
Dr Jesper Skottfelt
Cei Fellow
Biography
Professional biography
Jesper has worked at the Open University since 2015, where he started as a PostDoc creating a charge transfer simulation code for the CCDs for the VIS instrument on the ESA Euclid mission. in 2017 he became a Research Fellow with responsibility for the whole data analysis part of the Euclid VIS radiation damage campaign, working especially on the trap pumping method and analysis. He is now leading the trap pumping definition and analysis that will be performed as part of the in-orbit calibration routines for Euclid VIS.
He is also working on a number of other projects involving detector simulation, testing and development. This includes work on the radiation damage of the detectors on the Gaia space telescope, detector testing for the Canadian UV telescope CASTOR and NASA's Habitable Worlds Observatory (HWO), and building a setup for doing UV Quantum Efficiency measurements.
Jesper did his PhD in Astronomy at the Niels Bohr Institute at Copenhagen University in Denmark. Here he worked on an Electron Multiplying CCD instrument and was responsible for the for the instrument control software and data analysis software, and did the installation and testing of the instrument at the Danish 1.54m Telescope in Chile. Using this instrument he, among other things, worked on stellar variability studies of Galactic globular clusters, and is involved in the search for exoplanets using the gravitational microlensing method.
Research interests
- Detector testing and analysis
- Radiation damage
- Trap pumping technique
- CCD and CMOS technologies
- UV QE measurements
Projects
Euclid PLS 25 - 6 month bridge funding
The Euclid mission is now in the Post Launch Support phase. The CEI will continue to monitor the trap pumping data from the spacecraft and provide input to the radiation damage correction based on this data.
Euclid UK Science Ground Segment Bridging Grant Phase III - Post Launch Support Apr24 to Mar25
Post Launch support, development and analysis for the Trap pumping data products that has been implemented for the Euclid Science Ground Segment as part of the calibration routines for the VIS instrument.
CASTOR:UK - Oct 23 - Mar 25
The Canadian Space Agency (CSA) is developing a UV space telescope called CASTOR and they are now looking for partners to the project. Currently JPL/NASA is part of the collaboration, delivering the instrument. We are bidding for the UK to be part of the mission in two key areas where UK can play a leading role: One of these roles is the development of the UV-optimised detectors for the mission. With Te2v delivering the sensors, the CEI is a obvious partner for the main part of this work. We will be looking to utilise the full range of CEI capabilities, from Radiation environment and shielding simulations, General detector characterisation including UV QE measurements, to radiation damage and general characterisation of the detectors and flight device testing and delivery. The project is lead by UKATC and a number of institutions are involved in different parts of the project (Leicester, Birmingham, Edinburgh).
UK involvement in the Nancy Grace Roman Space Telescope: Promoting UK EMCCD technology and UK science strengths into future global space applications
This project merges the old WFIRST proposal (now called Roman Space Telescope) with a new activity in UV-sensitive detector development for future missions such as Castor (Canada), Luvoir and HabEx. These projects should be separate, however as they both work with JPL NASA they are being merged in an attempt to make this 3.5 month project >£250k (to meet the call demands). The key to this 3.5 month pre-study is to procure major equipment items for the long term and put in the effort to work with the partners and develop the long-term 4-year plan to start 1st April 2021.
Radiation damage in detectors: what really happens to silicon imaging detectors in orbit?
Te2v-sponsored STFC CASE Studentship on the analysis of calibration data from Euclid, including trap-pumping results. For Gaia, CEI PhD student Saah Ahmed investigated the differences between pre-launch predictions of radiation damage and what happened in-orbit using simple calibration data. His findings have shown interesting correlations with device batches, as well as fine-tuned the calibration process used in the RVS instrument. A first proper investigation of radiation damage while in-orbit will help our fundamental understanding, not just for CCDs but also for future CMOS missions. For Euclid, we have access to a highly accurate and much deeper analysis technique in trap-pumping, giving the power to analyse the performance in great detail and investigate many open questions that can’t be answered from ground testing, important to all future space missions, whether CCD or CMOS: - How does a 5 minute on-ground irradiation compare to a steady rate of increase over 5 years in-orbit? - How does a NIEL scaled 200MeV dose compare to a full spectra of particle energies? - How does annealing compete with new trap production? This is very timely for an October 2024 start as we will have ~1 year of data already and more arriving as the PhD progresses (towards EOL of the mission as the student writes-up).
Euclid UK Science Ground Segment Bridging Grant Phase III
Continuation of Euclid work to deliver Trap Pumping analysis data products for the Euclid Science Ground Segment.
STFC IAA 2018
The funding from the STFC IAA is being used to strategically focus on translating our space research, developing new opportunities and providing support to foster entrepreneurialism among our researchers and academics.
ESA NPI Gaia radiation damage
European Space Agency (ESA) Network Partnering Initiative (NPI) funding to support PhD student Saad Ahmed, who is working on radiation damage of the Gaia focal plane detectors. This funding will allow Saad to work more closely with ESA using in-orbit calibration data from the Gaia space telescope, and to get access to test equipment located at the ESA Research and Technology Centre (ESTEC) in Holland.
Euclid SGS 21-22
Supporting the radiation damage correction efforts for the Euclid VIS Instrument by delivering Trap Pumping analysis data products for the Euclid Science Ground Segment.
Publications
Journal Article
Euclid preparation : LX. The use of HST images as input for weak-lensing image simulations (2025)
Euclid: Testing photometric selection of emission-line galaxy targets (2024)
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk (2024)
Euclid preparation : XLVIII. The pre-launch Science Ground Segment simulation framework (2024)
Physical properties of near-Earth asteroid (2102) Tantalus from multi-wavelength observations (2022)
An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing (2022)
Precision measurement of a brown dwarf mass in a binary system in the microlensing event (2022)
Euclid preparation: I. The Euclid Wide Survey (2022)
A search for transit timing variations in the HATS-18 planetary system (2022)
Understanding the evolution of radiation damage on the Gaia CCDs after 72 months at L2 (2022)
Euclid preparation: XVI. Exploring the ultra-low surface brightness Universe with Euclid/VIS (2022)
OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf (2021)
Six Outbursts of Comet 46P/Wirtanen (2021)
Spitzer Microlensing Parallax Reveals Two Isolated Stars in the Galactic Bulge (2020)
OGLE-2013-BLG-0911Lb: A Secondary on the Brown-dwarf Planet Boundary around an M Dwarf (2020)
Large-scale changes of the cloud coverage in the ε Indi Ba,Bb system (2020)
A pair of temperate sub-Neptunes transiting the star EPIC 212737443 (2019)
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary (2019)
The mass and age of the first SONG target: the red giant 46 LMi (2018)
Importance of charge capture in interphase regions during readout of charge-coupled devices (2018)
OGLE-2017-BLG-1434Lb: Eighth q (2018)
The SMILE Soft X-ray Imager (SXI) CCD design and development (2018)
Evolution and impact of defects in a p-channel CCD after cryogenic proton-irradiation (2017)
Orbital alignment and star-spot properties in the WASP-52 planetary system (2017)
Exploring the crowded central region of ten Galactic globular clusters using EMCCDs (2016)
MOA-2011-BLG-028Lb: A Neptune-Mass Microlensing Planet in the Galactic Bulge (2016)
Spitzer parallax of OGLE-2015-BLG-0966: a cold Neptune in the Galactic disk (2016)
Mass Measurements of Isolated Objects from Space-Based Microlensing (2016)
Spitzer microlens measurement of a massive remnant in a well-separated binary (2015)
Red noise versus planetary interpretations in the microlensing event OGLE-2013-BLG-446 (2015)
Pluto's atmosphere from stellar occultations in 2012 and 2013 (2015)
Transits and starspots in the WASP-6 planetary system (2015)
A census of variability in globular cluster M 68 (NGC 4590) (2015)
Ogle-2011-BLG-0265LB: a jovian microlensing planet orbiting an M dwarf (2015)
The two-colour EMCCD instrument for the Danish 1.54 m telescope and SONG (2015)
High-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 and WASP-26 (2014)
A ring system detected around the Centaur (10199) Chariklo (2014)
Physical properties of the WASP-67 planetary system from multi-colour photometry (2014)
High-precision photometry by telescope defocusing - V. WASP-15 and WASP-16 (2013)
Microlensing discovery of a population of very tight, very low mass binary brown dwarfs (2013)
A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251 (2013)
Flux and color variations of the doubly imaged quasar UM673 (2013)
Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry (2013)
Microlensing binaries with candidate brown dwarf companions (2012)
A brown dwarf orbiting an M-dwarf: MOA 2009–BLG–411L (2012)
Microlensing binaries discovered through high-magnification channel (2012)
Discovery and mass measurements of a cold, 10 Earth mass planet and its host star (2011)
MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarf (2011)
Flux and color variations of the quadruply imaged quasar HE 0435-1223 (2011)
A sub-Saturn mass planet, MOA-2009-BLG-319Lb (2011)
Physical properties of the 0.94-day period transiting planetary system WASP-18 (2009)
Presentation / Conference
Tracking radiation damage of Euclid VIS detectors after 1 year in space (2024)
Assessing the suitability of CIS220 for low light astronomy (2024)
2D-doped silicon detectors for UV/optical/NIR and x-ray astronomy (2022)
Modelling charge transfer inefficiency in Gaia CCDs with in-flight and on-ground data (2022)
Calibrating and correcting charge transfer inefficiency in CCDs using Pyxel (2022)
Gaia CCDs: charge transfer inefficiency measurements between five years of flight (2020)
C3TM: CEI CCD charge transfer model for radiation damage analysis and testing (2018)
GravityCam: higher resolution visible wide-field imaging (2018)
VIS: the visible imager for Euclid (2018)
Mapping radiation-induced defects in CCDs through space and time (2016)
Comparing simulations and test data of a radiation damaged CCD for the Euclid mission (2016)
VIS: the visible imager for Euclid (2016)
The effect of radiation-induced traps on the WFIRST coronagraph detectors (2016)