THE SIZE–VIRIAL RADIUS RELATION OF GALAXIES

By Andrey V. Kravtsov. 2012

210 citations recorded by the source corpus.

I use the abundance matching ansatz, which has proven to be successful in reproducing galaxy clustering and other statistics, to derive estimates of the virial radius, R200, for galaxies of different morphological types and a wide range of stellar masses. I show that over eight orders of magnitude in stellar mass galaxies of all morphological types follow an approximately linear relation between half-mass radius of their stellar distribution, r1/2, and virial radius, r1/2 ≈ 0.015 R200, with scatter of ≈0.2 dex. Such scaling is in remarkable agreement with the expectation of models that assume that galaxy sizes are controlled by halo angular momentum, r1/2∝λR200, where λ is the spin of galaxy parent halo. The scatter about the relation is comparable with the scatter expected from the distribution of λ. Moreover, I show that when the stellar and gas surface density profiles of galaxies of different morphological types are rescaled by the radius rn = 0.015 R200, the rescaled profiles follow approximately universal exponential (for late types) and de Vaucouleurs (for early types) form with scatter of only ≈30%–50% at R ≈ 1–3rn. Remarkably, both late- and early-type galaxies have similar mean stellar surface density profiles at R ≳ 1rn. The main difference between their stellar distributions is thus at R < rn. The results of this study imply that galaxy sizes and radial distribution of baryons are shaped primarily by properties of their parent halos and that the sizes of both late-type disks and early-type spheroids are controlled by halo angular momentum.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/8c06709dbe72a6b9375bdd4b41f431491d1ef004

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

In Statistical and Nonlinear Physics

Citations in the corpus

Star formation in semi-analytic galaxy formation models with multiphase gas (2015, background): “Bigiel & Blitz (2012) showed that this is a fairly good representation, on average, of the disks of nearby spirals (see also Kravtsov 2013).”
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2 (2018, background): “…to halo radius, with log10[Rh/r200] −1, putting them 4σ above the average relation log10[Rh/r200] = −1.8 ± 0.2 describing sizes of the entire galaxy population in the abundance matching scheme of Kravtsov (2013), suggesting that such a relation might not hold for extreme cases like Ant 2.”
3D-HST+CANDELS: THE EVOLUTION OF THE GALAXY SIZE–MASS DISTRIBUTION SINCE z = 3 (2014, unknown): “The underlying assumption is that galaxy size is proportional to halo size (Kravtsov 2013), which we here take to be the case for late-type galaxies.”
Star formation sustained by gas accretion (2014, background): “Rvir is typically very large compared to the optical half-light radius of the resulting galaxies (∼ 70 times according to Kravtsov 2013).”
MORPHOLOGIES OF ∼190,000 GALAXIES AT z = 0–10 REVEALED WITH HST LEGACY DATA. I. SIZE EVOLUTION (2015, methodology): “For local galaxies, Kravtsov (2013) obtain re/rvir = 1.50 ± 0.07% by the fitting of size-luminosity relations.”
Dark matter cores all the way down (2015, result): “We find that the relationship between R1/2 and M200 for our simulations agrees within a factor of two with that found in Kravtsov (2013); Shibuya et al. (2015); Agertz & Kravtsov (2015b), namely: R1/2 ∼ r1/2 ∼ 0.015r200 (28) where r200 is related to the virial mass M200 via equation 4.”
First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies (2017, background): “Yet, the TNG relation does not agree with the one by Kravtsov (2013) in terms of normalization nor slope, with the latter scaling essentially like ∝M1/3200c (grey annotations in Figure 7, bottom panel), while ours is steeper, with a power-law slope in the range 0.41 − 0.53 depending on resolution…”
Gravitational probes of dark matter physics (2017, background): “radius enclosing half the mass of the baryonic component is at best a few percent of the virial radius for dark matter [43, 44].”
Toy models for galaxy formation versus simulations (2013, methodology): “Using abundance matching to determine halo virial radii, Kravtsov (2013) finds that the half-mass radii of today’s galaxies of all morphological types, Rhalf , are related to their today’s halo radius R200 as Rhalf ≃ 0.015R200.”
The size evolution of star-forming and quenched galaxies in the IllustrisTNG simulation (2017, methodology): “Huang et al. (2017) reproduced the Kravtsov (2013) result for early-type galaxies (also up to z ∼ 3) but found an approximately twice larger proportionality value for late-type galaxies.”
Dark matter heats up in dwarf galaxies (2018, background): “The purple line shows a maximally cored DM halo (equation 9) with M200 = 1010 M , n = 1, and R1/2 = 0.015 r200 = 0.7 kpc (Kravtsov 2013), corresponding to rc = 1.2 kpc.”
The z ∼ 6 Luminosity Function Fainter than −15 mag from the Hubble Frontier Fields: The Impact of Magnification Uncertainties (2016, background): “Nonetheless, as such small sizes for galaxies are unexpected (e.g., Liu et al. 2017; Kravtsov 2013), we also consider the impact of larger sizes (and a larger incompleteness) on the LF results throughout the paper.”
Galaxy assembly bias: a significant source of systematic error in the galaxy–halo relationship (2013, methodology): “The first is the widely used abundance matching technique (Kravtsov et al. 2004; Vale & Ostriker 2004; Tasitsiomi et al. 2004; Vale & Ostriker 2006; Conroy & Wechsler 2009; Guo et al. 2010; Simha et al. 2010; Neistein et al. 2011; Watson et al. 2012; Rodŕıguez-Puebla et al. 2012; Kravtsov 2013).”
Stellar Mass—Halo Mass Relation and Star Formation Efficiency in High-Mass Halos (2014, methodology): “What is remarkable, however, is that the resulting relation between galaxy sizes and virial radii of their host halos is close to linear over the entire range of stellar masses (Kravtsov 2013).”
NIHAO project – I. Reproducing the inefficiency of galaxy formation across cosmic time with a large sample of cosmological hydrodynamical simulations (2015, background): “The motivation for achieving a constant relative resolution, rather than a fixed physical resolution is that we wish to resolve the dark matter mass profile down to the galaxy half-light radius, which is typically 1-2% of the virial radius (Kravtsov 2013).”
A unified model for galactic discs: star formation, turbulence driving, and mass transport (2017, result): “…virial radius, the numerical value of 163 kpc is for a halo overdensity of 200, and the coefficient of 0.035 is roughly consistent with the findings by Kravtsov (2013) and Somerville et al. (2018) that galaxies have ratios of half-mass to virial radius rh/rvir 0.015–0.018.10 For the circular…”
Rapid Reionization by the Oligarchs: The Case for Massive, UV-bright, Star-forming Galaxies with High Escape Fractions (2019, unknown): “We add log-normal scatter while assigning sizes, s =l 0.22log dex, consistent with Kravtsov (2013), Somerville et al. (2018), and Jiang et al. (2019).”
Constraining the galaxy–halo connection over the last 13.3 Gyr: star formation histories, galaxy mergers and structural properties (2017, background): “But we note that there is a remarkable similarity in the surface density profiles of both early- and late-type galaxies when their profiles are rescaled to a fixed fraction of their virial radii, at least at low redshifts (Kravtsov 2013; Somerville et al. 2017).”
Ultradiffuse galaxies: the high-spin tail of the abundant dwarf galaxy population (2016, background): “We do not distinguish galaxies according to their morphology, implicitly assuming that the initial spin sets the size of stellar spheroids as it does for disks (Shen et al. 2003; Kravtsov 2013).”