Line Strengths and Line-Strength Gradients in S0 Galaxies

1996 ◽  
Vol 459 ◽  
pp. 110 ◽  
Author(s):  
David Fisher ◽  
Marijn Franx ◽  
Garth Illingworth
Keyword(s):  
Line Strength ◽  
S0 Galaxies ◽  
Line Strengths

scholarly journals Line-Strength Profiles in Early-Type Galaxies

1995 ◽  
Vol 164 ◽  
pp. 453-453
Author(s):  
David Fisher ◽  
Garth Illingworth ◽  
Marijn Franx
Keyword(s):  
Stellar Population ◽  
Velocity Dispersion ◽  
Line Strength ◽  
Strong Correlations ◽  
Metal Line ◽  
Cluster Galaxies ◽  
Brightest Cluster Galaxies ◽  
The Mean ◽  
S0 Galaxies ◽  
Line Strengths

Line-strengths and their gradients in Mg, Fe, and Hβ have been determined for a sample of 9 brightest cluster (BCG), 7 elliptical, and 15 S0 galaxies in order to study their stellar populations and investigate their relationship to one another. We find that BCGs follow the same relationship between central Mgb line-strength and central velocity dispersion found for ellipticals while the S0 galaxies show significant scatter with respect to this relation. Brightest cluster galaxies are in agreement with the known trend towards more massive ellipticals having larger [Mg/Fe] ratios while the internal gradients within our BCG and E galaxies are consistent with a roughly constant [Mg/Fe] ratio. We find that a correlation exists between the central [Mg/Fe] ratio and average Hβ line-strength in the sense that BCG and E galaxies with larger [Mg/Fe] ratios have lower Hβ strengths. For our BCG and E galaxies, Hβ is the best predictor of [Mg/Fe] ratio. The Mgb metallicity gradients for BCGs and ellipticals are similar and consistent with a reduction in the mean metallicity of the stellar population by about a factor of 2 over a factor of ten in radius. No strong correlations are found between the metallicity gradient sizes and either kinematic or line-strength parameters of the E and BCG galaxies. The S0 disks display roughly constant Mg, Fe, and Hβ line-strengths with radius indicating that they have uniform age and metallicity throughout. S0 galaxy minor axes ‘bulge’ metal line-strength gradients are similar to elliptical gradients and fall to values lower than those found in the disks.

scholarly journals Line-Strength Gradients in Early-Type Galaxies

1987 ◽  
Vol 127 ◽  
pp. 189-202
Author(s):  
J. Gorgas ◽  
G. Efstathiou
Keyword(s):  
Globular Clusters ◽  
Line Strength ◽  
Early Type ◽  
Metallic Line ◽  
Total Luminosity ◽  
Galactic Globular Clusters ◽  
Measured Line ◽  
Line Strengths

We have measured line-strength gradients in a sample of 15 early-type galaxies. The line-strength measures include the Mg2 index and the equivalent widths of Hβ and two iron blends at 5270Å and 5335Å. In most of the galaxies we find gradients in the metallic line-strengths. However, the gradients vary markedly from object to object and do not correlate strongly with other parameters such as total luminosity, rotation, etc. A comparison of the line-strengths in the outer parts of these galaxies with galactic globular clusters suggests relatively modest abundance gradients in early-type galaxies.

The Evolution of Balmer Absorption-Line Strengths in E/S0 Galaxies from [FORMULA][F]z=0[/F][/FORMULA] to [FORMULA][F]z=0.83[/F][/FORMULA]

2001 ◽  
Vol 552 (1) ◽  
pp. L17-L21 ◽  
Author(s):  
Daniel D. Kelson ◽  
Garth D. Illingworth ◽  
Marijn Franx ◽  
Pieter G. van Dokkum
Keyword(s):  
Absorption Line ◽  
S0 Galaxies ◽  
Line Strengths

Experimental Determination of Line Strengths for Selected Carbon Monoxide and Carbon Dioxide Absorption Lines at Temperatures between 295 and 1250 K

1994 ◽  
Vol 48 (11) ◽  
pp. 1442-1450 ◽  
Author(s):  
Patrick J. Medvecz ◽  
Kenneth M. Nichols
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Absorption Spectra ◽  
High Temperatures ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Line Strength ◽  
Temperature Data ◽  
Line Strengths

Fourier transform infrared absorption spectroscopy has been used for the determination of the line strengths of 41 CO and CO2 absorption lines at temperatures between 295 and 1250 K. The CO vibrational-rotational lines were from the P branch of the fundamental absorption band (2150–1950 cm−1) while the CO2 vibrational-rotational lines were from the far wing of the R branch of the v3 fundamental band (2395–2380 cm−1). The intensities of the lines were measured from absorption spectra recorded in a high-temperature gas cell containing known concentrations of CO/CO2/N2 gas mixtures at atmospheric pressure. Absorption spectra were recorded through the cell with the use of a moderate-resolution Fourier transform infrared spectrometer. The absorption spectra were mathematically corrected for distortions resulting from the finite resolution of the spectrometer and for peak overlap. Line strength measurements were made from the corrected peaks by using the Bouguer-Lambert law and assuming a Lorenztian line profile. The experimentally obtained line strengths were evaluated (1) by statistical calculations, (2) by consideration of the validity of the Bouguer-Lambert assumption for these data, (3) by comparison with existing room-temperature and high-temperature data, and (4) by comparison with theoretical calculations. For CO, the statistical analysis suggests that the reported values have an uncertainty of ±10–12%, which is similar to the observed discrepancies with other reported values at room temperature. At high temperatures, the difference between these data and previously reported data and theoretical predictions is less than 10%. For CO2, the statistical uncertainty associated with the line strength calculations is less than 5%, which is also the approximate level of agreement with existing room-temperature data. For lines with m indicies of 65–89, at high temperatures, the values reported in this work agree within 5 to 10% of theoretical calculations.

The effect of configuration interaction on forbidden line strengths

1956 ◽  
Vol 52 (1) ◽  
pp. 107-113 ◽  
Author(s):  
R. H. Garstang
Keyword(s):  
Configuration Interaction ◽  
Major Part ◽  
Energy Levels ◽  
Line Strength ◽  
Line Strengths

ABSTRACTThe calculation of the strengths of forbidden lines in the 1s22s22p2 configuration is extended to include the effect of interaction with the 1s22p4 configuration. For this case it is shown that if observed energy levels are used instead of theoretical energies in line-strength formulae which neglect configuration interaction the major part of the effect of configuration interaction is nevertheless taken into account. The results are illustrated by detailed computations on the Ca xv spectrum. The 1s22s22p4 configuration is also discussed.

scholarly journals Collision Strengths and Line Strengths for Transitions from the ls23ℓ, Levels to the ls2ℓ'3ℓ" Levels in Li-Like Ions

1984 ◽  
Vol 86 ◽  
pp. 110-113
Author(s):  
D.H. Sampson ◽  
S.J. Goett ◽  
G.V. Petrou ◽  
R.E.H. Clark
Keyword(s):  
Line Strength ◽  
Numerical Results ◽  
Spectral Lines ◽  
Atomic Data ◽  
Alternative Mechanism ◽  
Plasma Diagnostic ◽  
Exchange Method ◽  
Method Of Calculation ◽  
Configuration Mixing ◽  
Line Strengths

It is well known that radiation from the levels of the ls2ℓ2ℓ' and ls2ℓ3ℓ' configurations of Li-like ions form satellites of spectral lines from He-like ions that are of high interest for plasma diagnostic purposes. Recently Sampson et al (1984) have made calculations of the collision strengths for innershell excitation to these upper levels from the ls22s and ls22p levels for a large number of Li-like ions using a Coulomb-Born-exchange method. Here we consider the alternative mechanism for populating the ls2ℓ3ℓ' levels by collisional excitation from the ls23s, ls23p and ls23d levels. Although the poDulations of the ls23ℓ levels are lower than those of the ls22ℓ levels, this is at least partially compensated for by the fact that the collision strengths for the ls23ℓ − ls2ℓ'3ℓ" transitions are considerably larger on the average than those for the ls22ℓ − ls2ℓ'3ℓ" transitions. The method of calculation is the same as that used by Sampson et al (1984), where all possible configuration mixing, parentage mixing and intermediate coupling type mixing among the states in a complex (the states having the same n values, parity and J values) was included. Also the present application is sufficiently simple that after summation over J values for the initial level the results for the collision strength Ω can be expressed in a simple manner in terms of the Z scaled hydrogenic collision strengths Z2ΩH and analogous to Eqs (8)-(15) of Sampson et al (1984). The appropriate formulae and the numerical results for both excitation to upper fine structure levels and to upper energy terms for 19 Li-like ions have been submitted for publication to Atomic Data and Nuclear Data Tables. Here we give only the pertinent formula and sample numerical results for transitions between energy terms in Li-like iron. This formula iswhere due to configuration mixing neither ℓ need equal ℓ" nor ℓa need equal ℓ'. The recommended values for σ and σe are zero for transitions involving ls−2s and are −0.5 and 0.3, respectively, for transitions involving ls−2p. Numerical values for the coefficients A and Ae for Li-like iron are given in Tables I-III. Values for Z2ΩH and for impact electron energies up to 15 times threshold are given in Golden et al (1981) and Clark et al (1982) and are repeated in Table IV for convenience. Finally we note that the line strengths S for transitions involving ls−2p are obtained by multiplying the corresponding value for A(ls−2p) by the scaled hydrogenic line strength 1.665 and dividing by (Z-σ)2.

scholarly journals S0 Galaxy Line Strengths and Gradients

1996 ◽  
Vol 171 ◽  
pp. 374-374
Author(s):  
David Fisher ◽  
Marijn Franx ◽  
Garth Illingworth
Keyword(s):  
Stellar Populations ◽  
Elliptical Galaxies ◽  
S0 Galaxies ◽  
Line Strengths

Line strengths and their gradients in Mg, Fe, and Hβ have been determined for a sample of 20 S0 galaxies in order to study the stellar populations of their bulges and disks and to investigate their relationship to elliptical galaxies. The data were obtained with the Lick Observatory 3m telescope in the long-slit mode over the region 4215–5615 Å with resolution 3.1 Å.

Application of the Model Microfield Method to Stark Profiles of Alkali Metal Resonance Lines

1978 ◽  
Vol 33 (12) ◽  
pp. 1575-1580 ◽  
Author(s):  
A. Mazure ◽  
G. Nollez
Keyword(s):  
Alkali Metal ◽  
Close Agreement ◽  
Line Strength ◽  
Experimental Results ◽  
And Shifts ◽  
Line Strengths

Abstract Stark widths and shifts of alkali metal resonance lines are calculated by the model microfield method (MMM). The im pact results of Griem for the prevailing electronic broadening are recovered by the unified MMM. Both theories are in close agreement with recent experimental results. It is shown further that the shift values are very sensitive to the line strength values of the involved transitions. The reliability of the experimentally observed regularities through the alkali sequence is next discussed. On the basis of the MMM results these regularities can be understood in term s of the line strengths and frequencies of transitions from the main levels actually involved.

scholarly journals A Statistical Comparison of Line Strength Variations in Coma and Cluster Galaxies at z ~ 0·3

1998 ◽  
Vol 15 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Lewis A. Jones ◽  
Warrick J. Couch
Keyword(s):  
Line Strength ◽  
Principal Component ◽  
Strongly Coupled ◽  
Distant Cluster ◽  
Cluster Galaxies ◽  
Statistical Comparison ◽  
Cluster Data ◽  
Nearby Galaxies ◽  
Observed Behaviour ◽  
Line Strengths

AbstractWe present a statistical comparison between spectral line strength variations in Coma galaxies and galaxies in three rich clusters at z ~ 0.3. Using a principal component analysis, we have transformed the observable quantities, the line strengths, into new mutually orthogonal axes and found two specific results. First, more independent parameters are required to account for the line strength variations in the distant cluster data than in the Coma data, and second, line strengths which are not correlated in the distant cluster data are strongly coupled in the Coma data. These results suggest that galaxies in clusters have been homogenised such that most of the information from the conditions present at their formation has been destroyed. Hence, it may be possible that the present-day homogeneity of early-type galaxy properties, e.g. the fundamental plane relation, does not require a single formation scenario, but that a variety of formation scenarios for different galaxies could still yield the observed behaviour of nearby galaxies.

Line strength factors for E,F1Σ+g(v′ = 0, J′ = J′′) – X1Σ+g (v′′, J′′) (2 + 1) REMPI transitions in molecular hydrogen

2004 ◽  
Vol 82 (6) ◽  
pp. 723-729 ◽  
Author(s):  
Andrew E Pomerantz ◽  
Florian Ausfelder ◽  
Richard N Zare ◽  
Winifred M Huo
Keyword(s):  
Experimental Determination ◽  
Molecular Hydrogen ◽  
Line Strength ◽  
Chem Phys ◽  
Rotational States ◽  
Calculated Line ◽  
Hot Filament ◽  
Theoretical Results ◽  
Line Strengths

Experimentally and theoretically determined line strengths are presented for E,F1Σ+g(v′ = 0, J′ = J′′) – X1Σ+g (v′′, J′′) (2 + 1) REMPI transitions in H2, HD, and D2. The experimental technique employs a hot filament source of internally excited hydrogen that allows experimental determination of line strengths for the low rotational states of highly excited vibrational manifolds (v′′ ≤ 4). The line strengths are found to depend only weakly on J′′ for the states measured here, and theoretical results indicate that the line strengths depend strongly on v′′. These values are combined with previously measured and calculated line strengths for these transitions (K.-D. Rinnen, M.A. Buntine, D.A.V. Kliner, R.N. Zare, and W.M. Huo. J. Chem. Phys. 95, 214 (1991)), resulting in a more complete compilation of REMPI line strengths for molecular hydrogen. Key words: hydrogen, spectroscopy, REMPI, line strength, multiphoton.

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