Can Minor Merging Account for the Size Growth of Quiescent Galaxies? New Results From the Candels Survey

Newman, Andrew B.; Ellis, Richard S.; Bundy, Kevin; Treu, Tommaso

doi:10.1088/0004-637x/746/2/162

Cited by 454 publications

(723 citation statements)

References 136 publications

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“…This is important because the evolution of galaxy properties with redshift can cause systematic differences in their values, which may align with quenching and have no causal connection. For instance, the size of a galaxy of a given mass evolves with redshift as (1 + z) −a , where a ∼ 1 (e.g., Newman et al 2012). This results in galaxies which are quenched earlier in the history of the Universe having smaller sizes for their masses, and hence higher central mass concentrations and presumably central velocity dispersions.…”

Section: Alternative Explanations To Agn Feedback and Green Valley Fracmentioning

confidence: 99%

The impact of galactic properties and environment on the quenching of central and satellite galaxies: a comparison between SDSS, Illustris and L-Galaxies

Bluck

Mendel

Ellison

et al. 2016

Mon. Not. R. Astron. Soc.

135

226

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We quantify the impact that a variety of galactic and environmental properties have on the quenching of star formation. We collate a sample of ∼ 400,000 central and ∼ 100,000 satellite galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Specifically, we consider central velocity dispersion (σ c ), stellar, halo, bulge and disk mass, local density, bulge-to-total ratio, group-centric distance and galaxy-halo mass ratio. We develop and apply a new statistical technique to quantify the impact on the quenched fraction (f Quench ) of varying one parameter, while keeping the remaining parameters fixed. For centrals, we find that the f Quench − σ c relationship is tighter and steeper than for any other variable considered. We compare to the Illustris hydrodynamical simulation and the Munich semi-analytic model (L-Galaxies), finding that our results for centrals are qualitatively consistent with their predictions for quenching via radio-mode AGN feedback, hinting at the viability of this process in explaining our observational trends. However, we also find evidence that quenching in L-Galaxies is too efficient and quenching in Illustris is not efficient enough, compared to observations. For satellites, we find strong evidence that environment affects their quenched fraction at fixed central velocity dispersion, particularly at lower masses. At higher masses, satellites behave identically to centrals in their quenching. Of the environmental parameters considered, local density affects the quenched fraction of satellites the most at fixed central velocity dispersion.

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Section: Alternative Explanations To Agn Feedback and Green Valley Fracmentioning

confidence: 99%

The impact of galactic properties and environment on the quenching of central and satellite galaxies: a comparison between SDSS, Illustris and L-Galaxies

Bluck

Mendel

Ellison

et al. 2016

Mon. Not. R. Astron. Soc.

135

226

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“…and the factor 0.65 is the fraction of companions of massive galaxies that are already early-type/red galaxies (López-Sanjuan et al 2012;Newman et al 2012). As previously, we define the major merger efficiency as MM ≡ (z, M , M ,lim , μ max = 1, μ min = 1/4) and the minor merger efficiency as mm ≡ (z, M , M ,lim , μ max = 1/4, μ min = 1/10).…”

Section: Testing the Major Merger Origin Of Massive Early-type Galaxiesmentioning

confidence: 99%

MASSIV: Mass Assembly Survey with SINFONI in VVDS

López-Sanjuán

Fèvre

Tasca

et al. 2013

A&A

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Context. The contribution of the merging process to the early phase of galaxy assembly at z > 1 and, in particular, to the build-up of the red sequence, still needs to be accurately assessed. Aims. We aim to measure the major merger rate of star-forming galaxies at 0.9 < z < 1.8, using close pairs identified from integral field spectroscopy (IFS). Methods. We use the velocity field maps obtained with SINFONI/VLT on the MASSIV sample, selected from the star-forming population in the VVDS. We identify physical pairs of galaxies from the measurement of the relative velocity and the projected separation (r p ) of the galaxies in the pair. Using the well constrained selection function of the MASSIV sample, we derive at a mean redshift up to z = 1.54 the gas-rich major merger fraction (luminosity ratio μ = L 2 /L 1 ≥ 1/4), and the gas-rich major merger rate using merger time scales from cosmological simulations. Results. We find a high gas-rich major merger fraction of 20.8 +15.2 −6.8 %, 20.1 +8.0 −5.1 %, and 22.0 +13.7 −7.3 % for close pairs with r p ≤ 20 h −1 kpc in redshift ranges z = [0.94, 1.06], [1.2, 1.5), and [1.5, 1.8), respectively. This translates into a gas-rich major merger rate of 0.116 +0.084 −0.038 Gyr −1 , 0.147 +0.058 −0.037 Gyr −1 , and 0.127 +0.079 −0.042 Gyr −1 at z = 1.03, 1.32, and 1.54, respectively. Combining our results with previous studies at z < 1, the gas-rich major merger rate evolves as (1 + z) n , with n = 3.95 ± 0.12, up to z = 1.5. From these results we infer that ∼35% of the star-forming galaxies with stellar masses M = 10 10 −10 10.5 M have undergone a major merger since z ∼ 1.5. We develop a simple model that shows that, assuming that all gas-rich major mergers lead to early-type galaxies, the combined effect of gas-rich and dry mergers is able to explain most of the evolution in the number density of massive early-type galaxies since z ∼ 1.5, with our measured gas-rich merger rate accounting for about two-thirds of this evolution. Conclusions. Merging of star-forming galaxies is frequent at around the peak in star formation activity. Our results show that gasrich mergers make an important contribution to the growth of massive galaxies since z ∼ 1.5, particularly on the build-up of the red sequence.

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“…When Newman et al (2012) ask whether the size growth of quiescent galaxies could be due to mergers, they do not ask whether a predicted frequency of merging could account for the observed growth. They take orthodox cosmology for granted and ask whether the observed growth could be accounted for by mergers at all.…”

Section: Angular Sizementioning

confidence: 99%

From magnitudes and redshifts of supernovae, their light-curves, and angular sizes of galaxies to a tenable cosmology

Traunmüller

2014

Astrophys Space Sci

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Early physical cosmologies were based on interpretations of the cosmic redshift for which there was insufficient evidence and on theories of gravitation that appear to be falsified by galactic dynamics. Eventually, the big bang paradigm came to be guarded against refutation by ad hoc hypotheses (dark matter, cosmic inflation, dark energy) and free parameters. Presently available data allow a more satisfactory phenomenological approach. Using data on magnitude and redshift from 892 type Ia supernovae, it is first shown that these suggest that the redshift factor (1 + z) is simply an exponential function of distance and that, for "standard candles", magnitude m = 5 log[(1 + z) ln(1 + z)] + const. While these functions are incompatible with a big bang, they characterize certain tired light models as well as exponential expansion models. However, the former are falsified by the stretched light curves of distant supernovae and the latter by the absence of a predicted 1+z increase in the angular sizes of galaxies. Instead, the observations suggest that physical processes speed up and objects contract uniformly as an exponential function of time, standards of measurement not excluded, and only free waves being excepted. Distant events proceed, then, more slowly, while angular sizes remain unaffected, approximately as observed. Since all objects contract in proportion, the Universe retains a static appearance. A corresponding physical theory, which should also explain galactic dynamics, remains yet to be derived from first principles. A way to do this, satisfying also Mach"s principle, is vaguely suggested.

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Can Minor Merging Account for the Size Growth of Quiescent Galaxies? New Results From the Candels Survey

Cited by 454 publications

References 136 publications

The impact of galactic properties and environment on the quenching of central and satellite galaxies: a comparison between SDSS, Illustris and L-Galaxies

The impact of galactic properties and environment on the quenching of central and satellite galaxies: a comparison between SDSS, Illustris and L-Galaxies

MASSIV: Mass Assembly Survey with SINFONI in VVDS

From magnitudes and redshifts of supernovae, their light-curves, and angular sizes of galaxies to a tenable cosmology

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