Truncated disc surface brightness profiles produced by flares

AbstractPrevious studies have discarded that flares in galactic discs may explain the truncation that are frequently observed in highly-inclined galaxies (Kregel et al. 2002). However, no study has systematically analysed this hypothesis using realistic models for the disc, the flare and the bulge. We derive edge-on and face-on surface brightness profiles for a series of realistic galaxy models with flared discs that sample a wide range of structural and photometric parameters across the Hubble Sequence, accordingly to observations. The surface brightness profile for each galaxy model has been simulated for edge-on and face-on views to find out whether the flared disc produces a significant truncation in the disc in the edge-on view compared to the face-on view or not. In order to simulate realistic images of disc galaxies, we have considered the observational distribution of the photometric parameters as a function of the morphological type for three mass bins (10 < log10(M/M⊙) < 10.7, 10.7 < log10(M/M⊙) < 11 and log10(M/M⊙) > 11), and four morphological type bins (S0–Sa, Sb–Sbc, Sc–Scd and Sd–Sdm). For each mass bin, we have restricted the photometric and structural parameters of each modelled galaxy to their characteristic observational ranges (μ0, disc, μeff, bulge, B/T, Mabs, reff, nbulge, hR, disc) and the flare in the disc (hz, disc/hR, disc, ∂hz, disc/∂R, see de Grijs & Peletier 1997, Graham 2001, López-Corredoira et al. 2002, Yoachim & Dalcanton 2006, Bizyaev et al. 2014, Mosenkov et al. 2015).Contrary to previous claims, the simulations show that realistic flared disks can be responsible for the truncations observed in many edge-on systems, preserving the profile of the non-flared analogous model in face-on view. These breaks reproduce the properties of the weak-to-intermediate breaks observed in many real Type-II galaxies in the diagram relating the radial location of the break (RbrkII) in units of the inner disk scale-length with the break strength S (Laine et al. 2014). Radial variation of the scale-height of the disc (flaring) can explain the existence of many breaks in edge-on galaxies, especially of those with low break strengths $S=\log _{10}\frac{h_{o}}{h_{i}} \sim \ [-0.3,-0.1]$.

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The Fornax Deep Survey with the VST

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935433 ◽

2019 ◽

Vol 628 ◽

pp. A4 ◽

Cited By ~ 6

Author(s):

M. A. Raj ◽

E. Iodice ◽

N. R. Napolitano ◽

M. Spavone ◽

H-S. Su ◽

...

Keyword(s):

Surface Brightness ◽

Structural Parameters ◽

Absolute Magnitude ◽

Morphological Type ◽

High Density ◽

Molecular Gas ◽

Type Ii ◽

Type Iii ◽

Deep Survey ◽

Fornax Cluster

Context. We present the study of a magnitude limited sample (mB ≤ 16.6 mag) of 13 late type galaxies (LTGs), observed inside the virial radius, Rvir ∼ 0.7 Mpc, of the Fornax cluster within the Fornax Deep Survey (FDS). Aims. The main objective is to use surface brightness profiles and g − i colour maps to obtain information on the internal structure of these galaxies and find signatures of the mechanisms that drive their evolution in high-density environments inside the virial radius of the cluster. Methods. By modelling galaxy isophotes, we extract the azimuthally averaged surface brightness profiles in four optical bands. We also derive g − i colour profiles, and relevant structural parameters like total magnitude and effective radius. For ten of the galaxies in this sample, we observe a clear discontinuity in their typical exponential surface brightness profiles, derive their “break radius”, and classify their disc-breaks into Type II (down-bending) or Type III (up-bending). Results. We find that Type II galaxies have bluer average (g − i) colour in their outer discs while Type III galaxies are redder. The break radius increases with stellar mass and molecular gas mass while it decreases with molecular gas-fractions. The inner and outer scale-lengths increase monotonically with absolute magnitude, as found in other works. For galaxies with CO(1-0) measurements, there is no detected cold gas beyond the break radius (within the uncertainties). In the context of morphological segregation of LTGs in clusters, we also find that, in Fornax, galaxies with morphological type 5 < T ≤ 9 (∼60% of the sample) are located beyond the high-density, ETG-dominated regions, however there is no correlation between T and the disc-break type. We do not find any correlation between the average (g − i) colours and cluster-centric distance, but the colour-magnitude relation holds true. Conclusions. The main results of this work suggest that the disc-breaks of LTGs inside the virial radius of the Fornax cluster seem to have arisen through a variety of mechanisms (e.g. ram-pressure stripping, tidal disruption), which is evident in their outer-disc colours and the absence of molecular gas beyond their break radius in some cases. This can result in a variety of stellar populations inside and outside the break radii.

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Structural analysis of massive galaxies using HST deep imaging at z < 0.5

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936276 ◽

2020 ◽

Vol 634 ◽

pp. A11

Author(s):

Sandra N. dos Reis ◽

Fernando Buitrago ◽

Polychronis Papaderos ◽

Israel Matute ◽

José Afonso ◽

...

Keyword(s):

Surface Brightness ◽

Structural Parameters ◽

Structural Evolution ◽

Morphological Type ◽

Formation Mechanisms ◽

Massive Galaxies ◽

Local Mass ◽

Mass Size ◽

Mass Assembly ◽

Size Relation

Context. The most massive galaxies (Mstellar ≥ 1011 M⊙) in the local Universe are characterized by a bulge-dominated morphology and old stellar populations, in addition to being confined to a tight mass-size relation. Identifying their main components can provide insights into their formation mechanisms and subsequent mass assembly. Aims. Taking advantage of Hubble Space Telescope (HST) CANDELS data, we analyze the lowest redshift (z < 0.5) massive galaxies in the H and I band in order to disentangle their structural constituents and study possible faint non-axisymmetric features. Methods. Our final sample consists of 17 massive galaxies. Due to the excellent HST spatial resolution for intermediate redshift objects, they are hard to model by purely automatic parametric fitting algorithms. We performed careful single and double (bulge-disk decompositions) Sérsic fits to their galaxy surface brightness profiles. We compare the model color profiles with the observed ones and also derive multi-component global effective radii attempting to obtain a better interpretation of the mass-size relation. Additionally, we test the robustness of our measured structural parameters via simulations. Results. We find that the Sérsic index does not offer a good proxy for the visual morphological type for our sample of massive galaxies. Our derived multi-component effective radii give a better description of the size of our sample galaxies than those inferred from single Sérsic models with GALFIT. Our galaxy population lies on the scatter of the local mass-size relation, indicating that these massive galaxies have not experienced a significant growth in size since z ∼ 0.5. Interestingly, the few outliers are late-type galaxies, indicating that spheroids must reach the local mass-size relation earlier. For most of our sample galaxies, both single- and multi-component Sérsic models with GALFIT show substantial systematic deviations from the observed surface brightness profiles in the outskirts. These residuals may be partly due to several factors, namely a nonoptimal data reduction for low surface brightness features or the existence of prominent stellar haloes for massive galaxies, or they could also arise from conceptual shortcomings of parametric 2D image decomposition tools. They consequently propagate into galaxy color profiles. This is a significant obstacle to the exploration of the structural evolution of galaxies, which calls for a critical assessment and refinement of existing surface photometry techniques.

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Multiparametric scaling relations for dwarf irregular galaxies in different environments

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312021485 ◽

2012 ◽

Vol 8 (S289) ◽

pp. 236-239

Author(s):

M. E. Sharina ◽

V. E. Karachentseva ◽

D. I. Makarov

Keyword(s):

Small Groups ◽

Surface Brightness ◽

Structural Parameters ◽

Absolute Magnitude ◽

Rotation Velocity ◽

Lower Surface ◽

Morphological Type ◽

Distance Measurements ◽

Irregular Galaxies ◽

Dwarf Irregular Galaxies

AbstractWe study the correlations of rotation velocity and absolute magnitude with surface brightness for low surface brightness dwarf irregular galaxies (dIrrs). We find that isolated objects contribute most to the scatter in the Tully–Fisher relation (TFR). Excluding these extreme cases, we develop a three-parameter (luminosity, Hi line width at 20% of peak flux level, i.e., W20, effective surface brightness) TFR for 60 dIrrs (with revised Hubble type T > 8) in the Local Volume (LV) with Cepheid and tip-of-the-red-giant-branch distance measurements. The relation is applied to galaxies of the same morphological type with radial velocities vLG ≤ 3500 km s−1 in the Local Supercluster. We obtained surface photometry and determined structural parameters using sdss images. The rotational velocities and derived photometric parameters for most galaxies in small groups agree well with those corresponding to the three-parameter TFR. However, isolated galaxies appear to have systematically lower surface brightnesses and longer scale lengths for the same luminosity than galaxies in small groups. This may indicate on average twice larger Hi-to-optical disk size ratios for our sample of isolated dIrrs, because their Hi surface densities calculated using the optical diameters look normal.

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Importance of $${{d}}_{{{xy}}}$$ orbital and electron correlation in iron-based superconductors revealed by phase diagram for 1111-system

Scientific Reports ◽

10.1038/s41598-021-89231-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tsuyoshi Kawashima ◽

Shigeki Miyasaka ◽

Hirokazu Tsuji ◽

Takahiro Yamamoto ◽

Masahiro Uekubo ◽

...

Keyword(s):

Electron Correlation ◽

Weak Coupling ◽

Structural Parameters ◽

Structural Flexibility ◽

Superconducting Transition ◽

Iron Based Superconductors ◽

Wide Range ◽

Band Filling ◽

Iron Based ◽

Correlation Strength

AbstractThe structural flexibility at three substitution sites in LaFeAsO enabled investigation of the relation between superconductivity and structural parameters over a wide range of crystal compositions. Substitutions of Nd for La, Sb or P for As, and F or H for O were performed. All these substitutions modify the local structural parameters, while the F/H-substitution also changes band filling. It was found that the superconducting transition temperature $$T_{\text{c}}$$ T c is strongly affected by the pnictogen height $$h_{Pn}$$ h Pn from the Fe-plane that controls the electron correlation strength and the size of the $$d_{xy}$$ d xy hole Fermi surface (FS). With increasing $$h_{Pn}$$ h Pn , weak coupling BCS superconductivity switches to the strong coupling non-BCS one where electron correlations and the $$d_{xy}$$ d xy hole FS may be important.

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Deeply Learned Pose Invariant Image Analysis with Applications in 3D Face Recognition

Mathematical Problems in Engineering ◽

10.1155/2019/3547416 ◽

2019 ◽

Vol 2019 ◽

pp. 1-21 ◽

Cited By ~ 15

Author(s):

Naeem Ratyal ◽

Imtiaz Ahmad Taj ◽

Muhammad Sajid ◽

Anzar Mahmood ◽

Sohail Razzaq ◽

...

Keyword(s):

Face Recognition ◽

Superior Performance ◽

Support Vector ◽

Complex Nature ◽

Alignment Algorithm ◽

3D Face Recognition ◽

3D Face ◽

Norm Minimization ◽

Wide Range ◽

The Face

Face recognition aims to establish the identity of a person based on facial characteristics and is a challenging problem due to complex nature of the facial manifold. A wide range of face recognition applications are based on classification techniques and a class label is assigned to the test image that belongs to the unknown class. In this paper, a pose invariant deeply learned multiview 3D face recognition approach is proposed and aims to address two problems: face alignment and face recognition through identification and verification setups. The proposed alignment algorithm is capable of handling frontal as well as profile face images. It employs a nose tip heuristic based pose learning approach to estimate acquisition pose of the face followed by coarse to fine nose tip alignment using L2 norm minimization. The whole face is then aligned through transformation using knowledge learned from nose tip alignment. Inspired by the intrinsic facial symmetry of the Left Half Face (LHF) and Right Half Face (RHF), Deeply learned (d) Multi-View Average Half Face (d-MVAHF) features are employed for face identification using deep convolutional neural network (dCNN). For face verification d-MVAHF-Support Vector Machine (d-MVAHF-SVM) approach is employed. The performance of the proposed methodology is demonstrated through extensive experiments performed on four databases: GavabDB, Bosphorus, UMB-DB, and FRGC v2.0. The results show that the proposed approach yields superior performance as compared to existing state-of-the-art methods.

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Crystallographic and structural characterization of heterometallic platinum complexes Part VI. Heterohexanuclear complexes

Open Chemistry ◽

10.2478/s11532-014-0558-7 ◽

2014 ◽

Vol 12 (11) ◽

pp. 1101-1126 ◽

Cited By ~ 1

Author(s):

Milan Melník ◽

Peter Mikuš ◽

Clive Holloway

Keyword(s):

Metal Ion ◽

Structural Parameters ◽

Bond Distance ◽

Transition Element ◽

Platinum Complexes ◽

Hard Metals ◽

Wide Range ◽

Platinum Clusters ◽

Soft Metal ◽

Independent Molecules

AbstractThis review classifies and analyzes heterohexanuclear platinum clusters into seven types of metal combinations:Pt5M, Pt4M2, Pt3M3, Pt2M4, PtM5, Pt2M3M′, and Pt2M2M2′. The crystals of these clusters generally belong to six crystal classes: monoclinic, triclinic, orthorhombic, tetragonal, trigonal and cubic. Among the wide range of stereochemistry adopted by these clusters, octahedral and capped square-pyramidal are the most common. Although platinum is classified as a soft metal atom, it bonds to a variety of soft, borderline and hard metals. Nineteen different heterometal ions are involved in hexanuclear platinum clusters. The shortest Pt-M bond distance in the case of M being a non-transition element is 2.395(4) Å for germanium and for M being a transition metal ion it is 2.402(2) Å for Cobalt. The shortest Pt-Pt bond distance observed in these clusters is 2.532 Å. Several relationships between the structural parameters are identified and discussed. Some clusters exist in two isomeric forms and some show crystallographically independent molecules within the same crystal. Such isomers and independent molecules are examples of distortion isomerism.

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Lymphoedema after head and neck cancer treatment: an overview for clinical practice

British Journal of Community Nursing ◽

10.12968/bjcn.2021.26.sup4.s24 ◽

2021 ◽

Vol 26 (Sup4) ◽

pp. S24-S29

Author(s):

Claire Jeans ◽

Bena Brown ◽

Elizabeth C Ward ◽

Anne E Vertigan

Keyword(s):

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Lymphatic System ◽

Review Article ◽

Psychological Issues ◽

Wide Range ◽

The Face ◽

Protein Rich ◽

The Impact

Lymphoedema is a disorder of the lymphatic system that presents as an atypical swelling and accumulation of protein-rich fluid within the interstitial spaces. Head and neck lymphoedema (HNL) is highly prevalent in patients who have been treated for head and neck cancer (HNC) and may manifest externally on the face and neck; internally within the oral cavity, pharynx or larynx; or as a combination of both. HNL is known to contribute to a wide range of physical, functional and psychological issues, and presents several unique challenges in terms of its management. This review article provides an overview of HNL for clinicians and aims to improve awareness of this condition and the impact it has on patients.

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Multivariate design and analysis of aircraft HEX under multiple working conditions within flight envelope

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4052342 ◽

2021 ◽

pp. 1-18

Author(s):

Qihang Liu ◽

G.Q. Xu ◽

Jie Wen ◽

Yanchen Fu ◽

Laihe Zhuang ◽

...

Keyword(s):

Heat Transfer ◽

Working Conditions ◽

Design Method ◽

Structural Parameters ◽

Optimal Structure ◽

Clear Correlation ◽

Pressure Drops ◽

Design Variables ◽

Wide Range ◽

Common Weight

Abstract This paper presents a multi-condition design method for the aircraft heat exchanger (HEX), marking with light weight, compactness and wide range of working conditions. The quasi-traversal genetic algorithm (QT-GA) method is introduced to obtain the optimal values of five structural parameters including the height, the tube diameter, the tube pitch, and the tube rows. The QT-GA method solves the deficiency of the conventional GA in the convergence, and gives a clear correlation between design variables and outputs. Pressure drops, heat transfer and the weight of the HEX are combined in a single objective function of GA in the HEX design, thus the optimal structure of the HEX suitable for all the working conditions can be directly obtained. After optimization, the weight of the HEX is reduced to 2.250 kg, more than 20% lower than a common weight of around 3 kg. Based on the optimal structure, the off-design performance of the HEX is further analyzed. Results show that the extreme working conditions for the heat transfer and the pressure drops are not consistent. It proves the advance of the multi-condition design method over traditional single-condition design method. In general, the proposed QT-GA design method is an efficient way to solve the multi-condition problems related to the aircraft HEX or other energy systems.

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4D ARCHITEKTŪROJE

Journal of Architecture and Urbanism ◽

10.3846/tpa.2011.04 ◽

2011 ◽

Vol 35 (1) ◽

pp. 28-37 ◽

Cited By ~ 2

Author(s):

Kęstutis Lupeikis ◽

Algimantas M. Mačiulis

Keyword(s):

Modern Architecture ◽

Fourth Dimension ◽

Video Installation ◽

Internal Structures ◽

Wide Range ◽

The Face ◽

Intention To Change ◽

Contemporary Architecture

Recently, among other processes in modern architecture, a lot more attention is expressed towards the fourth dimension (4D). This process is caused as an opposition to pragmatic functionalism, utilitarity, unification, formal deconstructyvism, sophistication. The expression of 4D in contemporary architecture is an intention to change the face of modern architecture, giving it more expressiveness, modern innovation. It results in specific aims and priorities of architectural expression. Architecture of today contains a variety of artistic areas (video, installation, painting, sculpture, graphics) as integral parts of its surface or internal structures. A building becomes an object of interdisciplinary art. The integration of interactive hypersurfaces in exteriors and interiors leads to various aspects of 4D in modern architecture. The paper discusses various aspects of 4D in architecture, excluding several marginal cases showing a wide range of aspects and priorities. Santrauka Pastaruoju metu, šalia kitų reiškinių, šiuolaikinėje architektūroje vis aktyviau reiškiasi ketvirtosios dimensijos vaidmuo. Šį procesą lemia priešprieša pragmatiškam funkcionalizmui, utilitarumui, unifikacijai, formaliam dekonstrukciniam laužymui, įmantrumui, daugžodžiavimui. 4D raišką šiuolaikinėje architektūroje formuoja siekis keisti architektūros „veidą“, suteikiant jai daugiau išraiškingumo, įtaigumo ir šiuolaikinio novatoriškumo. Tai lemia specifinius architektūrinės raiškos tikslus ir prioritetus. Šiuolaikinė architektūra įtraukia į save įvairių meno krypčių (videomenas, instaliacija, tapyba, skulptūra, grafika) elementus ne kaip atskirus meno objektus, o kaip neatsiejamus pastato paviršiaus ar vidaus struktūrinius darinius. Pastatas tampa tarpdisciplininiu meno objektu. Interaktyvių hiperpaviršių integravimasis eksterjere ir interjere lemia įvairius ketvirtosios dimensijos aspektus šiuolaikinėje architektūroje, kurie ir yra nagrinėjami šiame straipsnyje. Straipsnyje aptariami įvairūs ketvirtosios dimensijos šiuolaikinėje architektūroje aspektai ir sritys, išskiriami kraštutiniai, charakteringi atvejai, atspindintys platų tikslų ir prioritetų diapazoną. Aptariami, autorių manymu, charakteringiausi šios raiškos atvejai, daugiausiai dėmesio skiriant hiperpaviršių įtakai ketvirtosios dimensijos pasireiškimui šiuolaikinėje architektūroje.

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Protecting the North Sea: New research for biodiversity recovery.

10.31230/osf.io/6dukn ◽

2020 ◽

Author(s):

Oceana ◽

Helena Álvarez ◽

Allison L. Perry ◽

Jorge Blanco ◽

Silvia Garcia ◽

...

Keyword(s):

North Sea ◽

Marine Biodiversity ◽

Legal Requirements ◽

Marine Life ◽

The North ◽

Marine Habitats ◽

Wide Range ◽

The Face ◽

The North Sea ◽

New Research

To help fill gaps in knowledge about marine biodiversity in the North Sea, Oceana carried out two eight week research expeditions, in 2016 and 2017. Oceana’s surveys documented a wide range of habitats and species that are considered priorities for conservation, under national, EU, and international frameworks that recognise them as threatened and/or establish legal requirements for their protection.Oceana’s research has underscored the fact that much remains to be discovered about marine life on the seabed of the North Sea. Continued research is critical for informing efforts to recover biodiversity, an urgent priority in the face of the multiple, intense pressures facing the North Sea’s marine habitats and species.

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