Please use this identifier to cite or link to this item:
http://hdl.handle.net/2289/8020| Title: | Detecting galaxies in a large H i spectral cube |
| Authors: | Shaw, Abinash Kumar Jagannath, Manoj Mazumder, Aishrila Chakraborty, Arnab Patra, Narendra Nath Mondal, Rajesh Choudhuri, Samir |
| Keywords: | statistical methods data analysis interformetric cosmology diffuse radiation |
| Issue Date: | 15-Dec-2022 |
| Publisher: | Indian Academy of Sciences, Bengaluru |
| Citation: | Journal of Astrophysics and Astronomy, 2022, Vol.43, Article Number 99 |
| Abstract: | The upcoming square kilometer array (SKA) is expected to produce humongous amount of data for undertaking H i science. We have developed an MPI-based Python pipeline to deal with the large data efficiently with the present computational resources. Our pipeline divides such large H i 21-cm spectral cubes into several small cubelets, and then processes them in parallel using publicly available H i source finder SoFiA-2. The pipeline also takes care of sources at the boundaries of the cubelets and also filters out false and redundant detections. By comapring with the true source catalog, we find that the detection efficiency depends on the SoFiA-2 parameters, such as the smoothing kernel size, linking length and threshold values. We find the optimal kernel size for all flux bins to be between 3–5 and 7–15 pixels, respectively, in the spatial and frequency directions. Comparing the recovered source parameters with the original values, we find that the output of SoFiA-2 is highly dependent on kernel sizes and a single choice of kernel is not sufficient for all types of H i galaxies. We also propose the use of alternative methods to SoFiA-2, which can be used in our pipeline to find sources more robustly. |
| Description: | Open Access from Indian Academy of Sciences |
| URI: | http://hdl.handle.net/2289/8020 |
| ISSN: | 0250-6335 0973-7758 (Online) |
| Alternative Location: | https://ui.adsabs.harvard.edu/abs/2022JApA...43...99S/abstract https://arxiv.org/abs/2211.02041 https://doi.org/10.1007/s12036-022-09880-1 |
| Copyright: | 2022 Indian Academy of Sciences, Bengaluru |
| Appears in Collections: | Research Papers (A&A) |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 2022_JAA_Vol.43_99.pdf Restricted Access | Open Access | 968 kB | Adobe PDF | View/Open Request a copy |
Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.