scholarly journals Fundamental Plane and Merger Scenario

1999 ◽  
Vol 186 ◽  
pp. 185-188
Author(s):  
K. Bekki
Keyword(s):  
Surface Brightness ◽  
Velocity Dispersion ◽  
Evolutionary Process ◽  
Elliptical Galaxies ◽  
Scaling Relation ◽  
Early Type ◽  
Dynamical Mass ◽  
Fundamental Plane ◽  
Apparent Deviation ◽  
The Mean

The Fundamental Plane (FP) is one of the most important universal relations in early type galaxies because it contains valuable information about the formative and evolutionary process of galaxies (Djorgovski & Davis 1987, Dressler et al. 1987). The commonly used form of the scaling relation in the FP is described as Re = σAIB, where Re, σ, and I are effective radius, central velocity dispersion, and mean surface brightness of elliptical galaxies, respectively. The exponents A, B are considered to be 1.56 ± 0.07 and −0.94 ± 0.09 in the FP derived by K band photometry, respectively, and these values deviate significantly from the values A = 2.0 and B = −1.0 expected from virial theorem (Pahre et al. 1995; Djorgovski, Pahre, & de Carvalho 1996). This apparent deviation requires that the ratio of dynamical mass (M) to luminosity of elliptical galaxies (L) depends on M as M/L ∝ Mα (α = 0.12 ± 0.03 for K band). Possible interpretations for the required dependence of M/L on M are generally considered to be divided into the following two. One is that the required dependence of M/L on M results from the fact that the mean stellar age and metalicity of elliptical galaxies depend systematically on M. The other is that the required dependence reflects the M dependence of structural and kinematical properties of elliptical galaxies (“nonhomology”). Although we should not neglect the importance of stellar populations in generating the M dependence of the M/L (Renzini & Ciotti 1993), we here consider that the origin of the required M dependence of M/L is closely associated with the structural and kinematical properties dependent on M or L in elliptical galaxies.

scholarly journals The Manifold of Elliptical Galaxies

1987 ◽  
Vol 127 ◽  
pp. 79-88
Author(s):  
S. Djorgovski
Keyword(s):  
Galaxy Formation ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Morphological Parameters ◽  
Strong Regularity ◽  
Fundamental Plane ◽  
Global Properties ◽  
Error Bars ◽  
Intrinsic Scatter

Global properties of elliptical galaxies, such as the luminosity, radius, projected velocity dispersion, projected luminosity density, etc., form a two-dimensional family. This “fundamental plane” of elliptical galaxies can be defined by the velocity dispersion and mean surface brightness, and its thickness is presently given by the measurement error-bars only. This is indicative of a strong regularity in the process of galaxy formation. However, all morphological parameters which describe the shape of the distribution of light, and reflect dynamical anisotropies of stars, are completely independent from each other, and independent of the fundamental plane. The M/L ratios show only a small intrinsic scatter in a luminosity range spanning some four orders of magnitude; this suggests a constant fraction of the dark matter contribution in elliptical galaxies.

scholarly journals Redshift evolution of the Fundamental Plane relation in the IllustrisTNG simulation

2020 ◽  
Vol 492 (4) ◽  
pp. 5930-5939 ◽  
Author(s):  
Shengdong Lu ◽  
Dandan Xu ◽  
Yunchong Wang ◽  
Shude Mao ◽  
Junqiang Ge ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Gravitational Constant ◽  
Velocity Dispersion ◽  
Numerical Models ◽  
Zero Point ◽  
Dynamical Mass ◽  
Fundamental Plane ◽  
Hydrodynamical Simulations ◽  
Powerful Constraint ◽  
The Right

ABSTRACT We investigate the Fundamental Plane (FP) evolution of early-type galaxies in the IllustrisTNG-100 simulation (TNG100) from redshift z = 0 to z = 2. We find that a tight plane relation already exists as early as z = 2. Its scatter stays as low as ∼0.08 dex across this redshift range. Both slope parameters b and c (where R ∝ σbIc with R, σ, and I being the typical size, velocity dispersion, and surface brightness) of the plane evolve mildly since z = 2, roughly consistent with observations. The FP residual $\rm Res$ ($\equiv \, a\, +\, b\log \sigma \, +\, c\log I\, -\, \log R$, where a is the zero-point of the FP) is found to strongly correlate with stellar age, indicating that stellar age can be used as a crucial fourth parameter of the FP. However, we find that 4c + b + 2 = δ, where δ ∼ 0.8 for FPs in TNG, rather than zero as is typically inferred from observations. This implies that a tight power-law relation between the dynamical mass-to-light ratio Mdyn/L and the dynamical mass Mdyn (where Mdyn ≡ 5σ2R/G, with G being the gravitational constant) is not present in the TNG100 simulation. Recovering such a relation requires proper mixing between dark matter and baryons, as well as star formation occurring with correct efficiencies at the right mass scales. This represents a powerful constraint on the numerical models, which has to be satisfied in future hydrodynamical simulations.

scholarly journals Scaling relations in early-type galaxies from integral-field stellar kinematics

2009 ◽  
Vol 5 (H15) ◽  
pp. 81-81
Author(s):  
M. Cappellari ◽  
N. Scott ◽  
K. Alatalo ◽  
L. Blitz ◽  
M. Bois ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Velocity Dispersion ◽  
Scaling Relations ◽  
Early Type ◽  
Stellar Kinematics ◽  
Fundamental Plane ◽  
The Past ◽  
Stellar Velocity ◽  
Integral Field ◽  
Significant Effort

Early-type galaxies (ETGs) satisfy a now classic scaling relation Re ∝ σ1.2eI−0.8e, the Fundamental Plane (FP; Djorgovski & Davis 1987; Dressler et al. 1987), between their size, stellar velocity dispersion and mean surface brightness. A significant effort has been devoted in the past twenty years to try to understand why the coefficients of the relation are not the ones predicted by the virial theorem Re ∝ σ2eI−1e.

scholarly journals Scaling relations of early-type galaxies in the 6dF Galaxy Survey

2009 ◽  
Vol 5 (H15) ◽  
pp. 84-84
Author(s):  
C. Magoulas ◽  
M. Colless ◽  
H. Jones ◽  
J. Mould ◽  
C. Springob
Keyword(s):  
Surface Brightness ◽  
Near Infrared ◽  
Velocity Dispersion ◽  
Three Dimensional ◽  
Gaussian Model ◽  
Early Type ◽  
Fundamental Plane ◽  
Infrared Wavelengths ◽  
Observational Errors ◽  
Intrinsic Scatter

Over 10,000 early-type galaxies from the 6dF Galaxy Survey (6dFGS) (Jones, D. H. et al. (2009), Jones et al. (2004)) have been used to determine the Fundamental Plane at optical and near-infrared wavelengths. We find that a maximum likelihood fit to an explicit three-dimensional Gaussian model for the distribution of galaxies in size, surface brightness and velocity dispersion can precisely account for selection effects, censoring and observational errors, leading to precise and unbiased parameters for the Fundamental Plane and its intrinsic scatter.

scholarly journals An HST Survey of Cores of Early-Type Galaxies

1996 ◽  
Vol 171 ◽  
pp. 105-116 ◽  
Author(s):  
John Kormendy ◽  
Yong-Ik Byun ◽  
E. A. Ajhar ◽  
Tod R. Lauer ◽  
Alan Dressler ◽  
...  
Keyword(s):  
Outer Surface ◽  
Surface Brightness ◽  
Hubble Space Telescope ◽  
Elliptical Galaxies ◽  
Core Radius ◽  
Early Type ◽  
Late Type ◽  
Fundamental Plane ◽  
The Core ◽  
Oblate Spheroidal

Photometry of the central parts of bulges and elliptical galaxies with the Hubble Space Telescope (HST) confirms and extends ground-based results. Most giant ellipticals have cuspy cores: at the “break radius” rb (formerly the core radius rc), the steep outer surface brightness profile turns down to a shallow inner power law I(r) ∝ r–γ, 0 ≤ γ ≲ 0.25. The corresponding slope of the deprojected profile is derived; the flattest cores allow box orbits to survive. Cores continue to satisfy fundamental plane parameter correlations like those found from the ground. In particular, HST confirms that the luminosity sequence of elliptical galaxies (from cDs to M 32) is physically unrelated to spheroidal galaxies like Fornax. The latter are closely related to late-type dwarfs. Low-luminosity ellipticals do not show cores: 0.5 ≲ γ ≲ 1.3. The most important new result is that global and core properties both show signs of a dichotomy between (i) low-luminosity ellipticals that rotate rapidly, that are nearly isotropic and oblate-spheroidal, that have disky-distorted isophotes, and that are coreless and (ii) giant ellipticals that are essentially nonrotating, anisotropic, and moderately triaxial, that are boxy-distorted, and that have cuspy cores.

scholarly journals The stellar mass Fundamental Plane: the virial relation and a very thin plane for slow rotators

2020 ◽  
Vol 494 (4) ◽  
pp. 5148-5160 ◽  
Author(s):  
M Bernardi ◽  
H Domínguez Sánchez ◽  
B Margalef-Bentabol ◽  
F Nikakhtar ◽  
R K Sheth
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Virial Theorem ◽  
Velocity Dispersion ◽  
Stellar Mass ◽  
Early Type ◽  
Fundamental Plane ◽  
Intrinsic Scatter ◽  
Virial Relation ◽  
Fast Rotating

ABSTRACT Early-type galaxies – slow and fast rotating ellipticals (E-SRs and E-FRs) and S0s/lenticulars – define a Fundamental Plane (FP) in the space of half-light radius Re, enclosed surface brightness Ie, and velocity dispersion σe. Since Ie and σe are distance-independent measurements, the thickness of the FP is often expressed in terms of the accuracy with which Ie and σe can be used to estimate sizes Re. We show that: (1) The thickness of the FP depends strongly on morphology. If the sample only includes E-SRs, then the observed scatter in Re is $\sim 16{{\ \rm per\ cent}}$, of which only $\sim 9{{\ \rm per\ cent}}$ is intrinsic. Removing galaxies with M* < 1011 M⊙ further reduces the observed scatter to $\sim 13{{\ \rm per\ cent}}$ ($\sim 4{{\ \rm per\ cent}}$ intrinsic). The observed scatter increases to $\sim 25{{\ \rm per\ cent}}$ usually quoted in the literature if E-FRs and S0s are added. If the FP is defined using the eigenvectors of the covariance matrix of the observables, then the E-SRs again define an exceptionally thin FP, with intrinsic scatter of only 5 per cent orthogonal to the plane. (2) The structure within the FP is most easily understood as arising from the fact that Ie and σe are nearly independent, whereas the Re−Ie and Re−σe correlations are nearly equal and opposite. (3) If the coefficients of the FP differ from those associated with the virial theorem the plane is said to be ‘tilted’. If we multiply Ie by the global stellar mass-to-light ratio M*/L and we account for non-homology across the population by using Sérsic photometry, then the resulting stellar mass FP is less tilted. Accounting self-consistently for M*/L gradients will change the tilt. The tilt we currently see suggests that the efficiency of turning baryons into stars increases and/or the dark matter fraction decreases as stellar surface brightness increases.

scholarly journals Stellar Populations of the Most Massive Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 459-459
Author(s):  
Alexander Fritz ◽  
Michael D. Hoenig ◽  
Ricardo P. Schiavon
Keyword(s):  
High Velocity ◽  
Surface Brightness ◽  
Stellar Populations ◽  
Spectroscopic Properties ◽  
Low Density ◽  
Early Type ◽  
Small Surface ◽  
Fundamental Plane ◽  
Massive Galaxies ◽  
Bona Fide

Within the hierarchical CDM framework, gas-poor mergers contribute substantially to the building of the most massive galaxies (Faber et al. 2007). We want to test this scenario by studying the fundamental plane (FP) and the stellar populations of the most massive galaxies. We investigate a well-defined sample of massive early-type galaxies at 0.1<z<0.4, identified from the SDSS database. Out of 42,000 possible targets in the SDSS database, we extracted 23 luminous early-type galaxies with bona fide high velocity dispersions of σ>350 km s−1. These systems are located either in high or low-density environments and show a variety of small surface-brightness structure. Using archival HST/ACS images and Gemini/GMOS spectroscopy, we will explore the photometric and spectroscopic properties of these galaxies.

A New Mass Modelling Trick

2006 ◽  
Vol 2 (S235) ◽  
pp. 88-89
Author(s):  
Dalia Chakrabarty
Keyword(s):  
Distribution Function ◽  
Velocity Dispersion ◽  
Type Systems ◽  
Elliptical Galaxies ◽  
Space Distribution ◽  
Early Type ◽  
Phase Space Distribution ◽  
Mass Distributions ◽  
Kinematic Information ◽  
System Geometry

The estimation of the distribution of the total (luminous and dark) mass in early type systems is hard! Even for the lucky few systems for which kinematic information is available, its implementation is mired in problems, given uncertainties about the assumptions that enter the calculations; the most critical of such assumptions involve considerations of the system geometry and the shape of its velocity ellipsoid. This work offers an independent means of getting to the mass distributions of early type galaxies, without relying directly on the phase space distribution function. The methodology is based upon the well established idea that in elliptical galaxies, the largest variations in normalised velocity dispersion profiles occur typically at R < 0.5Re (Re≡ half-light radius) and at R ≥ 2Re.

scholarly journals The Tilt of the Fundamental Plane of Elliptical Galaxies: Dynamical and Structural Effects

1996 ◽  
Vol 171 ◽  
pp. 403-403
Author(s):  
B. Lanzoni ◽  
L. Ciotti ◽  
A. Renzini
Keyword(s):  
Dark Matter ◽  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
Fine Tuning ◽  
Structural Effects ◽  
Fundamental Plane ◽  
Systematic Trend ◽  
Radial Anisotropy ◽  
Light Profiles

We explore several structural and dynamical effects on the projected velocity dispersion as possible causes of the fundamental plane (FP) tilt of elliptical galaxies (Ciotti, Lanzoni & Renzini, 1995). Specifically, we determine the size of the systematic trend along the FP in the orbital radial anisotropy, in the dark matter (DM) content and distribution relative to the bright matter, and in the shape of the light profile that would be needed to produce the tilt, under the assumption of a constant stellar mass to light ratio. Spherical, non rotating, two-components models are constructed, where the light profiles resemble the R1/4 law. For these we can exclude orbital anisotropy as the origin of the tilt, while a systematic increase in the DM content and/or concentration may formally produce it. Also a suitable variation of the light profile can produce the desired effect, and there may be some observational hints supporting this possibility. However, fine tuning is always required in order to reproduce the tilt, while preserving the tightness of the galaxies distribution about the FP.

Investigation on fundamental plane of open clusters

2017 ◽  
Vol 13 (S334) ◽  
pp. 331-332
Author(s):  
Xiao-Ying Pang ◽  
Chien-Cheng Lin
Keyword(s):  
Radial Velocity ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Open Clusters ◽  
Fundamental Plane ◽  
Average Surface ◽  
Magnitude Diagram ◽  
Formation And Evolution

AbstractThe fundamental plane (FP) is the relation between the surface brightness (I), velocity dispersion (σ) and radius (R). The tilt of FP from the virial plane (R = σ2 I) not only tells the dynamical states of the system but also its formation and evolution. We motivate to looking for an FP in Galactic open clusters (OCs). To form a sample of OCs, we access the most recent DR 14 data from the SDSS/APOGEE2 and the Gaia-ESO survey. Membership of stars is determined via radial velocity and metallicity, plus star’s location in the color-magnitude diagram. Besides the velocity dispersion (σrv) obtained from SDSS/APOGEE2 &amp; Gaia-ESO, the average surface brightness (IKs), and apparent radii (r2) of OCs are taken from known OC catalog. A weak relation is found: log(r2) ∝ -0.34 * log(σ) - 0.08 * IKs. An implication of this FP needs further investigation.

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