Press Release
Open Access

Table A.1.

EHT station flux density calibration parameters and their uncertainties for the 2018 observing campaign.

Station DPFU (K/Jy) gE

LSB-RCP LSB-LCP USB-RCP USB-LCP uncertainties B E0
ALMAa 1.19 1.19 1.19 1.19 ± 10% 0 0
APEXb 0.0253 0.0262 0.0259 0.0270 ± 5.5% 0.00002 ± 3.6% 36.6 ± 1.0%
GLTc - - 0.00885 0.00885 ± 7% 0 0
LMT 0.188 0.126 0.188 0.126 ± 22% 0 0
SMT 0.0188 0.0188 0.0182 0.0182 ± 6% 0.000082 ± 10.4 % 57.6 ± 2.0%
JCMTd 0.0296 - 0.0296 - ±(11–14)% 0 0
IRAM-30m 0.144 0.138 0.142 0.137 ± 19% 0.00018 ± 5.3% 43.7 ± 1.3%
SMAe 0.040 0.040 0.040 0.040 ±(5 – 15)% 0 0
SPT 0.00698 0.00731 0.00698 0.00731 ± 10% 0 0

Note. DPFU values are quoted for both lower (LSB) and upper (USB) sidebands, and both polarizations (RCP and LCP). For phased arrays (ALMA and SMA), the DPFUs represent the combined sensitivity of all phased dishes. The gain curve parameters B and E0 as a function of elevation E are given based on a gE = 1 − B(E − E0)2 parameterization (see Janssen et al. 2019b; Koay et al. 2023a, for further details). aThe ALMA DPFU uncertainty is based on the overall 10% systematic uncertainties associated with the QA2 flux calibration tables. bAPEX measures DPFUs for each of the four bands separately. LSB and USB DPFUs shown here are the mean of the bands 1 and 2 DPFUs, and bands 3 and 4 DPFUs, respectively. cGLT DPFU uncertainties are based on the scatter of three measurements, inclusive of flux density model errors, but may be larger due to significant antenna astigmatism. There is also a ∼15% uncertainty contributing to the total SEFD uncertainty. dFor the JCMT DPFU, the nighttime value is shown. eThe SMA DPFU uncertainty is based on the dominant 5−15% uncertainty on the phasing efficiency.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.