×
![]( "Buchcover ISBN 9783945931530")
Astroparticle Physics 2023
Highlights and Annual Report
| Forewords and news6
Astroparticle physics
at DESY
Director’s foreword
We live in challenging times. Even as the COVID-19 pandemic
receded, 2023 saw an increase in conicts that has numerous
implications for both the political situation and the scientic
landscape in Europe and beyond. As a research centre whose
success is founded on international collaboration, DESY rmly
upholds the democratic values on which our peaceful coexistence
and cooperation in Europe and with our partners around the world
is based.
As I wrote on the occasion of the second Diversity Day at DESY in
May 2023: “DESY is diverse, the people who work here come from
many nations, have different origins, bring different identities and
perspectives. Each and every one enriches us. This diversity is
sometimes exhausting, but it makes us strong. Especially in
difcult times, it is important to promote equal opportunities and
solidarity and to set an example for diversity.” It is this spirit of
open-mindedness, tolerance and mutual respect that makes DESY
such a great place to work – and that ensures its success as one of
the world’s top centres for research into the structure of matter
and the universe.
The progress of our research projects testies to the success of
this approach, with all the endeavours of the DESY Astroparticle
Physics Division reaching decisive milestones in 2023. In particular,
preparations are in full swing for the construction of the tele-
scopes and infrastructure for the upcoming Cherenkov Telescope
Array Observatory (CTAO) – a unique, world-class observatory for
gamma-ray astronomy with over 60 telescopes at two sites in Chile
and on the Canary Island of La Palma. Construction work on the
observatory’s Science Data Management Centre (SDMC) on our
Zeuthen campus proceeded as planned, with completion expected
in autumn 2024. In addition, DESY is in charge of providing a total
of 42 cameras for the Small-Sized Telescopes (SSTs), which are
approaching their nal design. In 2023, electronic components for
the cameras were manufactured and used to build a development
and test model of the camera. Furthermore, DESY is responsible
for the design and production of the Medium-Sized Telescopes
(MSTs). The DESY design was approved by CTAO at the end of 2023
after a thorough review. As the next step, two prototype MSTs will
be manufactured at DESY and prepared for installation at both
observatory sites.
The development of the camera for the ULTRASAT space tele-
scope, a satellite mission led by the Weizmann Institute of Science
(WIS) and the Israel Space Agency (ISA), made very good progress.
Major steps were taken towards the rst version of the camera,
and the production phase was initiated. First tests of the readout
chain of the sensors – which will take images in the near-ultraviolet
with 90 million pixels every ve minutes to search for time-varying
cosmic sources – were successful.
In neutrino astronomy, work continued to focus on the IceCube
neutrino telescope at the South Pole and on the Radio Neutrino
Observatory Greenland (RNO-G). IceCube is currently being
upgraded in collaboration with US partners, KIT in Karlsruhe and
several university groups. New optical modules with more
sensitive light detection, called multi-photomultiplier tube digital
optical modules (mDOMs), have been developed at DESY and
elsewhere for this purpose. Equipped with 24 photomultipliers
each, they have about twice the light-sensitive area of their
predecessors in IceCube and allow intrinsic directional determi-
nation of the measured light. Their development was successfully
completed in 2023 with a production readiness review, and the
integration and testing of 225 mDOMs at DESY is now well under
way. By the end of 2023, more than 100 mDOMs had been
produced and successfully tested. The detection of neutrinos with
petaelectronvolt (PeV) energies using radio waves is an important
addition to IceCube, which is being studied with the RNO-G pilot
array in Greenland. Here, the year 2023 was used to improve the
drilling technology and the autonomous energy supply and to
calibrate the stations already installed, building on the experience
gained with the rst seven stations.
IceCube also delivered one of the scientic highlights of the year,
which we are pleased to present to you in this report. Using a
novel analysis technique developed mainly at DESY and RWTH
Aachen, the IceCube researchers performed the most accurate
measurement of the cosmic neutrino spectrum to date. For the
rst time, evidence was found for a break in the spectral shape,
providing important clues about the nature of the environments in
which the neutrinos are produced. To further boost analysis
capabilities, DESY released the Astrophysical Multi-Messenger
Modeling (AM3) software, which can be used to simulate
multimessenger emission – including neutrinos – from active
galactic nuclei, blazars and gamma-ray bursts. Further scientic
highlights included the detection by the H. E. S. S. telescope of
very-high-energy gamma-ray emission from the outer jets of a
microquasar, insights from observations by the VERITAS telescope
that reveal the potential origin of a galactic “PeVatron” candidate
– a cosmic-ray factory that accelerates particles to PeV energies –
and a novel analysis of the production mechanisms of particle
cascades generated by gamma-rays from distant blazars.
These successes, which have been published in high-ranking
scientic journals, attest to the excellent research being carried
out in the DESY Astroparticle Physics Division despite the current
tight stafng situation. So do the prizes and awards conferred to
members of the division, including two distinctions for outstanding
PhD theses – for Annika Rudolph from the German Astronomical
Society and for Robert Stein from the German Physical Society –
as well as a Starting Grant from the European Research Council
(ERC) for Anna Nelles to fund the construction of the RNO-G
network of radio antennas on Greenland.
The Helmholtz–Weizmann International Research School for
Multimessenger Astronomy, in which DESY is strongly involved,
continues to deliver excellent results, with the students of the
second cohort having nished the School and new students
recruited for a doctorate for the sixth time. To further the public
understanding of science and inspire young people in particular
to take an interest in science, the division continued to actively
promote young talent and outreach activities, for example through
its School Lab, the rst AstroCamp, featuring the launch of a
research balloon, the rst DESY–Ukraine Winter School, the
traditional summer student programme and several other events
organised on the occasion of the “Science Year 2023 – Our
Universe” declared by the German Federal Ministry of Education
and Research (BMBF).
I would like to thank all our staff and our partners in Germany and
around the world for contributing to our joint successes in the past
year, and I am looking forward to continuing our cooperation –
based on our common values of open-mindedness, tolerance and
respect – in the years to come.
Astroparticle physics
at DESY
Director’s foreword
We live in challenging times. Even as the COVID-19 pandemic
receded, 2023 saw an increase in conicts that has numerous
implications for both the political situation and the scientic
landscape in Europe and beyond. As a research centre whose
success is founded on international collaboration, DESY rmly
upholds the democratic values on which our peaceful coexistence
and cooperation in Europe and with our partners around the world
is based.
As I wrote on the occasion of the second Diversity Day at DESY in
May 2023: “DESY is diverse, the people who work here come from
many nations, have different origins, bring different identities and
perspectives. Each and every one enriches us. This diversity is
sometimes exhausting, but it makes us strong. Especially in
difcult times, it is important to promote equal opportunities and
solidarity and to set an example for diversity.” It is this spirit of
open-mindedness, tolerance and mutual respect that makes DESY
such a great place to work – and that ensures its success as one of
the world’s top centres for research into the structure of matter
and the universe.
The progress of our research projects testies to the success of
this approach, with all the endeavours of the DESY Astroparticle
Physics Division reaching decisive milestones in 2023. In particular,
preparations are in full swing for the construction of the tele-
scopes and infrastructure for the upcoming Cherenkov Telescope
Array Observatory (CTAO) – a unique, world-class observatory for
gamma-ray astronomy with over 60 telescopes at two sites in Chile
and on the Canary Island of La Palma. Construction work on the
observatory’s Science Data Management Centre (SDMC) on our
Zeuthen campus proceeded as planned, with completion expected
in autumn 2024. In addition, DESY is in charge of providing a total
of 42 cameras for the Small-Sized Telescopes (SSTs), which are
approaching their nal design. In 2023, electronic components for
the cameras were manufactured and used to build a development
and test model of the camera. Furthermore, DESY is responsible
for the design and production of the Medium-Sized Telescopes
(MSTs). The DESY design was approved by CTAO at the end of 2023
after a thorough review. As the next step, two prototype MSTs will
be manufactured at DESY and prepared for installation at both
observatory sites.
The development of the camera for the ULTRASAT space tele-
scope, a satellite mission led by the Weizmann Institute of Science
(WIS) and the Israel Space Agency (ISA), made very good progress.
Major steps were taken towards the rst version of the camera,
and the production phase was initiated. First tests of the readout
chain of the sensors – which will take images in the near-ultraviolet
with 90 million pixels every ve minutes to search for time-varying
cosmic sources – were successful.
In neutrino astronomy, work continued to focus on the IceCube
neutrino telescope at the South Pole and on the Radio Neutrino
Observatory Greenland (RNO-G). IceCube is currently being
upgraded in collaboration with US partners, KIT in Karlsruhe and
several university groups. New optical modules with more
sensitive light detection, called multi-photomultiplier tube digital
optical modules (mDOMs), have been developed at DESY and
elsewhere for this purpose. Equipped with 24 photomultipliers
each, they have about twice the light-sensitive area of their
predecessors in IceCube and allow intrinsic directional determi-
nation of the measured light. Their development was successfully
completed in 2023 with a production readiness review, and the
integration and testing of 225 mDOMs at DESY is now well under
way. By the end of 2023, more than 100 mDOMs had been
produced and successfully tested. The detection of neutrinos with
petaelectronvolt (PeV) energies using radio waves is an important
addition to IceCube, which is being studied with the RNO-G pilot
array in Greenland. Here, the year 2023 was used to improve the
drilling technology and the autonomous energy supply and to
calibrate the stations already installed, building on the experience
gained with the rst seven stations.
IceCube also delivered one of the scientic highlights of the year,
which we are pleased to present to you in this report. Using a
novel analysis technique developed mainly at DESY and RWTH
Aachen, the IceCube researchers performed the most accurate
measurement of the cosmic neutrino spectrum to date. For the
rst time, evidence was found for a break in the spectral shape,
providing important clues about the nature of the environments in
which the neutrinos are produced. To further boost analysis
capabilities, DESY released the Astrophysical Multi-Messenger
Modeling (AM3) software, which can be used to simulate
multimessenger emission – including neutrinos – from active
galactic nuclei, blazars and gamma-ray bursts. Further scientic
highlights included the detection by the H. E. S. S. telescope of
very-high-energy gamma-ray emission from the outer jets of a
microquasar, insights from observations by the VERITAS telescope
that reveal the potential origin of a galactic “PeVatron” candidate
– a cosmic-ray factory that accelerates particles to PeV energies –
and a novel analysis of the production mechanisms of particle
cascades generated by gamma-rays from distant blazars.
These successes, which have been published in high-ranking
scientic journals, attest to the excellent research being carried
out in the DESY Astroparticle Physics Division despite the current
tight stafng situation. So do the prizes and awards conferred to
members of the division, including two distinctions for outstanding
PhD theses – for Annika Rudolph from the German Astronomical
Society and for Robert Stein from the German Physical Society –
as well as a Starting Grant from the European Research Council
(ERC) for Anna Nelles to fund the construction of the RNO-G
network of radio antennas on Greenland.
The Helmholtz–Weizmann International Research School for
Multimessenger Astronomy, in which DESY is strongly involved,
continues to deliver excellent results, with the students of the
second cohort having nished the School and new students
recruited for a doctorate for the sixth time. To further the public
understanding of science and inspire young people in particular
to take an interest in science, the division continued to actively
promote young talent and outreach activities, for example through
its School Lab, the rst AstroCamp, featuring the launch of a
research balloon, the rst DESY–Ukraine Winter School, the
traditional summer student programme and several other events
organised on the occasion of the “Science Year 2023 – Our
Universe” declared by the German Federal Ministry of Education
and Research (BMBF).
I would like to thank all our staff and our partners in Germany and
around the world for contributing to our joint successes in the past
year, and I am looking forward to continuing our cooperation –
based on our common values of open-mindedness, tolerance and
respect – in the years to come.