English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Ground-based observations at thermal infrared wavelengths suffer from largebackground radiation due to the sky, telescope and warm surfaces in theinstrument. This significantly limits the sensitivity of ground-basedobservations at wavelengths longer than 3 microns. We analyzed this backgroundemission in infrared high contrast imaging data, show how it can be modelledand subtracted and demonstrate that it can improve the detection of faintsources, such as exoplanets. We applied principal component analysis to modeland subtract the thermal background emission in three archival high contrastangular differential imaging datasets in the M and L filter. We describe howthe algorithm works and explain how it can be applied. The results of thebackground subtraction are compared to the results from a conventional meanbackground subtraction scheme. Finally, both methods for background subtractionare also compared by performing complete data reductions. We analyze theresults from the M dataset of HD100546 qualitatively. For the M band dataset ofbeta Pic and the L band dataset of HD169142, which was obtained with an annulargroove phase mask vortex vector coronagraph, we also calculate and analyze theachieved signal to noise (S/N). We show that applying PCA is an effective wayto remove spatially and temporarily varying thermal background emission down toclose to the background limit. The procedure also proves to be very successfulat reconstructing the background that is hidden behind the PSF. In the completedata reductions, we find at least qualitative improvements for HD100546 andHD169142, however, we fail to find a significant increase in S/N of beta Pic b.We discuss these findings and argue that in particular datasets with stronglyvarying observing conditions or infrequently sampled sky background willbenefit from the new approach.

A PCA-based approach for subtracting thermal background emission in high-contrast imaging data