J/ApJ/527/573 Line Strengths in Elliptical Galaxies (Kobayashi+, 1999)
Gradients of Absorption-Line Strengths in Elliptical Galaxies
Kobayashi, C., Arimoto N.
<Astrophys. J. 527, 573 (1999)>
=1999ApJ...527..573K 1999ApJ...527..573K
ADC_Keywords: Abundances, [Fe/H] ; Galaxies, optical ; Spectroscopy
Keywords: galaxies: abundances - galaxies: elliptical and lenticular,
cD - galaxies: formation - galaxies: interactions
Abstract:
We have restudied line-strength gradients of 80 elliptical galaxies.
Typical metallicity gradients of elliptical galaxies are
δ[Fe/H]/δlog(r)≃-0.3, which is flatter than the
gradients predicted by monolithic collapse simulations. The
metallicity gradients do not correlate with any physical properties of
galaxies, including central and mean metallicities, central velocity
dispersions σ0, absolute B magnitudes MB, absolute effective
radii Re, and dynamical masses of galaxies. By using the metallicity
gradients, we have calculated mean stellar metallicities for
individual ellipticals. Typical mean stellar metallicities are
<[Fe/H]> ≃ -0.3 and range from <[Fe/H]>≃-0.8 to +0.3, which is
contrary to what Gonzalez & Gorgas (1996) claimed; the mean
metallicities of ellipticals are not universal. The mean metallicities
correlate well with σ0σ and dynamical masses, though
relations for MB and Re include significant scatters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 219 Line-Strength Gradients of Ellipticals
table2.dat 115 80 Metallicity Gradients and Mean Metallicities
table4.dat 67 80 Physical Properties of Elliptical Galaxies
refs.dat 94 7 References for tables
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See also:
VII/176 : Photometry and Spectroscopy of Elliptical Galaxies (Faber+ 1989)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Elliptical galaxy name
14- 16 A3 --- r_Name Reference for Object (see refs.dat)
22- 29 A8 --- Index Index identification
31- 35 F5.3 --- Interc Index intercept at the effective radius (1)
39- 43 F5.3 --- e_Interc Error on Interc
47- 52 F6.3 --- Grad Index gradient (1)
56- 60 F5.3 --- e_Grad Error on Grad
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Note (1): Index(r) = Interc - Grad(log(r/reff))
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Elliptical galaxy name
14- 16 A3 --- r_Name Reference for Object (see refs.dat)
22- 27 F6.4 --- ZMg2 ? Mg2 metallicity at the effective radius
30- 35 F6.3 --- cMg2 ? Mg2 metallicity index (1)
38- 43 F6.4 --- ZMgb ? Mgb metallicity at the effective radius
46- 51 F6.3 --- cMgb ? Mgb metallicity index (1)
54- 59 F6.4 --- ZFe1 ? Fe1 metallicity at the effective radius
62- 67 F6.3 --- cFe1 ? Fe1 metallicity index (1)
70- 75 F6.4 --- ZFe2 ? Fe2 metallicity at the effective radius
78- 83 F6.3 --- cFe2 ? Fe2 metallicity index (1)
86- 90 F5.2 [Sun] [Fe/H]Mg2 ? Mean [Fe/H] derived from Mg2 index
93- 97 F5.2 [Sun] [Fe/H]Mgb ? Mean [Fe/H] derived from Mgb index
101-105 F5.2 [Sun] [Fe/H]Fe1 ? Mean [Fe/H] derived from Fe1 index
109-113 F5.2 [Sun] [Fe/H]Fe2 ? Mean [Fe/H] derived from Fe2 index
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Note (1): metallicity(r) = (metallicity at the effective radius)(r/reff)-c
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Elliptical galaxy name
14- 16 A3 --- r_Name Reference for Object (see refs.dat)
22- 23 A2 --- MType Galaxy morphology
30- 34 F5.3 mag Mg2 ? MgII line index from
Davies+ (1987ApJS...64..581D 1987ApJS...64..581D)
38- 42 F5.3 [km/s] LogVD ? Log of the velocity dispersion from
Davies+ (1987ApJS...64..581D 1987ApJS...64..581D)
46- 49 F4.2 kpc Rad ? Effective radius
54- 59 F6.2 mag BMag ? Absolute B band magnitude
62- 65 F4.2 --- MTrace ? Mass Tracer (1)
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Note (1): MTrace = (log(σ2o)+ log(Rad))/ 20.5
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Ref Reference code used in tables 1, 2 and 4
6- 24 A19 --- BibCode Bibcode of the reference
26-100 A75 --- Text Full reference
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History:
From the ApJ electronic edition
References:
Gonzalez, J. J., & Gorgas, J. 1996, in ASP Conf. Ser. 86, Fresh
Views of Elliptical Galaxies, ed. A. Buzzoni, A. Renzini, & A.
Serrano (San Francisco: ASP), 225
(End) Greg Schwarz [AAS] 20-Mar-2000