کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5487744 | 1523721 | 2017 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Validating a novel angular power spectrum estimator using simulated low frequency radio-interferometric data
ترجمه فارسی عنوان
اعتبارسنجی یک برآورد طیفی قدرت زاویه ای جدید با استفاده از داده های رادیو-تداخل سنجی با فرکانس شبیه سازی شده
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
نجوم و فیزیک نجومی
چکیده انگلیسی
The “Tapered Gridded Estimator” (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise bias, and suppresses the foreground contamination to a large extent by tapering the primary beam response through an appropriate convolution in the visibility domain. Here we demonstrate the effectiveness of TGE in recovering the diffuse emission power spectrum through numerical simulations. We present details of the simulation used to generate low frequency visibility data for sky model with extragalactic compact radio sources and diffuse Galactic synchrotron emission. We then use different imaging strategies to identify the most effective option of point source subtraction and to study the underlying diffuse emission. Finally, we apply TGE to the residual data to measure the angular power spectrum, and assess the impact of incomplete point source subtraction in recovering the input power spectrum Câ of the synchrotron emission. This estimator is found to successfully recovers the Câ of input model from the residual visibility data. These results are relevant for measuring the diffuse emission like the Galactic synchrotron emission. It is also an important step towards characterizing and removing both diffuse and compact foreground emission in order to detect the redshifted 21âcm signal from the Epoch of Reionization.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: New Astronomy - Volume 57, November 2017, Pages 94-103
Journal: New Astronomy - Volume 57, November 2017, Pages 94-103
نویسندگان
Samir Choudhuri, Nirupam Roy, Somnath Bharadwaj, Sk. Saiyad Ali, Abhik Ghosh, Prasun Dutta,