PRIMA is equipped with two science instruments (FIRESS and PRIMAger) offering a versatile set of observing modes that include spectroscopic imaging, high-resolution spectroscopy, and polarimetry. Both instruments employ low-noise kinetic inductance detectors (KIDs) and each uses a dedicated beam steering mirror (BSM) developed by the Max-Planck Institute in Heidelberg to enable fast scan and chopping functionality over a wide field of regard.
The PRIMA Exposure Time Calculator can be used to verify the feasibility of proposed future science observations.
FIRESS
PRIMA's Far Infrared Enhanced Survey Spectrometer (FIRESS) offers multi-mode spectroscopy capable of both area mapping as well as dedicated point source observations. At the heart of FIRESS are four slit-fed grating spectrometer modules which are logarithmically spaced in wavelength and combine to cover the full 24-235 μm band. In addition, a Fourier Transform Module (FTM) can be inserted in the light path of the grating modules to produce high-resolution spectroscopy across the full wavelength band. FIRESS is developed by a collaboration between the Jet Propulsion Laboratory, Goddard Space Flight Center, and Netherlands Institute for Space Research (SRON).
| Parameter | Band 1 | Band 2 | Band 3 | Band 4 |
|---|---|---|---|---|
| Spectral range [μm] | 24–43 | 42-76 | 74–134 | 130–235 |
| Resolving power (low-res) | 95–150 | 85–120 | 90–125 | 95–130 |
| Resolving power (FTM) | 20,000–11,000 | 12,000–6,500 | 6,600–4,000 | 3,800–2,100 |
| Array format | 24 spatial pixels × 84 spectral pixels | |||
| Pixel size ["] | 7.6 | 7.6 | 12.7 | 22.9 |
PRIMAger
PRIMAger (PRIMA imager) is a 24-261 μm camera designed to map large areas of the sky with a high degree of multiplexing in both spatial and spectral dimensions. The PRIMAger Hyperspectral Imager (PHI) covers the 24-84 μm range with a spectral resolution of R = λ/Δλ ≈ 10 using Linearly Varible Filters (LVFs). The four PRIMAger Polarimetric Imager (PPI) covers the 80-261 μm range with four filters (R ≈ 4). Each pixel of the PPI is sensitive to one out of three angles of linear polarization measuring the I, Q, and U Stokes parameters. PRIMAger is being developed by an international collaboration bringing together French institutes (Laboratoire d’Astrophysique de Marseille and CEA) through the Centre National d’Etudes Spatiales (CNES, France), SRON, and the Cardiff University (UK) in Europe, as well as the Jet Propulsion Laboratory (JPL) and Goddard Space Flight Center (GSFC) in the USA.
| Parameter | PRIMA Hyperspectral Imager | PRIMA Polarimetry Imager | ||||
|---|---|---|---|---|---|---|
| PHI1 | PHI2 | PPI1 | PPI2 | PPI3 | PPI4 | |
| Wavelength [μm] | 24–45 | 45–84 | 92 | 126 | 172 | 235 |
| Resolving power | 10 | 10 | 4 | 4 | 4 | 4 |
| Polarimetry | No | No | Yes | Yes | Yes | Yes |
| Band center FWHM [”] | 4.1 | 7.4 | 10.8 | 14.8 | 20.2 | 27.6 |
| Array format | 63×23 | 33×14 | 36×31 | 24×21 | 18×16 | 12×11 |
| Pixel size [”] | 4.1 | 7.4 | 10.8 | 14.8 | 20.2 | 27.6 |
| Field of view | 3.6'×1.5' | 3.6'×1.7' | 5.3'×5.3' | 4.9'×4.9' | 5.0'×5.1' | 4.6'×4.9' |
| Source type | PRIMA Hyperspectral Imager | PRIMA Polarimetry Imager | ||||
|---|---|---|---|---|---|---|
| PHI1 | PHI2 | PPI1 | PPI2 | PPI3 | PPI4 | |
| Wavelength [μm] | 24–45 | 45–84 | 92 | 126 | 172 | 235 |
| Point Source Flux Density (total, Fν; mJy) | 1.18–2.2 | 2.2–4.1 | 1.77 | 2.56 | 3.39 | 4.59 |
| Point Source Flux Density (polarized, pFν; mJy) | – | – | 2.50 | 3.62 | 4.65 | 6.49 |
| Surface brightness (total, Iν; MJy/sr) | 1.64–0.66 | 0.74–0.58 | 0.46 | 0.34 | 0.25 | 0.18 |
| Surface brightness (polarized, Pν; MJy/sr) | – | – | 0.65 | 0.47 | 0.35 | 0.25 |
| The values above correspond to the 5σ background-subtracted flux density limit in a 1 degree2 map observed for a total duration of 10h (overheads included). For PHI, the sensitivity is estimated for each of 6×2 sub-bands, individually spanning at 10% range in wavelength, under the assumption of R=10. Surface brightness sensitivity is measured per diffraction beam solid angle. | ||||||
