Bayesian analysis of the DES Supernova Survey

Lead Research Organisation: University of Portsmouth
Department Name: Institute of Cosmology and Gravitation

Abstract

The Dark Energy Survey (DES; www.darkenergysurvet.org) will end in 2018 having completed a 5 year survey of the southern sky. A key part of DES is a dedicated tranisent survey which has already detected more Type Ia Supernovae (SNeIa) than any previous search. By the end of DES, we expect to have detected and classified over 4000 SNeIa allowing us to accurately map the expansion history of the Universe over half its age.

Key to harnessing the power of these SNeIa will be controlling the systematic uncertainties, including photometric calibration, host galaxy correlations and mis-classifications. The latter represents a new challenge for DES as many of its SNeIa will be photometrically-classified leading to additional, presently unknown, contamination from other transient events.

This thesis will build on the work of previous ICG students (e.g. Campbell et al. 2013, https://arxiv.org/pdf/1211.4480.pdf) to include such uncertainties in the analysis of DES SNeIa. In particular, we will exploit new Bayesian techniques, only developed in the last few years, to create unbiased SNeIa samples for cosmology (Jones et al. 2017, https://arxiv.org/pdf/1611.07042.pdf). We will then use this sample to measure cosmological parameters (including the equation of state of dark energy) and investigate new opportunities to detect the gravitational lensing of SNeIa by foreground large-scale structures (Scovacricchi et al. 2017, https://arxiv.org/pdf/1611.01315.pdf).

This project will require the development of new statistical methodology and the creation of large simulations of the DES supernova survey.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/P006760/1 01/10/2017 30/09/2024
2021736 Studentship ST/P006760/1 01/10/2017 30/09/2021 Maria Vincenzi
 
Description Dark Energy Survey Collaboration 
Organisation Fermilab - Fermi National Accelerator Laboratory
Country United States 
Sector Public 
PI Contribution The Dark Energy Survey is an international collaboration that aim to probe the dynamics of the expansion of the Universe and the growth of large-scale structure.
Collaborator Contribution I am and active member of the Dark Energy Collaboration and in particular I work within the Supernova Working Group
Impact I am in process of publishing a paper with Dark Energy Survey data. As part of the collaboration, I have been able to access extra computing resources (High Performance Computer Midway at the University of Chicago). I received travel funding to participate to two Collaboration meeting organized by the Dark Energy Survey Collaboration meeting.
Start Year 2017
 
Description Supernova Cosmology Analysis Meeting 
Organisation University of Chicago
Department Kavli Institute for Cosmological Physics
Country United States 
Sector Academic/University 
PI Contribution I took part to a workshop on Supernova Cosmology Analysis at the University of Chicago. I received travel support to take part at the meeting.
Collaborator Contribution The University of Chicago organized the workshop and provided travel support for the participants.
Impact I delivered a seminar and significantly increase my network. I received travel support to take part at this workshop
Start Year 2019
 
Title PyCOCO: software to generate spectrophotometric templates of transients 
Description This software is a python package built to generate spectrophotometric templates of transients for which multi-band photometry and spectroscopy is provided. 
Type Of Technology Software 
Year Produced 2019 
Open Source License? Yes  
Impact Other people in the scientific community started to use this software to develop their own research. This software also resulted in a publication. 
 
Description Activities on Space and Universe for Primary School kids 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact I organized three activities on Space and Universe at the Broadlea Primary School. The activities were delivered within "the Isle of Wight Space Camps 2019" initiative and involved a class of kids in years One and Two and their science teachers.
Year(s) Of Engagement Activity 2019
 
Description Outreach student representative 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact As Outreach student representative I actively helped in the organization of the event "Stargazing night 2020". The event includes several scientific activities for the general public: stargazing with telescopes, scale models of experiments, other experiments to help the public understanding what is in the Universe through sight (images from telescopes), hearing and tact. During the activity several talks were also organized.
Year(s) Of Engagement Activity 2020
URL https://www.eventbrite.co.uk/e/stargazing-at-portsmouth-historic-dockyard-2020-tickets-85959016733#