Maximum parsimony analysis of the effect of the environment on the evolution of galaxies

Context. Galaxy evolution and the effect of the environment are most often studied using scaling relations or regression analyses around a given property. However, these approaches do not take into account the complexity of the physics of the galaxies and their diversity. Aims. We here investigate the effect of the cluster environment on the evolution of galaxies through multivariate, unsupervised classification and phylogenetic analyses applied to two relatively large samples from the Wide-field Nearby Galaxy-cluster Survey (WINGS), one of cluster members and one of field galaxies (2624 and 1476 objects, respectively). Methods. These samples are the largest ones ever analysed with a phylogenetic approach in astrophysics. To be able to use the maximum parsimony (cladistics) method, we first performed a pre-clustering in 300 clusters with a hierarchical clustering technique, before applying it to these pre-clusters. All these computations used seven parameters: B − V, log(Re), nV, ⟨μ⟩e, Hβ, D4000, and log(M*). Results. We have obtained a tree for the combined samples and do not find different evolutionary paths for cluster and field galaxies. However, the cluster galaxies seem to have accelerated evolution in the sense that they are statistically more diversified from a primitive common ancestor. The separate analyses show a hint of a slightly more regular evolution of the variables for the cluster galaxies, which may indicate they are more homogeneous compared to field galaxies in the sense that the groups of the latter appear to have more specific properties. On the tree for the cluster galaxies, there is a separate branch that gathers rejuvenated or stripped-off groups of galaxies. This branch is clearly visible on the colour-magnitude diagram, going back from the red sequence towards the blue one. On this diagram, the distribution and the evolutionary paths of galaxies are strikingly different for the two samples. Globally, we do not find any dominant variable able to explain either the groups or the tree structures. Rather, co-evolution appears everywhere, and could depend itself on environment or mass. Conclusions. This study is another demonstration that unsupervised machine learning is able to go beyond simple scaling relations by taking into account several properties together. The phylogenetic approach is invaluable in tracing the evolutionary scenarios and projecting them onto any bivariate diagram without any a priori modelling. Our WINGS galaxies are all at low redshift, and we now need to go to higher redshfits to find more primitive galaxies and complete the map of the evolutionary paths of present day galaxies.

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The parallelism between galaxy clusters and early-type galaxies

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038221 ◽

2020 ◽

Vol 641 ◽

pp. A94 ◽

Cited By ~ 2

Author(s):

M. D’Onofrio ◽

C. Chiosi ◽

M. Sciarratta ◽

P. Marziani

Keyword(s):

Galaxy Clusters ◽

Simulated Data ◽

Galaxy Cluster ◽

Star Formation History ◽

Wide Field ◽

Nearby Galaxy ◽

Early Type ◽

Massive Galaxies ◽

Evolving Systems ◽

Evolutionary Paths

Context. This is the second work dedicated to the observed parallelism between galaxy clusters (GCs) and early-type galaxies (ETGs). The focus is on the distribution of these systems in the scaling relations (SRs) observed when effective radii, effective surface brightness, total luminosities, and velocity dispersions are mutually correlated. Aims. Using the data of the Illustris simulation we speculate on the origin of the observed SRs. Methods. We compare the observational SRs extracted from the database of the WIde-field Nearby Galaxy-cluster Survey with the relevant parameters coming from the Illustris simulations. Then we use the simulated data at different redshift to infer the evolution of the SRs. Results. The comparison demonstrate that GCs at z ∼ 0 follow the same log(L)−log(σ) relation of ETGs and that both in the log(⟨I⟩e)−log(Re) and log(Re)−log(M*) planes the distribution of GCs is along the sequence defined by the brightest and massive early-type galaxies (BCGs). The Illustris simulation reproduces the tails of the massive galaxies visible both in the log(⟨I⟩e)−log(Re) and log(Re)−log(M*) planes, but fails to give the correct estimate of the effective radii of the dwarf galaxies that appear too large and those of GCs that are too small. The evolution of the SRs up to z = 4 permits to reveal the complex evolutionary paths of galaxies in the SRs and indicate that the line marking the zone of exclusion, visible in the log(⟨I⟩e)−log(Re) and the log(Re)−log(M*) planes, is the trend followed by virialized and passively evolving systems. Conclusions. We speculate that the observed SRs originate from the intersection of the virial theorem and a relation L = L0′σβ where the luminosities depend on the star formation history.

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WALLABY Early Science – IV. ASKAP H i imaging of the nearby galaxy IC 5201

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2063 ◽

2019 ◽

Vol 488 (4) ◽

pp. 5352-5369 ◽

Cited By ~ 3

Author(s):

D Kleiner ◽

B S Koribalski ◽

P Serra ◽

M T Whiting ◽

T Westmeier ◽

...

Keyword(s):

Spiral Galaxy ◽

Major Axis ◽

Position Angle ◽

Scaling Relations ◽

Wide Field ◽

Nearby Galaxy ◽

Maximum Difference ◽

Velocity Measurements ◽

Uv Photometry ◽

Barred Spiral Galaxy

ABSTRACT We present a Wide-field ASKAP L-Band Legacy All-sky Blind surveY (WALLABY) study of the nearby (vsys = 915 km s−1) spiral galaxy IC 5201 using the Australian Square Kilometre Array Pathfinder (ASKAP). IC 5201 is a blue, barred spiral galaxy that follows the known scaling relations between stellar mass, SFR, H i mass, and diameter. We create a four-beam mosaicked H i image cube from 175 h of observations made with a 12-antenna sub-array. The root mean square noise level of the cube is 1.7 mJy beam−1 per channel, equivalent to a column density of $N_{\rm H\, \small {I}}$ = 1.4 × 1020 cm−2 over 25 km s−1. We report nine extragalactic H i detections – five new H i detections including the first velocity measurements for two galaxies. These sources are IC 5201, three dwarf satellite galaxies, two galaxies, and a tidal feature belonging to the NGC 7232/3 triplet and two potential infalling galaxies to the triplet. There is evidence of a previous tidal interaction between IC 5201 and the irregular satellite AM 2220−460. A close fly-by is likely responsible for the asymmetric optical morphology of IC 5201 and warping its disc, resulting in the irregular morphology of AM 2220−460. We quantify the H i kinematics of IC 5201, presenting its rotation curve as well as showing that the warp starts at 14 kpc along the major axis, increasing as a function of radius with a maximum difference in position angle of 20°. There is no evidence of stripped H i, triggered or quenched star formation in the system as measured using DECam optical and GALEX UV photometry.

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The galaxy population within the virial radius of the Perseus cluster

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037574 ◽

2020 ◽

Vol 640 ◽

pp. A30

Author(s):

H. Meusinger ◽

C. Rudolf ◽

B. Stecklum ◽

M. Hoeft ◽

R. Mauersberger ◽

...

Keyword(s):

Profile Analysis ◽

Mass Function ◽

Wide Field ◽

Nearby Galaxy ◽

Cluster Galaxy ◽

Cluster Galaxies ◽

The Galaxy ◽

Galaxy Population ◽

Galaxy Luminosity Function ◽

Perseus Cluster

Context. The Perseus cluster is one of the most massive nearby galaxy clusters and is fascinating in various respects. Though the galaxies in the central cluster region have been intensively investigated, an analysis of the galaxy population in a larger field is still outstanding. Aims. This paper investigates the galaxies that are brighter than B ≈ 20 within a field corresponding to the Abell radius of the Perseus cluster. Our first aim is to compile a new catalogue in a wide field around the centre of the Perseus cluster. The second aim of this study is to employ this catalogue for a systematic study of the cluster galaxy population with an emphasis on morphology and activity. Methods. We selected the galaxies in a 10 square degrees field of the Perseus cluster on Schmidt CCD images in B and Hα in combination with SDSS images. Morphological information was obtained both from the “eyeball” inspection and the surface brightness profile analysis. We obtained low-resolution spectra for 82 galaxies and exploited the spectra archive of SDSS and redshift data from the literature. Results. We present a catalogue of 1294 galaxies with morphological information for 90% of the galaxies and spectroscopic redshifts for 24% of them. We selected a heterogeneous sample of 313 spectroscopically confirmed cluster members and two different magnitude-limited samples with incomplete redshift data. These galaxy samples were used to derive such properties as the projected radial velocity dispersion profile, projected radial density profile, galaxy luminosity function, supermassive black hole mass function, total stellar mass, virial mass, and virial radius, to search for indications of substructure, to select active galaxies, and to study the relation between morphology, activity, density, and position. In addition, we present brief individual descriptions of 18 cluster galaxies with conspicuous morphological peculiarities.

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Substructure in black hole scaling diagrams and implications for the coevolution of black holes and galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320001726 ◽

2019 ◽

Vol 15 (S359) ◽

pp. 37-39

Author(s):

Benjamin L. Davis ◽

Nandini Sahu ◽

Alister W. Graham

Keyword(s):

Black Hole ◽

Stellar Mass ◽

Host Galaxy ◽

Scaling Relations ◽

Black Hole Mass ◽

Physical Processes ◽

Stellar Velocity ◽

Galaxy Sample ◽

Evolutionary Paths ◽

Black Hole Masses

AbstractOur multi-component photometric decomposition of the largest galaxy sample to date with dynamically-measured black hole masses nearly doubles the number of such galaxies. We have discovered substantially modified scaling relations between the black hole mass and the host galaxy properties, including the spheroid (bulge) stellar mass, the total galaxy stellar mass, and the central stellar velocity dispersion. These refinements partly arose because we were able to explore the scaling relations for various sub-populations of galaxies built by different physical processes, as traced by the presence of a disk, early-type versus late-type galaxies, or a Sérsic versus core-Sérsic spheroid light profile. The new relations appear fundamentally linked with the evolutionary paths followed by galaxies, and they have ramifications for simulations and formation theories involving both quenching and accretion.

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A Precise Benchmark for Cluster Scaling Relations: Fundamental Plane, Mass Plane and IMF in the Coma Cluster from Dynamical Models

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1043 ◽

2020 ◽

Cited By ~ 2

Author(s):

Shravan Shetty ◽

Michele Cappellari ◽

Richard M McDermid ◽

Davor Krajnović ◽

P T de Zeeuw ◽

...

Keyword(s):

Galaxy Formation ◽

Scaling Relations ◽

Coma Cluster ◽

Dynamical Models ◽

Fundamental Plane ◽

Cluster Galaxies ◽

Dynamical Scaling ◽

Small Uncertainty ◽

Cluster Distance ◽

Using Data

Abstract We study a sample of 148 early-type galaxies in the Coma cluster using SDSS photometry and spectra, and calibrate our results using detailed dynamical models for a subset of these galaxies, to create a precise benchmark for dynamical scaling relations in high-density environments. For these galaxies, we successfully measured global galaxy properties, modeled stellar populations, and created dynamical models, and support the results using detailed dynamical models of 16 galaxies, including the two most massive cluster galaxies, using data taken with the SAURON IFU. By design, the study provides minimal scatter in derived scaling relations due to the small uncertainty in the relative distances of galaxies compared to the cluster distance. Our results demonstrate low (≤55% for 90th percentile) dark matter fractions in the inner 1Re of galaxies. Owing to the study design, we produce the tightest, to our knowledge, IMF-σe relation of galaxies, with a slope consistent with that seen in local galaxies. Leveraging our dynamical models, we transform the classical Fundamental Plane of the galaxies to the Mass Plane. We find that the coefficients of the mass plane are close to predictions from the virial theorem, and have significantly lower scatter compared to the Fundamental plane. We show that Coma galaxies occupy similar locations in the (M* - Re) and (M* - σe) relations as local field galaxies but are older. This, and the fact we find only three slow rotators in the cluster, is consistent with the scenario of hierarchical galaxy formation and expectations of the kinematic morphology-density relation.

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WINGS-SPE Spectroscopy in the WIde-field Nearby Galaxy-cluster Survey

Astronomy and Astrophysics ◽

10.1051/0004-6361:200810997 ◽

2009 ◽

Vol 495 (3) ◽

pp. 707-719 ◽

Cited By ~ 100

Author(s):

A. Cava ◽

D. Bettoni ◽

B. M. Poggianti ◽

W. J. Couch ◽

M. Moles ◽

...

Keyword(s):

Galaxy Cluster ◽

Wide Field ◽

Nearby Galaxy ◽

Cluster Survey

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WIDE-FIELD VLBI OBSERVATIONS OF M31: A UNIQUE PROBE OF THE IONIZED INTERSTELLAR MEDIUM OF A NEARBY GALAXY

The Astrophysical Journal ◽

10.1088/0004-637x/768/1/12 ◽

2013 ◽

Vol 768 (1) ◽

pp. 12 ◽

Cited By ~ 5

Author(s):

John S. Morgan ◽

Megan K. Argo ◽

Cathryn M. Trott ◽

Jean-Pierre Macquart ◽

Adam Deller ◽

...

Keyword(s):

Interstellar Medium ◽

Wide Field ◽

Nearby Galaxy ◽

Vlbi Observations ◽

Unique Probe

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ON PHASE TRANSITIONS ON BETHE LATTICES

Modern Physics Letters B ◽

10.1142/s0217984994001540 ◽

1994 ◽

Vol 08 (25) ◽

pp. 1587-1590 ◽

Cited By ~ 1

Author(s):

RAFFAELLA BURIONI ◽

DAVIDE CASSI

Keyword(s):

Phase Transitions ◽

Critical Temperature ◽

Simple Formula ◽

Mean Field ◽

Scaling Relations ◽

Long Range Order ◽

Rigorous Results ◽

Tree Structures ◽

Bethe Lattices ◽

The Mean

Starting from some recent rigorous results about correlation functions of statistical model on tree structures, we analyze the nature of phase transitions occurring on Bethe lattices, showing the lack of long range order and the purely geometrical origin of the thermodynamic singularities. This approach gives a very simple formula for the critical temperature for any model with compact symmetry group and immediately leads to the value 1 for the critical exponent γ. The “geometrical” critical behavior only partially coincides with the mean field solution and violates the usual scaling relations.

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