Velocity Dispersion Distribution Research Articles

On the properties of free floating planets originating in circumbinary planetary systems

Abstract Free-floating planets are a new class of planets recently discovered. These planets don’t orbit within stellar systems, instead living a nomadic life within the galaxy. How such objects formed remains elusive. Numerous works have explored mechanisms to form such objects, but have not yet provided predictions on their distributions that could differentiate between formation mechanisms. In this work we form these objects within circumbinary systems, where these planets are readily formed and ejected through interactions with the central binary stars. We find significant differences between planets ejected through planet-planet interactions and those by the binary stars. The main differences that arise are in the distributions of excess velocity, where binary stars eject planets with faster velocities. These differences should be observable amongst known free-floating planets in nearby star-forming regions. We predict that targeted observations of directly imaged free-floating planets in these regions should be able to determine their preferred formation pathway, either by planet formation in single or multiple stellar systems, or through processes akin to star formation. Additionally the mass distributions of free-floating planets can yield important insights into the underlying planet populations. We find that for planets more massive than 20 M⊕, their frequencies are similar to those planets remaining bound and orbiting near the central binaries. This similarity allows for effective and informative comparisons between mass distributions from microlensing surveys, to those of transit and radial velocities. Ultimately, by observing the velocity dispersion and mass distribution of free-floating planets, it will be possible to effectively compare with predictions from planet formation models, and to further understand the formation and evolution of these exotic worlds.

Galaxy cluster optical mass proxies from probabilistic memberships

ABSTRACT Robust galaxy cluster mass estimates are fundamental for constraining cosmological parameters from counts. For this reason, it is essential to search for tracers that, independent of the cluster’s dynamical state, have a small intrinsic scatter and can be easily inferred from observations. This work uses a simulated data set to focus on photometric properties and explores different optical mass proxies including richness, optical luminosity, and total stellar mass. We have developed a probabilistic membership assignment that makes minimal assumptions about the galaxy cluster properties, limited to a characteristic radius, velocity dispersion, and spatial distribution. Applying the estimator to over 919 galaxy clusters with zphot < 0.45 within a mass range of 1012.8–1015 M⊙, we obtain robust richness estimates that deviate from the median true value (from simulations) by −0.01 ± 0.12. The scatter in the mass–observable relations is $\sigma _{log_{10}(M|\mathcal {R})}=0.181 \pm 0.009$ dex for richness, $\sigma _{log_{10}(M|L_\lambda)}=0.151 \pm 0.007$ dex for optical luminosity, and $\sigma _{log_{10}(M|M_\lambda ^{*})}=0.097 \pm 0.005$ dex for stellar mass. We also discuss membership assignment, completeness and purity, and the consequences of small centre and redshift offsets. We conclude that the application of our method for photometric surveys delivers competitive cluster mass proxies.

Dynamics of Molecular Gas in the Central Region of the Quasar I Zwicky 1

We present a study of the molecular gas distribution and kinematics in the cicumnuclear region (radii ≲2 kpc) of the z ≈ 0.061 quasar I Zwicky 1 using a collection of available Atacama Large Millimeter/submillimeter Array observations of the carbon monoxide (CO) emission. With an angular resolution of ∼0.″36 (corresponding to ∼400 pc), the host-galaxy substructures including the nuclear molecular gas disk, spiral arms, and a compact bar-like component are resolved. We analyzed the gas kinematics based on the CO image cube and obtained the rotation curve and radial distribution of velocity dispersion. The velocity dispersion is about 30 km s−1 in the outer CO disk region and rises up to ≳100 km s−1 at radius ≲1 kpc, suggesting that the central region of the disk is dynamically hot. We constrain the CO-to-H2 conversion factor, α CO, by modeling the cold gas disk dynamics. We find that, with prior knowledge about the stellar and dark matter components, the α CO value in the circumnuclear region of this quasar host galaxy is , which is between the value reported in ultraluminous infrared galaxies and in the Milky Way. The central 1 kpc region of this quasar host galaxy has significant star formation activity, which can be identified as a nuclear starburst. We further investigate the high-velocity dispersion in the central region. We find that the interstellar medium (ISM) turbulent pressure derived from the gas velocity dispersion is in equilibrium with the weight of the ISM. This argues against extra power from active galactic nuclei feedback that significantly affects the kinematics of the cold molecular gas.

The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2

We present and analyze observations of polarized dust emission at 850 μm toward the central 1 × 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 − 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 ± 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 ± 0.02. Additionally, the mean Alfvén Mach number is 0.35 ± 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical.

The contribution of in situ and ex situ star formation in early-type galaxies: MaNGA versus IllustrisTNG

ABSTRACT We compare stellar mass surface density, metallicity, age, and line-of-sight velocity dispersion profiles in massive ($M_*\ge 10^{10.5}\, \mathrm{M_\odot }$) present-day early-type galaxies (ETGs) from the MaNGA survey with simulated galaxies from the TNG100 simulation of the IllustrisTNG suite. We find an excellent agreement between the stellar mass surface density profiles of MaNGA and TNG100 ETGs, both in shape and normalization. Moreover, TNG100 reproduces the shapes of the profiles of stellar metallicity and age, as well as the normalization of velocity dispersion distributions of MaNGA ETGs. We generally also find good agreement when comparing the stellar profiles of central and satellite galaxies between MaNGA and TNG100. An exception is the velocity dispersion profiles of very massive ($M_*\gtrsim 10^{11.5}\, \mathrm{M_\odot }$) central galaxies, which, on average, are significantly higher in TNG100 than in MaNGA ($\approx 50\, \mathrm{km\, s^{-1}}$). We study the radial profiles of in situ and ex situ stars in TNG100 and discuss the extent to which each population contributes to the observed MaNGA profiles. Our analysis lends significant support to the idea that high-mass ($M_*\gtrsim 10^{11}\, \mathrm{M_\odot }$) ETGs in the present-day Universe are the result of a merger-driven evolution marked by major mergers that tend to homogenize the stellar populations of the progenitors in the merger remnant.

Morphology, colour–magnitude, and scaling relations of galaxies in Abell 426

ABSTRACT We present photometric properties of 183 member galaxies in the Abell 426 cluster using the Sloan Digital Sky Survey (SDSS) imaging and spectroscopic observation. Detailed morphology based on visual classification followed by multicomponent image decomposition of 179 galaxies is presented in the SDSS g, r, i bands. More than 80 per cent of the members are early-type galaxies (ETGs), with elliptical, dwarf elliptical (dE), and lenticular morphology and follow the red-sequence in the colour–magnitude diagram (CMD). With a few dEs and spirals in the blue cloud, the cluster CMD is nearly unimodal. The dEs are ∼2-mag fainter and follow a different Sersic index and central velocity dispersion distribution than their bright counterparts. Further, we establish the Kormendy relation (KR) and the fundamental plane relation (FPR) for five different samples of ETGs constructed based on derived physical parameters such as Sersic index, concentration, central velocity dispersion in g, r, i bands. The mean r-band slope and zero-point of the KR are 3.02 ± 0.1 and 18.65 ± 0.03 in close agreement to other cluster ellipticals in the local and higher redshift. Kinematics-based ETG sample produces the least scatter in KR with zero-point getting brighter by ∼1.3 mag from g to i band. The dEs and other low-mass ETGs follow the KR with a similar slope but with ∼1.3 mag fainter zero-point and form a parallel KR. The bright ellipticals follow an FPR with a = 1.37 ± 0.003, b = 0.35 ± 0.05, and c = −9.37 ± 0.02 in the r band; galaxies tend to deviate from this relation at the low-mass end. A catalogue with morphology and 2D structural analysis is available online.

Two types of distribution of the gas velocity dispersion of MaNGA galaxies

The distribution of the gas velocity dispersion σ across the images of 1146 MaNGA galaxies is analyzed. We find that there are two types of distribution of the gas velocity dispersion across the images of galaxies: (i) the distributions of 909 galaxies show a radial symmetry with or without the σ enhancement at the center (“R distribution”, radial symmetry in the σ distribution) and (ii) distributions with a band of enhanced σ along the minor axis in the images of 159 galaxies with or without the σ enhancement at the center (“B distribution”, band in the σ distribution). The σ distribution across the images of 78 galaxies cannot be reliable classified. We select 806 galaxies with the best defined characteristics (this sample includes 687 galaxies with R distribution and 119 galaxies with B distribution) and compare the properties of galaxies with R and B distributions. We find that the median value of the gas velocity dispersion σm in galaxies with B distribution is higher by around 5 km s−1, on average, than that of galaxies with R distribution. The optical radius R25 of galaxies with B distribution is lower by around 0.1 dex, on average, than that of galaxies with similar masses with R distribution. Thus the properties of a galaxy are related to the type of distribution of the gas velocity dispersion σ across its image. This suggests that the presence of the band of the enhanced gas velocity dispersion can be an indicator of a specific evolution (or a specific stage in the evolution) of a galaxy.

Black Holes and the Supermassive Compact Object at the Galactic Center: Multi-arts of Thought and Nature

Black Holes and the Supermassive Compact Object at the Galactic Center: Multi-arts of Thought and Nature

Probabilistic Detection of Spectral Line Components

Abstract Resolved kinematical information, such as from molecular gas in star-forming regions, is obtained from spectral line observations. However, these observations often contain multiple line-of-sight components, making estimates harder to obtain and interpret. We present a fully automatic method that determines the number of components along the line of sight, or the spectral multiplicity, through Bayesian model selection. The underlying open-source framework, based on nested sampling and conventional spectral line modeling, is tested using the large area ammonia maps of NGC 1333 in the Perseus molecular cloud obtained by the Green Bank Ammonia Survey (GAS). Compared to classic approaches, the presented method constrains velocities and velocity dispersions in a larger area. In addition, we find that the velocity dispersion distribution among multiple components did not change substantially from that of a single-fit component analysis of the GAS data. These results showcase the power and relative ease of the fitting and model selection method, which makes it a unique tool to extract maximum information from complex spectral data.

Stellar population properties of ETGs in compact groups of galaxies

ABSTRACT We present results on the study of the stellar population in early-type galaxies (ETGs) belonging to 151 compact groups (CGs). We also selected a field sample composed of 846 ETGs to investigate environmental effects on galaxy evolution. We find that the dependences of mean stellar ages, [Z/H] and [α/Fe] on central stellar velocity dispersion are similar, regardless where the ETG resides, CGs or field. When compared to the sample of centrals and satellites from the literature, we find that ETGs in CGs behave similarly to centrals, especially those embedded in low-mass haloes ($M_{\mathrm{ h}} \lt 10^ {12.5}\, \mathrm{M}_{\odot }$). Except for the low-mass limit, where field galaxies present a star-forming signature, not seen in CGs, the ionization agent of the gas in CG and field galaxies seem to be similar due to hot, evolved low-mass stars. However, field ETGs present an excess of H α emission relative to ETGs in CGs. Additionally, we performed a dynamical analysis, which shows that CGs present a bimodality in the group velocity dispersion distribution – a high- and low-σ mode. Our results indicate that high-σ groups have a smaller fraction of spirals, shorter crossing times, and a more luminous population of galaxies than the low-σ groups. It is important to emphasize that our findings point to a small environmental impact on galaxies located in CGs. The only evidence we find is the change in gas content, suggesting environmentally driven gas loss.

Clocking the assembly of double-barred galaxies with the MUSE TIMER project

The formation of two stellar bars within a galaxy has proved challenging for numerical studies. It is yet not clear whether the inner bar is born via a star formation process promoted by gas inflow along the outer bar, or whether it is dynamically assembled from instabilities in a small-scale stellar disc. Observational constraints to these scenarios are scarce. We present a thorough study of the stellar content of two double-barred galaxies observed by the MUSE TIMER project, NGC 1291 and NGC 5850, combined with a two-dimensional multi-component photometric decomposition performed on the 3.6{\mu}m images from S4G. Our analysis confirms the presence of {\sigma}-hollows appearing in the stellar velocity dispersion distribution at the ends of the inner bars. Both galaxies host inner discs matching in size with the inner bars, suggestive of a dynamical formation for the inner bars from small-scale discs. The analysis of the star formation histories for the structural components shaping the galaxies provides constraints on the epoch of dynamical assembly of the inner bars, which took place >6.5 Gyr ago for NGC 1291 and >4.5 Gyr ago for NGC 5850. This implies that inner bars are long-lived structures.

Measurement of the Dispersion of an Antiresonant Hollow Core Fiber

Due to unique properties, antiresonant hollow core fibers have found widespread use in various fields of science and application. Particular regarding applications that involve ultrashort pulses, precise knowledge of group velocity dispersion is essential to understand the underlying physics and to optimize device performance. Here we report on the successful measurement of the spectral distribution of the group velocity dispersion of the fundamental mode of an antiresonant hollow core fiber in close proximity to and away from a strong strand resonance. The results show the variations of the hundreds of fs2/cm near the resonance region, whereas the dispersion is identical to that of a perfect cylindrical waveguide away from the resonance in accordance with a literature. An additional zero dispersion wavelength that is not present in the case of a capillary was experimentally verified. The possibility to tune dispersion via strand resonances opens up a novel pathway towards engineering pulse dispersion, with applications in fields such as nonlinear science and pulse propagation management.

Dense Gas Kinematics and a Narrow Filament in the Orion A OMC1 Region Using NH3

Abstract We present combined observations of the (J, K) = (1, 1) and (2, 2) inversion transitions toward OMC1 in Orion A obtained by the Karl G. Jansky Very Large Array and the 100 m Robert C. Byrd Green Bank Telescope. With an angular resolution of 6″ (0.01 pc), these observations reveal with unprecedented detail the complex filamentary structure extending north of the active Orion BN/KL region in a field covering ∼6′ × 7′. We find a 0.012 pc wide filament within OMC1, with an aspect ratio of ∼37:1, that was missed in previous studies. Its orientation is directly compared to the relative orientation of the magnetic field from the James Clerk Maxwell Telescope BISTRO survey in Orion A. We find a small deviation of ∼11° between the mean orientation of the filament and the magnetic field, suggesting that they are almost parallel to one another. The filament’s column density is estimated to be 2–3 orders of magnitude larger than the filaments studied with Herschel and is possibly self-gravitating, given the low values of turbulence found. We further produce maps of the gas kinematics by forward modeling the hyperfine structure of the (J, K) = (1, 1) and (2, 2) lines. The resulting distribution of velocity dispersions peaks at ∼0.5 km s−1, close to the subsonic regime of the gas. This value is about 0.2 km s−1 smaller than previously measured in single-dish observations of the same region, suggesting that higher angular and spectral resolution observations will identify even lower velocity dispersions that might reach the subsonic turbulence regime in dense gas filaments.

The Effect of Atmospheric Cooling on Vertical Velocity Dispersion and Density Distribution of Brown Dwarfs∗

Abstract We present a Monte Carlo simulation designed to predict the vertical velocity dispersion of brown dwarfs in the Milky Way. We show that since these stars are constantly cooling, the velocity dispersion has a noticeable trend with the spectral type. With realistic assumptions for the initial mass function, star formation history, and the cooling models, we show that the velocity dispersion is roughly consistent with what is observed for M dwarfs, decreases to cooler spectral types, and increases again for the coolest types in our study (∼T9). We predict a minimum in the velocity dispersions for L/T transition objects, however, the detailed properties of the minimum predominately depend on the star formation history. Since this trend is due to brown dwarf cooling, we expect that the velocity dispersion as a function of spectral type should deviate from the constancy around the hydrogen-burning limit. We convert from velocity dispersion to vertical scale height using standard disk models and present similar trends in disk thickness as a function of spectral type. We suggest that future, wide-field photometric and/or spectroscopic missions may collect sizable samples of distant ( kpc) dwarfs that span the hydrogen-burning limit. As such, we speculate that such observations may provide a unique way of constraining the average spectral type of hydrogen burning.

The shapes and alignments of the satellites of the Milky Way and Andromeda

We measure the intrinsic shapes and alignments of the dwarf spheroidal (dSph) galaxies of the Local Group. We find the dSphs of the Milky Way are intrinsically flatter (mean intrinsic ellipticity $\mu_E\sim0.6$) than those of M31 ($\mu_E\sim0.5$) and that the classical Milky Way dSphs ($M_V<-8.5\,\mathrm{mag}$) are rounder ($\mu_E\sim0.5$) than the ultrafaints ($\mu_E\sim0.65$) whilst in M31 the shapes of the classical and ultrafaint dSphs are very similar. The M31 dSphs are preferentially radially aligned with a dispersion of $\sim45\deg$. This signal is driven by the ultrafaint population whilst the classical M31 dSphs are consistent with a random orientation. We compare our results to the Aquarius mock stellar catalogues of Lowing et al. and find the subhalo radial alignment distribution matches the Local Group dSphs results, whilst the Aquarius intrinsic ellipticities are significantly smaller than the data ($\Delta\langle E\rangle\approx0.4$). We provide evidence that the major axes of the Milky Way satellites lie within a preferential plane with normal vector pointing towards $(\ell,b)=(127,5)\deg$. We associate this preferred direction with the Vast Polar Orbital structure although their respective great circles are offset by $\sim30\deg$. No signal in the alignments of the major axes is found in M31, suggesting that the Great Plane of Satellites is formed from recent accretion or chance alignment. Finally, we provide predictions for the discrepancy between the velocity dispersion versus scale radius distributions for the Milky Way and M31 populations and demonstrate that the projection effect from viewing similar populations from two different locations does not account for the discrepancy which is probably caused by increased tidal disruption in M31.

The Velocity Dispersion Function for Quiescent Galaxies in the Local Universe

Abstract We investigate the distribution of central velocity dispersions for quiescent galaxies in the SDSS at 0.03 ≤ z ≤ 0.10. To construct the field velocity dispersion function (VDF), we construct a velocity dispersion complete sample of quiescent galaxies with D n 4000 &gt; 1.5. The sample consists of galaxies with central velocity dispersion larger than the velocity dispersion completeness limit of the SDSS survey. Our VDF measurement is consistent with previous field VDFs for σ &gt; 200 km s−1. In contrast with previous results, the VDF does not decline significantly for σ &lt; 200 km s−1. The field and the similarly constructed cluster VDFs are remarkably flat at low velocity dispersion (σ &lt; 250 km s−1). The cluster VDF exceeds the field for σ &gt; 250 km s−1 providing a measure of the relatively larger number of massive subhalos in clusters. The VDF is a probe of the dark matter halo distribution because the measured central velocity dispersion may be directly proportional to the dark matter velocity dispersion. Thus the VDF provides a potentially powerful test of simulations for models of structure formation.

Orthogonal Vertical Velocity Dispersion Distributions Produced by Bars

Abstract In barred galaxies, the contours of stellar velocity dispersions (σ) are generally expected to be oval and aligned with the orientation of bars. However, many double-barred (S2B) galaxies exhibit distinct σ peaks on the minor axis of the inner bar, which we termed “σ-humps,” while two local σ minima are present close to the ends of inner bars, i.e., “σ-hollows.” Analysis of numerical simulations shows that -humps or hollows should play an important role in generating the observed σ-humps+hollows in low-inclination galaxies. In order to systematically investigate the properties of in barred galaxies, we apply the vertical Jeans equation to a group of well-designed three-dimensional bar+disk(+bulge) models. A vertically thin bar can lower along the bar and enhance it perpendicular to the bar, thus generating -humps+hollows. Such a result suggests that -humps+hollows can be generated by the purely dynamical response of stars in the presence of a sufficiently massive, vertically thin bar, even without an outer bar. Using self-consistent N-body simulations, we verify the existence of vertically thin bars in the nuclear-barred and S2B models that generate prominent σ-humps+hollows. Thus, the ubiquitous presence of σ-humps+hollows in S2Bs implies that inner bars are vertically thin. The addition of a bulge makes the -humps more ambiguous and thus tends to somewhat hide the -humps+hollows. We show that may be used as a kinematic diagnostic of stellar components that have different thicknesses, providing a direct perspective on the morphology and thickness of nearly face-on bars and bulges with integral field unit spectroscopy.

Segregation effects in DEEP2 galaxy groups

We investigate segregation phenomena in galaxy groups in the range of $0.2<z<1$. We study a sample of groups selected from the 4th Data Release of the DEEP2 galaxy redshift survey. We used only groups with at least 8 members within a radius of 4$\;$Mpc. Outliers were removed with the shifting gapper techinque and, then, the virial properties were estimated for each group. The sample was divided into two stacked systems: low($z\leq0.6$) and high($z>0.6$) redshift groups. Assuming that the color index ${(U-B)_0}$ can be used as a proxy for the galaxy type, we found that the fraction of blue (star-forming) objects is higher in the high-z sample, with blue objects being dominant at $M_{B}>-19.5$ for both samples, and red objects being dominant at $M_{B}<-19.5$ only for the low-z sample. Also, the radial variation of the red fraction indicates that there are more red objects with $R<R_{200}$ in the low-z sample than in the high-z sample. Our analysis indicates statistical evidence of kinematic segregation, at the 99%c.l., for the low-z sample: redder and brighter galaxies present lower velocity dispersions than bluer and fainter ones. We also find a weaker evidence for spatial segregation between red and blue objects, at the 70%c.l. The analysis of the high-z sample reveals a different result: red and blue galaxies have velocity dispersion distributions not statistically distinct, although redder objects are more concentrated than the bluer ones at the 95%c.l. From the comparison of blue/red and bright/faint fractions, and considering the approximate lookback timescale between the two samples ($\sim$3 Gyr), our results are consistent with a scenario where bright red galaxies had time to reach energy equipartition, while faint blue/red galaxies in the outskirts infall to the inner parts of the groups, thus reducing spatial segregation from $z\sim0.8$ to $z\sim0.4$.

THE PREVALENCE OF GAS OUTFLOWS IN TYPE 2 AGNs. II. 3D BICONICAL OUTFLOW MODELS

ABSTRACT We present 3D models of biconical outflows combined with a thin dust plane for investigating the physical properties of the ionized gas outflows and their effect on the observed gas kinematics in type 2 active galactic nuclei (AGNs). Using a set of input parameters, we construct a number of models in 3D and calculate the spatially integrated velocity and velocity dispersion for each model. We find that three primary parameters, i.e., intrinsic velocity, bicone inclination, and the amount of dust extinction, mainly determine the simulated velocity and velocity dispersion. Velocity dispersion increases as the intrinsic velocity or the bicone inclination increases, while velocity (i.e., velocity shifts with respect to systemic velocity) increases as the amount of dust extinction increases. Simulated emission-line profiles well reproduce the observed [O iii] line profiles, e.g., narrow core and broad wing components. By comparing model grids and Monte Carlo simulations with the observed [O iii] velocity–velocity dispersion distribution of ∼39,000 type 2 AGNs, we constrain the intrinsic velocity of gas outflows ranging from ∼500 to ∼1000 km s−1 for the majority of AGNs, and up to ∼1500–2000 km s−1 for extreme cases. The Monte Carlo simulations show that the number ratio of AGNs with negative [O iii] velocity to AGNs with positive [O iii] velocity correlates with the outflow opening angle, suggesting that outflows with higher intrinsic velocity tend to have wider opening angles. These results demonstrate the potential of our 3D models for studying the physical properties of gas outflows, applicable to various observations, including spatially integrated and resolved gas kinematics.

THE STELLAR MASS FUNDAMENTAL PLANE AND COMPACT QUIESCENT GALAXIES AT z &lt; 0.6

ABSTRACT We examine the evolution of the relation between stellar mass surface density, velocity dispersion, and half-light radius—the stellar mass fundamental plane (MFP)—for quiescent galaxies at z &lt; 0.6. We measure the local relation from galaxies in the Sloan Digital Sky Survey and the intermediate redshift relation from ∼500 quiescent galaxies with stellar masses 10 ≲ log(M */M ⊙) ≲ 11.5. Nearly half of the quiescent galaxies in our intermediate redshift sample are compact. After accounting for important selection and systematic effects, the velocity dispersion distribution of galaxies at intermediate redshifts is similar to that of galaxies in the local universe. Galaxies at z &lt; 0.6 appear to be smaller (≲0.1 dex) than galaxies in the local sample. The orientation of the stellar MFP is independent of redshift for massive quiescent galaxies at z &lt; 0.6 and the zero-point evolves by ∼0.04 dex. Compact quiescent galaxies fall on the same relation as the extended objects. We confirm that compact quiescent galaxies are the tail of the size and mass distribution of the normal quiescent galaxy population.