scholarly journals Modelling mass distribution in elliptical galaxies: mass profiles and their correlation with velocity dispersion profiles

2013 ◽  
Vol 437 (4) ◽  
pp. 3670-3687 ◽  
Author(s):  
Kyu-Hyun Chae ◽  
Mariangela Bernardi ◽  
Andrey V. Kravtsov
Keyword(s):  
Mass Distribution ◽  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Mass Profiles

scholarly journals Galaxy properties as revealed by MaNGA – III. Kinematic profiles and stellar population gradients in S0s

2020 ◽  
Vol 495 (3) ◽  
pp. 2894-2908 ◽  
Author(s):  
H Domínguez Sánchez ◽  
M Bernardi ◽  
F Nikakhtar ◽  
B Margalef-Bentabol ◽  
R K Sheth
Keyword(s):  
Stellar Population ◽  
Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Elliptical Galaxies ◽  
Element Abundance ◽  
High Signal ◽  
Galactocentric Distance ◽  
Massive Galaxies ◽  
Nearby Galaxies ◽  
Mass Functions

ABSTRACT This is the third paper of a series where we study the stellar population gradients (SP; ages, metallicities, α-element abundance ratios, and stellar initial mass functions) of early-type galaxies (ETGs) at $z$ ≤ 0.08 from the Mapping Nearby Galaxies at APO Data Release 15 (MaNGA-DR15) survey. In this work, we focus on the S0 population and quantify how the SP varies across the population as well as with galactocentric distance. We do this by measuring Lick indices and comparing them to SP synthesis models. This requires spectra with high signal-to-noise ratio which we achieve by stacking in bins of luminosity (Lr) and central velocity dispersion (σ0). We find that: (1) there is a bimodality in the S0 population: S0s more massive than $3\times 10^{10}\, \mathrm{M}_\odot$ show stronger velocity dispersion and age gradients (age and σr decrease outwards) but little or no metallicity gradient, while the less massive ones present relatively flat age and velocity dispersion profiles, but a significant metallicity gradient (i.e. [M/H] decreases outwards). Above $2\times 10^{11}\, \mathrm{M}_\odot$, the number of S0s drops sharply. These two mass scales are also where global scaling relations of ETGs change slope. (2) S0s have steeper velocity dispersion profiles than fast-rotating elliptical galaxies (E-FRs) of the same luminosity and velocity dispersion. The kinematic profiles and SP gradients of E-FRs are both more similar to those of slow-rotating ellipticals (E-SRs) than to S0s, suggesting that E-FRs are not simply S0s viewed face-on. (3) At fixed σ0, more luminous S0s and E-FRs are younger, more metal rich and less α-enhanced. Evidently for these galaxies, the usual statement that ‘massive galaxies are older’ is not true if σ0 is held fixed.

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 Can We Measure H0 with VLBI Observations of Gravitational Images?

1988 ◽  
Vol 129 ◽  
pp. 207-208
Author(s):  
E. E. Falco ◽  
M. V. Gorenstein ◽  
I. I. Shapiro
Keyword(s):  
Time Delay ◽  
Mass Distribution ◽  
Velocity Dispersion ◽  
Gravitational Lens ◽  
Lens System ◽  
Relative Time ◽  
Surface Mass ◽  
A Value ◽  
Vlbi Observations ◽  
The Difference

We have used the relative positions and magnifications of the A and B images in the gravitational lens system 0957+561, obtained from VLBI observations, to constrain a model for the surface mass distribution of the lens. With measurements of the difference ΔτBA in propagation times associated with A and B (the “relative time delay”) and of the velocity dispersion of the main lensing galaxy, both to be obtained, our model will yield a value for H0 with an uncertainty of ∼ 20% due mainly to uncertainties in our assumptions.

scholarly journals Mass Distribution of the E0 Galaxy NGC 6703 from Absorption Line Profile Kinematics

1999 ◽  
Vol 186 ◽  
pp. 189-190
Author(s):  
O.E. Gerhard ◽  
G. Jeske ◽  
R.P. Saglia ◽  
Ralf Bender
Keyword(s):  
Dark Matter ◽  
Absorption Line ◽  
Mass Distribution ◽  
Line Profile ◽  
Elliptical Galaxies ◽  
Velocity Profiles ◽  
Matter Content ◽  
Orbit Structure ◽  
Extensive Analysis ◽  
Preliminary Account

Absorption line velocity profiles (vps) contain important information on the anisotropy and mass distribution of elliptical galaxies (e.g., Gerhard 1993, Merritt 1993). Here we briefly present results of an extensive analysis of the E0 galaxy NGC 6703 (Gerhard et al. 1997). This work is part of an observational and theoretical program aimed at understanding the orbit structure and dark matter content of ellipticals at intermediate radii (a preliminary account is given in Saglia et al. 1997).

Formation Times for Rich Clusters of Galaxies

1977 ◽  
Vol 3 (2) ◽  
pp. 140-142 ◽  
Author(s):  
B. M. Lewis
Keyword(s):  
Gaussian Distribution ◽  
Large Scale ◽  
Velocity Dispersion ◽  
Large Scale Structure ◽  
Elliptical Galaxies ◽  
Scale Structure ◽  
Clusters Of Galaxies ◽  
Number Density ◽  
Radial Gradient ◽  
The Universe

Rich clusters of galaxies are a common feature of the large-scale structure of the Universe. Those studied so far, show striking regularities with (a)a smooth radial gradient of number density.(b)’isothermal’ distributions, which according to Bahcall (1975) have a scatter of only ±15% in the size of their characteristic core radii.(c)their limiting structural diameters are ~50 Mpc (cf. Abell, 1975), if they are identified with superclusters.(d)the magnitude of the velocity dispersion about their centres is generally 600-1000 km s-1, and the velocities are cpnsistent with a gaussian distribution (Yahil and Vidal, 1976; also Faber and Dressier, 1976).(e)The extreme velocities are generally within ±3000 km s-1, and for Coma are ∼2400 km s-1 (Tifft and Gregory, 1976).(f)elliptical galaxies tend to predominate near the centre, spirals in the surrounding loose groups.

scholarly journals Which Galaxy Property Best Predicts Quiescence?

2012 ◽  
Vol 8 (S295) ◽  
pp. 177-177
Author(s):  
Joel Leja ◽  
Pieter van Dokkum ◽  
Keyword(s):  
Spatial Distribution ◽  
Star Formation ◽  
Velocity Dispersion ◽  
High Redshift ◽  
Line Emission ◽  
Elliptical Galaxies ◽  
High Dispersion ◽  
Quenching Mechanism ◽  
Line Flux ◽  
Line Equivalent Width

AbstractIt is generally accepted that local elliptical galaxies assembled most of their mass in a burst of star formation between 1 < z < 3, yet today, their star formation has been almost entirely quenched. In order to constrain this quenching mechanism, we measure Hα line emission in galaxies sorted by multiple galaxy properties as a function of redshift to what galaxy parameter best predicts quiescence. This is done for samples of the most massive, most luminous, and galaxies with the highest velocity dispersion both locally (0.05 < z < 0.07 in the SDSS) and at high redshift (0.7 < z < 1.5 in 3D-HST). It is demonstrated through spectral stacking that velocity dispersion results in the lowest Hα line equivalent width both locally and at high redshift. The spatial distribution of the emission line flux is available from grism spectroscopy: the line flux from the high dispersion stack is centrally peaked and thus likely associated with AGN activity rather than star formation, strengthening this conclusion. Since velocity dispersion may also be the best predictor of halo mass (Wake et al. 2012), this may imply that the quenching mechanism is directly related to halo mass.

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.

scholarly journals The Age of Elliptical Galaxies in Clusters

1996 ◽  
Vol 171 ◽  
pp. 473-473
Author(s):  
Bodo Ziegler ◽  
Ralf Bender
Keyword(s):  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Population Synthesis ◽  
Small Scatter ◽  
Hubble Time

Nearby cluster ellipticals follow a very tight relation between velocity dispersion σ and Mg absorption (e.g. Bender et al. 1993, ApJ411, 153). The small scatter in Mg implies that the age and metallicity spread at a given σ in ellipticals is smaller than 15% (applying Worthey's population synthesis models 1994, ApJS95, 107). This means that ellipticals cannot have formed continuously over the Hubble time and ongoing merger processes represent only a tail of latecomers.

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 Starburst Feedback in Local, Massive Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 280-283
Author(s):  
Crystal L. Martin
Keyword(s):  
Surface Brightness ◽  
Milky Way ◽  
Velocity Dispersion ◽  
Rotation Speed ◽  
Far Infrared ◽  
Elliptical Galaxies ◽  
Evolutionary Path ◽  
Sky Surveys ◽  
Massive Galaxies ◽  
Stellar Velocity

Major mergers of gas-rich galaxies, each comparable in mass to the Milky Way, are rare at the present epoch. These events were readily identifed, however, two decades ago in far-infrared sky surveys (Soifer et al. 1986, 1987). Removal of the dust enshrouding these starbursts was almost immediately proposed as an evolutionary path to quasar formation (Sanders 1988). Recent measurements of the stellar velocity dispersion, rotation speed, and stellar surface brightness profile of these mergers suggest ULIRGs are indeed progenitors of field elliptical galaxies (Genzel et al. 2001; Tacconi et al. 2002).

Sign in / Sign up

Export Citation Format

Share Document