scholarly journals The VIMOS Ultra Deep Survey

2018 ◽  
Vol 612 ◽  
pp. A42 ◽  
Author(s):  
A. Durkalec ◽  
O. Le Fèvre ◽  
A. Pollo ◽  
G. Zamorani ◽  
B. C. Lemaux ◽  
...  

We present a study of the dependence of galaxy clustering on luminosity and stellar mass in the redshift range 2 < z < 3.5 using 3236 galaxies with robust spectroscopic redshifts from the VIMOS Ultra Deep Survey (VUDS), covering a total area of 0.92 deg2. We measured the two-point real-space correlation function wp(rp) for four volume-limited subsamples selected by stellar mass and four volume-limited subsamples selected by MUV absolute magnitude. We find that the scale-dependent clustering amplitude r0 significantly increases with increasing luminosity and stellar mass. For the least luminous galaxies (MUV < −19.0), we measured a correlation length r0 = 2.87 ± 0.22 h−1 Mpc and slope γ = 1.59 ± 0.07, while for the most luminous (MUV < −20.2) r0 = 5.35 ± 0.50 h−1 Mpc and γ = 1.92 ± 0.25. These measurements correspond to a strong relative bias between these two subsamples of Δb∕b* = 0.43. Fitting a five-parameter halo occupation distribution (HOD) model, we find that the most luminous (MUV < −20.2) and massive (M⋆ > 1010 h−1 M⊙) galaxies occupy the most massive dark matter haloes with ⟨Mh⟩ = 1012.30 h−1 M⊙. Similar to the trends observed at lower redshift, the minimum halo mass Mmin depends on the luminosity and stellar mass of galaxies and grows from Mmin = 109.73 h−1 M⊙ to Mmin = 1011.58 h−1 M⊙ from the faintest to the brightest among our galaxy sample, respectively. We find the difference between these halo masses to be much more pronounced than is observed for local galaxies of similar properties. Moreover, at z ~ 3, we observe that the masses at which a halo hosts, on average, one satellite and one central galaxy is M1 ≈ 4Mmin over all luminosity ranges, which is significantly lower than observed at z ~ 0; this indicates that the halo satellite occupation increases with redshift. The luminosity and stellar mass dependence is also reflected in the measurements of the large-scale galaxy bias, which we model as bg,HOD (>L) = 1.92 + 25.36(L/L*)7.01. We conclude our study with measurements of the stellar-to-halo mass ratio (SHMR). We observe a significant model-observation discrepancy for low-mass galaxies, suggesting a higher than expected star formation efficiency of these galaxies.

2020 ◽  
Vol 2 (1) ◽  
pp. 274-296
Author(s):  
Bakht Shaid ◽  
Hafiz Muhammad Sani

سیرت طیبہ پر استشراقی فکر کے اعتراضات کے اسباب و عوامل کا تاریخی و ارتقائی جائزہ Over the course of time and with the rapid increase in human population need for mutual relations become crucial. Resultantly on behalf of this closeness, separation, anti-standpoints and comparisons also emerged. As the time passed by hatred and hypocrisy and other social vices spread on large scale. Thus human society was waiting for such liberator who may lead and work for the betterment of this society. With the dawn of Islamic civilization all such issues were not only resolved but also provided with a model for containing the difference of opinion and multiple traditions under its unique worldview. Islamic History presents itself as a model where the minorities were provided with the opportunities of participating in political, social, educational and collective affairs. Thus in a society where tyranny, injustice, un-forbearance, religious intensity, terrorism and the activities of violating the human rights were very common, were substituted by the Islamic ideal  of forbearance. It is argued here that the solution of all these issues was only in religion contrary to what is being claimed about an idea of social harmony where religion is not given its due position. Today its our dire need to develop a sense of harmony, modesty, affection and peacefulness among the masses of various religions of Pakistani society. It is further argued that for this very noble cause all the religious scholars and their followers can come forward playing their pertinent role.  


2012 ◽  
Vol 68 (4) ◽  
pp. 454-467 ◽  
Author(s):  
Ian J. Tickle

The commonly used validation metrics for the local agreement of a structure model with the observed electron density, namely the real-space R (RSR) and the real-space correlation coefficient (RSCC), are reviewed. It is argued that the primary goal of all validation techniques is to verify the accuracy of the model, since precision is an inherent property of the crystal and the data. It is demonstrated that the principal weakness of both of the above metrics is their inability to distinguish the accuracy of the model from its precision. Furthermore, neither of these metrics in their usual implementation indicate the statistical significance of the result. The statistical properties of electron-density maps are reviewed and an improved alternative likelihood-based metric is suggested. This leads naturally to a χ2 significance test of the difference density using the real-space difference density Z score (RSZD). This is a metric purely of the local model accuracy, as required for effective model validation and structure optimization by practising crystallographers prior to submission of a structure model to the PDB. A new real-space observed density Z score (RSZO) is also proposed; this is a metric purely of the model precision, as a substitute for other precision metrics such as the B factor.


2020 ◽  
Vol 493 (1) ◽  
pp. 747-764 ◽  
Author(s):  
Hengxing Pan ◽  
Danail Obreschkow ◽  
Cullan Howlett ◽  
Claudia del P Lagos ◽  
Pascal J Elahi ◽  
...  

ABSTRACT We model the large-scale linear galaxy bias bg(x, z) as a function of redshift z and observed absolute magnitude threshold x for broad-band continuum emission from the far-infrared to ultraviolet, as well as for prominent emission lines, such as the H α, H β, Ly a, and [O ii] lines. The modelling relies on the semi-analytic galaxy formation model galform, run on the state-of-the-art N-body simulation surfs with the Planck 2015 cosmology. We find that both the differential bias at observed absolute magnitude x and the cumulative bias for magnitudes brighter than x can be fitted with a five-parameter model: bg(x, z) = a + b(1 + z)e(1 + exp [(x − c)d]). We also find that the bias for the continuum bands follows a very similar form regardless of wavelength due to the mixing of star-forming and quiescent galaxies in a magnitude-limited survey. Differences in bias only become apparent when an additional colour separation is included, which suggest extensions to this work could look at different colours at fixed magnitude limits. We test our fitting formula against observations, finding reasonable agreement with some measurements within 1σ statistical uncertainties, and highlighting areas of improvement. We provide the fitting parameters for various continuum bands, emission lines, and intrinsic galaxy properties, enabling a quick estimation of the linear bias in any typical survey of large-scale structure.


2020 ◽  
Vol 638 ◽  
pp. A60
Author(s):  
Ignacio G. Alfaro ◽  
Facundo Rodriguez ◽  
Andrés N. Ruiz ◽  
Diego Garcia Lambas

Context. Evidence shows that properties of dark matter haloes may vary with large-scale environment. Studying the halo occupation distribution in cosmic voids makes it possible to obtain useful information that can shed light on the subject. The history of the formation of the haloes and galaxies residing in these regions is likely to differ from the global behaviour given their extreme environment. Aims. Our goal is to characterise the halo occupation distribution in the interior of cosmic voids and compare with the general results to unveil the way galaxies populate haloes in simulated galaxy catalogues. Methods. We used two publicly accessible simulated galaxy catalogues constructed with different methods: a semi-analytical model and a hydrodynamic simulation. In both cases, we identified cosmic voids, and we measured the halo occupation distribution inside these regions for different absolute magnitude thresholds. We compared these determinations with the overall results, and we studied the dependence of different characteristics of the voids. We also analysed the stellar content and the formation time of the haloes inside voids and confronted the general halo population results. Results. Inside the voids, we find a significantly different halo occupation distribution with respect to the general results. This is present in all absolute magnitude ranges explored. We obtain no signs of variation related to void characteristics, indicating that the effects depend only on the density of the large-scale environment. Additionally, we find that the stellar-mass content also differs within voids that host haloes with less massive central galaxies (∼10%), as well as satellites with significantly lower stellar-mass content (∼30%). Finally, we find a slight difference between the formation times of the younger haloes in voids than the average population. These characteristics indicate that haloes populating voids have had a different formation history, inducing significant changes on the halo occupation distribution.


2020 ◽  
Vol 2 (1) ◽  
pp. 154-177
Author(s):  
Muhammad Mudassar Shafique ◽  
Abid Naeem

Inter-Faith Harmony and Contemporary Demands: An Analytical Study in the Light of Divine Teachings بین المذاہب ہم آہنگی اور عصر ی تقاضے : الہامی تعلیمات کی روشنی میں تجزیاتی مطالعہ Abstract Over the course of time and with the rapid increase in human population need for mutual relations become crucial. Resultantly on behalf of this closeness, separation, anti-standpoints and comparisons also emerged. As the time passed by hatred and hypocrisy and other social vices spread on large scale. Thus human society was waiting for such liberator who may lead and work for the betterment of this society. With the dawn of Islamic civilization all such issues were not only resolved but also provided with a model for containing the difference of opinion and multiple traditions under its unique worldview. Islamic History presents itself as a model where the minorities were provided with the opportunities of participating in political, social, educational and collective affairs. Thus in a society where tyranny, injustice, un-forbearance, religious intensity, terrorism and the activities of violating the human rights were very common, were substituted by the Islamic ideal  of forbearance. It is argued here that the solution of all these issues was only in religion contrary to what is being claimed about an idea of social harmony where religion is not given its due position. Today it’s our dire need to develop a sense of harmony, modesty, affection and peacefulness among the masses of various religions of Pakistani society. It is further argued that for this very noble cause all the religious scholars and their followers can come forward playing their pertinent role. Keywords: Interfaith harmony, present era, divine books, religious personalities, Peace


VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.


2015 ◽  
Vol 3 (2) ◽  
pp. 262-265
Author(s):  
Dr.Navdeep Kaur

Since its evolution environment has remained both a matter of awe and concern to man. The frontier attitude of the industrialized society towards nature has not only endangered the survival of all other life forms but also threatened the very existence of human life. The realization of such potential danger has necessitated the dissemination of knowledge and skill vis-a-vis environment protection at all stages of learning. Therefore, learners of all stages of learning need to be sensitized with a missionary zeal. This may ensure transformation of students into committed citizens for averting global environment crisis. The advancement of science and technology made the life more and more relaxed and man also became more and more ambitious. With such development, human dependence on environment increased. He consumed more resources and the effect of his activities on the environment became more and more detectable. Environment covers all the things present around the living beings and above the land, on the surface of the earth and under the earth. Environment indicates, in total, all of peripheral forces, pressures and circumstances, which affect the life, nature, behaviour, growth, development and maturation of living beings. Irrational exploitation (not utilization) of natural resources for our greed (not need) has endangered our survival, and incurred incalculable harm. Environmental Education is a science, a well-thought, permanent, lasting and integrated process of equipping learning experiences for getting awareness, knowledge, understanding, skills, values, technical expertise and involvement of learners with desirable attitudinal changes about their relationship with their natural and biophysical environment. Environmental Education is an organized effort to educate the masses about environment, its functions, need, importance, and especially how human beings can manage their behaviour in order to live in a sustainable manner.  The term 'environmental awareness' refers to creating general awareness of environmental issues, their causes by bringing about changes in perception, attitude, values and necessary skills to solve environment related problems. Moreover, it is the first step leading to the formation of responsible environmental behaviour (Stern, 2000). With the ever increasing development by modern man, large scale degradation of natural resources have been occurred, the public has to be educated about the fact that if we are degrading our environment we are actually harming ourselves. To encourage meaningful public participation and environment, it is necessary to create awareness about environment pollution and related adverse effects. This is the crucial time that environmental awareness and environmental sensitivity should be cultivated among the masses particularly among youths. For the awareness of society it is essential to work at a gross root level. So the whole society can work to save the environment.


Author(s):  
Angela Dranishnikova

In the article, the author reflects the existing problems of the fight against corruption in the Russian Federation. He focuses on the opacity of the work of state bodies, leading to an increase in bribery and corruption. The topic we have chosen is socially exciting in our days, since its significance is growing on a large scale at all levels of the investigated aspect of our modern life. Democratic institutions are being jeopardized, the difference in the position of social strata of society in society’s access to material goods is growing, and the state of society is suffering from the moral point of view, citizens are losing confidence in the government, and in the top officials of the state.


2021 ◽  
Vol 13 (6) ◽  
pp. 1180
Author(s):  
Da Guo ◽  
Xiaoning Song ◽  
Ronghai Hu ◽  
Xinming Zhu ◽  
Yazhen Jiang ◽  
...  

The Hindu Kush Himalayan (HKH) region is one of the most ecologically vulnerable regions in the world. Several studies have been conducted on the dynamic changes of grassland in the HKH region, but few have considered grassland net ecosystem productivity (NEP). In this study, we quantitatively analyzed the temporal and spatial changes of NEP magnitude and the influence of climate factors on the HKH region from 2001 to 2018. The NEP magnitude was obtained by calculating the difference between the net primary production (NPP) estimated by the Carnegie–Ames Stanford Approach (CASA) model and the heterotrophic respiration (Rh) estimated by the geostatistical model. The results showed that the grassland ecosystem in the HKH region exhibited weak net carbon uptake with NEP values of 42.03 gC∙m−2∙yr−1, and the total net carbon sequestration was 0.077 Pg C. The distribution of NEP gradually increased from west to east, and in the Qinghai–Tibet Plateau, it gradually increased from northwest to southeast. The grassland carbon sources and sinks differed at different altitudes. The grassland was a carbon sink at 3000–5000 m, while grasslands below 3000 m and above 5000 m were carbon sources. Grassland NEP exhibited the strongest correlation with precipitation, and it had a lagging effect on precipitation. The correlation between NEP and the precipitation of the previous year was stronger than that of the current year. NEP was negatively correlated with temperature but not with solar radiation. The study of the temporal and spatial dynamics of NEP in the HKH region can provide a theoretical basis to help herders balance grazing and forage.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chih-Chuen Lin ◽  
Phani Motamarri ◽  
Vikram Gavini

AbstractWe present a tensor-structured algorithm for efficient large-scale density functional theory (DFT) calculations by constructing a Tucker tensor basis that is adapted to the Kohn–Sham Hamiltonian and localized in real-space. The proposed approach uses an additive separable approximation to the Kohn–Sham Hamiltonian and an L1 localization technique to generate the 1-D localized functions that constitute the Tucker tensor basis. Numerical results show that the resulting Tucker tensor basis exhibits exponential convergence in the ground-state energy with increasing Tucker rank. Further, the proposed tensor-structured algorithm demonstrated sub-quadratic scaling with system-size for both systems with and without a gap, and involving many thousands of atoms. This reduced-order scaling has also resulted in the proposed approach outperforming plane-wave DFT implementation for systems beyond 2000 electrons.


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