Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization
B. Pindor A D , J. S. B. Wyithe A , D. A. Mitchell B , S. M. Ord B , R. B. Wayth C and L. J. Greenhill B
+ Author Affiliations
- Author Affiliations
A University of Melbourne, School of Physics, Parkville 3010, Australia
B Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138-1516, USA
C ICRAR/Curtin Institute of Radio Astronomy, GPO Box U1987, Perth, WA 6845, Australia
D Corresponding author. Email: bpindor@unimelb.edu.au
Publications of the Astronomical Society of Australia 28(1) 46-57 https://doi.org/10.1071/AS10023
Submitted: 2 July 2010 Accepted: 14 September 2010 Published: 5 January 2011
Abstract
Bright point sources associated with extragalactic active galactic nuclei and radio galaxies are an important foreground for low-frequency radio experiments aimed at detecting the redshifted 21-cm emission from neutral hydrogen during the epoch of reionization. The frequency dependence of the synthesized beam implies that the sidelobes of these sources will move across the field of view as a function of observing frequency, hence frustrating line-of-sight foreground subtraction techniques. We describe a method for subtracting these point sources from dirty maps produced by an instrument such as the MWA. This technique combines matched filters with an iterative centroiding scheme to locate and characterize point sources in the presence of a diffuse background. Simulations show that this technique can improve the dynamic range of epoch-of-reionization maps by 2–3 orders of magnitude.
Keywords: cosmology: diffuse radiation — methods: data analysis
References
Ali, S. S., Bharadwaj, S. and Chengalur, J. N., 2008, MNRAS, 385, 2166| Crossref | GoogleScholarGoogle Scholar |
Becker, R. H. et al., 2001, AJ, 122, 2850
| Crossref | GoogleScholarGoogle Scholar |
Bernardi, G. et al., 2009, A&A, 500, 965
| Crossref | GoogleScholarGoogle Scholar |
Bernardi, G. et al., 2010, arXiv1002.4177
Bowman, J. D., Morales, M. F. and Hewitt, J. N., 2009, ApJ, 695, 183
| Crossref | GoogleScholarGoogle Scholar |
Briggs, D. S., 1995, in Bulletin of the American Astronomical Society, Vol. 27, Bulletin of the American Astronomical Society, 1444
Briggs, D. S. & Cornwell, T. J., 1992, in Astronomical Society of the Pacific Conference Series, Vol. 25, Astronomical Data Analysis Software and Systems I, Eds. Worrall, D. M., Biemesderfer, C. & Barnes, J., 170
Ciardi, B. and Madau, P., 2003, ApJ, 596, 1
| Crossref | GoogleScholarGoogle Scholar |
Cohen, A. S., Röttgering, H. J. A., Jarvis, M. J., Kassim, N. E. and Lazio, T. J. W., 2004, ApJS, 150, 417
| Crossref | GoogleScholarGoogle Scholar |
Cornwell, T., Braun, R. & Briggs, D. S., 1999, in Astronomical Society of the Pacific Conference Series, Vol. 180, Synthesis Imaging in Radio Astronomy II, Eds. Taylor, G. B., Carilli, C. L. & Perley, R. A., 151
Cotton, W. D. and Uson, J. M., 2008, A&A, 490, 455
| Crossref | GoogleScholarGoogle Scholar |
Datta, A., Bhatnagar, S. and Carilli, C. L., 2009, ApJ, 703, 1851
| Crossref | GoogleScholarGoogle Scholar |
de Oliveira-Costa, A., Tegmark, M., Gaensler, B. M., Jonas, J., Landecker, T. L. and Reich, P., 2008, MNRAS, 388, 247
| Crossref | GoogleScholarGoogle Scholar |
Di Matteo, T., Perna, R., Abel, T. and Rees, M. J., 2002, ApJ, 564, 576
| Crossref | GoogleScholarGoogle Scholar |
Edgar, R. G., Clark, M. A., Dale, K., Mitchell, D. A., Ord, S. M., Wayth, R. B., Pfister, H., & Greenhill, L. J., 2010, ArXiv1003.5575
Field, G. B., 1959, ApJ, 129, 536
| Crossref | GoogleScholarGoogle Scholar |
Furlanetto, S. R., Oh, S. P. and Briggs, F. H., 2006, Phys. Rep., 433, 181
| Crossref | GoogleScholarGoogle Scholar |
Geil, P. M., Wyithe, J. S. B., Petrovic, N. and Oh, S. P., 2008, MNRAS, 390, 1496
Gleser, L., Nusser, A. and Benson, A. J., 2008, MNRAS, 391, 383
| Crossref | GoogleScholarGoogle Scholar |
Haehnelt, M. G. and Tegmark, M., 1996, MNRAS, 279, 545
Hales, S. E. G., Baldwin, J. E. and Warner, P. J., 1988, MNRAS, 234, 919
Harker, G. et al., 2009, MNRAS, 397, 1138
| Crossref | GoogleScholarGoogle Scholar |
Herranz, D., López-Caniego, M., Sanz, J. L. and González-Nuevo, J., 2009, MNRAS, 394, 510
| Crossref | GoogleScholarGoogle Scholar |
Högbom, J. A., 1974, A&AS, 15, 417
Intema, H. T., van der Tol, S., Cotton, W. D., Cohen, A. S., van Bemmel, I. M. and Röttgering, H. J. A., 2009, A&A, 501, 1185
| Crossref | GoogleScholarGoogle Scholar |
Jelić, V. et al., 2008, MNRAS, 389, 1319
| Crossref | GoogleScholarGoogle Scholar |
Komatsu, E. et al., 2009, ApJS, 180, 330
| Crossref | GoogleScholarGoogle Scholar |
Liu, A., Tegmark, M., Bowman, J., Hewitt, J. and Zaldarriaga, M., 2009a, MNRAS, 398, 401
| Crossref | GoogleScholarGoogle Scholar |
Liu, A., Tegmark, M. and Zaldarriaga, M., 2009b, MNRAS, 394, 1575
| Crossref | GoogleScholarGoogle Scholar |
Madau, P., Meiksin, A. and Rees, M. J., 1997, ApJ, 475, 429
| Crossref | GoogleScholarGoogle Scholar |
Mitchell, D. A., Greenhill, L. J., Wayth, R. B., Sault, R. J., Lonsdale, C. J., Cappallo, R. J., Morales, M. F. and Ord, S. M., 2008, IEEE Journal of Selected Topics in Signal Processing, vol. 2, issue 5, pp. 707–717, 2, 707
| Crossref | GoogleScholarGoogle Scholar |
Morales, M. F., 2005, ApJ, 619, 678
| Crossref | GoogleScholarGoogle Scholar |
Noordam, J. E., 2004, in Presented at the Society of Photo-Optical Instrumentation Engineers (SPIE) Conference, Vol. 5489, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Ed. Oschmann, J. M., Jr., 817
Pen, U., Chang, T., Peterson, J. B., Roy, J., Gupta, Y. & Bandura, K., 2008, in American Institute of Physics Conference Series, Vol. 1035, The Evolution of Galaxies Through the Neutral Hydrogen Window, Eds. Minchin, R. & Momjian, E., 75
Pier, J. R., Munn, J. A., Hindsley, R. B., Hennessy, G. S., Kent, S. M., Lupton, R. H. and Ivezić, Ž., 2003, AJ, 125, 1559
| Crossref | GoogleScholarGoogle Scholar |
Pritchard, J. R., Loeb, A. & Wyithe, J. S. B., 2009, ArXiv 0908.3891
Rogers, A. E. E. and Bowman, J. D., 2008, AJ, 136, 641
| Crossref | GoogleScholarGoogle Scholar |
Santos, M. G., Cooray, A. and Knox, L., 2005, ApJ, 625, 575
| Crossref | GoogleScholarGoogle Scholar |
Schwab, F. R., 1984, AJ, 89, 1076
| Crossref | GoogleScholarGoogle Scholar |
Schwarz, U. J., 1978, A&A, 65, 345
Shaver, P. A., Windhorst, R. A., Madau, P. and de Bruyn, A. G., 1999, A&A, 345, 380
Stetson, P. B., 1987, PASP, 99, 191
| Crossref | GoogleScholarGoogle Scholar |
Subrahmanyan, R., 2002, in IAU Symposium, Vol. 199, The Universe at Low Radio Frequencies, Eds. Pramesh Rao, A., Swarup, G. & Gopal-Krishna, 58
Tegmark, M. and de Oliveira-Costa, A., 1998, ApJL, 500, L83
| Crossref | GoogleScholarGoogle Scholar |
Thompson, A. R., Moran, J. M. & Swenson, G. W., Jr., 2001, Interferometry and Synthesis in Radio Astronomy, 2nd Edition
van der Tol, S., Jeffs, B. D. and van der Veen, A.-J., 2007, IEEE Transactions on Signal Processing, 55, 4497
| Crossref | GoogleScholarGoogle Scholar |
Voronkov, M. A. and Wieringa, M. H., 2004, Experimental Astronomy, 18, 13
| Crossref | GoogleScholarGoogle Scholar |
Wang, X., Tegmark, M., Santos, M. G. and Knox, L., 2006, ApJ, 650, 529
| Crossref | GoogleScholarGoogle Scholar |
Wouthuysen, S. A., 1952, AJ, 57, 31
| Crossref | GoogleScholarGoogle Scholar |
Wright, A. E. and Otrupcek, R., 1996, VizieR Online Data Catalog, 8015, 0
York, D. G. et al., 2000, AJ, 120, 1579
| Crossref | GoogleScholarGoogle Scholar |