Radio observations of the isotopic composition of the galaxy

1997 ◽  
Author(s):  
John H. Bieging
Keyword(s):  
Isotopic Composition ◽  
Radio Observations ◽  
The Galaxy

The Galaxy activity-interaction connection. II - Radio observations

1993 ◽  
Vol 105 ◽  
pp. 46 ◽  
Author(s):  
Eric P. Smith ◽  
Namir E. Kassim
Keyword(s):  
Radio Observations ◽  
The Galaxy

Radio observations of the galaxy clusters a 1187 and a 1890 at 102 MHz

Astrophysics ◽  
1991 ◽  
Vol 33 (2) ◽  
pp. 401-404 ◽  
Author(s):  
A. T. Kalloglyan ◽  
M. A. Ogannisyan
Keyword(s):  
Galaxy Clusters ◽  
Radio Observations ◽  
The Galaxy

scholarly journals Radio Observations of SN2004dk with VLITE Confirm Late-time Rebrightening

2021 ◽  
Vol 923 (1) ◽  
pp. 32
Author(s):  
A. Balasubramanian ◽  
A. Corsi ◽  
E. Polisensky ◽  
T. E. Clarke ◽  
N. E. Kassim
Keyword(s):  
Mass Loss ◽  
Strong Interaction ◽  
Light Curves ◽  
Core Collapse ◽  
Late Time ◽  
Spherically Symmetric ◽  
Complex Environment ◽  
Radio Observations ◽  
The Galaxy ◽  
Using Data

Abstract The study of stripped-envelope core-collapse supernovae (SNe), with evidence for strong interaction of SN ejecta with the circumstellar medium (CSM), provides insights into the pre-supernova progenitor, and a fast-forwarded view of the progenitor mass-loss history. In this context, we present late-time radio observations of SN 2004dk, a Type Ibc supernova located in the galaxy NGC 6118, at a distance of d L ≈ 23 Mpc. About 10 yr after explosion, SN 2004dk has shown evidence for Hα emission, possibly linked to the SN ejecta interacting with a H-rich CSM. Using data from the VLA Low Band Ionosphere and Transient Experiment (VLITE), we confirm the presence of a late-time radio rebrightening accompanying the observed Hα emission. We model the SN 2004dk radio light curves within the (spherically symmetric) synchrotron-self-absorption (SSA) model. Within this model, our VLITE observations combined with previously collected VLA data favor an interpretation of SN 2004dk as a strongly CSM-interacting radio SN going through a complex environment shaped by nonsteady mass loss from the SN progenitor.

scholarly journals X-ray and Radio Observations of the Radio Relic Galaxy Clusters 1RXS J0603.3+4214 and RXC J1053.7+5453

Galaxies ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 2 ◽  
Author(s):  
Motokazu Takizawa
Keyword(s):  
Mach Number ◽  
Galaxy Clusters ◽  
Galaxy Cluster ◽  
Shock Acceleration ◽  
Temperature Structure ◽  
Radio Observations ◽  
Diffusive Shock Acceleration ◽  
X Ray ◽  
Acceleration Model ◽  
The Galaxy

We study two galaxy clusters with radio relics, 1RXS J0603.3+4214 and RXC J1053.7+5453, through X-ray and radio observations. Radio relics are diffuse non-thermal radio sources found in outskirts of galaxy clusters. Because of their shape and location, they are thought to be related to cluster merger shocks. The galaxy cluster 1RXS J0603.3+4214 has a well-known linear-shape “toothbrush” radio relic. We investigate the temperature structure across the relic to constrain the Mach number of the associated shock. The results are compared with radio spectral results, which suggest that a simple diffusive shock acceleration model does not hold for this relic. The RXC J1053.7+5453 harbors a standard arc-like relic. We also get the Mach number from the temperature profile. In addition, we found an edge-like structure in the X-ray image between the X-ray peak and relic. We investigate the density and temperature profiles across the edge and found that the structure is likely relevant to not a shock but a contact discontinuity.

scholarly journals Ultra-steep spectrum emission in the merging galaxy cluster Abell 1914

2019 ◽  
Vol 622 ◽  
pp. A22 ◽  
Author(s):  
S. Mandal ◽  
H. T. Intema ◽  
T. W. Shimwell ◽  
R. J. van Weeren ◽  
A. Botteon ◽  
...  
Keyword(s):  
Low Frequency ◽  
Galaxy Cluster ◽  
Diffuse Emission ◽  
Radio Observations ◽  
Very Large Array ◽  
Radio Halo ◽  
The Galaxy ◽  
Distinct Source ◽  
Relativistic Particles ◽  
Massive Galaxy

A number of radio observations have revealed the presence of large synchrotron-emitting sources associated with the intra-cluster medium. There is strong observational evidence that the emitting particles have been (re-)accelerated by shocks and turbulence generated during merger events. The particles that are accelerated are thought to have higher initial energies than those in the thermal pool but the origin of such mildly relativistic particles remains uncertain and needs to be further investigated. The galaxy cluster Abell 1914 is a massive galaxy cluster in which X-ray observations show clear evidence of merging activity. We carried out radio observations of this cluster with the LOw Frequency ARay (LOFAR) at 150 MHz and the Giant Metrewave Radio Telescope (GMRT) at 610 MHz. We also analysed Very Large Array (VLA) 1.4 GHz data, archival GMRT 325 MHz data, CFHT weak lensing data and Chandra observations. Our analysis shows that the ultra-steep spectrum source (4C38.39; α ≲ −2), previously thought to be part of a radio halo, is a distinct source with properties that are consistent with revived fossil plasma sources. Finally, we detect some diffuse emission to the west of the source 4C38.39 that could belong to a radio halo.

scholarly journals Interstellar medium surrounding the WO star in the galaxy IC 1613: New optical and radio observations

2001 ◽  
Vol 45 (6) ◽  
pp. 417-427 ◽  
Author(s):  
T. A. Lozinskaya ◽  
A. V. Moiseev ◽  
V. L. Afanas’ev ◽  
E. Wilcots ◽  
W. M. Goss
Keyword(s):  
Interstellar Medium ◽  
Radio Observations ◽  
The Galaxy

scholarly journals Deep Imaging of SNRs at Low Frequencies Using the GMRT

2002 ◽  
Vol 199 ◽  
pp. 307-308
Author(s):  
Sanjay Bhatnagar
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Thermal Emission ◽  
Large Range ◽  
High Resolution Imaging ◽  
Radio Observations ◽  
Low Frequencies ◽  
Deep Imaging ◽  
The Galaxy ◽  
Resolution Imaging

Radio observations of large Supernova Remnants (SNRs) in the Galaxy are plagued with the problems of confusion and limitations of synthesis telescopes in imaging the emission at large angular scales. Since most SNRs are brighter at low radio frequencies, and the contamination due to thermal emission is reduced, deep and high resolution imaging of Galactic SNRs at meterwave lengths is most useful in their detection and classification. Relatively high resolution and sensitivity over a large range of angular scales provided by the GMRT at meterwave lengths makes it an ideal instrument for detailed multi-frequency imaging of Galactic SNRs.

scholarly journals Planetary Nebulae as a Part of the Galaxy

1968 ◽  
Vol 34 ◽  
pp. 7-22 ◽  
Author(s):  
L. Perek
Keyword(s):  
Total Mass ◽  
Neutral Hydrogen ◽  
Planetary Nebulae ◽  
Galactic Structure ◽  
Solar Neighbourhood ◽  
Early Type ◽  
Radio Observations ◽  
The Galaxy ◽  
Early Type Stars

Planetary nebulae form one of the most important subsystems of the Galaxy. If we knew more about this subsystem, an important gap in our ideas about the galactic structure would be filled. Very briefly, we are facing the following situation:Population I, which contributes to the total mass of the Galaxy by hardly more than 7 %, can be tracked almost over the entire Galaxy thanks to the radio observations of neutral hydrogen at 21 cm wavelength. Other data, for a wide solar neighbourhood, follow from observations of Cepheids and early-type stars.

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