The ASKAP EMU Early Science Project: radio continuum survey of the Small Magellanic Cloud
The ASKAP EMU Early Science Project: radio continuum survey of the Small Magellanic Cloud
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DOI：
10.1093/mnras/stz2650
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发表时间：
2019-09
影响因子：
4.8
通讯作者：
T. Joseph;M. Filipovi'c;E. Crawford;I. Bojivci'c;Elaine L. Alexander;G. Wong;H. Andernach;H. Leve
中科院分区：
文献类型：
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作者：
T. Joseph;M. Filipovi'c;E. Crawford;I. Bojivci'c;Elaine L. Alexander;G. Wong;H. Andernach;H. Leve
我们展示了澳大利亚平方公里阵列探路者(ASKAP)对小麦哲伦星云(SMC)方向的两幅新的射电连续图像。这些图像是宇宙进化地图(EMU)早期科学项目(ESP)对大小麦哲伦星云的调查的一部分。从这些图像产生的两个新的源列表包含在960 MHz(4489个源)和1320 MHz(5954个源)观测到的射电连续谱源，带宽为192 MHz，波束尺寸分别为30.0×30.0arcsec2和16.3×15.1arcsec2。中值均方根噪声值分别为186$Jy波束−1(960 MHz)和165$Jy波束−1(1320 MHz)。为了创建点源星表，我们使用这两个源星表，以及以前公布的莫龙格罗天文台综合望远镜(MOST)和澳大利亚望远镜紧凑型阵列(ATCA)点源星表，以估计在调查区域发现的整个射电点源群体的频谱指数。结合我们的ASKAP星表和这些射电连续谱调查，我们在30°2的区域内发现了7736个类似点的源。此外，我们还报告了在SMC中探测到的两个新的低表面亮度超新星遗迹候选者。新的ASKAP ESP测量的高灵敏度也使我们能够探测到SMC行星星云样本的亮端，102个光学已知的行星星云中有22个显示出点状射电连续发射。最后，我们给出了几个形态上很有趣的背景射电星系。
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.