Morphological classification and structural parameters for early-type 
galaxies in the Coma cluster

Andreon, S.; Davoust, E.; Michard, R.; Nieto, J. L.; Poulain, P.

doi:10.1051/aas:1996126

Cited by 34 publications

(70 citation statements)

References 12 publications

(22 reference statements)

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“…Most ellipticals look round or football-shaped, with modest ellipticities, or equivalently, large axis ratios. On the other hand, the ellipticity distribution of S0 galaxies is peaked at $ 0:5, while that of spirals is nearly flat at almost all ellipticities (Sandage, Freeman, & Stokes 1970;van den Bergh 1990;Fasano & Vio 1991;Franx, Illingworth, & de Zeeuw 1991;Lambas, Maddox, & Loveday 1992;Jørgensen & Franx 1994;Andreon et al 1996;Dressler et al 1997). Figure 18 presents the ellipticity distribution of the 145 GSS QS-E/S0's with 16:5 < I < 22 as the thick histogram (z phot sample included).…”

Section: Ellipticity Distributionmentioning

confidence: 99%

The DEEP Groth Strip Survey. X. Number Density and Luminosity Function of Field E/S0 Galaxies atz< 1

Simard

Faber

et al. 2002

ApJ

142

133

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We present the luminosity function and color-redshift relation of a magnitude-limited sample of 145 mostly red field E/S0 galaxies at zd1 from the DEEP Groth Strip Survey (GSS). Using nearby galaxy images as a training set, we develop a quantitative method to classify E/S0 galaxies based on smoothness, symmetry, and bulge-to-total light ratio. Using this method, we identify 145 E/S0's at 16:5 < I < 22 within the GSS, for which 44 spectroscopic redshifts (z spec ) are available. Most of the galaxies with spectroscopic redshifts (86%) form a '' red envelope '' in the redshift-color diagram, consistent with predictions of spectral synthesis models in which the dominant stellar population is formed at redshifts ze1:5. We use the tight correlation between VÀI and z spec for this red subset to estimate redshifts of the remaining E/S0's to an accuracy of $10%, with the exception of a small number (16%) of blue interlopers at low redshift that are quantitatively classified as E/S0's but are not contained within the red envelope. Constructing a luminosity function of the full sample of 145 E/S0's, we find that there is about 1.1-1.9 mag brightening in rest-frame B-band luminosity back to z ' 0:8 from z ¼ 0, consistent with other studies. Together with the red colors, this brightening is consistent with models in which the bulk of stars in red field E/S0's formed before z for e1:5 and have been evolving rather quiescently, with few large starbursts since then. Evolution in the number density of field E/ S0 galaxies is more difficult to measure, and uncertainties in the raw counts and their ratio to local samples might amount to as much as a factor of 2. Within that uncertainty, the number density of red E/S0's to z ' 0:8 seems relatively static, being comparable to or perhaps moderately less than that of local E/S0's, depending on the assumed cosmology. A doubling of E/S0 number density since z ¼ 1 can be ruled out with high confidence (97%) if m ¼ 1. Taken together, our results are consistent with the hypothesis that the majority of luminous field E/S0's were already in place by z $ 1, that the bulk of their stars were already fairly old, and that their number density has not changed by large amounts since then.

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Section: Ellipticity Distributionmentioning

confidence: 99%

The DEEP Groth Strip Survey. X. Number Density and Luminosity Function of Field E/S0 Galaxies atz< 1

Simard

Faber

et al. 2002

ApJ

142

133

View full text Add to dashboard Cite

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“…In order to increase the signal to noise in the colour term, the (U − V ) are taken from the smallest aperture, the 8.8 ′′ diameter aperture. The symbols represent the morphological types of the galaxies from Andreon (1996;1997). The small open symbols have no morphological information.…”

Section: Galaxy Identification Photometry and Astrometrymentioning

confidence: 99%

“…The morphological classification of galaxies is taken from Andreon et al (1996;1997) which gives morphologies for all V13 < 15.7 galaxies, but the morphologies don't go as faint as the redshifts. 90% of V13 < 16 galaxies, 68% of V13 < 17 galaxies and 38% of V13 < 18 galaxies have morphological information.…”

Section: Analysis Techniquementioning

confidence: 99%

“…The magnitudes are estimated total V magnitudes (V T ). Different colour symbols represent different morphological types as determined from Andreon et al (1996;1997). The solid line shows the best fit to the data using the biweight minimisation technique (see text).…”

Section: Environmental and Morphological Variationsmentioning

confidence: 99%

“…All with morphology: All member galaxies with a morphology from Andreon et al (1996;1997) (see table 4). 4 E&S0 morphology: All member galaxies with an elliptical or S0 morphological type (see table 4).…”

Section: Environmental and Morphological Variationsmentioning

confidence: 99%

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The colour-magnitude relation for galaxies in the Coma cluster

Terlevich

Caldwell

Bower

2001

Monthly Notices RAS

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We present a new photometric catalogue of the Coma galaxy cluster in the Johnson U-and V-bands. We cover an area of 3360arcmin 2 of sky, to a depth of V = 20 mag in a 13 arcsec diameter aperture, and produce magnitudes for ∼ 1400 extended objects in metric apertures from 8.8 to 26arcsec diameters. The mean internal RMS scatter in the photometry is 0.014 mag in V, and 0.026 mag in U, for V 13 < 17 mag.We place new limits on the levels of scatter in the colour-magnitude relation (CMR) in the Coma cluster, and investigate how the slope and scatter of the CMR depends on galaxy morphology, luminosity and position within the cluster. As expected, the lowest levels of scatter are found in the elliptical galaxies, while the late type galaxies have the highest numbers of galaxies bluewards of the CMR. We investigate whether the slope of the CMR is an artifact of colour gradients within galaxies and, show that it persists when the colours are measured within a diameter that scales with galaxy size. Looking at the environmental dependence of the CMR, we find a trend of systematically bluer galaxy colours with increasing projected radius from the center of the cluster. Surprisingly, this is accompanied by a decreased scatter of the CMR. We investigate whether this gradient could be due to dust in the cluster potential, however the reddening required would produce too large a scatter in the colours of the central galaxies. The gradient appears to be better reproduced by a gradient in the mean galactic ages with projected radius.

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On the emptiness of voids

1997

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The observability of a galaxy population inside of voids is estimated by assuming a void population similar to t h e one of nearby field galaxies in density as well as in morphological mixture. Obviously an extension to apparent magnitudes beyond rn = 22 for a complete sample of galaxies in a sufficient large field is needed to get reliable information on a void population.Iiey words: galaxy voids -field galaxies A A A subject classification: 157; 160 1. IntroductionSince the discovery of the cellular structure of the Universe and the presence of voids (Joeveer et al. 1978, Joeveer & Einasto 1978, Tarenghi et al. 1978, Tifft & Gregory 1978, Tully & Fisher 1978, Zeldovich et al. 1982) the knowledge on tlhe distribution of the visible matter in space is grown enormously owing to extensive redshift surveys. These observational data (Huchra et al. 1983, de Lapparent et al. 1986, Geller et al. 1987, Geller & Huchra 1989) reveal a general picture in which the galaxies are organized in shells and filaments enclosing large empty regions, the voids, which occupy more than 80 per cent of the whole space. An early review on voids is given by Rood (1988), while comprehensive lists of voids have been published by Kauffmann & Fairall (1991), Haque-Copilah &Basu (1992), andLindner et al. (1995).Some uncertainties exist on the exact definition of a void: whether a void should be defined as a volume which is completely empty of galaxies, or if it is merely a very low-dense region in the sample of galaxies under investigation. In the second case the existence and the properties, e.g. the diameter, of a void may depend on the richness and the completeness of the used sample of galaxies. Indeed, in a recent paper Lindner et al. (1995) have shown that the dimensions of voids are not only determined by these two factors but also depend on the luminosity of the investigated galaxies: bright galaxies show the more large-scale void structure, faint galaxies reveal detailed substructures. Thus, there seems to be a hierarchical structure of voids. Moreover, the size of a void presumably depends on the mean density of galaxies of the environment in the sense that the smaller voids are located in denser regions, on the average. Furthermore, the faint galaxies are found mainly in the outskirts of the shells defined by luminous systems.From a theoretical point of view some models like the galaxy formation scenario in biased cold dark-matter dominated cosmologies (Dekel & Silk 1986, Hoffman et al. 1992) predict a smoother distribution of dwarf galaxies in comparison to bright systems. In this context the distribution of absolute faint galaxies, especially irregular and low-surface brightness objects, have been investigated by several authors (Bothun et al. 1986, Eder et al. 1989, Salzer et al. 1990, Binggeli et al. 1990, Schombert et al. 1992) who all find similar distributions of these galaxies and of the bright systems. But all these surveys are restricted to objects not fainter than about m g = 17 in apparent magnitude.Several previous stud...

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Morphological classification and structural parameters for early-type galaxies in the Coma cluster

Cited by 34 publications

References 12 publications

The DEEP Groth Strip Survey. X. Number Density and Luminosity Function of Field E/S0 Galaxies atz< 1

The DEEP Groth Strip Survey. X. Number Density and Luminosity Function of Field E/S0 Galaxies atz< 1

The colour-magnitude relation for galaxies in the Coma cluster

On the emptiness of voids

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