ESO telescope uncovers closest pair of supermassive black holes yet

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Close-up and wide views of the nearest pair of supermassive black holes 

 

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Close-up view of the nearest pair of supermassive black holes 

 

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Bumps in the heavens 

 

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Wide-field view of the region of the sky hosting NGC 7727

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Videos

PR Video eso2117a

Supermassive Black Holes on a Collision Course (ESOcast 246 Light)

 

PR Video eso2117b

Journey to the closest pair of supermassive black holes 

 

PR Video eso2117c

How MUSE uncovered the closest pair of supermassive black holes

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Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have revealed the closest pair of supermassive black holes to Earth ever observed. The two objects also have a much smaller separation than any other previously spotted pair of supermassive black holes and will eventually merge into one giant black hole.

Located in the galaxy NGC 7727 in the constellation Aquarius, the supermassive black hole pair is about 89 million light-years away from Earth. Although this may seem distant, it beats the previous record of 470 million light-years by quite some margin, making the newfound supermassive black hole pair the closest to us yet.  

Supermassive black holes lurk at the centre of massive galaxies and when two such galaxies merge, the black holes end up on a collision course. The pair in NGC 7727 beat the record for the smallest separation between two supermassive black holes, as they are observed to be just 1600 light-years apart in the sky. “It is the first time we find two supermassive black holes that are this close to each other, less than half the separation of the previous record holder,” says Karina Voggel, an astronomer at the Strasbourg Observatory in France and lead author of the study published online today in Astronomy & Astrophysics.

“The small separation and velocity of the two black holes indicate that they will merge into one monster black hole, probably within the next 250 million years,” adds co-author Holger Baumgardt, a professor at the University of Queensland, Australia. The merging of black holes like these could explain how the most massive black holes in the Universe come to be.

Voggel and her team were able to determine the masses of the two objects by looking at how the gravitational pull of the black holes influences the motion of the stars around them. The bigger black hole, located right at the core of NGC 7727, was found to have a mass almost 154 million times that of the Sun, while its companion is 6.3 million solar masses.

It is the first time the masses have been measured in this way for a supermassive black hole pair. This feat was made possible thanks to the close proximity of the system to Earth and the detailed observations the team obtained at the Paranal Observatory in Chile using the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s VLT, an instrument Voggel learnt to work with during her time as a student at ESO. Measuring the masses with MUSE, and using additional data from the NASA/ESA Hubble Space Telescope, allowed the team to confirm that the objects in NGC 7727 were indeed supermassive black holes.

Astronomers suspected that the galaxy hosted the two black holes, but they had not been able to confirm their presence until now since we do not see large amounts of high-energy radiation coming from their immediate surroundings, which would otherwise give them away. “Our finding implies that there might be many more of these relics of galaxy mergers out there and they may contain many hidden massive black holes that still wait to be found,” says Voggel. “It could increase the total number of supermassive black holes known in the local Universe by 30 percent.”

The search for similarly hidden supermassive black hole pairs is expected to make a great leap forward with ESO’s Extremely Large Telescope (ELT), set to start operating later this decade in Chile’s Atacama Desert. “This detection of a supermassive black hole pair is just the beginning,” says co-author Steffen Mieske, an astronomer at ESO in Chile and Head of ESO Paranal Science Operations. “With the HARMONI instrument on the ELT we will be able to make detections like this considerably further than currently possible. ESO’s ELT will be integral to understanding these objects.”

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More Information

This research was presented in a paper titled "First Direct Dynamical Detection of a Dual Super-Massive Black Hole System at sub-kpc Separation" to appear in Astronomy & Astrophysics (doi: 10.1051/0004-6361/202140827).

The team is composed of Karina T. Voggel (Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, France), Anil C. Seth (University of Utah, Salt Lake City, USA [UofU]), Holger Baumgardt (School of Mathematics and Physics, University of Queensland, St. Lucia, Australia), Bernd Husemann (Max-Planck-Institut für Astronomie, Heidelberg, Germany [MPIA]), Nadine Neumayer (MPIA), Michael Hilker (European Southern Observatory, Garching bei München, Germany), Renuka Pechetti (Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK), Steffen Mieske (European Southern Observatory, Santiago de Chile, Chile), Antoine Dumont (UofU), and Iskren Georgiev (MPIA).

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.

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Contacts 

Karina Voggel
Strasbourg Observatory, University of Strasbourg
Strasbourg, France
Email: karina.voggel@astro.unistra.fr

Holger Baumgardt
School of Mathematics and Physics, University of Queensland
St. Lucia, Queensland, Australia
Tel: +61 (0)7 3365 3430
Email: h.baumgardt@uq.edu.au

Steffen Mieske
European Southern Observatory
Vitacura, Santiago, Chile
Tel: +56 22 463 3060
Email: smieske@eso.org

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670
Cell: +49 151 241 664 00
Email: press@eso.org

Source: ESO/News

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Hubble’s View of Planetary Nebula Reveals Complex Structure

NGC 6891

Image Credit: NASA, ESA, A. Hajian (University of Waterloo), H. Bond (Pennsylvania State University), and B. Balick (University of Washington); Processing: Gladys Kober (NASA/Catholic University of America)

NGC 6891 is a bright, asymmetrical planetary nebula in the constellation Delphinus, the Dolphin. This Hubble image reveals a wealth of structure, including a spherical outer halo that is expanding faster than the inner nebula, and at least two ellipsoidal shells that are orientated differently. The image also reveals filaments and knots in the nebula’s interior, surrounding the central white dwarf star. From their motions, astronomers estimate that one of the shells is 4,800 years old while the outer halo is some 28,000 years old, indicating a series of outbursts from the dying star at different times.

Hubble studied NGC 6891 as part of efforts to gauge the distances to nebulae, and to learn more about how their structures formed and evolved. NGC 6891 is made up of gas that’s been ionized by the central white dwarf star, which stripped electrons from the nebula’s hydrogen atoms. As the energized electrons revert from their higher-energy state to a lower-energy state by recombining with the hydrogen nuclei, they emit energy in the form of light, causing the nebula’s gas to glow.

Media Contact:

Claire Andreoli
NASA's Goddard Space Flight Center
301-286-1940

Editor: Andrea Gianopoulos

Source: NASA/Hubble

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Black Hole Collision May Have Exploded With Light

Image Credit: Caltech/R. Hurt (IPAC)

In a first, astronomers may have seen light from the merger of two black holes, providing opportunities to learn about these mysterious dark objects.

This artist's concept shows a supermassive black hole surrounded by a disk of gas. Embedded in this disk are two smaller black holes that may have merged together to form a new black hole.

When two black holes spiral around each other and ultimately collide, they send out gravitational waves - ripples in space and time that can be detected with extremely sensitive instruments on Earth. Since black holes and black hole mergers are completely dark, these events are invisible to telescopes and other light-detecting instruments used by astronomers. However, theorists have come up with ideas about how a black hole merger could produce a light signal by causing nearby material to radiate.

Now, scientists using Caltech's Zwicky Transient Facility (ZTF) located at Palomar Observatory near San Diego may have spotted what could be just such a scenario. If confirmed, it would be the first known light flare from a pair of colliding black holes.

The merger was identified on May 21, 2019, by two gravitational wave detectors – the National Science Foundation's Laser Interferometer Gravitational-wave Observatory, or LIGO, and the European Virgo detector – in an event called GW190521g. That detection allowed the ZTF scientists to look for light signals from the location where the gravitational wave signal originated. These gravitational wave detectors have also spotted mergers between dense cosmic objects called neutron stars, and astronomers have identified light emissions from those collisions.

Learn more: What Is a Black Hole?
Black Hole Image Makes History; NASA Telescopes Coordinated Observations

Editor: Yvette Smith

Source: NASA/Black Holes

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One Galaxy, Three Times

SGAS 0033+02

Credit: ESA/Hubble & NASA, E. Wuyts

This star- and galaxy-studded image was captured by Hubble’s Wide Field Camera 3 (WFC3), using data that were collected for scientific purposes. The object of interest was a galaxy that is visible in the bottom right corner of the image, named SGAS 0033+02. What makes this particular galaxy interesting is a little unusual — it appears not just once in this image, but three times. The thrice-visible galaxy is a little difficult to spot: it appears once as a curved arc and twice more as small round dots around the star.

SGAS 0033+02’s multiple appearances in the same image are not the result of an error, but instead are due to a remarkable phenomenon known as gravitational lensing. Gravitational lensing occurs when the light from a very distant galaxy — such as SGAS 0033+02 — is curved (or ‘lensed’) by the gravity of a massive celestial object that lies in the foreground, between the distant galaxy and the Earth. SGAS 0033+02 was discovered by its namesake, the Sloan Giant Arcs Survey (SGAS), which aimed to identify highly magnified galaxies that were gravitationally lensed by foreground galaxy clusters. SGAS 0033+02 is of special interest because of its highly unusual proximity in the sky to a very bright star. The star is useful, because it can be used to calibrate and correct observations of the lensed SGAS 0033+02.

Source: ESA/Hubble/potw

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New Deep Learning Method Adds 301 Planets to Kepler's Total Count

Over 4,5000 planets have been found around other stars, but scientists expect that our galaxy contains millions of planets. There are multiple methods for detecting these small, faint bodies around much larger, bright stars. Credit: NASA/JPL-Caltech

When a planet crosses directly between us and its star, we see the star dim slightly because the planet is blocking out a portion of the light. This is one method scientists use to find exoplanets. They make a plot called a light curve with the brightness of the star versus time. Using this plot, scientists can see what percentage of the star's light the planet blocks and how long it takes the planet to cross the disk of the star. Credit: NASA's Goddard Space Flight Center

Scientists have added a whopping 301 newly confirmed exoplanets to the total exoplanet tally

Scientists recently added a whopping 301 newly validated exoplanets to the total exoplanet tally. The throng of planets is the latest to join the 4,569 already validated planets orbiting a multitude of distant stars. How did scientists discover such a huge number of planets, seemingly all at once? The answer lies with a new deep neural network called ExoMiner.

Deep neural networks are machine learning methods that automatically learn a task when provided with enough data. ExoMiner is a new deep neural network that leverages NASA’s Supercomputer, Pleiades, and can distinguish real exoplanets from different types of imposters, or “false positives.” Its design is inspired by various tests and properties human experts use to confirm new exoplanets. And it learns by using past confirmed exoplanets and false positive cases.

ExoMiner supplements people who are pros at combing through data and deciphering what is and isn't a planet. Specifically, data gathered by NASA's Kepler spacecraft and K2, its follow-on mission. For missions like Kepler, with thousands of stars in its field of view, each holding the possibility to host multiple potential exoplanets, it's a hugely time-consuming task to pore over massive datasets. ExoMiner solves this dilemma.

NASA’s Eyes on Exoplanets shows the location of over 4,500 planets around other stars outside our solar system. Users can also see information about the physical features of the planets (where known) and the stars they orbit. View the full interactive experience at Eyes on Exoplanets.

“Unlike other exoplanet-detecting machine learning programs, ExoMiner isn't a black box – there is no mystery as to why it decides something is a planet or not,” said Jon Jenkins, exoplanet scientist at NASA's Ames Research Center in California's Silicon Valley. “We can easily explain which features in the data lead ExoMiner to reject or confirm a planet.”

What is the difference between a confirmed and validated exoplanet? A planet is “confirmed,” when different observation techniques reveal features that can only be explained by a planet. A planet is “validated” using statistics – meaning how likely or unlikely it is to be a planet based on the data.

In a paper published in the Astrophysical Journal, the team at Ames shows how ExoMiner discovered the 301 planets using data from the remaining set of possible planets – or candidates – in the Kepler Archive. All 301 machine-validated planets were originally detected by the Kepler Science Operations Center pipeline and promoted to planet candidate status by the Kepler Science Office. But until ExoMiner, no one was able to validate them as planets.

The paper also demonstrates how ExoMiner is more precise and consistent in ruling out false positives and better able to reveal the genuine signatures of planets orbiting their parent stars – all while giving scientists the ability to see in detail what led ExoMiner to its conclusion.

“When ExoMiner says something is a planet, you can be sure it's a planet,” added Hamed Valizadegan, ExoMiner project lead and machine learning manager with the Universities Space Research Association at Ames. “ExoMiner is highly accurate and in some ways more reliable than both existing machine classifiers and the human experts it's meant to emulate because of the biases that come with human labeling.”

None of the newly confirmed planets are believed to be Earth-like or in the habitable zone of their parent stars. But they do share similar characteristics to the overall population of confirmed exoplanets in our galactic neighborhood.

“These 301 discoveries help us better understand planets and solar systems beyond our own, and what makes ours so unique,” said Jenkins.

As the search for more exoplanets continues – with missions using transit photometry such as NASA’s Transiting Exoplanet Survey Satellite, or TESS, and the European Space Agency's upcoming PLAnetary Transits and Oscillations of stars, or PLATO, mission – ExoMiner will have more opportunities to prove it's up to the task.

“Now that we've trained ExoMiner using Kepler data, with a little fine-tuning, we can transfer that learning to other missions, including TESS, which we're currently working on,” said Valizadegan. “There's room to grow.”

NASA Ames managed the Kepler and K2 missions for NASA's Science Mission Directorate. JPL managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

News Media Contact

Rachel Hoover
650-604-4789
rachel.hoover@nasa.gov

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

Source: JPL-Caltech/News

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KPD 0005+5106: Roasted and Shredded by a Stellar Sidekick

KPD 0005+5106
Credit: Illustration: NASA/CXC/M. Weiss; X-ray (Inset): NASA/CXC/ASIAA/Y.-H. Chu, et al.

JPEG (309.4 kb)-Large JPEG (10.2 MB)- Tiff ( bytes) - More Images

A Tour of MG B2016+112 - More Animations

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A team of scientists used NASA's Chandra X-ray Observatory and ESA's XMM-Newton to investigate some unusual X-ray activity of a white dwarf star, as reported in our latest press release. The data suggest this white dwarf is blasting a companion object, which is either a low-mass star or planet, with waves of heat and radiation while pulling it apart through gravitational force.

Most stars, including the Sun, will become "white dwarfs" after they begin to run out of fuel, expand and cool into a red giant, and then lose their outer layers. This evolution leaves behind a stellar nub that slowly fades for billions of years. An artist's illustration shows a white dwarf as the blue-white sphere near the center.

Astronomers have observed that the white dwarf KPD 0005+5106, located about 1,300 light years from Earth, emits high-energy X-ray emission that regularly increases and decreases in X-ray brightness every 4.7 hours. This recurring ebb and flow of X-rays indicates that KPD 0005+5106 has an object in orbit around it — either a very low mass star or a planet — depicted in the illustration by the brown and red object on the right-hand side. The white dwarf pulls the material from the companion into a disk around itself, which the artist shows in orange, before it slams into its north and south poles.

The concentration of material hitting the white dwarf's poles is creating two bright spots of high-energy X-ray emission. As the white dwarf and its companion orbit around each other the hot spot facing more towards Earth would go in and out of view, causing the high-energy X-rays to regularly increase and decrease that Chandra observed.

The researchers looked at what would happen if this object was a planet with the mass about that of Jupiter, a possibility that agrees with the data more readily than a dim star or a brown dwarf. In their models, the white dwarf would pull material from the planet onto the white dwarf, a process that the planet could only survive for a few hundred million years before eventually being destroyed. This stolen material swirls around the white dwarf, which glows in X-rays that Chandra can detect.

A paper describing these results appeared in The Astrophysical Journal in April 2021 and a preprint is available online. The authors of the paper are You-Hua Chu (Institute of Astronomy and Astrophysics, Academia Sinica in Taiwan), Jesús Toala (National Autonomous University of Mexico), Martín Guerrero and Florian Bauer (The Institute of Astrophysics of Andalusia in Spain), and Jana Bilikova and Robert Gruendel (University of Illinois, Urbana).

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

A Quick Look at KPD 0005+5106

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Fast Facts for KPD 0005+5106:

Scale: X-ray image (inset) is about 1 arcmin (0.38 light years) across.
Category: White Dwarfs & Planetary Nebulas
Constellation: Cassiopeia
Observation Date: March 19, 2008
Observation Time: 13 hours 10 minutes
Obs. ID: 8942
Instrument: ACIS
References: Chu, Y-H., et al., 2021, ApJ, 910, 119; arXiv:2102.05035
Color Code: X-ray: purple
Distance Estimate: About 1,300 light years

Source:NASA's Chandra X- Ray Observatory

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Hubble Catches Celestial Prawn Drifting Through the Cosmic Deep

Prawn Nebula

Main Image Credit: NASA, ESA, and J. Tan (Chalmers University of Technology); Processing; Gladys Kober (NASA/Catholic University of America)

The Prawn Nebula is a massive stellar nursery located in the constellation Scorpius, about 6,000 light years from Earth. Though the nebula stretches 250 light-years and covers a space four times the size of the full moon, it emits light primarily in wavelengths the human eye cannot detect, making it extremely faint to earthbound viewers. Hubble’s gaze, however, shows a small section of the nebula here in both visible and invisible infrared light, capturing dazzling detail of the nebula’s structure, including bright areas of glowing gas.

The Prawn Nebula, also known as IC 4628, is an emission nebula, which means its gas has been energized, or ionized, by the radiation of nearby stars. The radiation from these massive stars strips electrons from the nebula’s hydrogen atoms. As the energized electrons revert from their higher-energy state to a lower-energy state by recombining with hydrogen nuclei, they emit energy in the form of light, causing the nebula’s gas to glow. In this image, red indicates the presence of ionized iron (Fe II) emission.

This Hubble Space Telescope image was captured as part of a survey of massive- and intermediate-size “protostars,” or newly forming stars. Astronomers used the infrared sensitivity of Hubble’s Wide Field Camera 3 to look for hydrogen ionized by ultraviolet light ionized by the protostars, jets from the stars, and other features.

The Prawn Nebula lies south of the star Antares in the constellation Scorpius, the Scorpion. Hubble's focused view captures just a small portion of the vast star-forming region. Credits: NASA, ESA, J. Tan (Chalmers University of Technology), and ESO; Processing; Gladys Kober (NASA/Catholic University of America) Main Image Credit: NASA, ESA, and J. Tan (Chalmers University of Technology); Processing; Gladys Kober (NASA/Catholic University of America)

Media Contact:

Claire Andreoli
NASA's Goddard Space Flight Center
301-286-1940

Editor: Andrea Gianopoulos

Source: NASA/Hubble

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Hubble Spies Newly Forming Star Incubating in IC 2631

IC 2631

Main Image Credit: NASA, ESA, T. Megeath (University of Toledo), and K. Stapelfeldt (Jet Propulsion Laboratory); Processing: Gladys Kober (NASA/Catholic University of America)

Hubble's sharp eye captures a protostar designated J1672835.29-763111.64 in the reflection nebula IC 2631. Credits: NASA, ESA, T. Megeath (University of Toledo), K. Stapelfeldt (Jet Propulsion Laboratory), and ESO; Processing: Gladys Kober (NASA/Catholic University of America)

Stars are born from clouds of gas and dust that collapse under their own gravitational attraction. As the cloud collapses, a dense, hot core forms and begins gathering dust and gas, creating an object called a “protostar.”

This Hubble infrared image captures a protostar designated J1672835.29-763111.64 in the reflection nebula IC 2631, part of the Chamaeleon star-forming region in the southern constellation Chamaeleon. Protostars shine with the heat energy released by clouds contracting around them and the accumulation of material from the nearby gas and dust. Eventually enough material collects, and the core of a protostar becomes hot and dense enough for nuclear fusion to begin, and the transformation into a star is complete. The leftover gas and dust can become planets, asteroids, comets, or remain as dust.

This image is part of a Hubble survey targeting 312 protostars within molecular clouds previously identified with the Spitzer and Herschel infrared space observatories. Protostars are visible primarily in infrared light since they emit a lot of heat energy, and their visible light is obscured by the dust around them. Hubble’s advanced infrared capabilities could better resolve the protostars and examine their structure, including the accumulating gas and dust and faint companion objects.

Source: NASA/Hubble

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Astronomical object found by amateur identified as new dwarf galaxy

The newly discovered dwarf galaxy may be a satellite of the Triangulum galaxy, which would reassure experts that their theories around how galaxies are formed are correct. Credit: Giuseppe Donatiello

Astrophysicists at the University of Surrey and the Instituto de Astrofísica de Andalucía have identified a speck in the sky found by an amateur astronomer as a ground-breaking new dwarf galaxy called Pisces VII/ Tri III.

Enthusiast Giuseppe Donatiello spotted the galaxy while scrutinising publicly available data and his finding was investigated by professional astrophysicists, led by Dr. David Martinez-Delgado from the Instituto de Astrofisica de Andalucia, who used deeper images taken with the Telescopio Nazionale Galileo. By processing the data and performing photometric calibration, they confirmed the finding is a new dwarf galaxy, but they need further images from even more powerful telescopes to confirm its precise location and significance.

Their analysis has identified Pisces VII/ Tri III as one of two things, either of which would make it an important astrophysical discovery. The team’s calculations show it is either an isolated dwarf galaxy, or it is a satellite of the Triangulum galaxy (M33). If it is isolated, it is thought to be the faintest field galaxy ever detected. If it is a satellite of M33, it could reassure experts that their theories around how galaxies are formed are correct.

Emily Charles, a PhD student at the University of Surrey who worked on the project, said:

“Theoretical knowledge about galaxy formation means we’d expect to see many more little galaxies orbiting the Triangulum galaxy, M33. However, so far it only has one known satellite. If this newly identified galaxy does belong to M33, it might imply that there are many more that haven’t been uncovered yet as they are too faint to show up in previous surveys of the system. M33 currently challenges astrophysicists’ assumptions, but this new finding starts reassuring us that our theories are correct.”

In order to confirm whether Pisces VII/ Tri III is isolated or an M33 satellite, the team needs to accurately measure the distance to the galaxy and see how it is moving compared to M33. Both require further imaging using other telescopes.

Noushin Karim, another PhD student at the University of Surrey who helped identify Pisces VII/ Tri III, said:

“Deep imaging from Hubble would allow us to reach fainter stars which act as more robust distance estimators, as they have a standard brightness. To confirm the new galaxy’s movement, we need imaging from an 8m or 10m telescope, like Keck or Gemini.”

A paper explaining their work and how they came to their conclusions is published in the peer-reviewed journal, Monthly Notices of the Royal Astronomical Society (MNRAS). Next the team will apply for access to other telescopes in order to continue their analysis.

Read the full paper: “Pisces VII: discovery of a possible satellite of Messier 33 in the DESI legacy imaging surveys” Monthly Notices of the Royal Astronomical Society, Volume 509, Issue 1, January 2022, https://doi.org/10.1093/mnras/stab2797

Source: University of Surrey/News

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Nebula Churns Out Massive Stars in New Hubble Image

G035.20-0.74

Main Image Credit: NASA, ESA, and J. Tan (Chalmers University of Technology); Processing; Gladys Kober (NASA/Catholic University of America). Hi-res image

The star-forming nebula (G035.20-0.74) in this Hubble image is in the constellation Aquila, the Eagle.

Credits: NASA, ESA, J. Tan (Chalmers University of Technology), and DSS; Processing; Gladys Kober (NASA/Catholic University of America). Hi-res image

Stars are born from turbulent clouds of gas and dust that collapse under their own gravitational attraction. As the cloud collapses, a dense, hot core forms and begins gathering dust and gas, creating a protostar. This star-forming nebula in the constellation Aquila, G035.20-0.74, is known for producing a particular kind of massive star known as a B-Type star. These stars are hot, young, blue stars up to five times hotter than our Sun.

Hubble observed this region because it is home to a massive protostar, specifically as part of a program examining jets of glowing gas blasted into space by massive protostars. These fast-moving jets, which form as gas collects around newly forming stars and last for only about 100,000 years, are known to play a role in star formation. Astronomers were interested to learn whether such jets influence the formation of massive stars similar to the way they affect the formation of lower-mass stars. Massive stars are typically rarer, more distant, and more hidden by dust than lower-mass stars, making studies of their jets more challenging.

Researchers combined infrared observations from Hubble with those from radio telescopes in order to see inside these dusty star-forming regions. They found a jet of material with properties similar to jets associated with young, low-mass stars. This implies that the mechanism creating the light emitted by these jets is similar in young stars of different masses, up to 10 times the mass of the Sun.

Media Contact:

Claire Andreoli
NASA's Goddard Space Flight Center
301-286-1940

Editor: Andrea Gianopoulos

Source: NASA/Hubble

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Hubble Images Dark Nebula Cloaking Stars Within Dusty Depths

LDN 1165

Credits: NASA, ESA, T. Megeath (University of Toledo), K. Stapelfeldt (Jet Propulsion Laboratory), and DSS; Processing: Gladys Kober (NASA/Catholic University of America)

Hubble imaged a small portion of the sinuous, inky-black dark nebula LDN 1165.

Lower left: star-studded image holds a sinuous, inky-black dark nebula at its center. Right two-thirds: Hubble's view, orange nebula emerges from dark nebula, with white nebula below stretching to the bottom of the image. Credits: NASA, ESA, T. Megeath (University of Toledo), K. Stapelfeldt (Jet Propulsion Laboratory), and DSS; Processing: Gladys Kober (NASA/Catholic University of America)

This Hubble image captures a portion of a dark nebula in the constellation Cepheus. LDN 1165 is part of a collection called Lynds’ Catalog of Dark Nebulae, originally published in 1962. Dark nebulae – also called absorption nebulae – are clouds of gas and dust that neither emit nor reflect light, instead blocking light coming from behind them. These nebulae tend to contain large amounts of dust, which allows them to absorb visible light from stars or nebulae beyond them. Dark nebulae are so dark that they’ve been referred to as “holes in the sky,” but in reality they may be full of activity, with stars sometimes forming inside their dense clouds.

Hubble observed this region as part of a study of protostars, hot dense cores of newly forming stars that are accumulating gas and dust as they undergo the starbirth process. The bright area in this image is likely a star-forming region that may hold one or more young protostars. Further study of dark nebulae like LDN 1165 will help us better understand the nature of these dark and dusty clouds and the stellar nurseries that may lurk within them.

Media Contact:

Claire Andreoli
NASA's Goddard Space Flight Center
301-286-1940

Editor: Andrea Gianopoulos

Source: NASA/Hubble

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SOFIA Observes Star Formation Near the Galactic Center

Left: An image of the Sagittarius B region in the Galactic center taken by SOFIA FORCAST combined with Herschel and Spitzer. Right: Ionized carbon intensity contours of the Sagittarius B region. The striped pattern is a scanning artifact due to the motion of the telescope. In both panels, crosses indicate the locations of the three star-forming cores of Sagittarius B2. Credit: Left: NASA/SOFIA/JPL-Caltech/ESA/Herschel; Right: Harris et al., 2021

Columbia, MD. The Stratospheric Observatory for Infrared Astronomy, SOFIA, imaged the ionized carbon characteristics of Sagittarius B (Sgr B), a molecular cloud of gas and dust in the center of the Milky Way. Studying the ionized carbon emission from Sagittarius B provides critical information about star formation in our own galaxy and beyond. In particular, observing the concentration of ionized carbon in a molecular cloud like Sgr B is a powerful method for probing the properties of the system, including its level of star formation.

Using SOFIA’s upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT), a team of researchers imaged the ionized carbon characteristics of Sgr B. GREAT has ample spectral resolution to study Sgr B in detail at scales ranging from small clouds to star formation regions, allowing the scientists to understand the dynamics of gas within our Galactic Center. UpGREAT’s rapid imaging capabilities and detailed velocity resolution were crucial for enabling the study, which is part of a much larger scan of the area.

Among a number of findings, astronomers noted the steady carbon emission from Sgr B implies the entire region is physically connected, making it one continuous structure spanning about 34 by 15 parsecs, or about 111 by 49 light-years. It is spatially complex, comprised of arcs and ridges undergoing large-scale, turbulent motion.

By comparing the brightness of different emission lines, the group obtained an estimate of the ratio of ionized carbon emission coming from regions dominated by ionized hydrogen compared to emission from photodissociation regions, areas heated by far-infrared radiation dominated by atomic and molecular hydrogen. They found about half of the emission in the system is coming from each of these types of environments.

Notably, the three star-forming cores of Sagittarius B2, within Sgr B, exhibit no ionized carbon emission, which is atypical of extreme star forming regions. They appear to be within a dark, narrow lane of dust which appears to be slightly physically distanced and in front of the rest of the region – though they remain, for the most part, dynamically related. This may answer the debate about the origin of star formation in Sgr B — dark dust lanes have been associated with cloud-cloud collisions and are a common sign of a shock-induced star formation trigger. This possibility is also consistent with the fact that multiple different star formation stages coexist within Sgr B, as a recent burst of star formation within Sgr B indicates some sort of trigger has likely occurred.

“The nuclear regions of galaxies are fascinating places, and our relatively nearby Galactic center lets us explore its gas clouds, stars, and black hole in far more detail than we can get in any other galaxy,” said Andrew Harris, astronomer at the University of Maryland and lead author on the upcoming paper. “The SOFIA results we found in our US-German project join those made at wavelengths across the electromagnetic spectrum made from telescopes all over the world and in space, allowing us to better understand not only our Galaxy but others as well.”

Source: USRA/Newsroom

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About SOFIA

Using SOFIA’s upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT), a team of researchers imaged the ionized carbon characteristics of Sgr B. GREAT has ample spectral resolution to study Sgr B in detail at scales ranging from small clouds to star formation regions, allowing the scientists to understand the dynamics of gas within our Galactic Center. UpGREAT’s rapid imaging capabilities and detailed velocity resolution were crucial for enabling the study, which is part of a much larger scan of the area.

About USRA

Founded in 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA), is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise. More information about USRA is available at www.usra.edu

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Source: USRA/Newsroom

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Simulations Provide Clue to Missing Planets Mystery

A protoplanetary disk as observed by ALMA (left), and a protoplanetary disk during planetary migration, as obtained from the ATERUI II simulation (right). The dashed line in the simulation represents the orbit of a planet, and the gray area indicates a region not covered by the computational domain of the simulation. (Credit: Kazuhiro D. Kanagawa, ALMA(ESO/NAOJ/NRAO)) Original size (704KB)

A comparison of the three phases of ring formation and deformation found in these simulations by ATERUI II (top) with real examples observed by ALMA (bottom). The dotted lines in the simulation represent the orbits of the planets, and the gray areas indicate regions not covered by the computational domain of the simulation. In the upper row, the simulated protoplanetary disks are shown from left to right at the start of planetary migration (Phase I), during planetary migration (Phase II), and at the end of planetary migration (Phase III). (Credit: Kazuhiro D. Kanagawa, ALMA(ESO/NAOJ/NRAO)) Original size (703KB)

Forming planets are one possible explanation for the rings and gaps observed in disks of gas and dust around young stars. But this theory has trouble explaining why it is rare to find planets associated with rings. New supercomputer simulations show that after creating a ring, a planet can move away and leave the ring behind. Not only does this bolster the planet theory for ring formation, the simulations show that a migrating planet can produce a variety of patterns matching those actually observed in disks.

Young stars are encircled by protoplanetary disks of gas and dust. One of the world’s most powerful radio telescope arrays, ALMA (Atacama Large Millimeter/submillimeter Array), has observed a variety of patterns of denser and less dense rings and gaps in these protoplanetary disks. Gravitational effects from planets forming in the disk are one theory to explain these structures, but follow-up observations looking for planets near the rings have largely been unsuccessful.

In this research a team from Ibaraki University, Kogakuin University, and Tohoku University in Japan used the world’s most powerful supercomputer dedicated to astronomy, ATERUI II at the National Astronomical Observatory of Japan, to simulate the case of a planet moving away from its initial formation site. Their results showed that in a low viscosity disk, a ring formed at the initial location of a planet doesn’t move as the planet migrates inwards. The team identified three distinct phases. In Phase I, the initial ring remains intact as the planet moves inwards. In Phase II, the initial ring begins to deform and a second ring starts forming at the new location of the planet. In Phase III, the initial ring disappears and only the latter ring remains.

These results help explain why planets are rarely observed near the outer rings, and the three phases identified in the simulations match well with the patterns observed in actual rings. Higher resolution observations from next-generation telescopes, which will be better able to search for planets close to the central star, will help determine how well these simulations match reality.

These results appeared as Kazuhiro D. Kanagawa et al. “Dust rings as a footprint of planet formation in a protoplanetary disk”in The Astrophysical Journal on November 12, 2021.

Related Link

• Simulations Provide Clue to Missing Planets Mystery (Center for Computational Astrophysics)

Source: National Astronomical Observatory of Japan (NAOJ)/News

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Caught in a spiral

NGC 3314a and NGC 3314b
Credit: ESO/Iodice et al.

The image shows a pair of overlapping spiral galaxies, NGC 3314a and b, in the top left, caught in a majestic cosmic dance — captured by ESO’s VLT Survey Telescope (VST).

But don’t let the perspective fool you! They are, in fact, not interacting at all. The two galaxies, located between 117 and 140 million light-years away in the constellation of Hydra, are actually physically unrelated and only appear to overlap when viewed from Earth. This unique alignment gives astronomers the opportunity to measure many properties of the galaxies, such as how dust absorbs starlight, and hence gain insight into their composition and evolution.

There is another hidden secret in this picture if you look closely at the lower right region: beyond this stunning cosmic dance you will find a faint yellowish smudge, the signature of an ultra-diffuse galaxy (UDG). UDGs are objects as large as the Milky Way but with 100 – 1000 times fewer stars. These galaxies are extremely faint and lack star-forming gas, which makes them appear almost like a smudge in the night sky. This UDG, named UDG 32, is one of the faintest and most spread out galaxies in the Hydra I cluster.

This image was taken as part of a much larger project, the VST Early-type Galaxy Survey (VEGAS), whose goal is to investigate very faint structures in galaxy clusters — large groups of galaxies held together by gravity. The study, led by Enrichetta Iodice from the Istituto Nazionale di Astrofisica in Italy, suggests that UDG 32 may have formed out of the filaments stemming from NGC 3314a, but more observations are needed to confirm this.

 

Source: ESO/Potw

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Black hole found hiding in star cluster outside our galaxy

PR Image eso2116a

Artist’s impression of the black hole in NGC 1850 distorting its companion star

 

PR Image eso2116b

NGC1850 as seen with the Very Large Telescope and Hubble

PR Image eso2116c

Location of the NGC 1850 cluster in the constellation Dorado

 

PR Image eso2116d

The Large Magellanic Cloud revealed by VISTA

 

 

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Videos

 

PR Video eso2116a

Black Hole Discovered in Galaxy Next Door (ESOcast 245 Light) 

 

PR Video eso2116b

A journey to NGC 1850 

 

PR Video eso2116c

How to find a black hole with MUSE

 

PR Video eso2116d

Artist’s animated view of the black hole in NGC 1850 distorting its companion star

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Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered a small black hole outside the Milky Way by looking at how it influences the motion of a star in its close vicinity. This is the first time this detection method has been used to reveal the presence of a black hole outside of our galaxy. The method could be key to unveiling hidden black holes in the Milky Way and nearby galaxies, and to help shed light on how these mysterious objects form and evolve.

The newly found black hole was spotted lurking in NGC 1850, a cluster of thousands of stars roughly 160 000 light-years away in the Large Magellanic Cloud, a neighbour galaxy of the Milky Way.

“Similar to Sherlock Holmes tracking down a criminal gang from their missteps, we are looking at every single star in this cluster with a magnifying glass in one hand trying to find some evidence for the presence of black holes but without seeing them directly,” says Sara Saracino from the Astrophysics Research Institute of Liverpool John Moores University in the UK, who led the research now accepted for publication in Monthly Notices of the Royal Astronomical Society. “The result shown here represents just one of the wanted criminals, but when you have found one, you are well on your way to discovering many others, in different clusters.”

This first “criminal” tracked down by the team turned out to be roughly 11 times as massive as our Sun. The smoking gun that put the astronomers on the trail of this black hole was its gravitational influence on the five-solar-mass star orbiting it.

Astronomers have previously spotted such small, “stellar-mass” black holes in other galaxies by picking up the X-ray glow emitted as they swallow matter, or from the gravitational waves generated as black holes collide with one another or with neutron stars.

However, most stellar-mass black holes don’t give away their presence through X-rays or gravitational waves. “The vast majority can only be unveiled dynamically,” says Stefan Dreizler, a team member based at the University of Göttingen in Germany. “When they form a system with a star, they will affect its motion in a subtle but detectable way, so we can find them with sophisticated instruments.”

This dynamical method used by Saracino and her team could allow astronomers to find many more black holes and help unlock their mysteries. “Every single detection we make will be important for our future understanding of stellar clusters and the black holes in them,” says study co-author Mark Gieles from the University of Barcelona, Spain.

The detection in NGC 1850 marks the first time a black hole has been found in a young cluster of stars (the cluster is only around 100 million years old, a blink of an eye on astronomical scales). Using their dynamical method in similar star clusters could unveil even more young black holes and shed new light on how they evolve. By comparing them with larger, more mature black holes in older clusters, astronomers would be able to understand how these objects grow by feeding on stars or merging with other black holes. Furthermore, charting the demographics of black holes in star clusters improves our understanding of the origin of gravitational wave sources.

To carry out their search, the team used data collected over two years with the Multi Unit Spectroscopic Explorer (MUSE) mounted at ESO’s VLT, located in the Chilean Atacama Desert. “MUSE allowed us to observe very crowded areas, like the innermost regions of stellar clusters, analysing the light of every single star in the vicinity. The net result is information about thousands of stars in one shot, at least 10 times more than with any other instrument,” says co-author Sebastian Kamann, a long-time MUSE expert based at Liverpool’s Astrophysics Research Institute. This allowed the team to spot the odd star out whose peculiar motion signalled the presence of the black hole. Data from the University of Warsaw’s Optical Gravitational Lensing Experiment and from the NASA/ESA Hubble Space Telescope enabled them to measure the mass of the black hole and confirm their findings.

ESO’s Extremely Large Telescope in Chile, set to start operating later this decade, will allow astronomers to find even more hidden black holes. “The ELT will definitely revolutionise this field,” says Saracino. “It will allow us to observe stars considerably fainter in the same field of view, as well as to look for black holes in globular clusters located at much greater distances.”

 

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More information

This research was presented in a paper to appear in Monthly Notices of the Royal Astronomical Society (https://doi.org/10.1093/mnras/stab3159).

The team is composed of S. Saracino (Astrophysics Research Institute, Liverpool John Moores University, UK [LJMU]), S. Kamann (LJMU), M. G. Guarcello (Osservatorio Astronomico di Palermo, Palermo, Italy), C. Usher (Department of Astronomy, Oskar Klein Centre, Stockholm University, Stockholm, Sweden), N. Bastian (Donostia International Physics Center, Donostia-San Sebastián, Spain, Basque Foundation for Science, Bilbao, Spain & LJMU), I. Cabrera-Ziri (Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany), M. Gieles (ICREA, Barcelona, Spain and Institut de Ciències del Cosmos, Universitat de Barcelona, Barcelona, Spain), S. Dreizler (Institute for Astrophysics, University of Göttingen, Göttingen, Germany [GAUG]), G. S. Da Costa (Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia), T.-O. Husser (GAUG) and V. Hénault-Brunet (Department of Astronomy and Physics, Saint Mary’s University, Halifax, Canada).

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.

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Contacts:

Sara Saracino
Astrophysics Research Institute, Liverpool John Moores University
Liverpool, United Kingdom
Email: S.Saracino@ljmu.ac.uk

Sebastian Kamann
Astrophysics Research Institute, Liverpool John Moores University
Liverpool, United Kingdom
Email: S.Kamann@ljmu.ac.uk

Stefan Dreizler
Institute for Astrophysics, University of Göttingen
Göttingen, Germany
Email: dreizler@astro.physik.uni-goettingen.de

Mark Gieles
ICREA, Barcelona, Spain and Institut de Ciències del Cosmos, Universitat de Barcelona
Barcelona, Spain
Email: mgieles@icc.ub.edu

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670
Cell: +49 151 241 664 00
Email: press@eso.org

Source: ESO/News

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ALMA Scientists Detect Signs of Water in a Galaxy Far, Far Away