J/ApJ/527/573 Line Strengths in Elliptical Galaxies (Kobayashi+, 1999) ================================================================================ Gradients of Absorption-Line Strengths in Elliptical Galaxies Kobayashi, C., Arimoto N. =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 {delta}[Fe/H]/{delta}log(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 {sigma}_0_, absolute B magnitudes M_B_, absolute effective radii R_e_, 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 {sigma}_0{sigma}_ and dynamical masses, though relations for M_B_ and R_e_ include significant scatters. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- See also: VII/176 : Photometry and Spectroscopy of Elliptical Galaxies (Faber+ 1989) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Note (1): Index(r) = Interc - Grad(log(r/r_eff_)) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Note (1): metallicity(r) = (metallicity at the effective radius)(r/r_eff_)^-c^ -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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) 38- 42 F5.3 [km/s] LogVD ? Log of the velocity dispersion from Davies+ (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) -------------------------------------------------------------------------------- Note (1): MTrace = (log({sigma}^2^_o_)+ log(Rad))/ 2^0.5^ -------------------------------------------------------------------------------- Byte-by-byte Description of file: refs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- 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