The psychiatric hospital as centre of community psychiatry

Strömgren, Erik

doi:10.1016/s0010-440x(63)80010-3

Cited by 74 publications

(105 citation statements)

References 2 publications

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“…Photometry in the uvby-β system (Strömgren 1963;Crawford 1966) is well suited to the determination of basic stellar atmospheric parameters for F-, G-, and K-type stars through the color indices (b-y), m 1 = (v-b) − (b-y) and c 1 = (u-v) − (v−b). Several empirical calibrations exist in the literature to transform (b-y) or β to T eff (e.g.…”

Section: Introductionmentioning

confidence: 99%

uvby–βphotometry of solar twins

Meléndez¹,

Schuster²,

Silva³

et al. 2010

A&A

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Aims. Solar colors have been determined on the uvby-β photometric system to test absolute solar fluxes, to examine colors predicted by model atmospheres as a function of stellar parameters (T eff , log g, [Fe/H]), and to probe zero-points of T eff and metallicity scales. Methods. New uvby-β photometry is presented for 73 solar-twin candidates. Most stars of our sample have also been observed spectroscopically to obtain accurate stellar parameters. Using the stars that most closely resemble the Sun, and complementing our data with photometry available in the literature, the solar colors on the uvby-β system have been inferred. Our solar colors are compared with synthetic solar colors computed from absolute solar spectra and from the latest Kurucz (ATLAS9) and MARCS model atmospheres. The zero-points of different T eff and metallicity scales are verified and corrections are proposed. Results. Our solar colors are (b − y) = 0.4105 ± 0.0015, m 1, = 0.2122 ± 0.0018, c 1, = 0.3319 ± 0.0054, and β = 2.5915 ± 0.0024. The (b − y) and m 1, colors obtained from absolute spectrophotometry of the Sun agree within 3-σ with the solar colors derived here when the photometric zero-points are determined from either the STIS HST observations of Vega or an ATLAS9 Vega model, but the c 1, and β synthetic colors inferred from absolute solar spectra agree with our solar colors only when the zero-points based on the ATLAS9 model are adopted. The Kurucz solar model provides a better fit to our observations than the MARCS model. For photometric values computed from the Kurucz models, (b − y) and m 1, are in excellent agreement with our solar colors independently of the adopted zero-points, but for c 1, and β agreement is found only when adopting the ATLAS9 zero-points. The c 1, color computed from both the Kurucz and MARCS models is the most discrepant, probably revealing problems either with the models or observations in the u band. The T eff calibration of Alonso and collaborators has the poorest performance (∼140 K off), while the relation of Casagrande and collaborators is the most accurate (within 10 K). We confirm that the Ramírez & Meléndez uvby metallicity calibration, recommended by Árnadóttir and collaborators to obtain [Fe/H] in F, G, and K dwarfs, needs a small (∼10%) zero-point correction to place the stars and the Sun on the same metallicity scale. Finally, we confirm that the c 1 index in solar analogs has a strong metallicity sensitivity.

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Section: Introductionmentioning

confidence: 99%

uvby–βphotometry of solar twins

Meléndez¹,

Schuster²,

Silva³

et al. 2010

A&A

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“…To answer this question, we compare, in Figure 3, canonical theoretical predictions from Catelan et al (1998) and , for a helium abundance of Y MS = 0.23 and a metallicity Z = 0.002, with high-precision photometry in the Strömgren (1963) system, from Grundahl et al (1998Grundahl et al ( , 1999. The empirical data were corrected for reddening following Harris (1996).…”

Section: The Case Of M3mentioning

confidence: 99%

The ages of stars: The horizontal branch

Catelan

2008

Proc. IAU

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“…Due to the narrow band and specific definition in u band, the Strömgren-Crawford (SC) system (Strömgren 1963(Strömgren , 1964Crawford et al 1970) provides a reliable method to determine stellar parameters for stars with a wide range of spectral types (e.g., early or late type stars, metal-poor stars). In particular, this photometric system can accurately identify stars at various evolutionary stages (Strömgren 1963(Strömgren ,Árnadóttir et al 2010.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, this photometric system can accurately identify stars at various evolutionary stages (Strömgren 1963(Strömgren ,Árnadóttir et al 2010. A recent evaluation of the importance of the capacity of the uvbyβ photometric system was presented by Bessell (2005).…”

Section: Introductionmentioning

confidence: 99%

Strömgren-Crawford uvbyβ all sky survey - towards understanding of the Galaxy

Wang¹,

Zhao²,

Chen³

et al. 2013

Proc. IAU

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Abstract. The Strömgren-Crawford (SC) intermediate-band photometric system is a very powerful and efficient one for the detailed study of stars, and therefore the Milky Way and local universe. However, due to the narrow bandwidth, low efficiency of detectors and serious atmospheric extinction in u band, and high photometric accuracy required, there was only one all sky survey in this system finished a decade ago, which is restricted to stars brighter than 8.3 mag in y (equal to V ) in the solar neighborhood. In this context, it is the right time to carry out an all sky survey to a completeness depth of ∼19 mag, equivalent to a volume-completed distance 4 kpc for solar-type stars. For stars brighter than 15 mag in V , the expected photometric accuracies are ∼0.01mag. With these stars, high precision 3D extinction map can be obtained thanks to the β index. Stellar atmospheric parameters can be determined with accuracies comparable to those from high-resolution spectroscopy. Fundamental parameters like stellar luminosities and distances can be reliably estimated as well. We propose to use the Nanshan 1m telescope to start the survey in early 2014 in the Northern sky. There are several 1-m class telescopes in Chile which can be used to perform the Southern sky survey. This entire survey, when finished, will greatly improve our knowledge on stars and the Galaxy, and will provide us the first 6D map of the Milky Way together with the LAMOST survey and the Gaia mission.

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The psychiatric hospital as centre of community psychiatry

Cited by 74 publications

References 2 publications

uvby–βphotometry of solar twins

uvby–βphotometry of solar twins

The ages of stars: The horizontal branch

Strömgren-Crawford uvbyβ all sky survey - towards understanding of the Galaxy

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