scholarly journals The merger-driven evolution of massive early-type galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 62-66
Author(s):  
Carlo Cannarozzo ◽  
Carlo Nipoti ◽  
Alessandro Sonnenfeld ◽  
Alexie Leauthaud ◽  
Song Huang ◽  
...  
Keyword(s):  
Mass Velocity ◽  
Selection Criteria ◽  
Velocity Dispersion ◽  
Ex Situ ◽  
Scaling Relations ◽  
Early Type ◽  
History Of ◽  
Kinematic Properties ◽  
Shed Light

AbstractThe evolution of the structural and kinematic properties of early-type galaxies (ETGs), their scaling relations, as well as their stellar metallicity and age contain precious information on the assembly history of these systems. We present results on the evolution of the stellar mass-velocity dispersion relation of ETGs, focusing in particular on the effects of some selection criteria used to define ETGs. We also try to shed light on the role that in-situ and ex-situ stellar populations have in massive ETGs, providing a possible explanation of the observed metallicity distributions.

scholarly journals The assembly history of the nearest S0 galaxy NGC 3115 from its kinematics out to six half-light radii

2020 ◽  
Vol 495 (1) ◽  
pp. 1321-1339 ◽  
Author(s):  
Arianna Dolfi ◽  
Duncan A Forbes ◽  
Warrick J Couch ◽  
Anna Ferré-Mateu ◽  
Sabine Bellstedt ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Dwarf Galaxies ◽  
Ex Situ ◽  
Mass Ratio ◽  
Rotating Disc ◽  
Rotation Pattern ◽  
History Of ◽  
Kinematic Properties ◽  
Fast Rotating

ABSTRACT Using new and archival data, we study the kinematic properties of the nearest field S0 galaxy, NGC 3115, out to ∼6.5 half-light radii (Re) from its stars (integrated starlight), globular clusters (GCs), and planetary nebulae (PNe). We find evidence of three kinematic regions with an inner transition at ∼0.2 Re from a dispersion-dominated bulge (Vrot/σ < 1) to a fast-rotating disc (Vrot/σ > 1), and then an additional transition from the disc to a slowly rotating spheroid at $\sim 2\!-\!2.5\, R_\mathrm{e}$, as traced by the red GCs and PNe (and possibly by the blue GCs beyond $\sim 5\, R_\mathrm{e}$). From comparison with simulations, we propose an assembly history in which the original progenitor spiral galaxy undergoes a gas-rich minor merger that results in the embedded kinematically cold disc that we see today in NGC 3115. At a later stage, dwarf galaxies, in mini mergers (mass ratio < 1:10), were accreted building up the outer slowly rotating spheroid, with the central disc kinematics largely unaltered. Additionally, we report new spectroscopic observations of a sample of ultracompact dwarfs (UCDs) around NGC 3115 with the Keck/KCWI instrument. We find that five UCDs are inconsistent with the general rotation field of the GCs, suggesting an ex situ origin for these objects, i.e. perhaps the remnants of tidally stripped dwarfs. A further seven UCDs follow the GC rotation pattern, suggesting an in situ origin and, possibly a GC-like nature.

scholarly journals The cosmic evolution of the stellar mass–velocity dispersion relation of early-type galaxies

2020 ◽  
Vol 498 (1) ◽  
pp. 1101-1120
Author(s):  
Carlo Cannarozzo ◽  
Alessandro Sonnenfeld ◽  
Carlo Nipoti
Keyword(s):  
Mass Velocity ◽  
Selection Criteria ◽  
Velocity Dispersion ◽  
State Of The Art ◽  
Stellar Mass ◽  
Early Type ◽  
Bayesian Hierarchical ◽  
Cosmic Evolution ◽  
Stellar Velocity ◽  
Intrinsic Scatter

ABSTRACT We study the evolution of the observed correlation between central stellar velocity dispersion σe and stellar mass M* of massive ($M_*\gtrsim 3\times 10^{10}\, \mathrm{M_\odot}$) early-type galaxies (ETGs) out to redshift z ≈ 2.5, taking advantage of a Bayesian hierarchical inference formalism. Collecting ETGs from state-of-the-art literature samples, we build a fiducial sample (0 ≲ z ≲ 1), which is obtained with homogeneous selection criteria, but also a less homogeneous extended sample (0 ≲ z ≲ 2.5). Based on the fiducial sample, we find that at z ≲ 1 the M*–σe relation is well represented by $\sigma _{\mathrm{e}}\propto M_*^{\beta }(1+z)^{\zeta}$, with β ≃ 0.18 independent of redshift and ζ ≃ 0.4 (at a given M*, σe decreases for decreasing z, for instance by a factor of ≈1.3 from z = 1 to z = 0). When the slope β is allowed to evolve, we find it increasing with redshift: β(z) ≃ 0.16 + 0.26log (1 + z) describes the data as well as constant β ≃ 0.18. The intrinsic scatter of the M*–σe relation is ≃0.08 dex in σe at given M*, independent of redshift. Our results suggest that, on average, the velocity dispersion of individual massive (M* ≳ 3 × 1011M⊙) ETGs decreases with time while they evolve from z ≈ 1 to z ≈ 0. The analysis of the extended sample, over the wider redshift range 0 ≲ z ≲ 2.5, leads to results similar to that of the fiducial sample, with slightly stronger redshift dependence of the normalization (ζ ≃ 0.5) and weaker redshift dependence of the slope (dβ/dlog (1 + z) ≃ 0.18) when β varies with time. At z = 2 ETGs with $M_*\approx 10^{11}\, \mathrm{M_\odot}$ have, on average, ≈1.7 higher σe than ETGs of similar stellar mass at z = 0.

scholarly journals Assembly Histories and Observational Properties of Simulated Early-type Galaxies

2012 ◽  
Vol 8 (S295) ◽  
pp. 354-357
Author(s):  
Peter H. Johansson
Keyword(s):  
Star Formation ◽  
Initial Growth ◽  
Early Type ◽  
Massive Galaxies ◽  
Main Galaxy ◽  
Two Phases ◽  
Late Growth ◽  
Kinematic Properties

AbstractWe demonstrate that massive simulated galaxies assemble in two phases, with the initial growth dominated by compact in situ star formation, whereas the late growth is dominated by accretion of old stars formed in subunits outside the main galaxy. We also show that 1) gravitational feedback strongly suppresses late star formation in massive galaxies contributing to the observed galaxy colour bimodality that 2) the observed galaxy downsizing can be explained naturally in the two-phased model and finally that 3) the details of the assembly histories of massive galaxies are directly connected to their observed kinematic properties.

scholarly journals Compact Groups of Galaxies

1999 ◽  
Vol 186 ◽  
pp. 367-373
Author(s):  
P. Hickson
Keyword(s):  
Galaxy Evolution ◽  
Mass Velocity ◽  
Velocity Dispersion ◽  
Continuous Process ◽  
Physical Nature ◽  
Compact Groups ◽  
Early Type ◽  
Natural Explanation ◽  
Groups Of Galaxies ◽  
Formation And Evolution

This paper reviews some of the outstanding questions concerning compact groups of galaxies. These relate to the physical nature and dynamical status of the groups, their formation and evolution, and their role in galaxy evolution. The picture that emerges is that compact groups are generally physically dense systems, although often contaminated by optical projections. Their evolution is likely a continuous process of infall, interaction and merging. As new galaxies are added, and previous ones merge, the membership of the group evolves. I suggest that while the size of the group changes little, other physical properties such as total mass, gas mass, velocity dispersion, fraction of early-type galaxies increase with time. This picture is at least qualitatively consistent with observations and provides a natural explanation for the strongest correlations found in compact group samples.

scholarly journals Preservation of Biological Diversity of Domestic Animals in Hungary

2002 ◽  
pp. 18-29
Author(s):  
Imre Bodó
Keyword(s):  
Mating Systems ◽  
Biological Diversity ◽  
Domestic Animals ◽  
Domestic Animal ◽  
Ex Situ ◽  
The World ◽  
History Of ◽  
Near Future ◽  
Selection Of

Since the 1992 Rio de Janeiro UNO Congress domestic animals belong also officially to the genetic diversity of the world. Non commercial domestic animal breeds should be maintained for many cultural and technical reasons. Conservation and preservation of living beings is nowadays in the programme of many regional, national and international organizations.The preservation of domestic animals is possible in situ (at the original place and conditions) and ex situ (by cryogenic methods).There are three era in the history of preservation of domestic animals: the epoch of spontaneous maintenance, the period of sporadic national activities and the era of international programme.Some of the questions to be solved by scientific research: the principles of selection of the candidate populations for maintenance, the different degrees of endangeredness, the necessary population size to be subsidized, the problem of inbreeding, the best mating systems etc.In Hungary the maintenance of endangered domestic animal breeds is based upon the low.The following breeds are on the list of protected breeds:− the Hungarian Grey cattle,− the Lipizzan, Shagya, Nonius, Gidran, Furioso,Kisbér Halfbred, Murinsulaner and Hucul horses,− the Racka, Tsigai and Cikta sheep,− the Mangalitsa pig,− the Hungarian yellow, white, speckled and the Transsylvanian naked necked hen,− the Bronze Turkey,− the Frizzle Feathered goose.Hopefully in the near future the breeders of traditional domestic animal breeds will find the possible niches for their special products.

scholarly journals Preserving grapevine variety Fioletoviy Ranniy in the collection in vitro

2021 ◽  
Vol 273 ◽  
pp. 01007
Author(s):  
Valentina Puzirnova ◽  
Natalia Doroshenko
Keyword(s):  
Biodiversity Conservation ◽  
Sustainable Management ◽  
Future Generations ◽  
Ex Situ ◽  
Grapevine Variety ◽  
The World ◽  
History Of ◽  
Slow Growing

The paper is devoted to the problem of plant biodiversity conservation. This problem is acute all over the world. Lower Don Region has a centuries old history of viticulture and winemaking. There are many valuable vine varieties which are worthy of preservation for future generations. Classical methods no longer cope with this task. Applying advances of biotechnology in addition to traditional methods of ex situ and in situ biodiversity conservation allows sustainable management of genetic resources. This article summarizes the study of methods for creation slow growing collection for grapevine variety Fioletoviy Ranniy. Keeping plants in a slow-growing collection is one of the best ways to preserve biodiversity. This study analyzed the effect of various media compounds on vigor of vine in order to elongate the time between replantings.

scholarly journals A sub-kiloparsec-scale view of un-lensed submillimeter galaxies

2019 ◽  
Vol 15 (S352) ◽  
pp. 287-290
Author(s):  
Ken-ichi Tadaki ◽  
Daisuke Iono
Keyword(s):  
Surface Density ◽  
Gravitational Instability ◽  
Effective Radius ◽  
The Other ◽  
Ex Situ ◽  
Submillimeter Galaxies ◽  
The Galaxy ◽  
Central Regions ◽  
Kinematic Properties

AbstractSubmillimeter galaxies at z > 3 building up their central cores through compact starbursts with an effective radius of 1–2 kpc. Our ALMA high-resolution observations reveal off-center gas clumps in a submillimeter galaxy at z = 4.3, COSMOS-AzTEC-1, as well as a rotation-dominated disk. Exploiting the kinematic properties and the spatial distribution of gas mass surface density, we find that the starburst disk is gravitationally unstable. This result is consistent with a scenario where in-situ clumps are formed through disk instability. On the other hand, we find evidence for an ex-situ clump that does not corotate with the starburst disk. The accretion of such a non-corotating clump could stimulate violent disk instability, driving gas inflows into the central regions of the galaxy. Our results suggest that compact cores are formed through an extreme starburst due to a gravitational instability, triggered by non-corotating clumps.

scholarly journals Time-average properties of z ∼ 0.6 major mergers: mergers significantly scatter high-z scaling relations

2019 ◽  
Vol 488 (1) ◽  
pp. 876-893 ◽  
Author(s):  
M Puech ◽  
H Flores ◽  
M Rodrigues ◽  
F Hammer ◽  
Y B Yang
Keyword(s):  
Velocity Dispersion ◽  
Scaling Relations ◽  
Gas Velocity ◽  
The Past ◽  
Gravitational Perturbations ◽  
Self Consistent ◽  
Major Merger ◽  
Consistent Picture ◽  
Time Average ◽  
Kinematic Properties

Abstract Interpreting the scaling relations measured by recent large kinematic surveys of z ≲ 1 galaxies has remained hampered by large observational scatter. We show that the observed ISM and morpho-dynamical properties along the average z ∼ 0.6 major merger describe a very self-consistent picture in which star formation is enhanced during first passage and fusion as a result of gravitational perturbations due to the interaction, while the gas velocity dispersion is simultaneously enhanced through shocks that convert kinematic energy associated with bulk orbital motions into turbulence at small scales. Angular momentum and rotation support in the disc are partly lost during the most perturbing phases, resulting in a morphologically compact phase. The fractions of present-day E/S0 versus later type galaxies can be predicted within only a few per cent, confirming that roughly half of local discs were reformed in the past 8–9 Gyr after gas-rich major mergers. Major mergers are shown to strongly scatter scaling relations involving kinematic quantities (e.g. the Tully–Fisher or Fall relations). Selecting high-z discs relying only on V/σ turns out to be less efficient than selecting discs from multiple criteria based on their morpho-kinematic properties, which can reduce the scatter of high-z scaling relations down to the values measured in local galaxy samples.

scholarly journals Genetic diversity and selection signatures in maize landraces compared across 50 years of in situ and ex situ conservation

Heredity ◽  
2021 ◽  
Author(s):  
Francis Denisse McLean-Rodríguez ◽  
Denise Elston Costich ◽  
Tania Carolina Camacho-Villa ◽  
Mario Enrico Pè ◽  
Matteo Dell’Acqua
Keyword(s):  
Genetic Diversity ◽  
Selection Criteria ◽  
Sampling Site ◽  
In Situ Conservation ◽  
Genetic Distances ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Genome Wide ◽  
Agrobiodiversity Conservation

AbstractGenomics-based, longitudinal comparisons between ex situ and in situ agrobiodiversity conservation strategies can contribute to a better understanding of their underlying effects. However, landrace designations, ambiguous common names, and gaps in sampling information complicate the identification of matching ex situ and in situ seed lots. Here we report a 50-year longitudinal comparison of the genetic diversity of a set of 13 accessions from the state of Morelos, Mexico, conserved ex situ since 1967 and retrieved in situ from the same donor families in 2017. We interviewed farmer families who donated in situ landraces to understand their germplasm selection criteria. Samples were genotyped by sequencing, producing 74,739 SNPs. Comparing the two sample groups, we show that ex situ and in situ genome-wide diversity was similar. In situ samples had 3.1% fewer SNPs and lower pairwise genetic distances (Fst 0.008–0.113) than ex situ samples (Fst 0.031–0.128), but displayed the same heterozygosity. Despite genome-wide similarities across samples, we could identify several loci under selection when comparing in situ and ex situ seed lots, suggesting ongoing evolution in farmer fields. Eight loci in chromosomes 3, 5, 6, and 10 showed evidence of selection in situ that could be related with farmers’ selection criteria surveyed with focus groups and interviews at the sampling site in 2017, including wider kernels and larger ear size. Our results have implications for ex situ collection resampling strategies and the in situ conservation of threatened landraces.

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