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Join us at the NASA Space Grant Symposium to delve into radio astronomy, learn about LOFAR, and uncover the mysteries of spectral index in radio galaxies. Discover the significance of long wavelengths and high resolution.
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Stephanie Stawinski1 Director: Evan Scannapieco1 Committee: Rogier Windhorst1, Karen Olsen1, Marcus Bruggen2 April 21-22, 2017 2017 NASA Space Grant Symposium Arizona State University1 and University of Hamburg2 First Half of Project Sponsored by NSF IRES Program and LOFAR ASTRON Studying Spectral Index of Radio Galaxies with LOFAR
Outline • Radio Astronomy: • What is it? • Why is it useful? • How does Radio Astronomy Work? • Basic Interferometry • How Does LOFAR work? • Cleaning an Image • Finding Sources and Source Matching • Positional offsets and Flux Scales • Spectral Index • What is it? • Our Results
Why Radio Astronomy? • 10 MHz - 100 GHz http://study.com/cimages/multimages/16/optical_vs_vla_small.jpg https://www.sciencelearn.org.nz/system/images/images/000/002/002/embed/Radiation-reaching-Earth20160922-23617-1fmhxkd.jpg?1474534015 In order to detect long wavelengths (radio waves) at a high resolution, you need a large diameter Interferometry can reach a higher resolution, without a giant single dish
LOFARHow does it work? HBA LBA http://media.lofar-se.org/2011/09/lofar_onsala_20110706.jpg van der Veldt 2011
https://science.nrao.edu/science/meetings/presentation/jdf.webinar.4.pdfhttps://science.nrao.edu/science/meetings/presentation/jdf.webinar.4.pdf Outputs of Clean?
Matching with TGSS:Large 150 MHz Survey using the GMRT (Giant Metrewave Radio Telescope)Corrected Offsets: Factor in DEC 0.0002
What is Spectral Index? Matched with FIRST Survey: 1435 MHz using the Very Large Array (VLA) Where S is the Flux and v is the Frequency v for LOFAR is 141 MHz v for FIRST is 1435 MHz
Comparison • De Brueck et. al 2000: 143,000 sources from the WENSS (325 MHz) and NVSS (1400 MHz)
Thank you to:NASA Space Grant Program,LOFAR, and NSF IRES Program