Calibration and performance of the NIKA2 camera at the IRAM 30-m Telescope

摘要: Context. NIKA2 is a dual-band millimetre continuum camera of 2 900 kinetic inductance detectors, operating at 150 and 260 GHz, installed the IRAM 30-m telescope in Spain. Open to scientific community since October 2017, will provide key observations for next decade address wide range open questions astrophysics cosmology. Aims. Our aim present calibration method performance assessment after one year observation. Methods. We used large data set acquired between January 2017 February 2018 including primary secondary calibrators faint sources that span whole observing elevations atmospheric conditions encountered by telescope. This allowed us test stability parameters against time evolution conditions. describe standard method, referred as “Baseline” translate raw into flux density measurements. includes determination detector positions sky, selection measurement beam pattern, estimation opacity, absolute scale, flat fielding, photometry. assessed robustness results using Baseline systematic effects comparing alternative methods. Results. report an instantaneous field view 6.5′ diameter, filled with average fraction 84%, 90% valid detectors respectively. The pattern characterised FWHM 17.6″ ± 0.1″ 11.1″ ± 0.2″, main-beam efficiency 47%±3%, 64%±3% point-source rms uncertainties are about 3% GHz 6% GHz. demonstrates accuracy methods we deployed correct attenuation. 5%, evaluated reference Winter below 1% both channels. noise equivalent 9 ± 1 mJy s1/2 30 ± 3 s1/2. state-of-the-art confers mapping speeds 1388 ± 174 111 ± 11 arcmin2 mJy−2 h−1 GHz. Conclusions. With these unique capabilities fast high (better 18″) angular resolution, providing unprecedented Universe.