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Title: Relations between the Sizes of Galaxies and Their Dark Matter Halos at Redshifts 0 < z < 3

Journal Article · · Astrophysical Journal
 [1]; ; ; ;  [2];  [3];  [4];  [5];  [6]
  1. University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States)
  2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  3. Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)
  4. Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)
  5. Departamento de Astrofísica, Facultad de CC. Física, Universidad Complutense de Madrid, E-28040, Madrid (Spain)
  6. Department of Physics, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom)

We derive relations between the effective radii R {sub eff} of galaxies and the virial radii R {sub 200} {sub c} of their dark matter halos over the redshift range 0 < z < 3. For galaxies, we use the measured sizes from deep images taken with Hubble Space Telescope for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey; for halos, we use the inferred sizes from abundance matching to cosmological dark matter simulations via a stellar mass–halo mass (SMHM) relation. For this purpose, we derive a new SMHM relation based on the same selection criteria and other assumptions as for our sample of galaxies with size measurements. As a check on the robustness of our results, we also derive R {sub eff}–R {sub 200} {sub c} relations for three independent SMHM relations from the literature. We find that galaxy R {sub eff} is proportional on average to halo R {sub 200} {sub c}, confirming and extending to high redshifts the z = 0 results of Kravtsov. Late-type galaxies (with low Sérsic index and high specific star formation rate (sSFR)) follow a linear R {sub eff}– R {sub 200} {sub c} relation, with effective radii at 0.5 < z < 3 close to those predicted by simple models of disk formation; at z < 0.5, the sizes of late-type galaxies appear to be slightly below this prediction. Early-type galaxies (with high Sérsic index and low sSFR) follow a roughly parallel R {sub eff}– R {sub 200} {sub c} relation, ∼0.2–0.3 dex below the one for late-type galaxies. Our observational results, reinforced by recent hydrodynamical simulations, indicate that galaxies grow quasi-homologously with their dark matter halos.

OSTI ID:
22661266
Journal Information:
Astrophysical Journal, Vol. 838, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English