MIRI Sensitivity Model Components

What is this page about? Ideal length:160 characters. 

On this page

1)  The JWST Observatory - Longward of ~17 μm, stray light from the observatory sunshield and the thermal emission of the telescope optics dominates the background.  At shorter wavelengths, especially at ~ 5 μm, the background is dominated by emission from the zodiacal dust concentrated in the ecliptic plane.

2) Photon Conversion Efficiency (PCE) - This number is the fraction of photons that are actually detected.  The PCE is a product of the optical transmission of all elements from the focal plane to the detector, which has an additional detector quantum efficiency (measured in detected electrons per incident photon).

3) Encircled Energy - Not all of the signal arriving from a point-like astronomical target will contribute to the photometric measurement. The signal is distributed over many pixels due to image broadening by diffraction, by the telescope and instrument optics, and by scattering and crosstalk in the detector itself. 

4) Detector Performance - The electrons generated in each pixel are used to charge a capacitor. The photocurrent is determined by sampling the pixel multiple times at a fixed interval and measuring the slope that best fits these samples.  The slope has measurement error that includes terms associated with the shot noise, the read noise, and the statistical effects of sampling up the ramp. 

The sensitivity for long-duration observations of faint sources is defined by the flux necessary to achieve a signal-to-noise ratio of 10 after a 10,000 second observation.  The sensitivity results are summarized in graphical and tabular format for the different MIRI modes below.



Section 

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam fermentum vestibulum est. Cras rhoncus. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Sed quis tortor. Donec non ipsum. Mauris condimentum, odio nec porta tristique, ante neque malesuada massa, in dignissim eros velit at tellus. Donec et risus in ligula eleifend consectetur. Donec volutpat eleifend augue. Integer gravida sodales leo. Nunc vehicula neque ac erat. Vivamus non nisl. Fusce ac magna. Suspendisse euismod libero eget mauris.

Subsection


Sub-subsection 



Section

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam fermentum vestibulum est. Cras rhoncus. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Sed quis tortor. Donec non ipsum. Mauris condimentum, odio nec porta tristique, ante neque malesuada massa, in dignissim eros velit at tellus. Donec et risus in ligula eleifend consectetur. Donec volutpat eleifend augue. Integer gravida sodales leo. Nunc vehicula neque ac erat. Vivamus non nisl. Fusce ac magna. Suspendisse euismod libero eget mauris.



References



Published

(enter date using //)

Latest updates
  • (enter date using //)
    Briefly describe change