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J/MNRAS/458/1057     EoR0 central field source catalog        (Offringa+, 2016)

Parametrizing Epoch of Reionization foregrounds: a deep survey of low-frequency point-source spectra with the Murchison Widefield Array. Offringa A.R., Trott C.M., Hurley-Walker N., Johnston-Hollitt M., McKinley B., Barry N., Beardsley A.P., Bowman J.D., Briggs F., Carroll P., Dillon J.S., Ewall-Wice A., Feng L., Gaensler B.M., Greenhill L.J., Hazelton B.J., Hewitt J.N., Jacobs D.C., Kim H.-S., Kittiwisit P., Lenc E., Line J., Loeb A., Mitchell D.A., Morales M.F., Neben A.R., Paul S., Pindor B., Pober J.C., Procopio P., Riding J., Sethi S.K., Shankar N.U., Subrahmanyan R., Sullivan I.S., Tegmark M., Thyagarajan N., Tingay S.J., Wayth R.B., Webster R.L., Wyithe J.S.B. <Mon. Not. R. Astron. Soc., 458, 1057-1070 (2016)> =2016MNRAS.458.1057O (SIMBAD/NED BibCode)
ADC_Keywords: Radio sources ; Interferometry ; Radio lines Keywords: methods: observational - techniques: interferometric - dark ages, reionization, first stars - radio continuum: general - radio lines: galaxies Abstract: Experiments that pursue detection of signals from the Epoch of Reionization (EoR) are relying on spectral smoothness of source spectra at low frequencies. This article empirically explores the effect of foreground spectra on EoR experiments by measuring high-resolution full-polarization spectra for the 586 brightest unresolved sources in one of the Murchison Widefield Array (MWA) EoR fields using 45h of observation. A novel peeling scheme is used to subtract 2500 sources from the visibilities with ionospheric and beam corrections, resulting in the deepest, confusion-limited MWA image so far. The resulting spectra are found to be affected by instrumental effects, which limit the constraints that can be set on source-intrinsic spectral structure. The sensitivity and power-spectrum of the spectra are analysed, and it is found that the spectra of residuals are dominated by point spread function sidelobes from nearby undeconvolved sources. We release a catalogue describing the spectral parameters for each measured source. Description: The observations used in this work have been made as part of the MWA EoR project. We have used observations that are centred at RA 0°, Dec. -27°, and recorded between 2013 August and October. The field around this target is referred to as the MWA EoR0 field - one of three fields that were selected based on having weak Galactic foregrounds and passing nearly through zenith at the MWA. The selected 15 nights are listed in Table 1. Of these 15 nights, 3 nights were not included in the analyses because they show RFI or unusual calibration solutions. The MWA can observe 30.72MHz simultaneously. To cover a larger redshift range, a total bandwidth of 138.9-197.7MHz is recorded by observing in two different bands. The low band covers 138.9-169.6MHz and the high band covers 167.0-197.7MHz. Together these cover the HI 21cm line at redshifts 6.1-9.2. The observations have a frequency resolution of 40kHz and time resolution of 0.5s. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 77 586 Catalog of sources in the central 10° radius of the EoR0 field
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 6 A6 --- --- [MWAEOR] 7- 20 A14 --- MWAEOR MWAEOR designation (JHHMMSS+DDMMSS) 22- 23 I2 h RAh Right ascension (J2000) 25- 26 I2 min RAm Right ascension (J2000) 28- 31 F4.1 s RAs Right ascension (J2000) 33 A1 --- DE- Declination sign (J2000) 34- 35 I2 deg DEd Declination (J2000) 37- 38 I2 arcmin DEm Declination (J2000) 40- 43 F4.1 arcsec DEs Declination (J2000) 45- 50 F6.3 Jy S168MHz Flux density at 168MHz 52- 56 F5.3 Jy e_S168MHz rms uncertainty on S168MHz 58- 62 F5.2 --- alpha Spectral index alpha at 168MHz (1) 64- 67 F4.2 --- e_alpha rms uncertainty on alpha 69- 73 F5.1 --- beta Spectral curvature beta at 168MHz (1) 75- 77 F3.1 --- e_beta rms uncertainty on beta
Note (1): we fit each spectrum to a second-order logarithmic polynomial: logS(nu)=logS0 + alphalog(nu/nu0) + beta(log(nu/nu0))2, where S0 is the source flux density at the reference frequency nu0=168.3MHz, alpha the spectral index at frequency nu0 et beta the spectral curvature.
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 26-May-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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