KARHUNEN-LOÈVE IMAGE PROJECTION ���QUANTIFYING HR8799 ANALOGS

REFERENCES Boss, A. 1997, Science, 276, 1836 Dodson-Robinson, S., Veras, D., Ford, E., Beichman, C. 2009, ApJ, 707, 79-88 Lafrenière, D., et al. 2007, ApJ, 660,770-780 Laughlin, G. 2000, ApJ, 545, 1064 Marois, C., et al. 2010, Nature 468, 1080–1083 Mizuno, H. 1980, Progress of Theoretical Physics, 64, 544 Murray, N., Chaboyer, B. 2002, ApJ, 566, 442 Perri, F., Cameron, A. 1974. Icarus 22, 416-425. Piso, A., Youdin, A. 2014, ApJ, 786, 21 Pollack, J., et al. 1996, Icarus, 124, 62 Safranov, V.1969, Nauka (Moscow), English translation: NASA TTF 677 (1972) Santos, N., Israelian, G., Mayor, M., Rebolo, R., Udry, S. 2003, A&A, 398, 363 SHMO. "Beautiful Human Faces.”. SAVOIA., 11 July 2012. Web. Soummer, R., Laurent, P., Larkin, J. 2012, ApJ, 755, L28 Williams, J., Cieza, L. 2011, ARA&A, 49, 67

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PRE-KLIP POST-KLIP

SYNTHETIC DATA

Signal/Noise = 2 Signal/Noise = 30

WHY HR8799? The formation of giant planets such as Jupiter is widely attributed to a process known as core accretion. In the core accretion model, a solid core with a is slowly accreted via gravitational collisions until the core reaches a critical mass that enables rapid gas accretion in the envelope (Perri and Cameron 1974; Mizuno, 1980; Pollack et al, 1996). The model typically assumes the planet forms at a fixed radius, which implies the speed of the planet formation depends on its radial separation from its host star.

The four directly imaged planets around HR8799 were found to be massive gas giants at far radial separations (Marois et al., 2010). By the standard core accretion model of planet formation, planets this massive should not have had enough time to form, given that the lifetime of debris disks are only a few million years (Williams and Cieza, 2011). Furthermore, the combined mass of the planetary system HR8799 is greater than the mass of our own system by a factor of approximately 30 (Marois et al.,2010). These discrepancies between HR8799 and our solar system prompt us to quantify the frequency of HR8799 analogs.

(Marois et al., 2010)

ABSTRACT The goal of this project is to quantify the frequency of HR8799 analogs using the largest survey to date of directly imaged A/F type stars. Since HR8799 is an anomalous system according to widely accepted models of planet formation, the frequency of analogs provides a measure indicative of the applicability of our current planet formation models. We examine a high-contrast angular differential imaging technique known as Karhunen-Loève Image Projection (KLIP) which boasts detection capability rivaling that of other modern ADI algorithms such as Locally Optimized Combination of Images (LOCI) but with increased computational efficiency, and our preliminary results show KLIP to be a promising technique for the reduction of our targets.

KARHUNEN-LOÈVE IMAGE PROJECTION (KLIP) KLIP is a direct imaging technique designed to detect faint astronomical sources in high contrast environments. The KLIP algorithm treats non-astronomical sources (typically due to imperfect optics) as stationary in time; this allows a principal component analysis to be performed which identifies and removes these sources - given an input set of reference images. In order to avoid removing all sources of PSF, Angular Differential Imaging (ADI) must be utilized. ADI allows the field of view to rotate while target images are obtained. Hence, any off-center PSF source, such as a planetary candidate, is angularly displaced between images in the reference set. No longer stationary in time, astronomical signal avoids principal component identification and can be detected.

JAKE HANSON, DANIEL APAI Steward Observatory and Lunar and Planetary Laboratory, The University of Arizona

KLIP VISUALIZATION Reference Library of Images:

Target Image (not in reference

library): Only unique

features remain after

KLIP

•  Assemble reference images into matrix R

•  Define Hermitian Matrix A=RRT

•  Find ranked eigenvectors of A •  Create Principal Component Basis Z •  Choose M eigen-images to retain •  Create PSF estimate E of target T •  Calculate Reduced Image F

ALGORITHM

SURVEY TARGETS Our survey targets 85 A and F type stars using Angular Differential Imaging in the L-band on the NACO-VLT system in Chile. The targets are part of the larger MEPHISTO survey (PI: Apai, NASA Proposal #10-OSS10-134) which aims to target all 138 known stars in the southern hemisphere around which we are capable of detecting planets greater than 5 Jupiter-masses on separations less than 70 AU.

(“Beautiful Human Faces”, 2012)

Principal Components of reference library:

ACKNOWLEDGEMENTS This work has been carried out with support from the NASA Origins of Solar Systems grant NNX11AG57G

hanjake1992@email.arizona.edu

RESULTS Our synthetic data reduction shows KLIP to be a viable method of planet detection. Furthermore, the KLIP algorithm has only a single free parameter (M) to explore after the principal component basis has been generated, which enables us to explore the full parameter space with minimal computational burden. Going forward, we plan to use KLIP as the primary detection method for HR8799 analogs in our survey.