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L-band gain calibrators

L-band gain calibrators

We present below updated, full Stokes, measurements of the MeerKAT L-band gain calibrators. Observations were conducted in August 2019 (RA range 11–23 hours) and August 2020 (RA range 00-11 hours). Please consult this memo for further details of the observations and processing. Full imaging products are available as a data release in the SARAO repository.

Data products are full Stokes parameter (Stokes I, Q, U, and V) Fits image cubes, total intensity spectra (PNG files) and other polarization spectral plots (PNG files). These images are provided for each calibrator source reported on in the memo.

The table below lists the following properties for each calibration source:

  • the flux density at 1400 MHz (S1.4GHz), from a power-law fit the to the Stokes I spectrum.

  • the in-band spectral index from the power-law fit to the Stokes I spectrum (Alpha). Errors are the formal error on the fit parameter from the covariance matrix.

  • a URL link to the peak Stokes I spectrum plot where flux values are the brightest pixels taken from the FITS cube.

  • the degree of polarized intensity and position angle at 1400 MHz (p_1.4, PA_1.4) measured as the average value of polarised intensity and polarization angle over the channels within +/- 20 MHz of 1400 MHz. The errors are the standard error on the mean derived from the RMS of the N values over the frequency interval divided by square-root(N).

  • the spectral index of polarized intensity (Beta) from a power-law fit to the spectrum of polarized intensity. Errors are the formal error on the fit parameter from the covariance matrix.

  • the Faraday depth of the dominant RM synthesis component with error.

  • the amplitude (polarized intensity) of the dominant RM synthesis component.

  • the median value of the fractional Stokes v=V/I over the band. The error is the standard error on the mean derived from the RMS of the values over the band.

 

Calibrator

name

RA

(J2000)

DEC

(J2000)

S1.4GHz (Jy)

Alpha

SED plot

p1.4GHz (%)

PA1.4GHz(deg)

Beta

RM (rad/m^2)

pmax (%)

med. v (%)

Calibrator

name

RA

(J2000)

DEC

(J2000)

S1.4GHz (Jy)

Alpha

SED plot

p1.4GHz (%)

PA1.4GHz(deg)

Beta

RM (rad/m^2)

pmax (%)

med. v (%)

J0010-4153

00:10:53

-41:53:11

4.545 +/- 0.102

-0.851 +/- 0.02

SED link

0.12 +/- 0.00

-60.2 +/- 0.7

-0.240 +/- 1.26

-1.20 +/- 18.7

0.14

0.008 +/- 0.002

J0022+0014

00:22:25

+00:14:56

2.900 +/- 0.065

-0.563 +/- 0.02

SED link

0.09 +/- 0.01

-11.3 +/- 1.6

-1.530 +/- 1.66

2.00 +/- 13.1

0.13

-0.080 +/- 0.003

J0024-4202

00:24:43

-42:02:04

2.871 +/- 0.065

0.639 +/- 0.06

SED link

0.10 +/- 0.01

-4.1 +/- 1.1

-0.360 +/- 1.42

4.60 +/- 13.2

0.13

-0.052 +/- 0.003

J0025-2602

00:25:49

-26:02:13

8.731 +/- 0.196

-0.733 +/- 0.01

SED link

0.17 +/- 0.00

72.8 +/- 1.1

0.310 +/- 0.94

-3.60 +/- 12.8

0.18

-0.077 +/- 0.004

J0059+0006

00:59:06

+00:06:52

2.449 +/- 0.055

-0.559 +/- 0.01

SED link

3.76 +/- 0.05

74.3 +/- 0.6

-0.680 +/- 0.23

-3.60 +/- 0.8

3.1

-0.098 +/- 0.005

J0108+0134

01:08:39

+01:35:00

3.113 +/- 0.070

-0.273 +/- 0.02

SED link

3.88 +/- 0.01

-79.7 +/- 0.2

0.130 +/- 0.06

-6.60 +/- 0.5

3.87

-0.033 +/- 0.007

J0137+3309

01:37:41

+33:09:35

16.112 +/- 0.362

-0.889 +/- 0.01

SED link

0.64 +/- 0.01

-36.4 +/- 0.5

-2.010 +/- 1.17

-55.40 +/- 4.6

0.49

-0.025 +/- 0.003

J0155-4048

01:55:37

-40:48:42

2.161 +/- 0.049

-0.456 +/- 0.01

SED link

0.07 +/- 0.01

29.9 +/- 2.2

1.710 +/- 0.90

0.00 +/- 30.5

0.08

-0.006 +/- 0.002

J0203-4349

02:03:41

-43:49:51

2.726 +/- 0.061

-0.825 +/- 0.01

SED link

0.91 +/- 0.01

-55.5 +/- 0.3

-7.370 +/- 0.97

-8.20 +/- 4.8

0.49

-0.018 +/- 0.002

J0210-5101

02:10:46

-51:01:02

3.402 +/- 0.077

0.127 +/- 0.02

SED link

1.24 +/- 0.01

30.7 +/- 0.2

-0.310 +/- 0.16

14.60 +/- 2.5

1.12

-0.031 +/- 0.003

J0238+1636

02:38:39

+16:36:59

0.528 +/- 0.014

-0.246 +/- 0.05

SED link

0.77 +/- 0.01

19.6 +/- 23.7

0.200 +/- 0.71

48.00 +/- 2.7

0.72

-0.075 +/- 0.007

J0240-2309

02:40:08

-23:09:16

5.938 +/- 0.134

-0.154 +/- 0.03

SED link

0.98 +/- 0.00

-42.2 +/- 0.2

-0.220 +/- 0.33

10.00 +/- 3.0

0.98

0.359 +/- 0.006

J0252-7104

02:52:46

-71:04:35

5.811 +/- 0.131

-0.972 +/- 0.01

SED link

0.18 +/- 0.01

-35.3 +/- 0.2

0.010 +/- 0.72

2.40 +/- 12.2

0.23

0.002 +/- 0.001

J0303-6211

03:03:51

-62:11:26

3.194 +/- 0.072

-0.093 +/- 0.01

SED link

4.71 +/- 0.01

46.6 +/- 0.5

-0.340 +/- 0.07

49.60 +/- 1.2