scholarly journals Securing the Faint End of the Galaxy Luminosity Function

2004 ◽  
Vol 21 (4) ◽  
pp. 356-359 ◽  
Author(s):  
Helmut Jerjen ◽  
Brent Tully ◽  
Neil Trentham
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Dwarf Galaxy ◽  
Full Range ◽  
Mass Function ◽  
Wide Field ◽  
Distance Information ◽  
The Galaxy ◽  
Brightness Fluctuation ◽  
Galaxy Luminosity Function

AbstractThe history of the formation of galaxies must leave an imprint in the properties of the mass function of collapsed objects and in its observational manifestation, the galaxy luminosity function. At present the faint end of the luminosity function is poorly known. Accurate knowledge of the luminosity function over the full range of galaxy clustering scales would provide serious constraints on both initial cosmological conditions and modulating astrophysical processes.Wide field imaging surveys with large ground-based telescopes now provide the capability to identify dwarf galaxy candidates to very faint levels (μR ≈ 26 mag arcsec–2), too low in surface brightness for spectroscopy (measuring redshifts) even with telescopes like Keck. Other means have to be explored to get distance information for these candidates in order to separate cluster members from back/foreground systems beyond doubt. On the quest to establish the properties (slope and possible turning point) of the the faint end of the galaxy luminosity function we are employing the surface brightness fluctuation (SBF) method to determine adequate distances, potentially resulting in the best definition ever of the luminosity function to MR ≈ –11 in the cluster and group environments.

scholarly journals A Flat Faint End of the Fornax Cluster Galaxy Luminosity Function

2007 ◽  
Vol 3 (S244) ◽  
pp. 331-335 ◽  
Author(s):  
S. Mieske ◽  
M. Hilker ◽  
L. Infante ◽  
C. Mendes de Oliveira
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Local Group ◽  
Dwarf Galaxy ◽  
High Mass ◽  
Wide Field ◽  
Early Type ◽  
Cluster Galaxy ◽  
Fornax Cluster ◽  
Galaxy Luminosity Function

AbstractWe analyse the photometric properties of the early-type Fornax cluster dwarf galaxy population (MV > −17 mag), based on a wide field imaging study of the central cluster area in V and I band-passes with IMACS/Magellan at Las Campanas Observatory. We create a fiducial sample of ~ 100 Fornax cluster dwarf ellipticals (dEs) with −16.6 < MV < −8.8 mag in the following three steps: (1) To verify cluster membership, we measured I-band surface brightness fluctuations (SBF) distances to candidate dEs known from previous surveys; (2) We re-assessed morphological classifications for those candidate dEs that are too faint for SBF detection; and (3) We searched for new candidate dEs in the size-luminosity regime close to the resolution limit of previous surveys. The resulting fiducial dE sample follows a well-defined surface brightness – magnitude relation, showing that Fornax dEs are about 40% larger than Local Group dEs. The sample also defines a colour-magnitude relation similar to that of Local Group dEs. The early-type dwarf galaxy luminosity function in Fornax has a very flat faint end slope α ≃ −1.1 ± 0.1. We compare the number of dwarfs per unit mass with those in other environments and find that the Fornax cluster fits well into a general trend of a lack of high-mass dwarfs in more massive environments.

scholarly journals Beyond the Galaxy Luminosity Function

2004 ◽  
Vol 21 (4) ◽  
pp. 344-351 ◽  
Author(s):  
Simon Driver
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Large Scale ◽  
Evolutionary Processes ◽  
Multivariate Distributions ◽  
Independent Investigation ◽  
Current State ◽  
The Galaxy ◽  
Galaxy Population ◽  
Galaxy Luminosity Function

AbstractWith the advent of large-scale surveys (i.e. Legacy Surveys) it is now possible to start looking beyond the galaxy luminosity function (LF) to more detailed statistical representations of the galaxy population, i.e multivariate distributions. In this review I first summarise the current state-of-play of the B-band global and cluster LFs and then briefly present two promising bivariate distributions: the luminosity–surface brightness plane (LSP) and the colour–luminosity plane (CLP). In both planes galaxy bulges and galaxy disks form marginally overlapping but distinct distributions, indicating two key formation/evolutionary processes (presumably merger and accretion). Forward progress in this subject now requires the routine application of reliable bulge–disk decomposition codes to allow independent investigation of these two key components.

DARK MATTER IN SPIRAL HALOS AND THE HALO MASS FUNCTION

1994 ◽  
Vol 03 (supp01) ◽  
pp. 87-92
Author(s):  
KEITH M. ASHMAN ◽  
PAOLO SALUCCI ◽  
MASSIMO PERSIC
Keyword(s):  
Dark Matter ◽  
Hierarchical Clustering ◽  
Galaxy Formation ◽  
Luminosity Function ◽  
Mass Function ◽  
Dark Halo ◽  
Constant Mass ◽  
High Luminosity ◽  
The Galaxy ◽  
Galaxy Luminosity Function

Evidence that low-luminosity spirals have a higher dark matter fraction than their high-luminosity counterparts is discussed. The empirical correlation between dark matter fraction and luminosity is used, in conjunction with the galaxy luminosity function of spirals, to derive the dark halo mass function of these galaxies. The mass function is shown to be consistent with hierarchical clustering models of galaxy formation. This contrasts with previous results based on the assumption of a constant mass-to-light ratio for all spirals, which predict too many low-luminosity galaxies.

scholarly journals The galaxy population within the virial radius of the Perseus cluster

2020 ◽  
Vol 640 ◽  
pp. A30
Author(s):  
H. Meusinger ◽  
C. Rudolf ◽  
B. Stecklum ◽  
M. Hoeft ◽  
R. Mauersberger ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Mass Function ◽  
Wide Field ◽  
Nearby Galaxy ◽  
Cluster Galaxy ◽  
Cluster Galaxies ◽  
The Galaxy ◽  
Galaxy Population ◽  
Galaxy Luminosity Function ◽  
Perseus Cluster

Context. The Perseus cluster is one of the most massive nearby galaxy clusters and is fascinating in various respects. Though the galaxies in the central cluster region have been intensively investigated, an analysis of the galaxy population in a larger field is still outstanding. Aims. This paper investigates the galaxies that are brighter than B ≈ 20 within a field corresponding to the Abell radius of the Perseus cluster. Our first aim is to compile a new catalogue in a wide field around the centre of the Perseus cluster. The second aim of this study is to employ this catalogue for a systematic study of the cluster galaxy population with an emphasis on morphology and activity. Methods. We selected the galaxies in a 10 square degrees field of the Perseus cluster on Schmidt CCD images in B and Hα in combination with SDSS images. Morphological information was obtained both from the “eyeball” inspection and the surface brightness profile analysis. We obtained low-resolution spectra for 82 galaxies and exploited the spectra archive of SDSS and redshift data from the literature. Results. We present a catalogue of 1294 galaxies with morphological information for 90% of the galaxies and spectroscopic redshifts for 24% of them. We selected a heterogeneous sample of 313 spectroscopically confirmed cluster members and two different magnitude-limited samples with incomplete redshift data. These galaxy samples were used to derive such properties as the projected radial velocity dispersion profile, projected radial density profile, galaxy luminosity function, supermassive black hole mass function, total stellar mass, virial mass, and virial radius, to search for indications of substructure, to select active galaxies, and to study the relation between morphology, activity, density, and position. In addition, we present brief individual descriptions of 18 cluster galaxies with conspicuous morphological peculiarities.

scholarly journals The Early-Type Dwarf Galaxy Population of the Fornax Cluster

2006 ◽  
Vol 2 (S235) ◽  
pp. 226-226
Author(s):  
Steffen Mieske
Keyword(s):  
Surface Brightness ◽  
Dwarf Galaxy ◽  
Wide Field ◽  
Early Type ◽  
Cluster Membership ◽  
Galaxy Population ◽  
Fornax Cluster ◽  
Galaxy Luminosity Function ◽  
Field Imaging ◽  
Wide Field Imaging

AbstractAIMS: We analyse the photometric properties of the early-type Fornax cluster dwarf galaxy population (MV> − 17 mag), based on a wide field imaging study of the central cluster area in V and I bandpasses. We used the instrument/telescope combination IMACS/Magellan at Las Campanas Observatory, providing much larger light collecting area and better image resolution than previous wide field imaging surveys.METHODS: We create a fiducial sample of Fornax cluster dwarf ellipticals (dEs) in the following three steps: (1) To verify cluster membership, we measured I-band surface brightness fluctuations (SBF) distances to candidate dEs known from previous surveys; (2) We re-assessed morphological classifications for those candidate dEs that are too faint for SBF detection; and (3) We searched for new candidate dEs in the size-luminosity regime close to the resolution limit of previous surveys.RESULTS: (1) We confirm cluster membership for 28 candidate dEs in the range −16.6 < MV < −10.1 mag by means of SBF measurement. We find no SBF background galaxy. (2) Of 51 further candidate dEs in the range −13.2 < MV < −8.6 mag, 2/3 are confirmed as probable cluster members by morphological re-assessment, while 1/3 are re-classified as probable background objects. (3) We find 12 new dE candidates in the range −12.3 < MV < −8.8 mag, two of which are directly confirmed via SBF measurement. The resulting fiducial dE sample follows a well-defined surface brightness – magnitude relation, showing that Fornax dEs are about 40% larger than Local Group dEs. The sample also defines a colour-magnitude relation that appears slightly shallower than that of Local Group dEs. The early-type dwarf galaxy luminosity function in Fornax has a very flat faint end slope α ≃ −1.1 ± 0.1. We discuss these findings in the context of structure formation theories.CONCLUSIONS: The SBF method is a very powerful tool to help constrain the faint end of the galaxy luminosity function in nearby galaxy clusters. For the Fornax cluster, morphological cluster memberships – if performed at sufficient resolution – are very reliable.This contribution is based on Mieske et al. (2006).

scholarly journals Luminosity Functions from the 2dF Galaxy Redshift Survey

2004 ◽  
Vol 21 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Matthew Colless
Keyword(s):  
Spectral Type ◽  
Surface Brightness ◽  
Luminosity Function ◽  
Local Density ◽  
Luminosity Functions ◽  
The Galaxy ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Galaxy Luminosity Function

AbstractA summary of the main results from the 2dF Galaxy Redshift Survey of over 221 000 galaxies on the galaxy luminosity function and its dependence on surface brightness, spectral type, environment, and local density.

scholarly journals Merging galaxies in compact groups: analytical theory

2000 ◽  
Vol 174 ◽  
pp. 423-427
Author(s):  
Victor M. Kontorovich
Keyword(s):  
Luminosity Function ◽  
Mass Function ◽  
Compact Groups ◽  
Merging Galaxies ◽  
Massive Galaxies ◽  
The Galaxy ◽  
Minor Mergers ◽  
Power Law Index ◽  
Galaxy Luminosity Function ◽  
Non Locality

AbstractThe predominance of minor mergers, i.e. the non-locality of mergings, results in a mass function slope (“Shechter” index) intermediate between a power-law index of a spectrum with constant mass flux and that of constant flux of the number of massive galaxies. The index proves to be close to that of the faint end of the galaxy luminosity function.

scholarly journals The Faint End of the Galaxy Luminosity Function in Rich Clusters

1999 ◽  
Vol 171 ◽  
pp. 60-67
Author(s):  
R.M. Smith ◽  
S. Phillips ◽  
S.P. Driver ◽  
W.J. Couch
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Large Population ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Low Surface Brightness Galaxies ◽  
Galaxy Luminosity Function

AbstractRecent results on the determination of the shape of the faint end of the galaxy luminosity function in rich clusters are discussed. There is increasing evidence that in many cases the faint end of the function is steep, indicating a large population of dwarf, possibly low surface-brightness, galaxies. In addition, the magnitude at which the turn-up appears is approximately constant with richness and distance. However, it is clear that not all clusters show such a feature.

scholarly journals Low Luminosity Galaxies in Large Surveys

1999 ◽  
Vol 171 ◽  
pp. 45-51
Author(s):  
John P. Huchra
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Morphological Type ◽  
Large Excess ◽  
Redshift Surveys ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Emission Line Galaxies ◽  
Low Surface Brightness Galaxies ◽  
Galaxy Luminosity Function

AbstractThe debate about the slope and amplitude of the galaxy luminosity function at the faint end is discussed w.r.t. faint galaxies in large surveys, in particular the second CfA (CfA2) and the Las Campanas (LCRS) redshift surveys. Large surveys are necessary to determine the statistics of rare objects or objects that can only be seen out to limited volumes. Both surveys show excesses of faint galaxies over Schechter function fits, but the parent sample for the LCRS survey generally does not contain large or low surface brightness galaxies which do appear in the CfA2 survey. The objects that comprise the relatively large excess of faint galaxies in the CfA2 survey are shown to be primarily of low surface brightness and late morphological type and are generally emission line galaxies. Galaxy samples constructed like the LCRS will generally always be deficient in low luminosity galaxies and thus are not useful for constraining the faint end of the galaxy luminosity function.

The Faint End of the Galaxy Luminosity Function in Abell 426 and 539

1998 ◽  
Vol 116 (3) ◽  
pp. 1118-1124 ◽  
Author(s):  
Roberto De Propris ◽  
Christopher J. Pritchet
Keyword(s):  
Luminosity Function ◽  
The Galaxy ◽  
Galaxy Luminosity Function
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