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J/A+A/512/A54     Teff and Fbol from Infrared Flux Method   (Casagrande+, 2010)

An absolutely calibrated Teff scale from the Infrared Flux Method. Dwarfs and subgiants. Casagrande L., Ramirez I., Melendez J., Bessell M., Asplund M. <Astron. Astrophys. 512, A54 (2010)> =2010A&A...512A..54C
ADC_Keywords: Stars, dwarfs ; Stars, giant; Effective temperatures ; Photometry, infrared ; Models, atmosphere Keywords: stars: fundamental parameters - stars: abundances - stars: atmospheres - infrared: stars - techniques: photometric Abstract: Various effective temperature scales have been proposed over the years. Despite much work and the high internal precision usually achieved, systematic differences of order 100K (or more) among various scales are still present. We present an investigation based on the Infrared Flux Method aimed at assessing the source of such discrepancies and pin down their origin. We break the impasse among different scales by using a large set of solar twins, stars which are spectroscopically and photometrically identical to the Sun, to set the absolute zero point of the effective temperature scale to within few degrees. Our newly calibrated, accurate and precise temperature scale applies to dwarfs and subgiants, from super-solar metallicities to the most metal-poor stars currently known. At solar metallicities our results validate spectroscopic effective temperature scales, whereas for [Fe/H]←2.5 our temperatures are roughly 100 K hotter than those determined from model fits to the Balmer lines and 200 K hotter than those obtained from the excitation equilibrium of Fe lines. Empirical bolometric corrections and useful relations linking photometric indices to effective temperatures and angular diameters have been derived. Our results take full advantage of the high accuracy reached in absolute calibration in recent years and are further validated by interferometric angular diameters and space based spectrophotometry over a wide range of effective temperatures and metallicities. Description: Sample stars used and fundamental physical parameters (Teff, Fbol, diam) derived via IRFM. The apparent bolometric magnitudes (mBol) have been computed according to Casagrande et al. (2006MNRAS.373...13C), where the absolute bolometric magnitude of the Sun MBol=4.74. For each star mBol is obtained using its bolometric flux (Fbol) and effective temperature (Teff) and therefore it is already corrected for reddening, if present. Notice however that the observed magnitudes given here are not: before computing bolometric corrections, the observed magnitudes should be dereddened using the E(B-V) given here. The correction into dereddened magnitudes as been done iteratively, as described in Section 2.1 of the paper. However, average relations between E(B-V) and various photometric bands can be found in literature e.g. McCall (2004AJ....128.2144M). Bolometric corrections in each band can be readily obtained using the dereddened magnitudes. E.g. BCV=mBol-V0, where BCV is the bolometric correction in V band, mBol is thw apparent bolometric magnitude, V0 is the dereddened apparent V magnitude (=Vmag if E(B-V)=0). Errors have been computed as described in the paper, without accounting for the uncertainty in E(B-V): changing it by ±0.01 would affect Teff by approximately ±50K. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table8.dat 151 423 Photometric data used in the paper and stellar fundamental parameters determined via InfraRed Flux Method (IRFM)
See also: J/A+A/282/899 : Teff and angular diameters from IRFM (Blackwell+ 1994) J/A+AS/129/505 : Effective temperatures by IFRM (Blackwell+ 1998) J/ApJ/626/446 : Effective temperature scale of FGK stars (Ramirez+, 2005) J/A+A/497/497 : Physical parameters from JHK flux (Gonzalez-Hernandez+, 2009) Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Name Star name 15- 18 F4.2 [cm/s2] logg Surface gravity 21- 25 F5.2 [Sun] [Fe/H] Metallicity 28- 33 F6.3 mag mBol IRFM apparent bolometric magnitude. (Mbol=4.74) 36- 48 E13.7 mW/m2 Fbol IRFM bolometric flux (on the Earth) 51- 61 E11.5 mW/m2 e_Fbol IRFM bolometric flux error 64- 67 I4 K Teff IRFM effective temperature 71- 73 I3 K e_Teff IRFM effective temperature error 76- 80 F5.3 mas Diam IRFM angular diameter 83- 87 F5.3 mas e_Diam IRFM angular diameter error 90- 95 F6.3 mag Bmag Johnson apparent B magnitude 98-103 F6.3 mag Vmag Johnson apparent V magnitude 106-111 F6.3 mag Rmag ?=- Cousins apparent R magnitude 114-119 F6.3 mag Imag ?=- Cousins apparent I magnitude 122-127 F6.3 mag Jmag 2MASS apparent J magnitude 130-135 F6.3 mag Hmag 2MASS apparent H magnitude 138-143 F6.3 mag Kmag 2MASS apparent Ks magnitude 147-151 F5.3 mag E(B-V) Reddening correction
Acknowledgements: Luca Casagrande, luca(at)mpa-garching.mpg.de
(End) Luca Casagrande [MPA, Germany], Patricia Vannier [CDS] 04-Feb-2010
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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