (OCs) using CCD UBV(RI) C photometric data observed with the 84 cm telescope at the San Pedro Mártir National Astronomical Observatory, México.The interstellar reddenings, metallicities, distances, and ages have been compared to the literature values. Significant differences are usually due to the usage of diverse empirical calibrations and differing assumptions, such as concerning cluster metallicity, as well as distinct isochrones which correspond to differing element-abundance ratios, internal stellar physics, and photometric systems. Different interstellar reddenings, as well as varying reduction and cluster-membership techniques, are also responsible for these kinds of systematic differences and errors.The morphological ages, which are derived from the morphological indices (δV and δ1) in the CM diagrams, are in good agreement with the isochrone ages of 12 OCs, those with good red clump (RC) and red giant (RG) star candidates. No metal abundance gradient is detected for the range 6.82 ≤ R GC ≤ 15.37 kpc, nor any correlation between the cluster ages and metal abundances for these 20 OCs.Young, metal-poor OCs, observed here in the third Galactic quadrant, may be associated with stellar over-densities, such as that in Canis Major (Martin et al.) and the Monoceros Ring (Newberg et al.), or signatures of past accretion events, as discussed by Yong et al. and Carraro et al.

show abstract

“…The procedure usually used for its estimation is based on its offset from a standard sequence, such as the absolute magnitude-colour diagram of the Hyades cluster. Examples can be found in Laird et al (1988); Nissen & Schuster (1991); Karaali et al (2003aKaraali et al ( , 2005; Karataş & Schuster (2006). The procedure of Ivezic et al (2008) is different than the cited ones, i.e.…”

Section: Introductionmentioning

confidence: 99%

Metallicity calibration and photometric parallax estimation: II. SDSS photometry

Güçtekin

Bilir

Karaali

et al. 2016

Astrophys Space Sci

View full text Add to dashboard Cite

We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess, δ 0.41 defined with ugr data in the SDSS. We estimated the M g absolute magnitudes for the same stars via the re-reduced Hipparcos parallaxes and calibrated the absolute magnitude offsets, ∆M g , relative to the intrinsic sequence of Hyades to a third order polynomial in terms of δ 0.41 . mean of the residuals and the corresponding standard deviation for the metallicity calibration are 0 and 0.137 mag; while, for the absolute magnitude calibration they are 0 and 0.179 mag, respectively. We applied our procedures to 23,414 dwarf stars in the Galactic field with the Galactic coordinates 85• and size 78 deg 2 . We estimated absolute magnitude M g dependent vertical metallicity gradients as a function of vertical distance Z. The gradients are deep in the range of 0 < Z ≤ 5 kpc, while they are very small positive numbers beyond Z = 5 kpc. All dwarfs with 5 < M g ≤ 6 mag are thin-disc stars and their distribution shows a mode at (g − r) 0 ≈ 0.38 mag, while the absolute magnitudes 4 < M g ≤ 5 are dominated by thick disc and halo stars, i.e. the apparently bright ones (g 0 ≤ 18 mag) are thick-disc stars with a mode at (g − r) 0 ∼ 0.38 mag, while the halo population is significant in the faint stars (g 0 > 18 mag).

show abstract

Metallicity and absolute magnitude calibrations for UBV photometry

Cited by 33 publications

References 31 publications

An Improved Metallicity Calibration with UBV Photometry

An Improved Metallicity Calibration with UBV Photometry

CCD UBV(RI)C photometry of twenty open clusters

Metallicity calibration and photometric parallax estimation: II. SDSS photometry

Contact Info

Product

Resources

About