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#author("2023-01-01T01:44:26+00:00","default:mimizuku","mimizuku") #author("2023-01-01T01:45:24+00:00","default:mimizuku","mimizuku") [[Observing]] *Available Modes [#wfb2ef48] Available spectroscopic modes are listed in the table below. To avoid saturation due to the strong emission from the diamond window, an ND filter with OD=2 is needed for observations in the LM band. |Name |Wavelength &br; range (um)|Resolving &br; power|Note|h |KL |2.0-4.0 |210 || |2.7-um|2.40-2.98 |660 || |LM+ND2|2.7-5.6 |200 |ND2 means a ND filter with OD=2| *Saturation limit [#u11f75f5] Saturation limits depend on wavelength as shown in the figures below, and the typical levels are summarized in the following table. In the water-vapor-absorbing bands, the saturation limits vary with PWV. |LEFT:100|LEFT:100|LEFT:100|c |&ref(saturation_dia_KL.jpg,,20%);|&ref(saturation_dia_2.7um.jpg,,20%);|&ref(saturation_dia_LM+ND2.jpg,,20%);| |Saturation limit of the KL band mode.|Saturation limit of the 2.7um band mode.|Saturation limit of the LM+ND2 band mode.| &br; |Name|Saturation limit|h |KL |7 Jy| |2.7-um|20 Jy| |LM+ND2|400 Jy| *Sensitivity [#n2b38c0f] 1-sigma 1-sec sensitivity is shown in the figures below. Since the sensitivity is limited by readout noise (assumed 100e^/read), it improves with longer 1-frame exposure times. In water-vapor-absorbing bands, it also depends on PWV. The truncation on the right edge shows the saturated region with the corresponding exposure time. The LM-mode sensitivity is significantly worse due to the ND filters and the strong absorption of the diamond window. 1-sigma 1-sec sensitivity is shown in the figures below. Since the sensitivity is limited by readout noise (assumed 100e-/read), it improves with longer 1-frame exposure times. In water-vapor-absorbing bands, it also depends on PWV. The truncation on the right edge shows the saturated region with the corresponding exposure time. The LM-mode sensitivity is significantly worse due to the ND filters and the strong absorption of the diamond window. **KL mode [#f1b0743f] |LEFT:100|LEFT:100|LEFT:100|c |&ref(sensitivity_dia_KL_PWV0.3.jpg,,20%);|&ref(sensitivity_dia_KL_PWV0.7.jpg,,20%);|&ref(sensitivity_dia_KL_PWV1.2.jpg,,20%);| |KL-mode sensitivity at PWV=0.3 mm.|KL-mode sensitivity at PWV=0.7 mm.|KL-mode sensitivity at PWV=1.2 mm.| **2.7-um mode [#x2bf35e0] |LEFT:100|LEFT:100|LEFT:100|c |&ref(sensitivity_dia_2.7um_PWV0.3.jpg,,20%);|&ref(sensitivity_dia_2.7um_PWV0.7.jpg,,20%);|&ref(sensitivity_dia_2.7um_PWV1.2.jpg,,20%);| |2.7um-mode sensitivity at PWV=0.3 mm.|2.7umL-mode sensitivity at PWV=0.7 mm.|2.7um-mode sensitivity at PWV=1.2 mm.| **LM+ND2 mode [#u3c19b80] |LEFT:100|LEFT:100|LEFT:100|c |&ref(sensitivity_dia_LM+ND2_PWV0.3.jpg,,20%);|&ref(sensitivity_dia_LM+ND2_PWV0.7.jpg,,20%);|&ref(sensitivity_dia_LM+ND2_PWV1.2.jpg,,20%);| |LM-mode (w/ ND2) sensitivity at PWV=0.3 mm.|LM-mode (w/ ND2) sensitivity at PWV=0.7 mm.|LM-mode (w/ ND2) sensitivity at PWV=1.2 mm.|
