• DOI:10.1051/0004-6361/201525837
• Corpus ID: 20174209

Improving Signal to Noise in the Direct Imaging of Exoplanets and Circumstellar Disks

@article{Wahhaj2015ImprovingST,
  title={Improving Signal to Noise in the Direct Imaging of Exoplanets and Circumstellar Disks},
  author={Z. Wahhaj and Lucas A. Cieza and Dimitri Mawet and Bin Yang and Hector C{\'a}novas and Jos de Boer and Simon Casassus and François M{\'e}nard and Matthias R. Schreiber and Michael C. Liu and Beth A. Biller and Eric L. Nielsen and Thomas L. Hayward},
  journal={arXiv: Earth and Planetary Astrophysics},
  year={2015}
}

• Z. Wahhaj, L. Cieza, +10 authors T. Hayward
• Published 10 February 2015
• Physics
• arXiv: Earth and Planetary Astrophysics

We present a new algorithm designed to improve the signal to noise ratio (SNR) of point and extended source detections in direct imaging data. The novel part of our method is that it nds the linear combination of the science images that best match counterpart images with signal removed from suspected source regions. The algorithm, based on the Locally Optimized Combination of Images (LOCI) method, is called Matched LOCI or MLOCI. We show using data obtained with the Gemini Planet Imager (GPI) and Near-Infrared Coronagraphic Imager (NICI) that the new algorithm can improve the SNR of point source detections by 30{400% over past methods. We also nd no increase in false detections rates. No prior knowledge of candidate companion locations is required to use MLOCI. While non-blind applications may yield linear combinations of science images which seem to increase the SNR of true sources by a factor >2, they can also yield false detections at high rates. This is a potential pitfall when trying to conrm marginal detections or to re-detect point sources found