J/A+A/335/823 Evolution models of elliptical galaxies. III. (Tantalo+ 1998)
Spectro-photometric evolution of elliptical galaxies.
III. Infall models with gradients in mass density and star formation
Tantalo R., Chiosi C., Bressan A., Marigo P., Portinari L.
<Astron. Astrophys. 335, 823 (1998)>
=1998A&A...335..823T 1998A&A...335..823T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Models, evolutionary
Keywords: galaxies: abundances - galaxies: elliptical and lenticular, cD -
galaxies: evolution - galaxies: stellar content
Abstract:
In this study we present a simple model of elliptical galaxies aimed
at interpreting the gradients in colours and narrow band indices
observed across these systems. Salient features of the model are the
gradients in mass density and star formation and infall of primordial
gas aimed at simulating the collapse of a galaxy into the potential
well of dark matter. Adopting a multi-zone model we follow in detail
the history of star formation, gas consumption, and chemical
enrichment of the galaxy and also allow for the occurrence of galactic
winds according to the classical supernova (and stellar winds) energy
deposit. The outline of the model, the time scale of gas accretion and
rate of star formation as a function of the galacto-centric distance
in particular, seek to closely mimic the results from Tree-SPH
dynamical models. Although some specific ingredients of the model can
be questioned from many points of view (of which we are well aware),
the model has to be considered as a gross tool for exploring the
consequences of different recipes of gas accretion and star formation
in which the simple one-zone scheme is abandoned. With the aid of this
model we discuss the observational data on the gradients in
metallicity, colours, and narrow band indices across elliptical
galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 121 66 Chemical Models at the Stage of Wind Ejection
table6.dat 103 197 Integrated magnitude and colours of galaxy models
tables.tex 141 495 LaTeX version of the tables
tables.ps 72 1055 Post-Script version of the tables
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See also:
J/A+A/311/361 : Evolution models of elliptical galaxies. II. (Tantalo+, 1996)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 F5.3 solMass M(LT12) Asymptotic mass M{L,T,12}
7- 12 F6.1 --- nu Efficiency of star formation ν(rj/2)
14- 17 F4.2 --- zeta IMF parameter ζ
19- 22 F4.2 Gyr tau Time scale of mass accretion τ(rj/2)
24- 30 F7.5 solMass M(Lt) Value reached by ML,t at the onset of
galactic wind
32- 35 F4.2 Gyr Age Age at which the galactic wind occurs,
tgω
37- 41 F5.3 --- G(rt) Dimensionless mass of gas G(rj/2,t)
43- 47 F5.3 --- S(rt) Dimensionless mass of living stars S(rj/2,t)
49- 54 F6.4 Sun Zmax Maximum metallicity, Z(rj/2,t)
56- 61 F6.4 Sun Zmean Mean metallicity, <Z(rj/2,t)>
63- 70 E8.2 solMass/yr Psi Rate of star formation Ψ(rj/2,t)
72- 79 E8.2 --- Omegag Gravitational binding energy of the gas
Ωg(rj/2,t)
81- 88 E8.2 10+43J Eg Total thermal energy of this Eg(rj/2_,t)
90- 97 E8.2 10+43J ESNI Contributions to the thermal energy by
Type I supernovae
99-106 E8.2 10+43J ESNII Contributions to the thermal energy by
Type II supernovae
108-115 E8.2 10+43J ESW Contributions to the thermal energy by
stellar winds;
117-121 F5.3 --- r Mid shell fractionary radius rj/2
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 5 F5.3 10+12solMass M(lt12) Asymptotic mass of the model, Ml,t,12
7- 13 F7.2 --- nu Efficiency of star formation, ν(rj/2)
15- 18 F4.2 Gyr tau Time scale of gas accretion, τ(rj/2)
20- 26 F7.5 10+12solMass M(lt) Asymptotic mass of each zone, Ml,t
28- 33 F6.3 Gyr Age Age
35- 41 F7.3 mag Mbol Integrated absolute bolometric of each zone
43- 49 F7.3 mag Mvis Integrated visual magnitudes of each zone
51- 55 F5.3 mag U-B Integrated colours (U-B)
57- 61 F5.3 mag B-V Integrated colours (B-V)
63- 67 F5.3 mag V-R Integrated colours (V-R)
69- 73 F5.3 mag V-I Integrated colours (V-I)
75- 79 F5.3 mag V-J Integrated colours (V-J)
81- 85 F5.3 mag V-H Integrated colours (V-H)
87- 91 F5.3 mag V-K Integrated colours (V-K)
93- 98 F6.3 mag 1550-V Integrated colours (1550-V)
100-103 F4.2 --- Rad Fractionary radii rj/2
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Acknowledgements: Rosaria Tantalo
References:
Bressan et al., Paper I. 1994ApJS...94...63B 1994ApJS...94...63B
Tantalo et al., Peper II. 1996, Cat. J/A+A/311/361
(End) Patricia Bauer [CDS] 26-May-1998