Data for 'Overcoming Confusion Noise with Hyperspectral Imaging from PRIMAger' (2024)

Data for paper published in Monthly Notices of the Royal Astronomical Society, Volume 532, Issue 2, August 2024, Pages 1966–1979

Description of data:

• The simulated PRIMAger maps generated via the SIDES simulation on which the analysis of the article was conducted are stored within the PRIMA_data_availability/PRIMAger_simulated_maps_w_instrumental_noise folder. There are 16 maps in total; 6 representing the PHI1 channels (PHI1_1 - PHI1_6), 6 representing the PHI2 channels (PHI2_1 - PHI2_6) and 4 representing the PPI channels (PPI1 - PPI4). These maps contain both realistic confusion and instrumental noise. The generation of these maps are discussed in details in Section 2 of the article.
• The full catalogue of all sources and their true physical parameters generated from the SIDES simulation is stored as PRIMA_data_availability/pySIDES_PRIMA.fits. The simulated maps are generated from this simulation catalogue, which also contains the true fluxes of each source in all 16 of the PRIMAger channels.
• The Wiener-filtered prior source catalogue which is described in Section 3.2 is stored as joined_full_w_first_detected_centroid.fits.
• The catalogue of fluxes extracted from XID+ across all 16 PRIMAger channels using the Wiener-filtered prior source catalogue is stored as PRIMA_data_availability/XID_plus_output/wiener_filtered_prior_cat_results_catalogue.fits. The results from this catalogue are discussed in Section 5.1 of the article.
• The full posteriors outputted from XID+ across all 16 PRIMAger channels using the Deep prior source catalogue with some prior flux knowledge are stored within PRIMA_data_availability/XID_plus_output/deep_prior_catalogue_posteriors. Within this folder there are subfolders for each of the 16 PRIMAger channels which contain .pkl files for 4 HEALpix tiles, each of which contain the full XID+ flux posteriors for a subset of the simulated sources. The median value of these flux posteriors form the results from Section 5.2 of the article.
• In order to reproduce the above results from the simulated PRIMAger maps, the software package XID+ must be employed, as detailed in Section 4.1 of the article and is available here.

Article Abstract:

The PRobe far-Infrared Mission for Astrophysics (PRIMA) concept aims to perform mapping with spectral coverage and sensitivities inaccessible to previous FIR space telescopes. PRIMA’s imaging instrument, PRIMAger, provides unique hyperspectral imaging simultaneously covering 25–235 μm. We synthesise images representing a deep, 1500 hr deg−2 PRIMAger survey, with realistic instrumental and confusion noise. We demonstrate that we can construct catalogues of galaxies with a high purity (> 95 per cent) at a source density of 42k deg−2 using PRIMAger data alone. Using the XID+ deblending tool we show that we measure fluxes with an accuracy better than 20 per cent to flux levels of 0.16, 0.80, 9.7 and 15 mJy at 47.4, 79.7, 172, 235 μm respectively. These are a factor of ∼2 and ∼3 fainter than the classical confusion limits for 72–96 μm and 126–235 μm, respectively. At 1.5 ⩽ 𝑧 ⩽ 2, we detect and accurately measure fluxes in 8–10 of the 10 channels covering 47–235 μm for sources with 2 ≲ log(SFR) ≲ 2.5, a 0.5 dex improvement on what might be expected from the classical confusion limit. Recognising that PRIMager will operate in a context where high quality data will be available at other wavelengths, we investigate the benefits of introducing additional prior information. We show that by introducing even weak prior flux information when employing a higher source density catalogue (more than one source per beam) we can obtain accurate fluxes an order of magnitude below the classical confusion limit for 96–235 μm.