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

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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Optical counterparts of an ultraluminous X-Ray Source X-1 in NGC 2500

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2160 ◽

2019 ◽

Vol 488 (4) ◽

pp. 5935-5940 ◽

Cited By ~ 1

Author(s):

N Aksaker ◽

A Akyuz ◽

S Avdan ◽

H Avdan

Keyword(s):

Hubble Space Telescope ◽

Optical Emission ◽

Spectral Energy ◽

Wide Field ◽

Nearby Galaxy ◽

X Rays ◽

Energy Distributions ◽

X Ray ◽

Photon Index ◽

Absolute Magnitudes

ABSTRACT We present the results of a search for optical counterparts of ultraluminous X-ray source (ULX) X-1 in the nearby galaxy NGC 2500 by using archival images taken with the Hubble Space Telescope Wide Field Camera (WFC3)/UVIS. We identified four optical sources as possible counterparts within the 2σ error radius of 0$^{\prime \prime }_{.}$3 in the images. However, only two of them were investigated as candidates for counterparts due to their point-like features and their identification in various filters. These two faint candidates have absolute magnitudes of MV ≈ −3.4 and −3.7. The spectral energy distributions of two candidates were modelled by a power-law spectrum with a photon index (α) ∼1.5, but the spectrum of one candidate shows a deviation. This may suggest that at least two components are responsible for the optical emission. The red part of the spectrum could arise from the companion star and the blue part could be interpreted as an evidence of reprocessing of the X-rays from the disc.

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Galactic Plane Surveys at Low Frequencies

Symposium - International Astronomical Union ◽

10.1017/s0074180900169050 ◽

2002 ◽

Vol 199 ◽

pp. 251-258

Author(s):

A.R. Taylor

Keyword(s):

Interstellar Medium ◽

Atomic Hydrogen ◽

Angular Resolution ◽

Spatial Scales ◽

High Sensitivity ◽

Hydrogen Gas ◽

Dimensional Structure ◽

High Angular Resolution ◽

Wide Field ◽

The Galaxy

Until recently, high angular resolution and high sensitivity surveys of the radio emission from the plane of our Galaxy were available only at frequencies of several GHz, where large single dish radio telescopes provide arcminute scale angular resolution. At these frequencies thermal radiation from HII regions and diffuse ionized gas comprise a major component of the Galactic emission. Advances in wide field interferometric imaging techniques now make it possible to carry out high sensitivity surveys of the Galaxy with arcminute scale angular resolution at 1.4 GHz and below. Over the past few years initial synthesis surveys have been made. More ambitious surveys that combined sensitive continuum observations with full polarimetry and images of the 3-dimensional structure of atomic hydrogen gas at pc scales are currently underway in the northern (DRAO) and southern (ATNF) hemispheres. The interstellar medium of the Galaxy contains structure on all spatial scales, and these surveys combined data from aperture synthesis telescopes and signal dish antennas to provide full spatial frequency coverage to the resolution limit. Preliminary results reveal wide-spread features and processes in the the interstellar medium that are not readily visible by other means, including, for example, unusual atomic hydrogen structures related to the vertical transfer of matter and radiation between the disk and halo of the Galaxy, Faraday rotation structures that allow study of the magnetic field and diffuse ionized component in the plane of the Galaxy, and a cold atomic phase of the neutral medium that may provide a link between global shock phenomena in the galaxy and the formation of molecular clouds.

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WINGS: a WIde-field Nearby Galaxy-cluster Survey

Astronomy and Astrophysics ◽

10.1051/0004-6361:20053816 ◽

2006 ◽

Vol 445 (3) ◽

pp. 805-817 ◽

Cited By ~ 123

Author(s):

G. Fasano ◽

C. Marmo ◽

J. Varela ◽

M. D'Onofrio ◽

B. M. Poggianti ◽

...

Keyword(s):

Galaxy Cluster ◽

Wide Field ◽

Nearby Galaxy ◽

Cluster Survey

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SUPERNOVA REMNANTS AND THE INTERSTELLAR MEDIUM OF M83: IMAGING AND PHOTOMETRY WITH THE WIDE FIELD CAMERA 3 ON THEHUBBLE SPACE TELESCOPE

The Astrophysical Journal ◽

10.1088/0004-637x/710/2/964 ◽

2010 ◽

Vol 710 (2) ◽

pp. 964-978 ◽

Cited By ~ 44

Author(s):

Michael A. Dopita ◽

William P. Blair ◽

Knox S. Long ◽

Max Mutchler ◽

Bradley C. Whitmore ◽

...

Keyword(s):

Interstellar Medium ◽

Supernova Remnants ◽

Wide Field ◽

Space Telescope

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Structural and dynamical modeling of WINGS clusters

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935081 ◽

2019 ◽

Vol 631 ◽

pp. A131 ◽

Cited By ~ 5

Author(s):

G. A. Mamon ◽

A. Cava ◽

A. Biviano ◽

A. Moretti ◽

B. Poggianti ◽

...

Keyword(s):

Spiral Galaxies ◽

Selection Effect ◽

Wide Field ◽

Nearby Galaxy ◽

Cluster Galaxy ◽

Lenticular Galaxies ◽

Major Cluster ◽

Bayesian Evidence ◽

Orbit Modeling ◽

Cluster Mergers

The orbital shapes of galaxies of different classes are a probe of their formation and evolution. The Bayesian MAMPOSSt mass-orbit modeling algorithm is used to jointly fit the distribution of elliptical, spiral-irregular, and lenticular galaxies in projected phase space, on three pseudo-clusters (built by stacking the clusters after re-normalizing their positions and velocities) of 54 regular clusters from the Wide-field Nearby Galaxy-clusters Survey (WINGS), with at least 30 member velocities. Our pseudo-clusters (i.e., stacks) contain nearly 5000 galaxies with available velocities and morphological types. Thirty runs of MAMPOSSt with different priors are presented. The highest MAMPOSSt likelihoods are obtained for generalized Navarro-Frenk-White (NFW) models with steeper inner slope, free-index Einasto models, and double NFW models for the cluster and the brightest cluster galaxy. However, there is no strong Bayesian evidence for a steeper profile than the NFW model. The mass concentration matches the predictions from cosmological simulations. Ellipticals usually best trace the mass distribution while S0s are close. Spiral galaxies show increasingly elongated orbits at increasing radii, as do S0s on two stacks, and ellipticals on one stack. The inner orbits of all three types in the three stacks are consistent with isotropy. Spiral galaxies should transform rapidly into early-types given their much larger extent in clusters. Elongated outer orbits are expected for the spirals, a consequence of their recent radial infall into the cluster. The less elongated orbits we find for early-types could be related to the longer time spent by these galaxies in the cluster. We demonstrate that two-body relaxation is too slow to explain the inner isotropy of the early types, which suggests that inner isotropy is the consequence of violent relaxation during major cluster mergers or dynamical friction and tidal braking acting on subclusters. We propose that the inner isotropy of the short-lived spirals is a selection effect of spirals passing only once through pericenter before being transformed into early-type morphologies.

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Cosmic ray production and emission in M82

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312009490 ◽

2011 ◽

Vol 7 (S284) ◽

pp. 397-399

Author(s):

Tova Yoast-Hull ◽

John Everett ◽

J. S. Gallagher ◽

Ellen Zweibel

Keyword(s):

Interstellar Medium ◽

First Principles ◽

Energetic Particle ◽

Gamma Ray ◽

Cosmic Ray ◽

Injection Rate ◽

Starburst Galaxy ◽

Nearby Galaxy ◽

Electron Positron ◽

Particle Spectra

AbstractStarting from first principles, we construct a simple model for the evolution of energetic particles produced by supernovae in the starburst galaxy M82. The supernova rate, geometry, and properties of the interstellar medium are all well observed in this nearby galaxy. Assuming a uniform interstellar medium and constant cosmic-ray injection rate, we estimate the cosmic-ray proton and primary & secondary electron/positron populations. From these particle spectra, we predict the gamma ray flux and the radio synchrotron spectrum. The model is then compared to the observed radio and gamma-ray spectra of M82 as well as previous models by Torres (2004), Persic et al. (2008), and de Cea del Pozo et al. (2009). Through this project, we aim to build a better understanding of the calorimeter model, in which energetic particle fluxes reflect supernova rates, and a better understanding of the radio-FIR correlation in galaxies.

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