Hello
I'm a researcher at the Argelander Institut für Astronomie (AIfA) of the University of Bonn.
My work here was sponsored by a postdoctoral research fellowship of the Alexander von Humboldt Foundation.
You're only one click away from my
list of publications (ADS labs).
Collaborators: if you cannot find what you are looking for on this front page, you probably didn't log in!
Contact
Malte Tewes
Argelander-Institut für Astronomie
Auf dem Hügel 71
D - 53121 Bonn
Germany
Room 2.007
My previous home, at EPFL
Research
My research area is observational cosmology with weak and strong gravitational lensing.
On the weak lensing side, I work on the problem of accurate measurement of gravitational shear on small and noisy galaxy images, in the context of the Euclid survey. I develop machine learning algorithms to address the intricate systematic error sources affecting these measurements.
On the strong lensing side, I was heavily involved in COSMOGRAIL, a collaboration aimed at measuring the time delays between multiple images of gravitationally lensed quasars.
Key motivations behind these projects are to learn about the nature of dark energy and dark matter, and to test the standard cosmological model.
Fun
- D3CS
Interactive Curve Shifting, in your browser, using the D3.js library - cosmicruler
Code to generate cosmology nomograms in svg, used for goodies of the EC meeting 2018. - QCgravlens
Strong gravitational lens simulation with Quartz Composer
Teaching
- I'm coordinating the master-level optical astronomy labs at AIfA. Of broader interest might be my image reduction and photometry tutorial (astropy-based).
- 2017-2022: teaching astro847 “Optical Observations” (1/2 of it)
Outreach
I'm the lead author of Project Andromeda, an open educational resource (in German) about building a distance ladder to M31 with Gaia and HST data. We use this notably for some internships at AIfA.
Public code
sewpy 1.0dev, yet another Source Extractor Wrapper, hosted on GitHub
tenbilac, an experimental inverse regression ANN, on GitHub
MomentsML, for ML shear measurement
PyCS, to measure time delays
alipy 2.0, to find geometrical transforms between optical astronomical images
And the good old f2n.py (FITS to png in python, with annotation capabilities) and cosmics.py (L.A.Cosmic in python : cosmic ray identification and cleaning).
Photography
- Some images are available in the ESO archive here, as I'm an ESO Photo Ambassador.
- Old Flickr photostream, with some pics from observing runs
- Euler Virtual Tours
Indoor panoramas of the Euler telescope