Tag Archives: Quasar

Webb Observes Four Views of a Gravitationally Lensed Quasar

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The quasar, called RX J1131-1231, lies about 6 billion light-years away in the constellation Crater.

This Webb image shows the galaxy RX J1131-1231 distorted by gravitational lensing into a dark ring. At the top of the ring are three very bright spots next to each other, emitting diffraction spikes. These are copies of a single quasar in the lensed galaxy, duplicated by gravitational lensing. In the center of the ring, the lensing elliptical galaxy appears as a small blue spot. Image credit: NASA / ESA / CSA / Webb / A. Nierenberg.

RXJ1131-1231 The galaxy is thought to be one of the best lensed quasars ever discovered, as the foreground lensing effect blurs the image of the background quasar into a bright arc, creating four celestial images.

“Gravitational lensing effect“This phenomenon, first predicted by Albert Einstein, acts as a natural telescope, magnifying the light from these sources and providing a rare opportunity to study the regions close to the black holes in distant quasars,” astronomer Webb said.

“All matter in the universe distorts the space around it, and the more mass there is, the more pronounced this effect.”

“Around very massive objects like galaxies, light passing nearby travels through this distorted space, appearing to bend visibly from its original path.”

“One of the inevitable effects of gravitational lensing is the magnification of distant objects, allowing astronomers to study objects that would otherwise be too faint or too far away.”

“Measuring the X-ray emission from a quasar can provide an indication of how fast the central black hole is rotating, which could give researchers important clues about how black holes grow over time,” the researchers added.

“For example, if black holes grow primarily through collisions and mergers between galaxies, then the accumulation of material in a stable disk and the steady supply of new material from the disk should cause the black hole to rotate rapidly.”

“On the other hand, if a black hole grows through many small accretion episodes, then material will accumulate from random directions.”

“Observations show that the black hole in RX J1131-1231 is rotating at more than half the speed of light, suggesting that the black hole grew by merging rather than by attracting matter from different directions.”

New images of RX J1131-1231 can be found at Webb's MIRI (Mid-Infrared Instrument) As part of an observational program to study dark matter.

“Dark matter is an invisible substance that makes up most of the mass of the universe,” the researchers said.

“Webb's quasar observations allow us to probe the nature of dark matter on smaller scales than ever before.”

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This article is a version of a press release provided by NASA.

Source: www.sci.news

Astronomers find the farthest merging quasar pair ever recorded

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Astronomers have discovered a pair of merging quasars observed just 900 million years after the Big Bang. Not only is this the most distant pair of merging quasars ever found, but it’s also the first pair identified during a period in the history of the universe known as the “cosmic dawn.”

This image taken with the Subaru Telescope’s HyperSupreme-Cam shows a pair of quasars in the process of merging, HSC J121503.42-014858.7 (C1) and HSC J121503.55-014859.3 (C2). Image courtesy NOIRLab / NSF / AURA / TA Rector, University of Alaska Anchorage & NSF NOIRLab / D. de Martin, NSF NOIRLab / M. Zamani, NSF NOIRLab.

The dawn of the universe lasted from about 50 million to 1 billion years after the Big Bang.

During this period the first stars and galaxies began to appear and the dark universe was filled with light for the first time.

The appearance of the first stars and galaxies marked the beginning of a new era in the formation of the universe, known as the Reionization Epoch.

The epoch of reionization that occurred during the cosmic dawn was a period of cosmic transition.

About 400 million years after the Big Bang, ultraviolet light from the first stars, galaxies, and quasars spread throughout the universe, interacting with intergalactic matter and beginning a process called ionization, which stripped electrons from the universe’s primordial hydrogen atoms.

The reionization epoch is a crucial period in the history of the universe, marking the end of the cosmic dark ages and sowing the seeds of the large structures we observe in the local universe today.

To understand exactly what role quasars played during the reionization period, astronomers are interested in discovering and studying quasars that existed during this earlier, distant era.

“The statistical properties of quasars during the reionization stage can tell us a lot, including the progress and origin of reionization, the formation of supermassive black holes at the dawn of the universe, and the earliest evolution of the quasars’ host galaxies,” said Dr Yoshiki Matsuoka, an astronomer at Ehime University.

About 300 quasars have been discovered during the reionization period, but none have been found in pairs.

But as Dr. Matsuoka and his team were reviewing images taken with the Subaru Telescope’s HyperSupreme-Cam, a faint red spot caught their eye.

“While screening images for potential quasars, we noticed two similar, very red sources next to each other. This discovery was pure coincidence,” Dr Matsuoka said.

The distant quasar candidates are contaminated by many other sources, including foreground stars and galaxies and gravitational lensing, so the authors were unsure whether they were quasar pairs.

To confirm the nature of these objects, named HSC J121503.42-014858.7 and HSC J121503.55-014859.3, the team carried out follow-up spectroscopic measurements using the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope and the Gemini Near-Infrared Spectrograph (GNIRS) on the Gemini North Telescope.

The spectra obtained by GNIRS resolved the light emitted by the source into its constituent wavelengths and were crucial for characterizing the properties of the quasar pair and its host galaxy.

“GNIRS observations have shown that quasars are too faint to be detected in near-infrared light, even with the largest ground-based telescopes,” said Dr Matsuoka.

This allowed astronomers to deduce that some of the light detected in the visible wavelength range comes not from the quasar itself, but from ongoing star formation in its host galaxy.

The two black holes were also found to be enormous, with masses 100 million times that of the Sun.

This, combined with the presence of a bridge of gas extending between the two quasars, suggests that the two quasars and their host galaxies are undergoing a major merger.

“The existence of merging quasars during the reionization period has long been predicted, but this has now been confirmed for the first time,” said Dr Matsuoka.

This discovery paper In Astrophysical Journal Letters.

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Yoshiki Matsuoka others2024. Discovery of twin quasars merging at z = 6.05. Apu JL 965, L4; doi: 10.3847/2041-8213/ad35c7

Source: www.sci.news

Astronomers find previously unknown quasar in far-off galaxy cluster

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Astronomers used NASA’s Chandra X-ray Observatory and NSF’s Carl G. Jansky Very Large Array (VLA) to locate H1821+643, the closest quasar hosted by a galaxy cluster, about 3.4 billion light years away. The quasar was found to be more powerful than many supermassive black holes in other galaxy clusters.

This composite image shows quasar H1821+643.Image credit: NASA / CXC / University of Nottingham / Russell other. / NSF / NRAO / VLA / SAO / N. Walk.

Quasars are a rare and extreme class of supermassive black holes that violently pull matter inward, producing intense radiation and sometimes powerful jets.

This quasar, known as H1821+643, is about 3.4 billion light-years from Earth and contains a black hole with a mass of 4 billion solar masses.

Most growing supermassive black holes pull matter in at a slower rate than quasars.

Astronomers have been studying the effects of these more common black holes by observing black holes at the centers of galaxy clusters.

Periodic explosions from such black holes prevent the massive amount of superheated gas embedded in the black hole from cooling down, increasing the number of stars forming in its host galaxy and the fuel pouring toward the black hole. limit the amount of

Little is known about how much influence quasars within galaxy clusters have on their surroundings.

“Our research shows that quasars appear to have given up much of the control imposed by slower-growing black holes. The appetite of black holes is unmatched in their influence,” Nottingham said. University astronomer Dr Helen Russell said.

To reach this conclusion, Russell and his colleagues used Chandra to study the hot gas surrounding H1821+643 and its host galaxy.

But the bright X-rays from quasars have made it difficult to study the weaker X-rays from hot gases.

“To reveal the effects of a black hole, we had to carefully remove the X-ray glare. Then we found that it actually had little effect on its surroundings,” says Harvard University. said Dr. Paul Nalsen, an astronomer at the Smithsonian Center for Astrophysics.

Using Chandra, astronomers discovered that the density of gas near the black hole at the center of a galaxy is much higher than in more distant regions, and the temperature of the gas is much cooler.

Researchers believe that when there is little or no energy input (usually from an explosion from a black hole), hot gas behaves this way to prevent it from cooling and flowing toward the center of the cluster. Expect.

“The supermassive black hole generates far less heat than other black holes at the center of galaxy clusters. This allows the hot gas to cool rapidly and form new stars, which fuel the black hole. It also acts as a source,” said Dr Lucy Crews, an astronomer at the Open University.

The researchers determined that the equivalent of about 3,000 solar masses per year of hot gas has cooled to the point where it is no longer visible in X-rays.

This rapid cooling easily supplies enough material for the 120 solar masses of new stars observed to form each year within the host galaxy and the 40 solar masses consumed by black holes each year. be able to.

The scientists also investigated the possibility that radiation from quasars directly causes cooling of the cluster's hot gases.

This involves photons of light from the quasar colliding with electrons in the hot gas, increasing the energy of the photons and causing the electrons to lose energy and cool down.

This study showed that this type of cooling is probably occurring within the cluster containing H1821+643, but is too weak to explain the large amount of gas cooling seen.

Dr Thomas Braben, an astronomer at the University of Nottingham, said: “This black hole may not be producing enough because it isn't pumping any heat into its surroundings, but the current situation won't last forever.'' ” he said.

“Ultimately, the rapid uptake of fuel by the black hole should increase the jet's power and strongly heat the gas.”

“After that, the growth of the black hole and its galaxy should slow down significantly.”

team's paper will be published in Royal Astronomical Society Monthly Notices.

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HR Russell other. 2024. Cooling flow around low-redshift quasar H1821+643. MNRAS, in press. arXiv: 2401.03022

Source: www.sci.news

Brightest Quasar Ever Observed Discovered by Astronomers

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The black hole in the newly discovered quasar SMSS J052915.80-435152.0 (J0529-4351) accretes about 1 solar mass per day on top of its existing mass of 17 billion solar masses.

This image of the exceptional quasar J0529-4351 is from the Dark Energy Camera Legacy Survey DR10. Adjacent M stars are displayed in red.Image credit: Wolf other., doi: 10.1038/s41550-024-02195-x.

In 1963, Dutch-born American astronomer Maarten Schmidt identified the first quasar, known as 3C 273. It appeared as a very bright star of magnitude 12, and its redshift suggested that it was one of the most distant objects known in the universe. time.

These two facts suggest an incredibly huge light output, and ever since, newly discovered quasars have impressed with their ability to emit enormous amounts of energy from small regions of the universe. Ta.

This can only be explained by the conversion of gravitational energy into heat and light in a highly viscous accretion disk around a supermassive black hole.

Currently, about 1 million quasars are known, but a few specimens stand out. In 2015, ultraluminous quasar J0100+2802 was confirmed to be a supermassive black hole with 10 billion solar masses.

In 2018, an even brighter object, J2157-3602, was discovered, which contains a supermassive black hole with a mass of 24 billion solar masses.

Its brightness suggests rapid growth, but its existence is difficult to explain. When black holes start from the debris of a star's collapse and grow temporarily, they are not expected to reach appreciable mass in the time between the Big Bang and the black hole era. observation.

The quasar that broke the new record is so far from Earth that it took more than 12 billion years for its light to reach us.

The object, called J0529-4351, was first detected using the 2.3 meter telescope at the ANU Siding Spring Observatory.

Australian National University astronomer Christian Wolff and colleagues then turned to ESO's Very Large Telescope, one of the world's largest telescopes, to confirm the full nature of the black hole and measure its mass. Toward.

“We have discovered the fastest growing black hole ever known. It has a mass of 17 billion suns and eats just over one sun a day. This makes it the fastest growing black hole in the known universe. It will be a bright object,” Dr. Wolf said.

The material drawn into this black hole in the form of a disk emits so much energy that J0529-4351 is more than 500 trillion times brighter than the Sun.

“All this light comes from a hot accretion disk seven light-years in diameter, which must be the largest accretion disk in the universe,” said Dr. Student Samuel Lai.

“Given what we know about many other less impressive black holes, it's surprising that it hasn't been detected before. It was hiding in plain sight,” says the Australian National said Dr. Christopher Onken of the university.

This finding is reported in the following article: paper in diary natural astronomy.

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C.Wolf other. Accretion of solar masses per day by a 17 billion solar mass black hole. Nat Astron, published online on February 19, 2024. doi: 10.1038/s41550-024-02195-x

Source: www.sci.news