J/ApJ/897/5 90 sources radio flux density from GLEAM and HERA (Nunhokee+, 2020)
Measuring HERA's Primary Beam in Situ: Methodology and First Results.
Nunhokee C.D., Parsons A.R., Kern N.S., Nikolic B., Pober J.C., Bernardi G.,
Carilli C.L., Abdurashidova Z., Aguirre J.E., Alexander P., Ali Z.S.,
Balfour Y., Beardsley A.P., Billings T.S., Bowman J.D., Bradley R.F.,
Burba J., Cheng C., DeBoer D.R., Dexter M., de Lera Acedo E., Dillon J.S.,
Ewall-Wice A., Fagnoni N., Fritz R., Furlanetto S.R., Gale-Sides K.,
Glendenning B., Gorthi D., Greig B., Grobbelaar J., Halday Z.,
Hazelton B.J., Hewitt J.N., Jacobs D.C., Julius A., Kerrigan J.,
Kittiwisit P., Kohn S.A., Kolopanis M., Lanman A., La Plante P.,
Lekalake T., Liu A., MacMahon D., Malan L., Malgas C., Maree M.,
Martinot Z.E., Matsetela E., Mesinger A., Molewa M., Morales M.F.,
Mosiane T., Neben A.R., Patra N., Pieterse S., Razavi-Ghods N.,
Ringuette J., Robnett J., Rosie K., Sims P., Smith C., Syce A.,
Thyagarajan N., Williams P.K.G., Zheng H.
<Astrophys. J., 897, 5 (2020)>
=2020ApJ...897....5N 2020ApJ...897....5N
ADC_Keywords: Radio sources; Galaxies
Keywords: Cosmology ; H I line emission ; Radio astronomy
Abstract:
The central challenge in 21cm cosmology is isolating the cosmological
signal from bright foregrounds. Many separation techniques rely on the
accurate knowledge of the sky and the instrumental response, including
the antenna primary beam. For drift-scan telescopes, such as the
Hydrogen Epoch of Reionization Array (HERA), that do not move, primary
beam characterization is particularly challenging because standard
beam-calibration routines do not apply (Cornwell et al.) and current
techniques require accurate source catalogs at the telescope
resolution. We present an extension of the method from Pober et al.
where they use beam symmetries to create a network of overlapping
source tracks that break the degeneracy between source flux density
and beam response and allow their simultaneous estimation. We fit the
beam response of our instrument using early HERA observations and find
that our results agree well with electromagnetic simulations down to a
-20dB level in power relative to peak gain for sources with high
signal-to-noise ratio. In addition, we construct a source catalog with
90 sources down to a flux density of 1.4Jy at 151MHz.
Description:
The measurements used in this paper are taken from the Hydrogen Epoch
of Reionization Array (HERA) Phase I configuration, comprising 52
antennas that reach out to a uv distance of 75λ. Once we have
the deconvolved images as described in Section 3.2, we run the source
finder software Python Blob Detection and Source Finder (PyBDSF) to
find potential point sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 62 90 List of sources used in this work and their
derived flux density
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See also:
VIII/35 : Radio Sources observed with Culgoora Circular Array (Slee 1995)
VIII/100 : GaLactic and Extragalactic All-sky MWA survey (Hurley-Walker+, 2016)
J/ApJ/771/105 : MWA Stokes I 189MHz sources (Bernardi+, 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
-------------------------------------------------------------------------------
1- 14 A14 --- GLEAM Source identification
16 A1 --- f_GLEAM [*] Flag on Name; brightest source in the cluster
18- 23 F6.2 deg RAdeg [22.5/160] Right ascension measured by PyBDSF (J2000)
25- 30 F6.2 deg RA0 [22.6/160] Right ascension measured by GLEAM
32- 37 F6.2 deg DEdeg [-37.3/-24.7] Declination measure by PyBDSF (J2000)
39- 44 F6.2 deg DE0 [-37.2/-24.8] Declination measured by GLEAM
46- 50 F5.2 Jy F151 [1.44/55.7] Flux density at 151MHz
52- 56 F5.2 Jy e_F151 [1/11] Error on F151
58- 62 F5.2 Jy FG151 [1.62/55.94] Flux density at 151MHz with GLEAM
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History:
From electronic version of the journal
(End) Prepared by Coralie Fix [CDS], 08-Oct-2021