Results for ShaneAO - Spectroscopy

Low-resolution spectroscopy ($R=500$) in the new system is expected to be much improved because of long-exposure stability, slit rotation capability, and diffraction-limited, Nyquist-sampled PSFs in all bands. Repeated, reliable co-adds will make it possible to raise SNR and track night sky line variation. The current slit is 100 $\mu$m wide, which represents 24 mas at the detector in the spectral direction. The diffraction-limited disk is currently truncated by the slit in $H$ and $K$ bands.

Figure 8 shows the minimum amount of exposure time needed to no longer be limited by the detector noise and background noise.

Figure 8: Minimum exposure time required at each wavelength for sky background and dark current to equal read noise (background limited) and for source flux to equal 2$\times$sky flux (source limited).

Limiting magnitudes in the $JHKs$ bands for spectroscopy with the ShARCS 8 subaperture (the initial configuration) and ShARCS 16 setup are shown in Figure 9

Figure 9: Magnitude limits (SNR=5) versus wavelength for point source spectroscopy with ShARCS 8 and ShARCS 16 configurations.