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 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.

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 & 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.

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 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.

Open Cluster Dynamics via Fundamental Plane

2017 ◽  
Vol 12 (S330) ◽  
pp. 233-234
Author(s):  
Chien-Cheng Lin ◽  
Xiao-Ying Pang
Keyword(s):  
Radial Velocity ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Open Cluster ◽  
Dynamical Evolution ◽  
Stellar Dynamics ◽  
Open Clusters ◽  
Fundamental Plane ◽  
Cluster Age ◽  
Internal Effect

AbstractOpen clusters (OCs) are important objects for stellar dynamics studies. The short survival timescale of OCs makes them closely related to the formation of Galactic field stars. We motivate to investigate the dynamical evolution of OCs on the aspect of internal effect and the external influence. Firstly, we make use of the known OC catalog to obtain OCs masses, effective radii. Additionally, we estimate OCs kinematics properties by OC members cross-matched with radial velocity and metallicity from SDSSIV/APOGEE2. We then establish the fundamental plane of OCs based on the radial velocity dispersion, the effective radius, and average surface brightness. The deviation of the fundamental plane from the Virial Plane, so called the tilt, and the r.m.s. dispersion of OCs around the average plane are used to indicate the dynamical status of OCs. Parameters of the fitted plane will vary with cluster age and distance.

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 The SAMI Galaxy Survey: stellar population and structural trends across the Fundamental Plane

2021 ◽  
Author(s):  
Francesco D’Eugenio ◽  
Matthew Colless ◽  
Nicholas Scott ◽  
Arjen van der Wel ◽  
Roger L Davies ◽  
...  
Keyword(s):  
Stellar Population ◽  
Mass Density ◽  
Empirical Relation ◽  
Zero Point ◽  
High Signal ◽  
Fundamental Plane ◽  
Surface Mass ◽  
Integral Field Spectroscopy ◽  
Surface Mass Density ◽  
Photometric Measurements

Abstract We study the Fundamental Plane (FP) for a volume- and luminosity-limited sample of 560 early-type galaxies from the SAMI survey. Using r −band sizes and luminosities from new Multi-Gaussian Expansion (MGE) photometric measurements, and treating luminosity as the dependent variable, the FP has coefficients a = 1.294 ± 0.039, b = 0.912 ± 0.025, and zero-point c = 7.067 ± 0.078. We leverage the high signal-to-noise of SAMI integral field spectroscopy, to determine how structural and stellar-population observables affect the scatter about the FP. The FP residuals correlate most strongly (8σ significance) with luminosity-weighted simple-stellar-population (SSP) age. In contrast, the structural observables surface mass density, rotation-to-dispersion ratio, Sérsic index and projected shape all show little or no significant correlation. We connect the FP residuals to the empirical relation between age (or stellar mass-to-light ratio ϒ⋆ ) and surface mass density, the best predictor of SSP age amongst parameters based on FP observables. We show that the FP residuals (anti-)correlate with the residuals of the relation between surface density and ϒ⋆ . This correlation implies that part of the FP scatter is due to the broad age and ϒ⋆ distribution at any given surface mass density. Using virial mass and ϒ⋆ we construct a simulated FP and compare it to the observed FP. We find that, while the empirical relations between observed stellar population relations and FP observables are responsible for most (75 per cent) of the FP scatter, on their own they do not explain the observed tilt of the FP away from the virial plane.

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.

scholarly journals Measuring turbulence and gas motions in galaxy clusters via synthetic Athena X-IFU observations

2018 ◽  
Vol 618 ◽  
pp. A39 ◽  
Author(s):  
M. Roncarelli ◽  
M. Gaspari ◽  
S. Ettori ◽  
V. Biffi ◽  
F. Brighenti ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Velocity Dispersion ◽  
Emission Measure ◽  
Systematic Errors ◽  
X Ray ◽  
Fitting Method ◽  
Metal Abundance ◽  
Centroid Shift ◽  
Hydrodynamical Simulations ◽  
Field Unit

Context. The X-ray Integral Field Unit (X-IFU) that will be on board the Athena telescope will provide an unprecedented view of the intracluster medium (ICM) kinematics through the observation of gas velocity, ν, and velocity dispersion, w, via centroid-shift and broadening of emission lines, respectively. Aims. The improvement of data quality and quantity requires an assessment of the systematics associated with this new data analysis, namely biases, statistical and systematic errors, and possible correlations between the different measured quantities. Methods. We have developed an end-to-end X-IFU simulator that mimics a full X-ray spectral fitting analysis on a set of mock event lists, obtained using SIXTE. We have applied it to three hydrodynamical simulations of a Coma-like cluster that include the injection of turbulence. This allowed us to assess the ability of X-IFU to map five physical quantities in the cluster core: emission measure, temperature, metal abundance, velocity, and velocity dispersion. Finally, starting from our measurements maps, we computed the 2D structure function (SF) of emission measure fluctuations, ν and w, and compared them with those derived directly from the simulations. Results. All quantities match with the input projected values without bias; the systematic errors were below 5%, except for velocity dispersion whose error reaches about 15%. Moreover, all measurements prove to be statistically independent, indicating the robustness of the fitting method. Most importantly, we recover the slope of the SFs in the inertial regime with excellent accuracy, but we observe a systematic excess in the normalization of both SFν and SFw ascribed to the simplistic assumption of uniform and (bi-)Gaussian measurement errors. Conclusions. Our work highlights the excellent capabilities of Athena X-IFU in probing the thermodynamic and kinematic properties of the ICM. This will allow us to access the physics of its turbulent motions with unprecedented precision.

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