Showing posts with label Gravitational-Waves. Show all posts
Showing posts with label Gravitational-Waves. Show all posts

Sunday, July 26, 2026

The AEI plays a leading role in the development of LISA’s key instruments

Artist's impression of the LISA mission satellites in the solar system observing gravitational waves from a distant galaxy.
Credit:
University of Florida / Simon Barke (CC BY 4.0)

This picture shows a Back-End Electronics (BEE) module of LISA’s Phasemeter during tests with simulated signals in the Interferometric Signal Processing Lab at the AEI Hannover. In LISA, the BEE tracks signals from each satellite’s optical bench, containing information about the passing gravitational waves. © Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI)



To the point:
  • Preparations for LISA: LISA is a space-based observatory for gravitational waves and a mission of the European Space Agency (ESA) with contributions from NASA. It is scheduled to launch into space in the 2030s and will gather entirely new information about the Universe. The satellites and their high-precision measurement instruments are currently being developed.

  • Scientific expertise: The AEI is receiving a grant from the DLR. Under this grant, the institute is entrusted with leading the development of key LISA instruments as well as the investigation and verification of additional components through 2030. The grant totals 35 million euros.

  • Next steps for the phasemeter: On behalf of and under the leadership of the AEI, OHB Systems AG will develop and manufacture the engineering models, qualification models, and flight hardware for one component of the phasemeter. The phasemeter is LISA’s central measuring instrument.



The AEI receives a grant totaling 35 million euros from the DLR to develop key components of the instruments for the satellite mission

"This grant underscores the leading role of our institute and that of the Max Planck Society in the development of LISA, the European Space Agency’s gravitational-wave observatory

Guido Müller, director at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI)


Scientific expertise at the AEI

“The grant strengthens the scientific expertise – grown over decades – at the Max Planck Institute for Gravitational Physics in the development, investigation, and verification of methods and instruments for gravitational-wave observation in space,” says Jens Reiche Program Manager for space projects at the AEI.

With this latest grant of 35 million euros, the German Space Agency at the German Aerospace Center (DLR) is funding the next phase of development of instruments for LISA’s optical measurement system at the AEI. Additional funding for subsequent project phases has already been planned.

The funding is being provided as part of the implementation phase: The AEI is initially responsible for developing and providing the engineering models of the phasemeter – which is classified as mission-critical – and its signal processing within the optical measurement system. This includes extensive testing, encompassing all relevant interfaces

Next steps for the phasemeter

The LISA phasemeter is the heart of this measurement system. It will measure the minute changes in the laser light imprinted by gravitational waves in the laser beams as they travel back and forth over millions of kilometers between the three LISA satellites. Therefore, the phasemeter is the instrument that will detect gravitational waves and thereby enable a new era of astronomy.

The AEI is responsible for the phasemeter’s hardware and software and their verification. To this end, the institute will develop and operate mathematical models, simulators, and experiments.

“On our behalf and under our leadership, our industry partner OHB Systems AG is developing and manufacturing the engineering models, qualification models, and flight hardware for one of the two components of the phase meter,” says Kanioar Karan, the project manager for phasemeter development at AEI.

The institute also organizes and supports the verification of the LISA measurement system and manages its interaction with other components of the satellite hardware. To this end, the AEI develops and operates technical models of the instruments and simulators, as well as various experimental setups. Using these setups, scientists at the AEI will test the functionality of several components of the satellite hardware and verify whether they meet the strict requirements for measurement accuracy. These experimental setups in the institute’s laboratories could also help during commissioning of LISA in space following its launch in the 2030s.

Preparing for LISA measurements

In addition, researchers at the AEI will work with ESA to further develop methods for LISA’s science operations. The goal is to analyze the LISA measurement data after launch and commissioning in the 2030s and to derive as many scientific insights from them as possible. To this end, the scientists will develop and operate models and simulators of LISA instruments and will develop and refine new methods for analyzing the LISA data.

“Beyond basic research and its application in astronomy with LISA, the AEI also supports technology transfer to industry,” says Guido Müller. “The insights and experience gained from our research on high-precision, laser-based measurements are intended to enable novel technical applications.”

Background information

LISA


LISA will be the first gravitational-wave observatory in space. It will consist of three satellites that will move in a triangular configuration – connected by 2.5 million kilometer-long arms of laser light – in an Earth-like orbit around the Sun.

LISA will be able to detect gravitational waves from sources throughout the Universe, going back almost to the Big Bang. These gravitational waves will cause tiny changes (smaller than the diameter of an atom) in the laser arms. LISA will measure these length changes by using laser light to monitor the movements of test masses that are in free fall inside the satellites.

LISA research at the AEI

The institute has LISA research groups at its locations in Hanover and Potsdam. It plays a leading role in the development of key hardware components, research into laser interferometry for LISA, and in source modeling, data analysis, and the application of scientific results.

Gravitational-wave astronomy with LISA

Gravitational waves are ripples in spacetime that arise when masses are accelerated. Current detectors on Earth measure gravitational waves originating from merging pairs of neutron stars and black holes with masses of up to several hundred solar masses.

LISA will detect gravitational waves in the as-yet unexplored window between 0.1 mHz and 1 Hz – at frequencies that detectors on Earth cannot observe. Waves in this frequency range are generated when black holes with masses ranging from about 10,000 to 100 million times that of the Sun collide and merge at the centers of distant young galaxies. LISA will detect these processes throughout the history of the Universe, thereby directly investigating the as-yet-unknown origin and growth of extremely massive black holes.

What makes LISA unique is its ability to detect gravitational waves originating from black holes with masses ranging from about 100 to 10,000 solar masses that orbit massive black holes in galactic centers. These signals allow us to study the geometry of spacetime and test the nature of gravity. LISA will not only detect a large number of binary and multiple systems of compact objects in our Milky Way – which will provide insights into the evolution of binary stars – but will also “see” the galaxy beyond the galactic center. This includes many objects that are invisible to all other astronomical instruments.

Since LISA uses gravity as a signal source, the mission will complete our understanding of the origin, evolution, and structure of our Universe. The study of gravitational waves also offers enormous potential for discovering previously inaccessible parts of the Universe; these include, among other things, the echo of the Big Bang (ripples in spacetime caused by disturbances in the plasma shortly after the Big Bang) and other, as yet unknown phenomena. Together with other astronomical methods and gravitational-wave observatories on Earth, LISA researchers will contribute to the next major discoveries to answer questions such as “What are the fundamental laws of the Universe?” and “How did the Universe come into being, and what is it made of?”




Media contact:

Dr. Benjamin Knispel
Press Officer AEI Hannover
Tel:
+49 511 762-19104
Email: benjamin.knispel@aei.mpg.de

Prof. Dr. Guido Müller
Managing Director
Tel:
+49 511 762-12424
Email:  guido.mueller@aei.mpg.de
v Dr. Jens Reiche
Project Leader
Tel:
+49 511 762-12130
Tel: +49 511 762-5844
Email:  jens.reiche@aei.mpg.de

Dr. Kanioar Karan
Project Manager
Tel:
+49 511 762-12181
Email:  kanioar.karan@aei.mpg.de

Dr. Ada Agnieszka Uminska
Project Leader
Tel:
+49 511 762-14059
Email:  guido.mueller@aei.mpg.de



Further information

Aeneas Rooch: LISA listens to space (MaxPlanckResearch 2/2024)>

The largest astronomical observatory is so large that it won’t fit on Earth. It’s called LISA, and it will be able to detect when a 2.5-million-kilometer segment of space shrinks by even one atomic diameter. Researchers at the Max Planck Institute for Gravitational Physics in Hanover and Potsdam helped develop the gravitational-wave detector. By observing cosmic waves, they hope to gain an insight into strange processes deep in outer space.

Observing gravitational waves in space with LISA

Benjamin Knispel, “Observing gravitational waves in space with LISA” in: Einstein Online Band 15 (2024), 1001


Wednesday, June 23, 2021

The Future of the Search for a Gravitational-Wave Background


Artist's illustration of the Earth and surrounded pulsars embedded in spacetime that is deformed by an ocean of background gravitational waves. Credits: Tonia Klein / NANOGrav


Mrk 739 is an example of a galaxy merger where the two nuclei at the center of the newly-formed galaxy are still in the process of merging. Credit: SDSS

For decades, scientists have used networks of pulsars to search for a faint, background gravitational-wave signal that should pervade our universe. What have they found so far, and what can we expect in the future? A new publication details the possibilities.

Humming in the Background

In recent years, the LIGO and Virgo gravitational-wave detectors have clocked dozens of observations of stellar-mass black hole binary mergers. But what about larger black holes? When galaxies collide, the supermassive black holes at their centers should also form binaries, inspiral, and merge. The combination of all inspiraling supermassive black hole binaries across the universe should produce a deep background hum of gravitational waves — a signal that we could detect, with the right tool. Enter: pulsar timing arrays (PTAs).

Cosmic Clocks

PTAs rely on the remarkably consistent timing of flashes of light from a network of spinning neutron stars — pulsars — to measure the stretching of the spacetime in which these pulsars are embedded.

As gravitational waves pass through spacetime, signals from the various pulsars in the network have to travel longer or shorter distances to reach us. PTAs measure those timing differences to search for a stochastic background gravitational-wave signal.


An artist’s illustration showing how a network of pulsars could be used to search for the ripples in space-time
Credits: David Champion/NASA/JPL

A Hint of a Signal

How are PTAs doing so far? The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has been searching for the gravitational-wave background for more than a decade — until now, without success. But the longer we observe the timings of a set of pulsars, the more subtle a signal we can detect.

The 12.5-year dataset released this year offers a first glimpse of hope: this most sensitive dataset yet shows signs of a signal consistent with the predicted gravitational-wave background. Definitive evidence of the background will require longer observations with NANOGrav to beat down the noise and reveal an expected set of correlations between pairs of pulsars.

So when can we hope to robustly detect this signal, and what will it tell us? In a new publication led by Nihan Pol (Vanderbilt University, West Virginia University), a team of scientists emulates and extends the NANOGrav dataset into the future and tries to recover injected gravitational-wave-background signals to learn what we can expect.


The gravitational wave spectrum and detectors. Here, frequency of the gravitational waves is plotted against strain (the fractional change in the separation between objects caused by the passage of the gravitational wave).
Click to enlarge. [NANOGrav]

Milestones Ahead 

 Pol and collaborators identify three key milestones that we should soon achieve.
  1. Robust evidence of the gravitational-wave background should be possible with 15–17 years of data — only another 2–5 years beyond the 12.5-year dataset already published.
  2. The signal detected at this time will already contain enough information to identify whether the gravitational-wave background is caused by supermassive black hole binaries, as anticipated, or if it instead has more exotic origins, like primordial black holes or cosmic strings.
  3. If the signal is caused by supermassive black holes, the initial detection will also be sufficient to distinguish between different population models for supermassive black hole binaries.
This work illustrates that NANOGrav has the potential to provide us with a wealth of information in the next few years! What’s more, those results will come even faster with the addition of new pulsars to NANOGrav’s network, or the combination of data from multiple PTAs. Gravitational-wave astronomy is truly only just getting started!


Top: Evolution of the signal-to-noise ratio as a function of time observing the pulsars. Middle: The predicted correlation signal between pulsars after 12 years, 15 years, and 20 years, compared to the model (dashed red line) showing the presence of a gravitational-wave background. Bottom: The signal-to-noise ratio of the correlation signal as a function of observing time. [Pol et al. 2021]

Citation

“Astrophysics Milestones for Pulsar Timing Array Gravitational-wave Detection,” Nihan S. Pol et al 2021 ApJL 911 L34.
doi:10.3847/2041-8213/abf2c9

By Susanna Kohler