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J/A+A/503/913    Synthetic spectrophotometry for C-rich giants  (Aringer+, 2009)

Synthetic photometry for carbon rich giants. I. Hydrostatic dust-free models. Aringer B., Girardi L., Nowotny W., Marigo P., Lederer M.T. <Astron. Astrophys., 503, 913-928 (2009)> =2009A&A...503..913A
ADC_Keywords: Models, evolutionary ; Photometry ; Spectroscopy Keywords: stars: late-type - stars: AGB and post-AGB - stars: atmospheres - infrared: stars - stars: carbon - Hertzsprung-Russell (HR) and C-M diagrams Abstract: Carbon rich objects represent an important phase during the late stages of evolution of low and intermediate mass stars. They contribute significantly to the chemical enrichment and to the infrared light of galaxies. A proper description of their atmospheres is crucial for the determination of fundamental parameters such as effective temperature or mass loss rate. We study the spectroscopic and photometric properties of carbon stars. In the first paper of this series we focus on objects that can be described by hydrostatic models neglecting dynamical phenomena like pulsation and mass loss. As a consequence, the reddening due to circumstellar dust is not included. Our results are collected in a database, which can be used in conjunction with stellar evolution and population synthesis calculations involving the AGB. We have computed a grid of 746 spherically symmetric COMARCS atmospheres covering effective temperatures between 2400 and 4000K, surface gravities from log(g[cm/s2])=0.0 to -1.0, metallicities ranging from the solar value down to one tenth of it and C/O ratios in the interval between 1.05 and 5.0. Subsequently, we used these models to create synthetic low resolution spectra and photometric data for a large number of filter systems. The tables including the results are electronically available. First tests of the application on stellar evolution calculations are shown. We have selected some of the most commonly used colours in order to discuss their behaviour as a function of the stellar parameters. A comparison with measured data shows that down to 2800K the agreement between predictions and observations of carbon stars is good and our results may be used to determine quantities like the effective temperature. Below this limit the synthetic colours are much too blue. The obvious reason for these problems is the neglect of circumstellar reddening and structural changes due to pulsation and mass loss. Description: The following bolometric correction tables have been calculated from COMA07/SPHREAD03 spectra based on COMARCS04 hydrostatic models. Reddening due to circumstellar dust is not included. Each of the 36 tables contains a photometric system including different filters. If a certain filter curve is not covered by the synthetic spectra (below 4444 and above 250000A) a value of -999999 is listed for the bolometric correction. Details concerning the photometric systems are given in Marigo, P., Girardi, L., Bressan, A., et al., 2008A&A...482..883M and in . File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file photom.dat 141 36 List of photometric system files spectra.dat 89 746 List of spectra phot/* 368 36 Individual photometric files with bolometric corrections spec/* 31 746 Individual synthetic spectra
Byte-by-byte Description of file: photom.dat
Bytes Format Units Label Explanations
1- 15 A15 --- FileName Name of the file in subdirectory phot 17-141 A125 --- Filt Filters for which bolometric corrections are presented in the file
Byte-by-byte Description of file: spectra.dat
Bytes Format Units Label Explanations
1- 4 I4 --- Mod [1/746] Model number 7 I1 --- Ver [3/4] Version of COMARCS model 9- 12 I4 K Teff [2400/4000] Effective temperature 14- 18 F5.2 [cm/s2] logg [-1.00/+0.00] Surface gravity 20- 24 F5.2 solMass Mass [1/99] Mass 26- 29 F4.2 Sun Z (0.10, 0.33, 1.00) Metallicity (in solar metallicity) 32- 35 F4.2 --- C/O [1.05/5.00] C/O abundance ratio 37- 39 F3.1 km/s xi [2.5] Microturbulent velocity 41- 89 A49 --- SpFileName Name of the spectrum in subdirectory spec
Byte-by-byte Description of file: phot/*
Bytes Format Units Label Explanations
1- 4 I4 --- Mod [1/746] Model number 10- 13 I4 K Teff Effective temperature 15- 19 F5.2 [cm/s2] logg Surface gravity 21- 24 F4.1 solMass Mass Mass 26- 30 F5.2 [Sun] Z Metallicity (in solar metallicity) 32- 36 F5.2 --- C/O C/O abundance ratio 38- 42 F5.2 [solLum] logL Luminosity 44- 47 F4.1 km/s xi microturbulent velocity 50 I1 --- Ver [3/4] Version of COMARCS model 51- 58 A8 --- Band1 Band name 60- 66 F7.3 mag BC1 ?=- Bolometric correction in Band1 filter (1) 69- 76 A8 --- Band2 Band name 79- 85 F7.3 mag BC2 ?=- Bolometric correction in Band2 filter (1) 88- 95 A8 --- Band3 Band name 98-104 F7.3 mag BC3 ?=- Bolometric correction in Band3 filter (1) 107-114 A8 --- Band4 Band name 117-123 F7.3 mag BC4 ?=- Bolometric correction in Band4 filter (1) 126-133 A8 --- Band5 Band name 136-142 F7.3 mag BC5 ?=- Bolometric correction in Band5 filter (1) 145-152 A8 --- Band6 Band name 155-161 F7.3 mag BC6 ?=- Bolometric correction in Band6 filter (1) 164-171 A8 --- Band7 Band name 173-179 F7.3 mag BC7 ?=- Bolometric correction in Band7 filter (1) 182-189 A8 --- Band8 Band name 192-198 F7.3 mag BC8 ?=- Bolometric correction in Band8 filter (1) 201-208 A8 --- Band9 Band name 211-217 F7.3 mag BC9 ?=- Bolometric correction in Band9 filter (1) 220-227 A8 --- Band10 Band name 230-236 F7.3 mag BC10 ?=- Bolometric correction in Band10 filter (1) 238-246 A9 --- Band11 Band name 249-255 F7.3 mag BC11 ?=- Bolometric correction in Band11 filter (1) 257-265 A9 --- Band12 Band name 268-274 F7.3 mag BC12 ?=- Bolometric correction in Band12 filter (1) 276-284 A9 --- Band13 Band name 287-293 F7.3 mag BC13 ?=- Bolometric correction in Band13 filter (1) 296-303 A8 --- Band14 Band name 306-312 F7.3 mag BC14 ?=- Bolometric correction in Band14 filter (1) 315-322 A8 --- Band15 Band name 325-331 F7.3 mag BC15 ?=- Bolometric correction in Band15 filter (1) 334-341 A8 --- Band16 Band name 344-350 F7.3 mag BC16 ?=- Bolometric correction in Band16 filter (1) 353-360 A8 --- Band17 Band name 362-368 F7.3 mag BC17 ?=- Bolometric correction in Band17 filter (1)
Note (1): If a certain filter curve is not covered by the synthetic spectra (below 4444 and above 250000Å) a value of --- is listed for the bolometric correction.
Byte-by-byte Description of file: spec/*
Bytes Format Units Label Explanations
2- 11 F10.3 0.1nm lambda Wavelength 15- 20 F6.4 --- nFlux [0/2] Continuum normalized flux (1) 22- 31 E10.5 10-7W nuL(nu) Frequency times specific luminosity ν.Lν
Note (1): Normalized to calculation without atomic and molecular line opacities
Acknowledgements: Aringer Bernhard, aringer (at)
(End) Bernhard Aringer [INAF, Padova], Patricia Vannier [CDS] 08-Sep-2009
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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