Walker, Simon R. (2013) Analysis and optimisation of ground based transiting exoplanet surveys. PhD thesis, University of Warwick.

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Abstract

One of the most surprising aspects of the exoplanet population is the existence
of Jupiter sized planets orbiting close to their parent stars. It is currently
uncertain how these planets reached such small separations, and they are thought
to be markers for the dominant migration mechanism. The Wide Angle Search for
Planets (WASP) project is ideally suited for studying these planets, as it has detected
the largest number of hot Jupiters to date. I have inverted the observed sample
of WASP planets to calculate the underlying population of hot Jupiters through
a quantitative study of the selection biases in the WASP project. To achieve this, I
synthesised transiting systems and inserted them into WASP data to calculate the
probability of detection. The observed population ofWASP planets is then corrected
through application of this probability to determine the underlying population. I
find a clear pile up in the underlying population at orbital periods between 3 to
5 days, and apply a joint constraint with the underlying population measurement
from the Kepler project to propose a new model for the underlying population of
giant planets. I propose a model consisting of a rising power law win period with
index 1:0 - 0:3, with a Gaussian excess at 3:7 - 0:1 days to model the period pile
up. The observed period pile up places crucial constraints on models of hot Jupiter
migration.
The Next Generation Transit Survey (NGTS) is a new transiting exoplanet
survey designed to find Neptunes and super Earths around nearby stars. These stars
will be bright, allowing the characterisation of the bulk densities and atmospheric
compositions by current and next generation instruments. These planets are numerous
but they cause shallow transits, so we must achieve a higher level of precision
than has been previously achieved by a wide angle ground based survey. To test
the design characteristics and that the required high levels of precision would be
achieved, prototype instruments were constructed on La Palma and Geneva. We
found that we were able to reach < 0:1% precision on an ensemble of bright stars
on the typical transit timescales, indicating that the instrument will be capable
of detecting smaller planets. We use Monte Carlo simulations coupled with a detectability
analysis to predict that NGTS will detect 200 Neptunes and 30 super
Earths with the next generation instrument ESPRESSO.

Item Type:	Thesis or Dissertation (PhD)
Subjects:	Q Science > QB Astronomy
Library of Congress Subject Headings (LCSH):	Extrasolar planets, Transits
Official Date:	September 2013
Dates:	Date Event September 2013 Submitted
Institution:	University of Warwick
Theses Department:	Department of Physics
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Wheatley, Peter J.
Extent:	xiii, 199 leaves : illustrations, charts.
Language:	eng

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