Table 2
Estimation of the limiting magnitude mT in each of the K, H, J, and R bands.
| K | H | J | R | Unit | ||
|
|
||||||
| Wavelength | λ | 2.22 | 1.60 | 1.26 | 0.64 | μm |
| Bandwidth | Δλ/λ | 0.23 | 0.23 | 0.16 | 0.23 | |
| Zero magnitude flux | m 0 | 670 | 1080 | 1600 | 3080 | Jy |
|
|
||||||
| Fried parameter | r 0 | 41 | 28 | 22 | 7 | cm |
| Coherence time | τ 0 | 8.9 | 6.1 | 4.7 | 1.5 | ms |
|
|
||||||
| Telescope diameter (2r0) | D | 81 | 56 | 43 | 14 | cm |
| Fringe sensor frequency (1 /τ0) | f | 112.7 | 165.1 | 211.8 | 666.7 | Hz |
|
|
||||||
| Photons per exposure | N hν | 10.7 × 106 | 5.5 × 106 | 2.7 × 106 | 0.24 × 106 | hν |
|
|
||||||
| Limiting magnitude | m 100% | 13.3 | 12.6 | 11.8 | 9.2 | mag |
| (phase SNR of 10) | m 5% | 10.1 | 9.4 | 8.6 | 5.9 | mag |
Notes. The assumptions are a seeing strength of 1.5′′, a seeing speed of τ0 =1.5 ms. From these, the telescope diameter D and the fringe tracker rate fFT can be deduced at each wavelength. The limiting magnitude mT is given in each band considering a reasonable T = 5% total transmission to the fringe tracker (T = 100% gives an indication of the transmission loss effect).
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.