From The MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE)
2.23.23
Contacts
Dr. Stefanie Komossa
Max Planck Institute for Radio Astronomy, Bonn
+49 228 525-386
skomossa@mpifr-bonn.mpg.de
Dr. Alex Kraus
Max Planck Institute for Radio Astronomy, Bonn
+49 2257 301-101
akraus@mpifr-bonn.mpg.de
Prof. Dr. Dirk Grupe
+1 859 572-6549
Northern Kentucky University
gruped1@nku.edu
Dr. Norbert Junkes
Press and Public Outreach
MPG Institute for Radio Astronomy, Bonn
+49 228 525-399
njunkes@mpifr-bonn.mpg.de
Large-scale observational campaign provides new insights into an assumed black hole binary at the centre of the active galaxy OJ 287. A long-term study with data from four telescopes, ranging from radio to high energy frequencies, has penetrated to the core of the much-discussed active galaxy OJ 287, revealing further details about its interior. The results of the international team, led by Stefanie Komossa of the MPG Institute for Radio Astronomy, strengthen the evidence for a binary black hole system and place the primary black hole back on the scale.
The left panel shows a deep ultraviolet image, centered on OJ 287. The image was taken with the spaceborne Swift-Telescope.
The source of the ultraviolet light is the nucleus of the active galaxy OJ 287, which cannot be further resolved with this telescope. The right panel depicts an artist’s view of the nucleus, including the disk of matter, the jet, and the assumed pair of black holes. The secondary black hole is orbiting the more massive one. © S. Komossa et al.; NASA/JPL-Caltech.
Blazars are a special class of active galaxies characterized by high activity and extreme luminosity. The driving engines of these galaxies are black holes hidden inside their cores, millions to billions of times heavier than our Sun. Through the course of the history of the universe, these engines were fueled especially when galaxies collided. The subsequent merger of the galaxies created supermassive binary black holes. The study of such black-hole pairs reveals a lot about the evolution of galaxies and the growth of black holes.
Black hole on the scale
OJ 287 is one of the best candidates to host a compact supermassive binary black hole. One indication of this is the exceptional bursts of radiation produced by processes at the centre of the galaxy, which repeat every 11 to 12 years. Strictly speaking, each outburst consists of two peaks separated by roughly one year. These repeating outbursts are so remarkable that several different binary models have been proposed and discussed in the literature to explain them. The team led by Stefanie Komossa at the Max Planck Institute for Radio Astronomy has now revised the previously favored model by carrying out an unprecedented and systematic observational campaign. In the process, the researchers have also directly determined the mass of the primary black hole for the first time. At 100 million solar masses, it is probably about a hundred times smaller than previously thought. The new estimate of the black hole mass also seems to explain the entire history of OJ 287’s radiation outbursts, which have now been mapped in great detail.
Unveiling the invisible
The galaxy OJ 287 is too distant for telescopes to resolve the compact nucleus around the suspected black holes. However, since this region dominates the brightness of the whole galaxy, the radiation emerging from the core is both easily detectable on Earth and allows astronomers to reconstruct, with some limitations, the processes hidden inside the bright core. To do this, it helps to know the underlying processes. Matter from a disk surrounding the black hole that drifts inward loses gravitational energy in the form of optical and ultraviolet radiation. A jet launched from the surroundings of the central engine accelerates particles outwards. This often highly relativistic stream of matter emits intense radiation ranging from the radio to the X-rays and gamma-rays.
Two radio telescopes, the 100-metre Effelsberg radio telescope in Germany and the Submillimetre-Array in Hawaii, and two satellite observatories were used for the observations. Among the latter, Fermi covers gamma-ray frequencies, while the Neil-Gehrels-Swift Observatory [above] observes optical, UV and X-ray frequencies.
“OJ 287 is an excellent laboratory for studying the physical processes that reign in one of the most extreme astrophysical environments: disks and jets of matter in the immediate vicinity of one or two supermassive black holes”, says Stefanie Komossa from the MPG Institute for Radio Astronomy, the leading author of the two studies presented here. “Therefore, we initiated the project Momo („Multiwavelength Observations and Modelling of OJ 287“). It consists of high-cadence observations of OJ 287 at more than 14 frequencies from the radio to the high energy regime lasting for years, plus dedicated follow-ups at multiple ground- and space-based facilities when the blazar is found at exceptional states.”
The outbursts of OJ 287 can be explained by the model of a binary black hole system, in particular by the motion of the second, lower-mass black hole orbiting the primary one. On its inclined orbit, it disturbs either the jet or the disk of matter, thus causing OJ 287’s periodic bursts. Measurements with the 100-metre Effelsberg radio telescope attribute the most recent burst directly to the jet. It is like looking into a glaring spotlight that outshines everything behind it.
Strong evidence for two supermassive black holes in the core
The state-of-the-art model describing the processes in the centre of OJ 287 assumed a primary black hole ten billion times heavier than the Sun. According to this model, the next outburst would have been due in October 2022. The actual data did not confirm this prediction. Instead, thanks to the dense coverage of the Momo campaign, the astronomers discovered this outburst much earlier, between 2016 and 2017. The previously favored model was therefore falsified. The researchers then reassessed the mass of the primary black hole. It turns out to be a hundred times lighter than previously thought. As a result, the orbit of the secondary black hole around the primary black hole should wobble much less. This behavior has direct implications for the predicted outbursts, which are now consistent with both historical and recent measurements. “This result is very important, as the mass is a key parameter in the models that study the evolution of this binary system: How far are the black holes separated, how quickly will they merge, how strong is their gravitational wave signal?” says Dirk Grupe of the Northern Kentucky University, a co-author of both studies.
Gravitational waves and a photograph?
The Momo results make the authors optimistic that future space-based observatories will be able to detect gravitational waves from this or similar binary systems. It may even be possible to spatially resolve the two black holes in OJ 287 with a large network of radio telescopes, such as the Event Horizon Telescope known from the media or the Square Kilometre Array still under construction. This would be the first direct detection of a close system of two supermassive black holes in the centre of a galaxy.
MNRAS
The Astrophysical Journal
Fig. 1.
Multifrequency radio light curves of OJ 287 between 2015 December and 2022 June obtained with the Effelsberg telescope in the course of the MOMO program. Note that some receivers and/or frequencies have slightly changed in the course of the monitoring. See Table 1 for details in the science paper.
Fig. 2.
SMA radio light curve of OJ 287 between 2015 October and 2022
June (filled circles: 1.3 mm band, open green circles: 1.1 mm band, open blue
circles: 870 μm band).
For further images see the science paper.
Astronomical Notes
See the science paper for instructive material with images.
See the full article here .
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The MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie] (DE) is located in Bonn, Germany. It is one of 80 institutes in the MPG Society.
By combining the already existing radio astronomy faculty of the University of Bonn led by Otto Hachenberg with the new MPG institute the MPG Institute for Radio Astronomy was formed. In 1972 the 100-m radio telescope in Effelsberg was opened. The institute building was enlarged in 1983 and 2002.
The institute was founded in 1966 by the MPG Society as the “MPG Institut für Radioastronomie (MPIfR) (DE)”.
The foundation of the institute was closely linked to plans in the German astronomical community to construct a competitive large radio telescope in (then) West Germany. In 1964, Professors Friedrich Becker, Wolfgang Priester and Otto Hachenberg of the Astronomische Institute der Universität Bonn submitted a proposal to the Stiftung Volkswagenwerk for the construction of a large fully steerable radio telescope.
In the same year the Stiftung Volkswagenwerk approved the funding of the telescope project but with the condition that an organization should be found, which would guarantee the operations. It was clear that the operation of such a large instrument was well beyond the possibilities of a single university institute.
Already in 1965 the MPG Society decided in principle to found the MPG Institut für Radioastronomie. Eventually, after a series of discussions, the institute was officially founded in 1966.
MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.] is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.
According to its primary goal, the MPG Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014) MPG Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.
The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.
The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.
History
The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.
The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.
The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.
MPG Institutes and research groups
The MPG Society consists of over 80 research institutes. In addition, the society funds a number of Max Planck Research Groups (MPRG) and International Max Planck Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University (US) focusing on neuroscience.
The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.
Internally, MPG Institutes are organized into research departments headed by directors such that each MPI has several directors, a position roughly comparable to anything from full professor to department head at a university. Other core members include Junior and Senior Research Fellows.
In addition, there are several associated institutes:
International Max Planck Research Schools
Together with the Association of Universities and other Education Institutions in Germany, the Max Planck Society established numerous International Max Planck Research Schools (IMPRS) to promote junior scientists:
• Cologne Graduate School of Ageing Research, Cologne
• International Max Planck Research School for Intelligent Systems, at the Max Planck Institute for Intelligent Systems located in Tübingen and Stuttgart
• International Max Planck Research School on Adapting Behavior in a Fundamentally Uncertain World (Uncertainty School), at the Max Planck Institutes for Economics, for Human Development, and/or Research on Collective Goods
• International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering, Magdeburg
• International Max Planck Research School for Astronomy and Cosmic Physics, Heidelberg at the MPI for Astronomy
• International Max Planck Research School for Astrophysics, Garching at the MPI for Astrophysics
• International Max Planck Research School for Complex Surfaces in Material Sciences, Berlin
• International Max Planck Research School for Computer Science, Saarbrücken
• International Max Planck Research School for Earth System Modeling, Hamburg
• International Max Planck Research School for Elementary Particle Physics, Munich, at the MPI for Physics
• International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Marburg at the Max Planck Institute for Terrestrial Microbiology
• International Max Planck Research School for Evolutionary Biology, Plön at the Max Planck Institute for Evolutionary Biology
• International Max Planck Research School “From Molecules to Organisms”, Tübingen at the Max Planck Institute for Developmental Biology
• International Max Planck Research School for Global Biogeochemical Cycles, Jena at the Max Planck Institute for Biogeochemistry
• International Max Planck Research School on Gravitational Wave Astronomy, Hannover and Potsdam MPI for Gravitational Physics
• International Max Planck Research School for Heart and Lung Research, Bad Nauheim at the Max Planck Institute for Heart and Lung Research
• International Max Planck Research School for Infectious Diseases and Immunity, Berlin at the Max Planck Institute for Infection Biology
• International Max Planck Research School for Language Sciences, Nijmegen
• International Max Planck Research School for Neurosciences, Göttingen
• International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen
• International Max Planck Research School for Marine Microbiology (MarMic), joint program of the Max Planck Institute for Marine Microbiology in Bremen, the University of Bremen, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, and the Jacobs University Bremen
• International Max Planck Research School for Maritime Affairs, Hamburg
• International Max Planck Research School for Molecular and Cellular Biology, Freiburg
• International Max Planck Research School for Molecular and Cellular Life Sciences, Munich
• International Max Planck Research School for Molecular Biology, Göttingen
• International Max Planck Research School for Molecular Cell Biology and Bioengineering, Dresden
• International Max Planck Research School Molecular Biomedicine, program combined with the ‘Graduate Programm Cell Dynamics And Disease’ at the University of Münster and the Max Planck Institute for Molecular Biomedicine
• International Max Planck Research School on Multiscale Bio-Systems, Potsdam
• International Max Planck Research School for Organismal Biology, at the University of Konstanz and the Max Planck Institute for Ornithology
• International Max Planck Research School on Reactive Structure Analysis for Chemical Reactions (IMPRS RECHARGE), Mülheim an der Ruhr, at the Max Planck Institute for Chemical Energy Conversion
• International Max Planck Research School for Science and Technology of Nano-Systems, Halle at Max Planck Institute of Microstructure Physics
• International Max Planck Research School for Solar System Science at the University of Göttingen hosted by MPI for Solar System Research
• International Max Planck Research School for Astronomy and Astrophysics, Bonn, at the MPI for Radio Astronomy (formerly the International Max Planck Research School for Radio and Infrared Astronomy)
• International Max Planck Research School for the Social and Political Constitution of the Economy, Cologne
• International Max Planck Research School for Surface and Interface Engineering in Advanced Materials, Düsseldorf at Max Planck Institute for Iron Research GmbH
• International Max Planck Research School for Ultrafast Imaging and Structural Dynamics, Hamburg
Max Planck Schools
• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics
Max Planck Center
• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang
Max Planck Institutes
Among others:
• Max Planck Institute for Neurobiology of Behavior – caesar, Bonn
• Max Planck Institute for Aeronomics in Katlenburg-Lindau was renamed to Max Planck Institute for Solar System Research in 2004;
• Max Planck Institute for Biology in Tübingen was closed in 2005;
• Max Planck Institute for Cell Biology in Ladenburg b. Heidelberg was closed in 2003;
• Max Planck Institute for Economics in Jena was renamed to the Max Planck Institute for the Science of Human History in 2014;
• Max Planck Institute for Ionospheric Research in Katlenburg-Lindau was renamed to Max Planck Institute for Aeronomics in 1958;
• Max Planck Institute for Metals Research, Stuttgart
• Max Planck Institute of Oceanic Biology in Wilhelmshaven was renamed to Max Planck Institute of Cell Biology in 1968 and moved to Ladenburg 1977;
• Max Planck Institute for Psychological Research in Munich merged into the Max Planck Institute for Human Cognitive and Brain Sciences in 2004;
• Max Planck Institute for Protein and Leather Research in Regensburg moved to Munich 1957 and was united with the Max Planck Institute for Biochemistry in 1977;
• Max Planck Institute for Virus Research in Tübingen was renamed as Max Planck Institute for Developmental Biology in 1985;
• Max Planck Institute for the Study of the Scientific-Technical World in Starnberg (from 1970 until 1981 (closed)) directed by Carl Friedrich von Weizsäcker and Jürgen Habermas.
• Max Planck Institute for Behavioral Physiology
• Max Planck Institute of Experimental Endocrinology
• Max Planck Institute for Foreign and International Social Law
• Max Planck Institute for Physics and Astrophysics
• Max Planck Research Unit for Enzymology of Protein Folding
• Max Planck Institute for Biology of Ageing
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