scholarly journals Radio Continuum of the Small Magellanie Cloud at Wavelengths 6 and 3·4 cm

1976 ◽  
Vol 29 (4) ◽  
pp. 329 ◽  
Author(s):  
RX McGee ◽  
Lynette M Newton ◽  
PW Butler
Keyword(s):  
Neutral Hydrogen ◽  
Magellanic Cloud ◽  
Radio Continuum ◽  
Radio Sources ◽  
Spectral Indices ◽  
Small Magellanic Cloud ◽  
Ionized Gas

The radio continuum at wavelength 6 cm has been surveyed in the direction of the Small Magellanic Cloud with a telescope beam of 4'�1 arc. Only 27 radio sources have been delineated in this galaxy, and details of their positions, flux densities and spectral indices are given. Some supporting observations were made of the stronger sources at 3�4 cm wavelength. The distribution of the 6 cm emission is compared with the distributions of the ionized gas and neutral hydrogen.

scholarly journals New 20-cm radio-continuum study of the small Magellanic cloud - part III: Compact Hii regions

2012 ◽  
pp. 53-64 ◽  
Author(s):  
G.F. Wong ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
N.F.H. Tothill ◽  
Horta de ◽  
...  
Keyword(s):  
Hii Regions ◽  
Magellanic Cloud ◽  
Radio Continuum ◽  
Spectral Indices ◽  
Emission Mechanism ◽  
Small Magellanic Cloud ◽  
Southwestern Part ◽  
Continuum Image ◽  
Compact Array ◽  
Compact Hii Regions

We present and discuss a new catalogue of 48 compact Hii regions in the Small Magellanic Cloud (SMC) and a newly created deep 1420 MHz (?=20 cm) radio-continuum image of the N19 region located in the southwestern part of the SMC. The new images were created by merging 1420 MHz radiocontinuum archival data from the Australian Telescope Compact Array. The majority of these detected radio compact Hii regions have rather flat spectral indices which indicates, as expected, that the dominant emission mechanism is of thermal nature.

scholarly journals The Radio Continuum of the Large Magellanic Cloud. IV. Spectra of Sources

1972 ◽  
Vol 25 (5) ◽  
pp. 619 ◽  
Author(s):  
RX McGee ◽  
Lynette M Newton
Keyword(s):  
Supernova Remnants ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Radio Continuum ◽  
Radio Sources ◽  
Spectral Indices ◽  
Class 1 ◽  
Background Continuum ◽  
Continuum Radio ◽  
The Continuum

The continuum radio sources in the direction of the Large Magellanic Cloud are classified in terms of their spectral indices. Of 52 sources for which spectral data were available three distinct classes exist: (1) sources with spectral indices = ?0�20, of which 21 out of 23 have been identified with HII regions in the Henize catalogue; (2) sources with spectral indices < ?0�20 that have been identified with Henize objects, of which it is possible that many are supernova remnants; and (3) sources with spectral indices < ?0�20 that have not been identified with optical objects and are considered to be outside the LMC. Six "double sources" with one member belonging to class (1) and the other to class (2) were found. The background continuum radiation is also discussed.

scholarly journals Radio observations of evaporating objects in the Cygnus OB2 region

2019 ◽  
Vol 627 ◽  
pp. A58 ◽  
Author(s):  
N. L. Isequilla ◽  
M. Fernández-López ◽  
P. Benaglia ◽  
C. H. Ishwara-Chandra ◽  
S. del Palacio
Keyword(s):  
Thermal Emission ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Spectral Indices ◽  
Ionized Gas ◽  
Low Frequencies ◽  
Thermal Origin ◽  
Index Maps ◽  
Photoionization Rate ◽  
Gas Component

We present observations of the Cygnus OB2 region obtained with the Giant Metrewave Radio Telescope (GMRT) at frequencies of 325 and 610 MHz. In this contribution we focus on the study of proplyd-like objects (also known as free-floating evaporating gas globules or frEGGs) that typically show an extended cometary morphology. We identify eight objects previously studied at other wavelengths and derive their physical properties by obtaining their optical depth at radio-wavelengths. Using their geometry and the photoionization rate needed to produce their radio-continuum emission, we find that these sources are possibly ionized by a contribution of the stars Cyg OB2 #9 and Cyg OB2 #22. Spectral index maps of the eight frEGGs were constructed, showing a flat spectrum in radio frequencies in general. We interpret these as produced by optically thin ionized gas, although it is possible that a combination of thermal emission, not necessarily optically thin, produced by a diffuse gas component and the instrument response (which detects more diffuse emission at low frequencies) can artificially generate negative spectral indices. In particular, for the case of the Tadpole we suggest that the observed emission is not of non-thermal origin despite the presence of regions with negative spectral indices in our maps.

scholarly journals The ASKAP EMU Early Science Project: radio continuum survey of the Small Magellanic Cloud

2019 ◽  
Vol 490 (1) ◽  
pp. 1202-1219 ◽  
Author(s):  
T D Joseph ◽  
M D Filipović ◽  
E J Crawford ◽  
I Bojičić ◽  
E L Alexander ◽  
...  
Keyword(s):  
Point Source ◽  
High Sensitivity ◽  
Magellanic Cloud ◽  
Point Sources ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Small Magellanic Cloud ◽  
Science Project ◽  
New Radio ◽  
Low Surface Brightness

ABSTRACT We present two new radio continuum images from the Australian Square Kilometre Array Pathfinder (ASKAP) survey in the direction of the Small Magellanic Cloud (SMC). These images are part of the Evolutionary Map of the Universe (EMU) Early Science Project (ESP) survey of the Small and Large Magellanic Clouds. The two new source lists produced from these images contain radio continuum sources observed at 960 MHz (4489 sources) and 1320 MHz (5954 sources) with a bandwidth of 192 MHz and beam sizes of 30.0 × 30.0 arcsec2 and 16.3 × 15.1 arcsec2, respectively. The median root mean square (RMS) noise values are 186 $\mu$Jy beam−1 (960 MHz) and 165 $\mu$Jy beam−1 (1320 MHz). To create point source catalogues, we use these two source lists, together with the previously published Molonglo Observatory Synthesis Telescope (MOST) and the Australia Telescope Compact Array (ATCA) point source catalogues to estimate spectral indices for the whole population of radio point sources found in the survey region. Combining our ASKAP catalogues with these radio continuum surveys, we found 7736 point-like sources in common over an area of 30 deg2. In addition, we report the detection of two new, low surface brightness supernova remnant candidates in the SMC. The high sensitivity of the new ASKAP ESP survey also enabled us to detect the bright end of the SMC planetary nebula sample, with 22 out of 102 optically known planetary nebulae showing point-like radio continuum emission. Lastly, we present several morphologically interesting background radio galaxies.

scholarly journals New 6 and 3-cm radio-continuum maps of the Small Magellanic Cloud, Part I: The maps

2011 ◽  
pp. 95-102 ◽  
Author(s):  
E. Crawford ◽  
M.D. Filipovic ◽  
Horta de ◽  
G.F. Wong ◽  
N.F.H. Tothill ◽  
...  
Keyword(s):  
Radio Source ◽  
Magellanic Cloud ◽  
Radio Continuum ◽  
Source Population ◽  
Small Magellanic Cloud ◽  
Extended Structure ◽  
Future Studies

We present new 6 and 3-cm radio-continuum maps of the Small Magellanic Cloud (SMC), created with the "peeling" technique and a joint deconvolution. The maps have resolutions of 3000 and 2000 and r.m.s., noise of 0.7 and 0.8 mJy/beam at 6 and 3 cm, respectively. These maps will be used for future studies of the SMC's radio source population and overall extended structure.

scholarly journals Spatial Variations of Turbulent Properties of Neutral Hydrogen Gas in the Small Magellanic Cloud Using Structure-function Analysis

2017 ◽  
Vol 845 (1) ◽  
pp. 53 ◽  
Author(s):  
David Nestingen-Palm ◽  
Snežana Stanimirović ◽  
Diego F. González-Casanova ◽  
Brian Babler ◽  
Katherine Jameson ◽  
...  
Keyword(s):  
Structure Function ◽  
Function Analysis ◽  
Neutral Hydrogen ◽  
Spatial Variations ◽  
Magellanic Cloud ◽  
Hydrogen Gas ◽  
Small Magellanic Cloud

scholarly journals The Diffuse Ionized Gas Halo of the Small Magellanic Cloud

2019 ◽  
Vol 887 (1) ◽  
pp. 16 ◽  
Author(s):  
B. M. Smart ◽  
L. M. Haffner ◽  
K. A. Barger ◽  
A. Hill ◽  
G. Madsen
Keyword(s):  
Magellanic Cloud ◽  
Small Magellanic Cloud ◽  
Ionized Gas ◽  
Diffuse Ionized Gas

scholarly journals GASP XXV: neutral hydrogen gas in the striking jellyfish galaxy JO204

2020 ◽  
Vol 494 (4) ◽  
pp. 5029-5043 ◽  
Author(s):  
Tirna Deb ◽  
Marc A W Verheijen ◽  
Marco Gullieuszik ◽  
Bianca M Poggianti ◽  
Jacqueline H van Gorkom ◽  
...  
Keyword(s):  
Neutral Hydrogen ◽  
Turbulent Medium ◽  
Hydrogen Gas ◽  
Radio Continuum ◽  
Absorption Profile ◽  
Ionized Gas ◽  
Absorption Column ◽  
Continuum Source ◽  
Neutral Gas ◽  
Ram Pressure

ABSTRACT We present JVLA-C observations of the H i gas in JO204, one of the most striking jellyfish galaxies from the GASP survey. JO204 is a massive galaxy in the low-mass cluster A957 at z = 0.04243. The H i map reveals an extended 90 kpc long ram-pressure stripped tail of neutral gas, stretching beyond the 30 kpc long ionized gas tail and pointing away from the cluster centre. The H i mass seen in emission is $(1.32\pm 0.13) \times 10^{9} \, \rm M_{\odot }$, mostly located in the tail. The northern part of the galaxy disc has retained some H i gas, while the southern part has already been completely stripped and displaced into an extended unilateral tail. Comparing the distribution and kinematics of the neutral and ionized gas in the tail indicates a highly turbulent medium. Moreover, we observe associated H i absorption against the 11 mJy central radio continuum source with an estimated H i absorption column density of 3.2 × 1020 cm−2. The absorption profile is significantly asymmetric with a wing towards higher velocities. We modelled the H i absorption by assuming that the H i and ionized gas discs have the same kinematics in front of the central continuum source, and deduced a wider absorption profile than observed. The observed asymmetric absorption profile can therefore be explained by a clumpy, rotating H i gas disc seen partially in front of the central continuum source, or by ram pressure pushing the neutral gas towards the centre of the continuum source, triggering the AGN activity.

scholarly journals New 20-cm radio-continuum study of the Small Magellanic Cloud, part II: Point sources

2011 ◽  
pp. 103-106 ◽  
Author(s):  
G.F. Wong ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
N.F.H. Tothill ◽  
Horta de ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Magellanic Cloud ◽  
Point Sources ◽  
Radio Continuum ◽  
Small Magellanic Cloud

We present a new catalogue of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). This catalogue contains sources previously not found in 2370 MHz (?=13 cm) with sources found at 1400 MHz (?=20 cm) and 843 MHz (?=36 cm). 45 sources have been detected at 13 cm, with 1560 sources at 20 cm created from new high sensitivity and resolution radio-continuum images of the SMC at 20 cm from paper I. We also created a 36 cm catalogue to which we listed 1689 radio-continuum sources.

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