NASA's Hubble Takes the Closest-Ever Look at a Quasar

Quasar 3C 273

A Hubble Space Telescope image of the core of quasar 3C 273. A coronagraph on Hubble blocks out the glare coming from the supermassive black hole at the heart of the quasar. This allows astronomers to see unprecedented details near the black hole such as weird filaments, lobes, and a mysterious L-shaped structure, probably caused by small galaxies being devoured by the black hole. Located 2.5 billion light-years away, 3C 273 is the first quasar (quasi-stellar object) ever discovered, in 1963. Credits/Image: NASA, ESA, Bin Ren (Université Côte d’Azur/CNRS); Acknowledgment: John Bahcall (IAS); Image Processing: Joseph DePasquale (STScI)

Astronomers have used the unique capabilities of NASA's Hubble Space Telescope to peer closer than ever into the throat of an energetic monster black hole powering a quasar. A quasar is a galactic center that glows brightly as the black hole consumes material in its immediate surroundings.

The new Hubble views of the environment around the quasar show a lot of "weird things," according to Bin Ren of the Côte d'Azur Observatory and Université Côte d'Azur in Nice, France. "We've got a few blobs of different sizes, and a mysterious L-shaped filamentary structure. This is all within 16,000 light-years of the black hole."

Some of the objects could be small satellite galaxies around the black hole, and so they could offer the materials that will accrete onto the central super massive black hole, powering the bright lighthouse. "Thanks to Hubble's observing power, we're opening a new gateway into understanding quasars," said Ren. "My colleagues are excited because they've never seen this much detail before."

Quasars look starlike as point sources of light in the sky (hence the name quasi-stellar object). The quasar in the new study, 3C 273, was identified in 1963 by astronomer Maarten Schmidt as the first quasar. At a distance of 2.5 billion light-years it was too far away for a star. It must have been more energetic than ever imagined, with a luminosity over 10 times brighter than the brightest giant elliptical galaxies. This opened the door to an unexpected new puzzle in cosmology: What is powering this massive energy production? The likely culprit was material accreting onto a black hole.

In 1994 Hubble's new sharp view revealed that the environment surrounding quasars is far more complex than first suspected. The images suggested galactic collisions and mergers between quasars and companion galaxies, where debris cascades down onto supermassive black holes. This reignites the giant black holes that drive quasars.

For Hubble, staring into the quasar 3C 273 is like looking directly into a blinding car headlight and trying to see an ant crawling on the rim around it. The quasar pours out thousands of times the entire energy of stars in a galaxy. One of closest quasars to Earth, 3C 273 is 2.5 billion light-years away. (If it was very nearby, a few tens of light-years from Earth, it would appear as bright as the Sun in the sky!) Hubble's STIS instrument can serve as a coronagraph to block light from central sources, not unlike how the Moon block the Sun's glare during a total solar eclipse. Astronomers have used STIS to unveil dusty disks around stars to understand the formation of planetary systems, and now they can use STIS to better understand quasars’ host galaxies. The Hubble coronograph allowed astronomers to look eight times closer to the black hole than ever before.

Scientists got rare insight into the quasar's 300,000-light-year-long extragalactic jet of material blazing across space at nearly the speed of light. By comparing the STIS coronagraphic data with archival STIS images with a 22-year separation, the team led by Ren concluded that the jet is moving faster when it is farther away from the monster black hole.

"With the fine spatial structures and jet motion, Hubble bridged a gap between the small-scale radio interferometry and large-scale optical imaging observations, and thus we can take an observational step towards a more complete understanding of quasar host morphology. Our previous view was very limited, but Hubble is allowing us to understand the complicated quasar morphology and galactic interactions in detail. In the future, looking further at 3C 273 in infrared light with the James Webb Space Telescope might give us more clues," said Ren.

At least 1 million quasars are scattered across the sky. They are useful background "spotlights" for a variety of astronomical observations. Quasars were most abundant about 3 billion years after the big bang, when galaxy collisions were more common.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute (STScI) in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Source: HubbleSite/News

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About This Release

Credits:

Media Contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Bin Ren
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, France

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• Science Paper: The science paper by Bin Ren et al., PDF (8.06 MB)
• NASA's Hubble Portal

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Astronomers Observed the Innermost Structure of a Quasar Jet

The left image shows the deepest look yet into the plasma jet of the quasar 3C 273, which will allow scientists to further study how quasar jets are collimated, or narrowed. The powerful, collimated jet extends for hundreds of thousands of light-years beyond the host galaxy, as seen in the right panel image taken by the Hubble Space Telescope. Scientists use radio images at different scales to measure the shape of the entire jet. The arrays used are the Global Millimeter VLBI Array (GMVA) joined by the Atacama Large Millimeter/submillimeter Array (ALMA) and the High Sensitivity Array (HSA). Credits: Hiroki Okino and Kazunori Akiyama; GMVA+ALMA and HSA images: Okino et al.; HST Image: ESA/Hubble & NASA.

The radio telescopes of the Global Millimeter VLBI Array (GMVA) and ALMA, combined into a powerful global array called GMVA+ALMA, which was used in this project. Credit: Kazunori Akiyama

The blue points are the telescopes of the Global Millimeter VLBI Array (GMVA) joined by ALMA. The yellow points are the telescopes of the High Sensitivity Array used in this project. Green indicates where both networks were used. Credit: Kazunori Akiyama

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At the heart of nearly every galaxy lurks a supermassive black hole. But not all supermassive black holes are alike: there are many types. Quasars, quasi-stellar objects, are one of the brightest and most active types of supermassive black holes.

An international group of scientists has published new observations of the first quasar ever identified — the one labeled 3C 273, located in the Virgo constellation – that show the innermost, most profound parts of the quasar’s main plasma jet.

Active supermassive black holes emit narrow, mighty jets of plasma that escape at nearly the speed of light. These jets have been studied throughout the modern era of astronomy, yet their formation process is still a mystery to astronomers and astrophysicists. An unresolved issue has been how and where the jets are collimated or concentrated into a narrow beam, which allows them to extend to extreme distances beyond their host galaxy and even affect galactic evolution. These new observations are thus far the deepest into the heart of a black hole, where the plasma flow is collimated into a narrow beam.

This new study, published in The Astrophysical Journal (Okino et al., 2022), includes observations of the 3C 273 jet at the highest angular resolution to date, obtaining data for the innermost portion of the jet, close to the central black hole. The ground-breaking work was made possible by using a closely coordinated set of radio antennas around the globe, a combination of the Global Millimeter VLBI Array (GMVA) and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Coordinated observations were also made with the High Sensitivity Array (HSA) to study 3C 273 on different scales and measure the jet’s global shape.

“3C 273 has been studied for decades as the ideal closest laboratory for quasar jets,” says Hiroki Okino, lead author of this paper and a Ph.D. student at the University of Tokyo and the National Astronomical Observatory of Japan. “However, even though the quasar is a close neighbor, until recently, we didn’t have an eye sharp enough to see where this powerful narrow flow of plasma is shaped.”

The image of the 3C 273 jet gives scientists the very first view of the innermost part of the jet in a quasar, where the collimation or narrowing of the beam occurs. The team further found that the angle of the plasma stream flowing from the black hole is tightened up over a very long distance. This narrowing part of the jet continues incredibly far, well beyond the area where the black hole’s gravity rules.

“It is striking to see that the shape of the powerful stream is slowly formed over a long distance in an extremely active quasar. This has also been discovered nearby in much fainter and less active supermassive black holes,” says Kazunori Akiyama, a research scientist at MIT Haystack Observatory and project lead. “The results pose a new question: how does the jet collimation happen consistently across such varied black hole systems?”

The new, incredibly sharp images of the 3C 273 jet were made possible by including ALMA observations. The GMVA and ALMA were connected across continents using very long baseline interferometry (VLBI) to obtain detailed information about distant astronomical sources. The remarkable VLBI capability of ALMA was enabled by the ALMA Phasing Project (APP) team. The international APP team, led by MIT Haystack Observatory, developed the hardware and software to turn ALMA, an array of 66 telescopes, into the world’s most sensitive astronomical interferometry station. Collecting data at these wavelengths dramatically increases the resolution and sensitivity of the array.

“The ability to use ALMA as part of global VLBI networks has been a complete game-changer for black hole science,” says Lynn Matthews, Haystack principal research scientist and commissioning scientist for the APP. “It enabled us to obtain the first-ever images of supermassive black holes, and now it is helping us to see for the first time incredible new details about how black holes power their jets.”

This study opens the door to further exploration of jet collimation processes in other black holes. Data obtained at higher frequencies allows scientists to observe finer details within quasars and other black holes.

“Formation mechanism of the jets from supermassive black holes is still elusive, though they were first identified more than 100 years ago,” says Hiroshi Nagai, project associate professor at NAOJ ALMA Project. “The sharpest images with the aid of ALMA and GMVA have significantly improved our understanding of the jets, and we hope to advance this study with even better angular resolution.”

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Additional Information

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The GMVA observes at the 3mm wavelength, using the following stations for this research in April 2017: eight antennas of Very Long Baseline Array (VLBA), the Effelsberg 100m Radio Telescope of the Max-Planck-Institut für Radioastronomie (MPIfR), the IRAM 30m Telescope, the 20m telescope of the Onsala Space Observatory, and the 40m Radio Telescope of Yebes Observatory. The data were correlated at the DiFX VLBI correlator at the MPIfR in Bonn, Germany.

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Contacts:

Nicolas Lira Turpaud
Joint ALMA Observatory, Chile
ALMA EPO Coordinator
nicolas.lira@alma.cl
+56 9 94 45 77 26

Alvaro Gonzalez
NAOJ · interim NAOJ ALMA Officer
Alvaro.Gonzalez@nao.ac.jp
+81-422-34-3889

Nancy Wolfe Kotary
[ MIT Haystack Observatory, USA
nwk@mit.edu
+1-617-715-5400

Source: ALMA (Atacama Large Millimeter/submillimeter Array)/News

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Quasars as Cosmic Standard Candles

The quasar 3C 273 with its jet, as seen by the Chandra X-ray Observatory. Astronomers have found that the X-ray and ultraviolet luminosities of quasars are so tightly correlated, even for quasars at large cosmological distances, that quasars can be used as new "standard candles" to help determine cosmic distances and probe other fundamental cosmological parameters. Credit: Chandra X-ray Observatory

In 1929, Edwin Hubble published observations that galaxies' distances and velocities are correlated, with the distances determined using their Cepheid stars. Harvard astronomer Henrietta Swan Leavitt had discovered that a Cepheid star varies periodically with a period that is related to its intrinsic luminosity. She calibrated the effect, and when Hubble compared those calculated values with his observed luminosities he was able to determine their distances. But even today only Cepheid stars in relatively nearby galaxies can be studied in this way.In order to extend the distance scale back to earlier times in cosmic history, astronomers have used supernovae (SN) - the explosive deaths of massive stars – which can be seen to much greater distances. By comparing the observed brightness of a SN with its intrinsic brightness, based on its classification, astronomers are able to determine its distance; comparing that with the host galaxy's velocity (its redshift, measured spectroscopically) yields the "Hubble relation" relating the galaxy's velocity to its distance. The most reliable supernovae for this purpose, because of their cosmic uniformity, are so-called "Type Ia" supernovae, which are thought to be "standard candles," all having the same intrinsic brightness. However even SN become harder to study in this way as they lie farther away; to date the most distant Type Ia SN with a reliable velocity determination dates from an epoch about 3 billion years after the big bang.

CfA astronomers Susanna Bisogni, Francesca Civano, Martin Elvis and Pepi Fabbiano and their colleagues propose using quasars as a new standard candle. The most distant known quasars have been spotted from an era only about seven hundred million years after the big bang, dramatically extending the range of standard candle redshifts. Another advantage of quasars is that hundreds of thousands of them have been discovered in the past few years. Not least, the physical processes in quasars are different from those in SN, providing completely independent measures of cosmological parameters.

The new scheme proposed by the astronomers relies on their discovery that the X-ray and ultraviolet emission in quasars are tightly correlated. At the heart of a quasar is a supermassive black hole surrounded by a very hot disk of accreting material that emits in the ultraviolet. The disk in turn is surrounded by hot gas with electrons moving at speeds close to that of light, and when ultraviolet photons encounter these electrons their energy is boosted into the X-rays. The team, building on their previous methods, analyzed X-ray measurements of 2332 distant quasars in the new Chandra Source Catalog and compared them to ultraviolet results from the Sloan Digital Sky Survey. They found that the tight correlation already known to exist between the ultraviolet and X-ray luminosity of local quasars continues in distant quasars, back over 85% of the age of the Universe, becoming even tighter at earlier times. The implication is that these two quantities can determine the distance of each quasar, and those distances can then be used to test cosmological models. If the results are confirmed, they will provide astronomers with a dramatic new tool with which to measure the properties of the evolving universe.

Reference:

The Chandra view of the relation between X-ray and UV emission in quasars,” S. Bisogni, E. Lusso, F. Civano, E. Nardini, G. Risaliti, M. Elvis, and G. Fabbiano,  Astronomy & Astrophysics, in press, 2021.

Scientists:

• Francesca M Civano
• Martin Elvis
• Giuseppina (Pepi) Fabbiano

Source: Harvard-Smithsonian Center for Astrophysics (CfA)

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Most detailed-ever images of galaxies revealed using LOFAR

A compilation of the science results. Credit from left to right starting at the top: N. Ramírez-Olivencia et el. [radio]; NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), edited by R. Cumming [optical], C. Groeneveld, R. Timmerman; LOFAR & Hubble Space Telescope,. Kukreti; LOFAR & Sloan Digital Sky Survey, A. Kappes, F. Sweijen; LOFAR & DESI Legacy Imaging Survey, S. Badole; NASA, ESA & L. Calcada, Graphics: W.L. Williams.

After almost a decade of work, an international team of astronomers has published the most detailed images yet seen of galaxies beyond our own, revealing their inner workings in unprecedented detail. The images were created from data collected by the Low Frequency Array (LOFAR), a radio telescope built and maintained by ASTRON, LOFAR is a network of more than 70,000 small antennae spread across nine European counties, with its core in Exloo, the Netherlands. The results come from the team’s years of work, led by Dr Leah Morabito at Durham University. The team was supported in the UK by the Science and Technology Facilities Council (STFC).

As well as supporting science exploitation, STFC also funds the UK subscription to LOFAR including upgrade costs and operation of its LOFAR station in Hampshire.

Revealing a hidden universe of light in HD

The universe is awash with electromagnetic radiation, of which visible light comprises just the tiniest slice. From short-wavelength gamma rays and X-rays, to long-wavelength microwave and radio waves, each part of the light spectrum reveals something unique about the universe. The LOFAR network captures images at FM radio frequencies that, unlike shorter wavelength sources like visible light, are not blocked by the clouds of dust and gas that can cover astronomical objects. Regions of space that seem dark to our eyes, actually burn brightly in radio waves – allowing astronomers to peer into star-forming regions or into the heart of galaxies themselves.

The new images, made possible because of the international nature of the collaboration, push the boundaries of what we know about galaxies and super-massive black holes. A special issue of the scientific journal Astronomy & Astrophysics is dedicated to 11 research papers describing these images and the scientific results.

Better resolution by working together

The images reveal the inner-workings of nearby and distant galaxies at a resolution 20 times sharper than typical LOFAR images. This was made possible by the unique way the team made use of the array.

The 70,000+ LOFAR antennae are spread across Europe, with the majority being located in the Netherlands. In standard operation, only the signals from antennae located in the Netherlands are combined, and creates a ‘virtual’ telescope with a collecting ‘lens' with a diameter of 120 km. By using the signals from all of the European antennae, the team have increased the diameter of the ‘lens’ to almost 2,000 km, which provides a twenty-fold increase in resolution.

Unlike conventional array antennae that combine multiple signals in real time to produce images, LOFAR uses a new concept where the signals collected by each antenna are digitised, transported to central processor, and then combined to create an image. Each LOFAR image is the result of combining the signals from more than 70,000 antennae, which is what makes their extraordinary resolution possible.

This shows real radio galaxies from Morabito et al. (2021). The gif fades from the standard resolution to the high resolution, showing the detail we can see by using the new techniques. Credit: L.K. Morabito; LOFAR Surveys KSP.

Revealing jets and outflows from super-massive black holes

Super-massive black holes can be found lurking at the heart of many galaxies and many of these are ‘active’ black holes that devour in-falling matter and belch it back out into the cosmos as powerful jets and outflows of radiation. These jets are invisible to the naked eye, but they burn bright in radio waves and it is these that the new high-resolution images have focused upon.

Dr Neal Jackson of The University of Manchester, said: “These high resolution images allow us to zoom in to see what’s really going on when super-massive black holes launch radio jets, which wasn’t possible before at frequencies near the FM radio band,”

The team’s work forms the basis of nine scientific studies that reveal new information on the inner structure of radio jets in a variety of different galaxies.

Hercules A is powered by a supermassive black hole located at its centre, which feeds on the surrounding gas and channels some of this gas into extremely fast jets. Our new high-resolutions observations taken with LOFAR have revealed that this jet grows stronger and weaker every few hundred thousand years. This variability produces the beautiful structures seen in the giant lobes, each of which is about as large as the Milky Way galaxy. Credit: R. Timmerman; LOFAR & Hubble Space Telescope

A decade-long challenge

Even before LOFAR started operations in 2012, the European team of astronomers began working to address the colossal challenge of combining the signals from more than 70,000 antennae located as much as 2,000 km apart. The result, a publicly-available data-processing pipeline, which is described in detail in one the scientific papers, will allow astronomers from around the world to use LOFAR to make high-resolution images with relative ease.

Dr Leah Morabito of Durham University, said: “Our aim is that this allows the scientific community to use the whole European network of LOFAR telescopes for their own science, without having to spend years to become an expert.”

Super images require supercomputers

The relative ease of the experience for the end user belies the complexity of the computational challenge that makes each image possible. Because LOFAR doesn’t just ‘take pictures’ of the night sky, it must stitch together the data gathered by more than 70,000 antennae, which is a huge computational task. To produce a single image, more than 13 terabits of raw data per second – the equivalent of more than a three hundred DVDs – must be digitised, transported to a central processor and then combined.

Frits Sweijen of Leiden University, said: “To process such immense data volumes we have to use supercomputers. These allow us to transform the terabytes of information from these antennas into just a few gigabytes of science-ready data, in only a couple of days.”

Media

All images and video's belonging to this press release can be found in high resolution here.

Links to Arxiv (free) papers can be found here.

About LOFAR

The International LOFAR Telescope is a trans-European network of radio antennas, with a core located in Exloo in the Netherlands. LOFAR works by combining the signals from more than 70,000 individual antenna dipoles, located in ‘antenna stations’ across the Netherlands and in partner European countries. The stations are connected by a high-speed fibre optic network, with powerful computers used to process the radio signals in order to simulate a trans-European radio antenna that stretches over 1,300 kilometres. The International LOFAR Telescope is unique, given its sensitivity, wide field-of-view, and image resolution or clarity. The LOFAR data archive is the largest astronomical data collection in the world.

LOFAR was designed, built and is presently operated by ASTRON, the Netherlands Institute for Radio Astronomy. France, Germany, Ireland, Italy, Latvia, the Netherlands, Poland, Sweden and the UK are all partner countries in the International LOFAR Telescope.

Source: ASTRON/News

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To the center of the brightest quasar

Artistic view of a quasar; a super-massive black hole in the center is being fed by a disk of gas and dust, producing collimated jets of ejected material moving at nearly the speed of light. © Wolfgang Steffen, Institute for Astronomy, UNAM, Mexico 

Artistic view of the 10-meter space radio telescope on board of the Russian satellite Spektr-R comprising the space-borne component of the RadioAstron mission.© Astro Space Center of Lebedev Physical Institute

RadioAstron observations of the extremely hot heart of quasar 3C 273

The space mission RadioAstron employing a 10-meter radio telescope on board of the Russian satellite Spektr-R has revealed the first look at the finest structure of the radio emitting regions in the quasar 3C 273 at wavelengths of 18, 6, and 1.3 cm. These ground breaking observations have been made by an international research team with four of the largest radio telescopes on Earth, including the Effelsberg 100-meter antenna. They provide an unprecedented sensitivity to radio emission at angular scales as small as 26 microarcseconds. This resolution was achieved by combining signals recorded at all antennas and effectively creating a telescope of almost 8 Earth’s diameters in size.

The results are published in the current issue of the "The Astrophysical Journal".

Supermassive black holes, containing millions to billions times the mass of our Sun, reside at the centers of all massive galaxies. These black holes can drive powerful jets that emit prodigiously, often outshining all the stars in their host galaxies. But there is a limit to how bright these jets can be – when electrons get hotter than about 100 billion degrees, they interact with their own emission to produce X-rays and Gamma-rays and quickly cool down.

Astronomers have just reported a startling violation of this long-standing theoretical limit in the quasar 3C 273. "We measure the effective temperature of the quasar core to be hotter than 10 trillion degrees!" comments Yuri Kovalev (Astro Space Center, Lebedev Physical Institute, Moscow, Russia), the RadioAstron project scientist. “This result is very challenging to explain with our current understanding of how relativistic jets of quasars radiate."

To obtain these results, the international team used the Earth-to-Space Interferometer RadioAstron. The interferometer consists of an orbiting radio telescope working together with the largest ground telescopes:  the 100-meter Effelsberg Telescope, the 110-m Green Bank Telescope, the 300-m Arecibo Observatory, and the Very Large Array. Operating together, these observatories provide the highest direct resolution ever achieved in astronomy, thousands of times finer than the Hubble Space Telescope.

“The fact  that RadioAstron has measured extreme brightness temperatures already in several objects, including the recently reported observations of BL Lacertae, these measurements indeed point out to new underlying physics behind the energetic sources of radiation in quasars”, states Andrei Lobanov, the coordinator of RadioAstron activities at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany.

However, the incredibly high temperatures were not the only surprise the RadioAstron team has found in 3C 273. The team also discovered an effect never seen before in an extragalactic source: the image of 3C 273 has substructure caused by the effects of peering through the dilute interstellar material of the Milky Way.

"Just as the flame of a candle distorts an image viewed through the hot turbulent air above it, the turbulent plasma of our own galaxy distorts images of distant astrophysical sources, such as quasars," explains Michael Johnson of the Harvard-Smithsonian Center for Astrophysics (CfA), who led the scattering study. He continues: "These objects are so compact that we had never been able to see this distortion before. The amazing angular resolution of RadioAstron gives us a new tool to understand the extreme physics near the central supermassive black holes of distant galaxies and the diffuse plasma pervading our own galaxy."

“Our research team has been working for a long time on extending the VLBI technique to space antennas reaching baselines much larger than our Earth”, concludes Anton Zensus, director at the MPIfR and head of its Radio Astronomy/VLBI research department.  “The new discoveries on 3C 273 are a wonderful example for our successful cooperation within the RadioAstron project.”

Source: Max Planck Institute for Radio Astronomy

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Local Contact:

Dr. Andrei Lobanov

Phone:+49 228 525-191

Email: alobanov@mpifr-bonn.mpg.de

Max-Planck-Institut für Radioastronomie, Bonn

Prof. Dr. J. Anton Zensus

Director and Head of "Radio Astronomy/VLBI" Research Dept.

Phone:+49 228 525-298 (secretary)

Email: azensus@mpifr-bonn.mpg.de

Max-Planck-Institut für Radioastronomie, Bonn

Dr. Norbert Junkes

Press and Public Outreach

Phone:+49 228 525-399

Email: njunkes@mpifr-bonn.mpg.de

Max-Planck-Institut für Radioastronomie, Bonn

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Original papers

RadioAstron Observations of the Quasar 3C273: A Challenge to the Brightness Temperature Limit

Y. Y. Kovalev, N. S. Kardashev, K. I. Kellermann, A. P. Lobanov, M. D. Johnson, L. I. Gurvits, P. A. Voitsik, J. A. Zensus, J. M. Anderson, U. Bach, D. L. Jauncey, F. Ghigo, T. Ghosh, A. Kraus, Yu. A. Kovalev, M. M. Lisakov, L. Yu. Petrov, J. D. Romney, C. J. Salter, and K. V. Sokolovsky, The Astrophysical Journal Letters, Volume 820, Issue 1, article id. L9, 6 pp. (2016).

Extreme Brightness Temperatures and Refractive Substructure in 3C273 with RadioAstron

Johnson, Michael D.; Kovalev, Yuri Y.; Gwinn, Carl R.; Gurvits, Leonid I.; Narayan, Ramesh; Macquart, Jean-Pierre; Jauncey, David L.; Voitsik, Peter A.; Anderson, James M.; Sokolovsky, Kirill V.; Lisakov, Mikhail M., The Astrophysical Journal Letters, Volume 820, Issue 1, article id. L10, 6 pp. (2016).

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The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries.

The Spektr-R antenna of RadioAstron is at an elliptical orbit around Earth reaching a maximum apogee distance of 350,000 km which would result in a virtual radio telescope of up to 27 times the Earth’s diameter.

This research is partly based on observations with the 100 m telescope of the MPIfR at Effelsberg.

MPIfR scientists involved in the project are Andrei Lobanov, J. Anton Zensus, James Anderson, Uwe Bach and Alex Kraus. Yuri Kovalev is affiliated as guest scientist with the MPIfR.

3C 273 is a quasar (active galactic nucleus) in the direction to the constellation Virgo. With a magnitude of 12.9 it is the optically brightest quasar in the sky, its redshift of 0.158 corresponding to a distance of approximately 2.4 billion light years.

The quasar 3C 273 is one of the target stations of the “Galaxy walk” at the Effelsberg Radio Observatory. Scaled 1:5x10²², the Galaxy Walk runs from Milky Way and Andromeda Galaxy (50 cm apart) to the edge of the Universe. 3C 273 forms station no. 7. With a distance of  2,4 billion light years it shows up only 450 meters away from the start (at a total length of 2.6 km for the Galaxy walk) .

Best image of bright quasar 3C 273

Quasar 3C 273

Credit: ESA/Hubble & NASA

This image from Hubble’s Wide Field and Planetary Camera 2 (WFPC2) is likely the best of ancient and brilliant quasar 3C 273, which resides in a giant elliptical galaxy in the constellation of Virgo (The Virgin). Its light has taken some 2.5 billion years to reach us. Despite this great distance, it is still one of the closest quasars to our home. It was the first quasar ever to be identified, and was discovered in the early 1960s by astronomer Allan Sandage.

The term quasar is an abbreviation of the phrase “quasi-stellar radio source”, as they appear to be star-like on the sky. In fact, quasars are the intensely powerful centres of distant, active galaxies, powered by a huge disc of particles surrounding a supermassive black hole. As material from this disc falls inwards, some quasars — including 3C 273  — have been observed to fire off super-fast jets into the surrounding space. In this picture, one of these jets appears as a cloudy streak, measuring some 200 000 light-years in length.

Quasars are capable of emitting hundreds or even thousands of times the entire energy output of our galaxy, making them some of the most luminous and energetic objects in the entire Universe. Of these very bright objects, 3C 273 is the brightest in our skies. If it was located 30 light-years from our own planet — roughly seven times the distance between Earth and Proxima Centauri, the nearest star to us after the Sun — it would still appear as bright as the Sun in the sky.  

WFPC2 was installed on Hubble during shuttle mission STS-125. It is the size of a small piano and was capable of seeing images in the visible, near-ultraviolet, and near-infrared parts of the spectrum.

Source: ESA/Hubble - Space Telescope