OPENING THE 21 cm EPOCH OF REIONIZATION WINDOW: MEASUREMENTS OF FOREGROUND ISOLATION WITH PAPER

Journal Article · Fri May 10 00:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/768/2/L36· OSTI ID:22130666

Pober, Jonathan C.; Parsons, Aaron R.; Ali, Zaki ^[1]; Aguirre, James E.; Moore, David F. ^[2]; Bradley, Richard F. ^[3]; Carilli, Chris L. ^[4]; DeBoer, Dave; Dexter, Matthew; MacMahon, Dave ^[5]; Gugliucci, Nicole E. ^[6]; Jacobs, Daniel C. ^[7]; Klima, Patricia J. ^[8]; Manley, Jason; Walbrugh, William P. ^[9]; Stefan, Irina I. ^[10]

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1. Astronomy Department, U. California, Berkeley, CA (United States)
2. Department of Physics and Astronomy, U. Pennsylvania, Philadelphia, PA (United States)
3. Department of Electrical and Computer Engineering, U. Virginia, Charlottesville, VA (United States)
4. National Radio Astronomy Observatory, Socorro, NM (United States)
5. Radio Astronomy Laboratory, U. California, Berkeley, CA (United States)
6. Department of Astronomy, U. Virginia, Charlottesville, VA (United States)
7. School of Earth and Space Exploration, Arizona State U., Tempe, AZ (United States)
8. National Radio Astronomy Observatory, Charlottesville, VA (United States)
9. Square Kilometer Array, South Africa Project, Cape Town (South Africa)
10. Cavendish Laboratory, Cambridge (United Kingdom)

We present new observations with the Precision Array for Probing the Epoch of Reionization with the aim of measuring the properties of foreground emission for 21 cm epoch of reionization (EoR) experiments at 150 MHz. We focus on the footprint of the foregrounds in cosmological Fourier space to understand which modes of the 21 cm power spectrum will most likely be compromised by foreground emission. These observations confirm predictions that foregrounds can be isolated to a {sup w}edge{sup -}like region of two-dimensional (k , k{sub Parallel-To })-space, creating a window for cosmological studies at higher k{sub Parallel-To} values. We also find that the emission extends past the nominal edge of this wedge due to spectral structure in the foregrounds, with this feature most prominent on the shortest baselines. Finally, we filter the data to retain only this ''unsmooth'' emission and image its specific k{sub Parallel-To} modes. The resultant images show an excess of power at the lowest modes, but no emission can be clearly localized to any one region of the sky. This image is highly suggestive that the most problematic foregrounds for 21 cm EoR studies will not be easily identifiable bright sources, but rather an aggregate of fainter emission.

• OSTI ID: 22130666
• Journal Information: Astrophysical Journal Letters, Vol. 768, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
COSMOLOGY
EMISSION
FILTERS
IMAGES
MHZ RANGE
SIMULATION
SKY
SPACE
SPECTRA
STARS