ALICE Data Release: A revaluation of HST-NICMOS coronagraphic images

TL;DR

This paper re-analyzes HST-NICMOS coronagraphic images using advanced PSF subtraction, providing high-quality data products for exoplanet and disk studies, and introduces a new standard data format for high-contrast imaging.

Contribution

It presents a re-processed archive of NICMOS coronagraphic data with improved methods and introduces the HCI-FITS format for data sharing.

Findings

Re-processed ~400 NICMOS coronagraphic images with advanced PSF subtraction.

Delivered high-level science products to the community via MAST.

Developed and released the HCI-FITS format for data exchange.

Abstract

The Hubble Space Telescope (HST) NICMOS instrument has been used from 1997 to 2008 to perform coronagraphic observations of about 400 targets. Most of them were part of surveys looking for substellar companions or resolved circumstellar disks to young nearby stars, making the NICMOS coronagraphic archive a valuable database for exoplanets and disks studies. As part of the Archival Legacy Investigations of Circumstellar Environments (ALICE) program, we have consistently re-processed a large fraction of the NICMOS coronagrahic archive using advanced PSF subtraction methods. We present here the high-level science products of these re-analyzed data, which we delivered back to the community through the Mikulski Archive for Space Telescopes (MAST) http://dx.doi.org/10.17909/T9W89V . We also present the second version of the HCI-FITS format (for High-Contrast Imaging FITS format), which we developed as a standard format for data exchange of imaging reduced science products. These re-analyzed products are openly available for population statistics studies, characterization of specific targets, or detected point source identification.