Personal information

  • Name: Johannes Buchner
  • Hobbies: Swimming, Hiking, Travelling, Volleyball, Martial arts, Juggling

Curriculum Vitae

  • 2019-: Postdoctoral researcher at the Max Planck Institute for Extraterrestrial Physics (MPE), Germany. Researching galaxy-black hole co-evolution with the over one million black holes in the eROSITA all-sky survey, in combination with data from WISE, DESI, SDSS-V, HSC, VHS and Euclid.
  • 2019: Visiting researcher at Harvard University / Center for Astrophysics, USA (2 months). Collaboration with Dr. F. Civano towards reliably associating the Chandra Source Catalog (315,000 X-ray sources) to optical and infrared all-sky catalogs.
  • 2015-2018: FONDECYT fellow at Pontificia Universidad Católica (PUC), Chile. Researching galaxy-black hole co-evolution, uncovering the nuclear and galactic obscuration near the black hole with X-ray and multi-wavelength surveys. Awarded a FONDECYT fellowship (3 years).
  • 2011-2015: Doctoral thesis in Astronomy awarded 14/04/2015 by Ludwig-Maximilian University, Germany. Thesis title: "On the obscuration of the growing supermassive black hole population". Advisor: Prof. Kirpal Nandra, Director of the Max Planck for Extraterrestrial Physics (MPE). Awarded Max Planck doctoral stipend.
  • 2009-2011: MSc degree in Computer Science and Software Engineering at AUT University (New Zealand), at the IRASR radio telescope institute. Preparatory research for SKA. Awarded Kordia scholarship.
  • 2006-2009: BSc degree for Software Engineering at TU Vienna and studying towards BSc in Astronomy at University of Vienna, Austria. Analysis of sun-like pulsating stars, under Prof. Werner W. Weiss. Awarded merit scholarship.
visited 42 countries, lived in 6 countries

Formal roles

  • 2023-: Chair of the AGN working group in the German eROSITA consortium (55 members)
  • 2024: Chair of SOC for the international eROSITA conference 2024 (170 participants)
  • 2019-: Head of X-ray spectral analysis work package for the German eROSITA AGN working group
  • 2021-2024: Chair of the Athena science working group "Formation and growth of earliest SMBH" (SWG2.1)
  • 2021-: Chair of the SDSS-V Black Hole Mapper "Demographics" working group (40 members)
  • 2022-: Member of Euclid & 4MOST consortia; LSST AGN science collaboration

Grants & Fellowships

  • 2015: Awarded FONDECYT post-doctoral fellowship at PUC, 3 years (ca. 100,000 USD).
  • 2011: Awarded Max Planck doctoral stipend at MPE in 2011, 3.5 years (ca. 60,000 USD).
  • 2010: Awarded Kordia Scholarship for second MSc year at AUT University.
  • 2008: Awarded Leistungsstipendium (merit stipend) by University of Vienna.

Teaching & Mentoring

Advising
  • Direct advisor and supervisor to 2 BSc, 2 MSc and 1 PhD students
  • 2022-: PhD committee member for Jack O'Brien (MSU), William Roster (TUM), Sophia Waddell (LMU)
  • 2021-2024: PhD committee member for Michigan State University
  • 2017-2018: BSc thesis supervision of Charlotte Simmonds (PUC), published in A&A; went on to a doctoral position in Geneva.
Mentoring
  • 2023-: Mentor of 1 female PhD student
  • 2019-: Co-advising and co-mentoring post-graduate students in the high-energy group
  • 2019: Weekly skill exchange meetings at MPE; ca. 10 attendees
Lecturing
  • 2021: "Practical Inference for Researchers in the Physical Sciences"
    Block course 2 weeks x 4 days at TUM, 15 MSc/PhD from particle & astrophysics
  • 2021: Lecture at BiD4BEST astrostatistics workshop; ca. 15 PhD students
  • 2019: Held a 2-day workshop on statistics analysis of high energy data at MPE, 44 attendees from graduate to senior researcher level
  • 2018: 2 lectures in Astronomy 112 at PUC, Chile; ca. 50 students
Tutoring
  • 2020: Data Science Block Courses, ORIGINS excellence cluster
  • 2010: "Physical database systems"; ca. 30 students, AUT University
  • 2010: "Foundations of Physics A"; ca. 60 students, AUT University
  • 2008: "Theoretical Computer Science and Logic", 4 classes x 20 students x 2 semesters, TU Vienna

Talks and workshops

see Talks and Workshops page

Publications

see Publications page

Outreach

see Outreach page

Service for the community and institute

  • Chair of scientific working groups in the eROSITA and SDSS-V collaborations (~30 members each), coordination and conflict resolution in diverse scientific teams
  • Scientific organiser of eROSITA conference 2024 and "Frontiers of nested sampling" workshop (MaxEnt2023)
  • Hiring committee member in 5 post-doc and 6 PhD position calls; Lead initiatives to reduce unconscious bias
  • Regular referee for ApJ, A&A, MNRAS, Nature Astronomy
  • Time Allocation Committee member for Chandra, XMM-Newton and Hubble Space Telescope
  • Host of monthly DEI seminar series, since 2024
  • PostDoc representative and organiser of monthly PostDoc pizza lunch
  • Commenting on PhD, MSc and BSc theses, informal co-advising of high-energy group students
  • Editing press releases for scientific breakthroughs in German
I am among the most active members of the Astrostatistics Facebook group (4438 members). I regularly answer statistics questions to colleagues world-wide, in particular related to nested sampling and high-energy astronomy. Within the institute (PUC previously and MPE), I actively make myself available as a resource for consulting on topics related to statistics, computing and astrophysics.

Selected Software Projects

(see https://github.com/JohannesBuchner, over 100 original repositories, favorited or forked by 5829 people on GitHub)
  • UltraNest: Scalable inference nested sampling, for Bayesian model fitting.
  • PyMultiNest: Pythonic MultiNest interface and analysis (Python).
  • BXA: Bayesian X-ray analysis (spectral analysis for xspec/sherpa, using PyMultiNest/UltraNest).
  • NWAY: Bayesian cross-matching of large multi-wavelength catalogues.
  • XARS: X-ray Monte Carlo simulator for reflection spectroscopy.
  • GRAHSP: Genuine Retrieval of the AGN Host Stellar Population: photometry fitter.
  • imagehash: A Python perceptual image hashing module (favorited by over 2700 developers, adopted by Thorn to help stop the spread of child abuse material online).
  • PosteriorStacker: Sample distributions from heterogeneous posteriors.
  • Languagecheck: Semi-automated language editing for LaTeX papers.
  • 2006-2010: Patches and Bugtracking for Open Source projects: Videolan VLC, Pidgin, evince.
  • 2005/06: Mozilla Foundation (6 months): IRC-Support, Bug-Squadding for Firefox, Thunderbird, Calendar; developer of several extensions.

Skills

  • Fluent in English, spoken and written. German as mother-tongue. Basic Spanish.
  • Programming languages: C/C++, Java, Prolog, Haskell, Visual Basic
  • Scripting languages: Python, PHP, Javascript, GNU Bash, Microsoft Windows Batch.
  • Scientific packages: Scipy, R, Matlab, Maxima, Wolfram-Alpha, IDL
  • Hydrodynamic Simulations: Analysis of EAGLE and Illustris simulations, N-body simulations.
  • Databases: Multiple years of experience with MySQL and Oracle DB (10-11); SQL; XML
  • FOSS, GNU/Linux, FreeBSD, OpenBSD. Competent knowledge of the operating systems and use as server. Extensive knowledge of applications, configuration and networking, Cisco certified.