All Tables

Table 1: Water vapour seeing at three astronomical sites. The Fried parameter r₀ is given at 500 nm, adapted from the values of Racine (2005). References for the PWV data are given in the last column. The standard deviation of water vapour seeing at Dome C is deduced from the data at Cerro Paranal and Mauna Kea following Eq. (1). Water vapour seeing was measured on a baseline of 66 m (resp. 100 m) at Paranal (resp. Mauna Kea), and we assume that our estimate at Dome C is valid for a similar range of baseline lengths.
Table 2: Atmospheric parameters adopted for the performance simulation of ALADDIN at Dome C, assuming that the instrument is located about 30 m above the ground level. The equivalent wind speed is the wind speed integrated across the whole turbulence profile (above 30 m).
Table 3: Summary of the instrumental parameters assumed for the performance simulation of ALADDIN. The throughput and emissivity are directly computed from the baseline instrumental design, which is based on a simplified version of the GENIE instrument.
Table 4: Control loop performance and optimum repetition frequencies (0 Hz means that no control loop is used) as simulated on a 100 s observation sequence, for the GENIE instrument working on the 8-m Unit Telescopes (UT) at the VLTI (results taken from Paper I) and the ALADDIN instrument at Dome C. The observations are carried out in the L band for a Sun-like G2V star located at 20 pc using either the 47-m UT2-UT3 baseline at the VLTI (waveband: 3.5-4.1 $\mu$ m) or a baseline length of 20 m for ALADDIN (waveband: 3.1-4.1 $\mu$ m). The goal performance for exozodiacal disc detection discussed in Paper I appears in the last column. The total null is the mean nulling ratio including both the geometric and instrumental leakage contributions. The last line gives the standard deviation of the instrumental nulling ratio for this 100 s sequence (note that we give here the standard deviation of the mean instrumental nulling ratio computed on the whole time sequence, which is more representative than the frame-to-frame deviation presented in Paper I).
Table 5: Comparison of the angular resolution provided by the optimum ALADDIN baseline length ( $4 \le b \le 30$ m) with the characteristic position of the habitable zone of the target systems.
Table 6: Comparison of the GENIE and ALADDIN performance expressed in detectable exozodiacal disc densities as compared to the solar zodiacal disc. Four different levels of uncertainty have been assumed on the angular diameter of the target stars. The simulations are performed in the L band, which extends from 3.5 to 4.1 $\mu$ m in the case of GENIE and from 3.1 to 4.1 $\mu$ m in the case of ALADDIN. An integration time of 30 min is assumed in all cases.