Large-Scale Effects of Supernova Remnants on the Galaxy: Generation and Maintenance of a Hot Network of Tunnels

1974 ◽  
Vol 189 ◽  
pp. L105 ◽  
Author(s):  
Donald P. Cox ◽  
Barham W. Smith
Keyword(s):  
Supernova Remnants ◽  
Large Scale ◽  
Scale Effects ◽  
The Galaxy

The non-thermal radio-emission from the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 337-354 ◽  
Author(s):  
J. E. Baldwin
Keyword(s):  
Supernova Remnants ◽  
Large Scale ◽  
Cosmic Ray ◽  
Radio Spectrum ◽  
List Type ◽  
Continuum Radiation ◽  
Radio Halo ◽  
Normal Galaxies ◽  
Thermal Radio Emission ◽  
The Galaxy

In this review of the non-thermal continuum radiation from the Galaxy, the following issues are discussed:(1)The non-thermal continuum radiation in the disk.(2)Evidence for spiral arms in the non-thermal continuum, and the origin of the radiation in sources or in large-scale magnetic fields.(3)The nature of the spurs extending to high galactic latitudes.(4)Evidence for the existence or absence of a radio halo.(5)The galactic radio spectrum and its relation to the cosmic-ray electron spectrum.(6)Supernova remnants, their structure and spectra.(7)A comparison of the Galaxy with other normal galaxies.(8)Observational needs.

scholarly journals Large Scale Galactic Structure

1995 ◽  
Vol 148 ◽  
pp. 258-266
Author(s):  
Gerard Gilmore ◽  
Rodrigo Ibata
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Scale Effects ◽  
Essential Feature ◽  
Chemical Abundance ◽  
Small Satellites ◽  
The Galaxy ◽  
Moving Groups ◽  
Scale Properties

AbstractModern models of Galaxy formation make fairly specific predictions which are amenable to detailed tests with galactic kinematic and chemical abundance data. For example, popular Cold Dark Matter models ‘predict’ growth of the Galaxy about a central core, which should contain the oldest stars. Later accretion of material forms the outer halo and the disks, while continuing accretion will continue to affect the kinematic structure of both the outer halo and the thin disk. This picture, which contains aspects of both the monolithic (‘ELS’) and the multifragment (‘Searle-Zinn’) pictures often discussed in chemical evolution models, makes some specific predictions which can be tested. The essential feature of these predictions is that they are believable only for the largest scale effects. Large scale properties of the Galaxy must be measured to test them. It is these studies which need large angular scale data. One specific example of current interest is the ‘prediction’ that mergers of small satellites are an essential feature of galactic evolution. This leads one to look for kinematic and spatial structures, and ‘moving groups’, as a primary test of such models.

scholarly journals The Large-Scale Distribution of Synchrotron Emissivity in the Galaxy

1981 ◽  
Vol 94 ◽  
pp. 223-224 ◽  
Author(s):  
S. Kearsey ◽  
J. L. Osborne ◽  
S. Phillipps ◽  
C.G.T. Haslam ◽  
C. J. Salter ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Large Scale ◽  
Galactic Plane ◽  
Thermal Emission ◽  
Radio Continuum ◽  
3 Dimensional ◽  
The Galaxy ◽  
Dimensional Distribution ◽  
Alternative Approaches ◽  
Best Fit

The all-sky radio continuum map at 408 MHz presented at this symposium by Haslam et al. can be interpreted in terms of the large-scale 3-dimensional distribution of synchrotron emissivity in the Galaxy when due allowance is made for the thermal emission. Its derivation from a 2-dimensional map must involve a number of assumptions so it is instructive to compare the results of alternative approaches (described in detail in forthcoming papers by the present authors). In both cases the variation of emissivity in the galactic plane is obtained from the observed intensity profile at b=0o and then the z-variation is chosen to give the best fit to the complete map. The observed profile is shown in the figure with and without the contributions of catalogued supernova remnants and HII regions.

scholarly journals Proceedings of Observatories: Nuffield Radio Astronomy Laboratories Jodrell Bank

1971 ◽  
Vol 8 ◽  
pp. 65-75
Author(s):  
Bernard Lovell
Keyword(s):  
Recent Work ◽  
Radio Astronomy ◽  
Supernova Remnants ◽  
Large Scale ◽  
Continuum Emission ◽  
Small Scale ◽  
Line Radiation ◽  
Transmission Properties ◽  
The Galaxy ◽  
The Continuum

The structure of the Galaxy can be studied by the following techniques: (i) measurements of the continuum emission, both on the large scale and from discrete objects such as supernova remnants; (ii) measurements of line radiation, again both from large and small scale features; and (iii) measurements of the transmission properties of the interstellar medium. All these techniques have been pursued in recent work at Jodrell Bank. This section describes work in the categories (i) and (iii); work under (ii) is described in Sections 6 and 7.

scholarly journals Observations of Magnetic Fields in Galaxies

1992 ◽  
Vol 9 ◽  
pp. 81-86
Author(s):  
R. Wielebinski
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Supernova Remnants ◽  
Large Scale ◽  
Galactic Plane ◽  
Building Blocks ◽  
Galactic Centre ◽  
Definitive Evidence ◽  
The Galaxy ◽  
The Universe

AbstractMagnetic fields are present in every corner of the Universe. The Earth, the Sun and most of the planets are known to possess dipolar magnetic fields. In the Galaxy many individual objects like stars, pulsars, bipolar nebulae and supernova remnants are found to have associated magnetic fields. It seems that the rotation plays a significant role in the ability of a cosmic object to develop a magnetic field. The magnetic field of the Galaxy is observed to be oriented along the galactic plane as evidenced by both optical and radio polarization observations. Radio maps of the Galactic centre reveal poloidal magnetic fields as ‘wisps’ or ‘strings’ around Sagittarius A. Observations of nearby galaxies give us remarkable information about the large-scale magnetic fields in these building blocks of the Universe. Magnetic fields play an important role in the formation of jets of radio galaxies. Further out, in clusters of galaxies, definitive evidence has been given for the existence of intergalactic magnetic fields.

scholarly journals Star Formation and the Galaxy

1977 ◽  
Vol 75 ◽  
pp. 3-19
Author(s):  
F. J. Kerr
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Scale Effects ◽  
The Galaxy ◽  
First Session

My task is to discuss the galactic context of star formation and to consider how large-scale phenomena in the Galaxy can influence the processes of star formation. This review, and the whole of the first session, are supposed to set the stage for the later consideration of protostellar and prestellar objects and smaller-scale effects in general.

scholarly journals 50 YEARS OF RESEARCH IN CONTINUUM AT THE UTR-2 RADIO TELESCOPE

2021 ◽  
Vol 26 (4) ◽  
pp. 287-313
Author(s):  
M. A. Sidorchuk ◽  
◽  
N. M. Vasilenko ◽  
O. M. Ulyanov ◽  
O. O. Konovalenko ◽  
...  
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Supernova Remnants ◽  
Large Scale ◽  
Low Frequencies ◽  
Decameter Wavelength ◽  
Galactic Clusters ◽  
The Galaxy ◽  
Continuum Radio ◽  
First Time

Purpose: The results of research in continuum decameter-wave radio emission of the Galaxy background, ionized hydrogen regions, supernova remnants, extragalactic discrete sources, extended galaxies, galactic clusters, extragalactic background are given. The aim of this work is reviewing the results achieved for over 50-years of the UTR-2 radiotelescope research of our Galaxy and its population, as well as extragalactic radio sources in the continuum radio emission spectrum at extremely low frequencies for the ground based observations. Design/methodology/approach: The review, analysis, collection of archival data in various publications related to the subjectof this work. Findings: The basic results of studying the ionized hydrogen regions, supernova remnants, Galaxy background emission and its large-scale structure are given, and the maps of these sources are obtained. The catalog of extragalactic discrete radio sources of the most Northern sky part and the cosmological conclusions based on its analysis are described; the estimate of the isotropic extragalactic background brightness temperature is obtained; for the first time, the observational results for the Andromeda galaxy and two galactic clusters Coma and A2255 are given briefly. Conclusions: All the results presented here emphasize the uniqueness and importance of research in the decameter wavelength range, and the large area, flexibility of structure, continuous improvement make the UTR-2 radio telescope an indispensable tool for solving the most important tasks of modern radio astronomy, despite its respectable age. For example, only in the range of 10 to 30 MHz the ionized part of the most common element in the universe, the hydrogen, becomes optically thick and begins to absorb the synchrotron emission on the line of sight, which allows rather easy separation of thermal and non-thermal components of radioemission. This property allows to determine the ionized hydrogen regions’ electron temperature and the electron concentration on the line of sight independently in studying the hydrogen emission regions. When studying the supernova remnants, we can determine the ionized matter location by their spectrum drops ‒ before, inside or behind the remnant. Based on the HB3 supernova remnant radio imagies, an assumption was made on the existence of an ionized hydrogen relic shell aroundit, being caused by the initial ultraviolet flash of a supernova. For the first time, the maps of the Northern sky large-scale structure in the declination range from ‒15° to +85° at extremely low frequencies 10, 12.6, 14.7, 16.7, 20 and 25 MHz for the ground-based observations are published, which, besides their own scientific value, may allow to correct the UTR-2 radio telescope imaging results. Using the full-resolution UTR-2 maps and the developed method of multifrequency T‒T diagrams, it was possible to separate the background radiation into galactic and extragalactic components and construct the spectrum of the latter. From the analysis of the most complete decameter wavelength range catalog of discrete sources, it follows that there is a gap in the redshift spatial distribution for all classes of extragalactic sources. The existence of an ionized hydrogen ring in the Andromeda Nebula disk has been suggested. It is shown that the main partof the galaxy clusters decameter-wave emission comes from haloes and relics. Key words: decameter range; discrete sources; supernovaremnants; catalog; continuum radio emission; HII regions; UTR-2; background emission

scholarly journals The Second Epoch Molonglo Galactic Plane Survey: Images and Candidate Supernova Remnants

2014 ◽  
Vol 31 ◽  
Author(s):  
A. J. Green ◽  
S. N. Reeves ◽  
T. Murphy
Keyword(s):  
Interstellar Medium ◽  
Supernova Remnants ◽  
Large Scale ◽  
Supernova Remnant ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Postage Stamps ◽  
The Galaxy ◽  
Complete Survey ◽  
Extended Sources

AbstractThe second epoch Molonglo Galactic Plane Survey covers the area 245° ⩽l⩽ 365° and |b| ⩽ 10° at a frequency of 843 MHz and an angular resolution of 45 arcsec × 45 arcsec cosec(δ). The sensitivity varies between 1–2 mJy beam− 1depending on the presence of strong extended sources. This survey is currently the highest resolution and most sensitive large-scale continuum survey of the southern Galactic plane. In this paper, we present the images of the complete survey, including postage stamps of some new supernova remnant (SNR) candidates and a discussion of the highly structured features detected in the interstellar medium. The intersection of these two types of features is discussed in the context of the ‘missing’ SNR population in the Galaxy.

scholarly journals Radio Studies of Cosmic Rays in the Galaxy

1991 ◽  
Vol 144 ◽  
pp. 187-196
Author(s):  
W. Reich
Keyword(s):  
Supernova Remnants ◽  
Large Scale ◽  
Galactic Halo ◽  
Galactic Plane ◽  
Thermal Emission ◽  
Galactic Disk ◽  
Cosmic Ray ◽  
Radio Continuum ◽  
The Galaxy ◽  
Radio Studies

Changes of the cosmic ray electron spectrum throughout the Galaxy have been found, based on the comparison of large-scale radio continuum surveys. These observations are not compatible with the assumption of a static Galactic halo, but indicate the existence of a Galactic wind. Galactic plane surveys reveal sources of cosmic ray electrons in the Galactic disk. Recent studies of the population of radio sources show no evidence for a large number of compact Galactic non-thermal sources. Most of the extended sources are probably HII-regions. Relatively few new supernova remnants (SNRs) with low surface brightness could be identified. Most of the non-thermal emission in the disk-halo interface seems diffuse or unresolved, even at arcmin angular resolution.

scholarly journals Investigating the properties of a galaxy group at z = 0.6

2020 ◽  
Vol 15 (S359) ◽  
pp. 188-189
Author(s):  
Daniela Hiromi Okido ◽  
Cristina Furlanetto ◽  
Marina Trevisan ◽  
Mônica Tergolina
Keyword(s):  
Large Scale ◽  
The Other ◽  
Numerical Density ◽  
Spectroscopy Data ◽  
Stellar Kinematics ◽  
Galaxy Groups ◽  
The Galaxy ◽  
The Difference ◽  
The Impact ◽  
The Universe

AbstractGalaxy groups offer an important perspective on how the large-scale structure of the Universe has formed and evolved, being great laboratories to study the impact of the environment on the evolution of galaxies. We aim to investigate the properties of a galaxy group that is gravitationally lensing HELMS18, a submillimeter galaxy at z = 2.39. We obtained multi-object spectroscopy data using Gemini-GMOS to investigate the stellar kinematics of the central galaxies, determine its members and obtain the mass, radius and the numerical density profile of this group. Our final goal is to build a complete description of this galaxy group. In this work we present an analysis of its two central galaxies: one is an active galaxy with z = 0.59852 ± 0.00007, while the other is a passive galaxy with z = 0.6027 ± 0.0002. Furthermore, the difference between the redshifts obtained using emission and absorption lines indicates an outflow of gas with velocity v = 278.0 ± 34.3 km/s relative to the galaxy.

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