A comparison of analytical depth of search metrics with mission simulations for exoplanet imagers

Dmitry Savransky; Daniel Garrett; Bruce A. Macintosh

doi:10.1117/12.2231746

29 July 2016 A comparison of analytical depth of search metrics with mission simulations for exoplanet imagers

Dmitry Savransky, Daniel Garrett, Bruce A. Macintosh

Proceedings Volume 9904, Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave; 99041T (2016) https://doi.org/10.1117/12.2231746
Event: SPIE Astronomical Telescopes + Instrumentation, 2016, Edinburgh, United Kingdom

Abstract

While new, advanced, ground-based instrumentation continues to produce new exoplanet discoveries and provide further insights into exoplanet formation and evolution, our desire to discover and characterize planets of Earth size about stars of all types and ages necessitates dedicated, imaging space instruments. Given the high costs and complexities of space observatories, it is vital to build confidence in a proposed instrument’s capabilities during its design phase, and much effort has been devoted to predicting the performance of various flavors of space- based exoplanet imagers. The fundamental problem with trying to answer the question of how many exoplanets a given instrument will discover is that the number of discoverable planets is unknown, and so all results are entirely dependent on the assumptions made about the population of planets being studied. Here, we explore an alternate approach, which involves explicitly separating instrumental and mission biasing from the assumptions made about planet distributions. This allows us to calculate a mission’s ‘depth of search’-a metric independent of the planetary population and defined as the fraction of the contrast–projected separation space reached by a given instrument for a fixed planetary radius and semi-major axis. When multiplied by an assumed occurrence rate for planets at this radius and semi-major axis (derived from an assumed planetary population), this yields the expected number of detections by the instrument for that population. Integrating over the full ranges of semi-major axis and planetary radius provides estimates of planet yield for a full mission. We use this metric to evaluate the coronagraphs under development for the WFIRST mission under different operating assumptions. We also compare the results of convolving the depth of search with an assumed planetary population to those derived by running full mission simulations based on that same population.

Citation Download Citation

Dmitry Savransky, Daniel Garrett, and Bruce A. Macintosh "A comparison of analytical depth of search metrics with mission simulations for exoplanet imagers", Proc. SPIE 9904, Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, 99041T (29 July 2016); https://doi.org/10.1117/12.2231746

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available