Simulation of the Pneumatic System of a Seed Drill with a Vertical Flow Direction

Кравцов, Артем; Коновалов, Владимир; Zaĭtsev, V. K.; Петров, А. М.; Petrova, S. S.

doi:10.18502/kls.v5i1.6060

Cited by 4 publications

(4 citation statements)

References 4 publications

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“…The simulations are performed with the Eulerian gasdynamics and N-body Adaptive Refinement Tree code (ART, Kravtsov et al 1997;Kravtsov 1999;Rudd et al 2008). They are run from cosmological initial conditions that contain a main dark matter halo of total mass M 200 ≈ 10 12 M at z = 0, within a periodic box of 4 comoving Mpc in size.…”

Section: Simulation Suitementioning

confidence: 99%

Star cluster formation in cosmological simulations – III. Dynamical and chemical evolution

Gnedin

2019

Monthly Notices of the Royal Astronomical Society

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In previous papers of this series, we developed a new algorithm for modelling the formation of star clusters in galaxy formation simulations. Here we investigate how dissolution of bound star clusters affects the shape of the cluster mass function and the metallicity distribution of surviving clusters. Cluster evolution includes the loss of stars that become unbound due to tidal disruption as well as mass-loss due to stellar evolution. We calculate the tidal tensor along cluster trajectories and use it to estimate the instantaneous mass-loss rate. The typical tidal tensor exhibits large variations on a time-scale of ∼ 100 Myr, with maximum eigenvalue of 10 7 Gyr −2 , and median value of 10 4 Gyr −2 for the first Gyr after cluster formation. As a result of dynamical disruption, at the final available output of our simulations at redshift z ≈ 1.5, the cluster mass function has an approximately log-normal shape peaked at ∼ 10 4.3 M . Extrapolation of the disruption to z = 0 results in too many low-mass clusters compared to the observed Galactic globular clusters (GCs). Over 70% of GC candidates are completely disrupted before the present; only 10% of the total GC candidate mass remains in surviving clusters. The total mass of surviving clusters at z = 0 varies from run to run in the range (2 − 6) × 10 7 M , consistent with the observed mass of GC systems in Milky Way-sized galaxies. The metallicity distributions of all massive star clusters and of the surviving GCs have similar shapes but different normalization because of cluster disruption. The model produces a larger fraction of very metal-poor clusters than observed. A robust prediction of the model is the age-metallicity relation, in which metal-rich clusters are systematically younger than metal-poor clusters by up to 3 Gyr.

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Section: Simulation Suitementioning

confidence: 99%

Star cluster formation in cosmological simulations – III. Dynamical and chemical evolution

Gnedin

2019

Monthly Notices of the Royal Astronomical Society

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“…The sizes of galaxies reflect their assembly histories and their connection to their dark matter halos (Mo et al 1997;Kravtsov 2012;Jiang et al 2018). Different modes of assembly of stars in galaxies lead to a different growth of their radii: passive evolution will cause no significant growth in size or mass, but only a maturation of the existing stellar population; dry major mergers lead to a proportional growth in size and mass as the two bodies come to dynamic equilibrium; and dry minor mergers increase the size of galaxies more rapidly by building an outer envelope (Bezanson et al 2009;Naab et al 2009).…”

Section: Introductionmentioning

confidence: 99%

“…When gas physics are considered the evolution can be more complex; e.g., "wet" gas-rich mergers may trigger compact starbursts leading to larger post-merger disks (Hernquist & Lars 1989;Robertson et al 2005), while gas flows to the central regions may both form compact bulges and feed a central black hole (Efstathiou et al 1982;Dekel & Burkert 2013;Barro et al 2017). The size of a galaxy may also hold information on the properties of the dark matter halo; galaxy size may be proportional to the halo virial radius as a result of conservation of angular momentum during the collapse and cooling of a galaxy (Mo et al 1997;Dutton et al 2006;Shankar et al 2011;Kravtsov 2012;Porter et al 2014;Somerville et al 2017), although it is unclear whether this expected correlation is actually preserved in the galaxy formation process (DeFelippis et al 2017;Jiang et al 2018).…”

Section: Introductionmentioning

confidence: 99%

COSMOS-DASH: The Evolution of the Galaxy Size–Mass Relation since z ∼ 3 from New Wide-field WFC3 Imaging Combined with CANDELS/3D-HST

Mowla

Dokkum

Brammer

et al. 2019

ApJ

197

239

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We present COSMOS-Drift And SHift (DASH), a Hubble Space Telescope WFC3 imaging survey of the COSMOS field in the H 160 filter. The survey comprises 456 individual WFC3 pointings corresponding to an area of 0.49 deg 2 (0.66 deg 2 when including archival data) and reaches a 5σ point-source limit of H 160 = 25.1 (0. 3 aperture). COSMOS-DASH is the widest HST/WFC3 imaging survey in H 160 filter, tripling the extragalactic survey area in the near-infrared at HST resolution. We make the reduced H 160 mosaic available to the community. We use this dataset to measure the sizes of 162 galaxies with log(M /M ) > 11.3 at 1.5 < z < 3.0, and augment this sample with 748 galaxies at 0.1 < z < 1.5 using archival ACS imaging. We find that the median size of galaxies in this mass range changes with redshift as r eff = (10.4 ± 0.4) × (1 + z) (−0.65±0.05) kpc. Separating the galaxies into star forming and quiescent galaxies using their restframe U −V and V − J colors, we find no statistical difference between the median sizes of the most massive star-forming and quiescent galaxies at z = 2.5: they are 4.9 ± 0.9 kpc and 4.3 ± 0.3 kpc respectively. However, we do find a significant difference in the Sèrsic index between the two samples, such that massive quiescent galaxies have higher central densities than star forming galaxies. We extend the size-mass analysis to lower masses by combining it with the 3D-HST/CANDELS sample of van der Wel et al. (2014), and derive empirical relations between size, mass, and redshift. Fitting a relation of the form r eff = A × m α , with m = M /5 × 10 10 M and r eff in kpc, we find log A = −0.25 log (1 + z) + 0.79 and α = −0.13 log(1 + z) + 0.27. We also provide relations for the subsamples of star forming and quiescent galaxies. Our results confirm previous studies that were based on smaller samples or ground-based imaging.

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“…This approximation is justified because we only work with galaxies in the local universe. For a given M (0), we find the virial mass of the galaxy's host halo, M v (0), using the fit in [25] (see Eqs. A3-A4 in their appendix).…”

Section: B Galactic Atmospheres: Electron Densitymentioning

confidence: 99%

Probing gaseous galactic halos through the rotational kinematic Sunyaev-Zeldovich effect

Matilla

Haiman

2020

Phys. Rev. D

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The rotational kinematic Sunyaev-Zeldovich (rkSZ) signal, imprinted on the cosmic microwave background (CMB) by the gaseous halos (spinning "atmospheres") of foreground galaxies, would be a novel probe of galaxy formation. Although the signal is too weak to detect in individual galaxies, we analyze the feasibility of its statistical detection via stacking CMB data on many galaxies for which the spin orientation can be estimated spectroscopically. We use an "optimistic" model, in which fully ionized atmospheres contain the cosmic baryon fraction and spin at the halo's circular velocity vcirc, and a more realistic model, based on hydrodynamical simulations, with multi-phase atmospheres spinning at a fraction of vcirc. We incorporate realistic noise estimates into our analysis. Using low-redshift galaxy properties from the MaNGA spectroscopic survey (with median halo mass of 6.6 × 10 11 M ), and CMB data quality from Planck, we find that a 3σ detection would require a few×10 4 galaxies, even in the optimistic model. This is too high for current surveys, but upcoming higher-angular resolution CMB experiments will significantly reduce the requirements: stacking CMB data on galaxy spins in a ∼ 10 deg 2 can rule out the optimistic models, and ≈350 deg 2 will suffice for a 3σ detection with ACT. As a proof-of-concept, we stacked Planck data on the position of ≈ 2, 000 MaNGA galaxies, aligned with the galaxies' projected spin, and scaled to their halos' angular size. We rule out average temperature dipoles larger than ≈ 1.9 µK around field spiral galaxies.

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Simulation of the Pneumatic System of a Seed Drill with a Vertical Flow Direction

Cited by 4 publications

References 4 publications

Star cluster formation in cosmological simulations – III. Dynamical and chemical evolution

Star cluster formation in cosmological simulations – III. Dynamical and chemical evolution

COSMOS-DASH: The Evolution of the Galaxy Size–Mass Relation since z ∼ 3 from New Wide-field WFC3 Imaging Combined with CANDELS/3D-HST

Probing gaseous galactic halos through the rotational kinematic Sunyaev-Zeldovich effect

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