Tag Archives: Farthest

Astronomers Find the Farthest Blazar Ever Detected

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Astronomers have discovered a blazar — a quasar with a jet aligned along our line of sight — at redshift of 7. Named VLASS J041009.05-013919.88, this object is the most distant blazar ever identified, providing a rare glimpse into the epoch of reionization when the Universe was less than 800 million years old.

An artist's impression of a blazar. Image credit: DESY / Science Communication Lab.

VLASS J041009.05-013919.88 (J0410-0139 for short) is powered by a black hole with a mass of 700 million solar masses.

Multi-wavelength observations show that its radio variability, compact structure, and X-ray properties identify it as a blazar with a jet aligned toward Earth.

The discovery of J0410-0139 implies the existence of a much larger population of similar jetted sources in the early Universe.

These jets likely enhance black hole growth and significantly affect their host galaxies.

“The fact that J0410–0139 is a blazar, a jet that by chance happens to point directly towards Earth, has immediate statistical implications,” said Dr. Eduardo Bañados, an astronomer at the Max Planck Institute for Astronomy.

“As a real-life analogy, imagine that you read about someone who has won $100 million in a lottery.”

“Given how rare such a win is, you can immediately deduce that there must have been many more people who participated in that lottery but have not won such an exorbitant amount.”

“Similarly, finding one active galactic nucleus with a jet pointing directly towards us implies that at that time, there must have been many active galactic nuclei in that period of cosmic history with jets that do not point at us.”

“Where there is one, there's one hundred more,” said Dr. Silvia Belladitta, also from the Max Planck Institute for Astronomy.

Observations with instruments such as NSF's Very Large Array, NSF's Very Long Baseline Array, NASA's Chandra X-ray Observatory, and the Atacama Large Millimeter/submillimeter Array (ALMA) indicate that J0410-0139 exhibits radio emission amplified by relativistic beaming, a hallmark of blazers.

Its spectrum also confirms stable accretion and emission regions typical of active black holes.

This discovery raises questions about how supermassive black holes grow so rapidly in the Universe's infancy.

Models may need to account for jet-enhanced accretion or obscured, super-Eddington growth to reconcile this finding with the known black hole population at such high redshifts.

“This blazar offers a unique laboratory to study the interplay between jets, black holes, and their environments during one of the Universe's most transformative epochs,” said Dr. Emmanuel Momjian, an astronomer at NSF's National Radio Astronomy Observatory.

“The alignment of J0410-0139's jet with our line of sight allows astronomers to peer directly into the heart of this cosmic powerhouse.”

“The existence of J0410-0139 at such an early time suggests that current radio surveys might uncover additional jetted quasars from the same era.”

“Understanding these objects will illuminate the role of jets in shaping galaxies and growing supermassive black holes in the early Universe.”

The results appear in two papers (paper #1 and paper #2) in the journal Nature Astronomy and the Astrophysical Journal Letters.

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E. Bañados et al. A blazar in the epoch of reionization. Nat Astronpublished online December 17, 2024; doi: 10.1038/s41550-024-02431-4

Eduardo Bañados et al.2025. [C ii] Properties and Far-infrared Variability of az = 7 Blazar. ApJL 977, L46; doi: 10.3847/2041-8213/ad823b

Source: www.sci.news

Astronomers find farthest rotating disk galaxy ever observed: REBELS-25

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According to one researcher, REBELS-25 existed until 700 million years after the Big Bang. paper Published in Royal Astronomical Society Monthly Notices.

This image shows the galaxy REBELS-25, observed by ALMA, superimposed on infrared images of other stars and galaxies. This infrared image was taken by ESO's Visible Infrared Survey Telescope for Astronomy (VISTA). Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Roland others. / Dunlop others. / Cas / Kare.

The galaxies we see today are very different from the chaotic, clumpy galaxies that astronomers typically observed in the early universe.

These messy early galaxies merge with each other and evolve into smoother shapes at an incredibly slow pace.

Current theory suggests that it would take billions of years of evolution for galaxies to become as ordered as our Milky Way, a rotating disk with an orderly structure like spiral arms.

However, the detection of REBELS-25 casts doubt on that timescale.

“Our understanding of galaxy formation predicts that most early galaxies appear small and messy,” said Dr Jacqueline Hodge, an astronomer at Leiden University.

In their study, Dr. Hodge and colleagues found that REBELS-25 existed at redshift z = 7.3 (when the universe was only 700 million years old), making it the most distant object ever discovered. They discovered that it was a strongly rotating disk galaxy.

“Seeing galaxies so similar to our own Milky Way and with strong rotational dominance adds to our understanding of how galaxies in the early universe evolved into the ordered galaxies of today's universe. It raises questions,” says Lucy Roland, a PhD student at Leiden University. University.

REBELS-25 was detected by the authors using the Atacama Large Millimeter/Submillimeter Array (ALMA).

To precisely identify the galaxy's structure and motion, they conducted follow-up observations at higher resolution with ALMA, confirming its record-breaking nature.

Surprisingly, the data suggested more developed features similar to the Milky Way, such as an elongated central bar and spiral arms, but more observations are needed to confirm this. Probably.

“Finding further evidence of a more evolved structure would be an interesting discovery, as this would be the most distant galaxy in which such a structure has been observed to date,” Rowland said.

“These future observations from REBELS-25, along with other discoveries of early rotating galaxies, could change our understanding of early galaxy formation and the evolution of the universe as a whole.”

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Lucy E. Rowland others. REBELS-25: Dynamically cold disk galaxy discovered at z = 7.31. MNRASpublished online October 7, 2024. doi: 10.1093/mnras/stae2217

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

Webb finds the farthest galaxy ever recorded

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Astronomers NIR Specs The NASA/ESA/CSA James Webb Space Telescope (Near-Infrared Spectrometer) instrument Obtained Spectrum of the record-breaking galaxy JADES-GS-z14-0, observed just 290 million years after the Big Bang. Redshift It’s about 14, a measure of how much the galaxy’s light has been stretched by the expansion of the universe.

This infrared image from Webb’s NIRCam shows the record-breaking galaxy JADES-GS-z14-0. Image credit: NASA / ESA / CSA / STScI / B. Robertson, UC Santa Cruz / B. Johnson, CfA / S. Tacchella, Cambridge / P. Cargile, CfA.

JADES-GS-z14-0, located in the constellation Fornax, JWST: Advanced Deep Extragalactic Exploration (Jade).

The galaxy is much brighter than expected, with a resolved radius of 260 parsecs (848 light years).

The discovery proves that luminous galaxies were already in existence 300 million years after the Big Bang, and that they are more common than expected before Webb.

“The Webb instrument is designed to discover and understand the oldest galaxies, and in its first year of observing as part of JADES, it has found hundreds of candidate galaxies spanning the first 650 million years after the Big Bang,” said Dr. Stefano Carniani of the École Normale Supérieure in Pisa, Italy, and Dr. Kevin Hainline of the University of Arizona, Tucson.

“Early in 2023, we discovered a galaxy in our data with strong evidence of being at a redshift greater than 14. This was very exciting, but some properties of its source made us wary.”

“The source was incredibly bright, something not expected in such a distant galaxy, and it was so close to another galaxy that the two appeared to be part of a single, larger object.”

“When Webb observed the source again in October 2023 as part of the JADES Origins Field, NIR Cam (Near-infrared camera) filters further supported the high-redshift hypothesis.”

“We knew we needed a spectrum, because anything we learn would be of immense scientific importance, either as a new milestone in Webb’s study of the early universe or as a mysterious outlier in a middle-aged galaxy.”

“In January 2024, NIRSpec observed JADES-GS-z14-0 for almost 10 hours, and when the spectrum was first processed, there was unequivocal evidence that the galaxy is indeed at redshift 14.32, breaking the previous record for the most distant galaxy, JADES-GS-z13-0.”

“Seeing this spectrum was very exciting for the whole team, given that its source remained a mystery.”

“This discovery was not just a new distance record for our team. The most important thing about JADES-GS-z14-0 is that it shows that at this distance, this galaxy must be intrinsically very luminous.”

“The images show that the source is more than 1,600 light-years in diameter, proving that the light we are seeing is coming primarily from young stars, and not from the vicinity of a growing supermassive black hole.”

“This much starlight suggests that the galaxy’s mass is hundreds of millions of times that of the Sun!”

“This raises the question: How could nature create such a bright, massive and large galaxy in less than 300 million years?”

“The data reveal other important aspects of this remarkable galaxy,” the astronomers said.

“We found that the galaxy’s color is not inherently blue, which indicates that even at its very earliest stages, some of its light is being reddened by dust.”

They also confirmed that JADES-GS-z14-0 was detected at Webb’s longer wavelengths. Milli (mid-infrared observation instrument), a remarkable achievement considering its distance.

MIRI’s observations cover wavelengths of light emitted in the visible range that are redshifted and cannot be seen by Webb’s near-infrared instrument.

According to the analysis, the brightness of the source suggested by the MIRI observations exceeds that estimated from measurements by other Webb instruments, indicating the presence of strong ionized gas emission in the galaxy in the form of bright emission lines from hydrogen and oxygen.

The presence of oxygen so early in the galaxy’s life was surprising, suggesting that several generations of very massive stars had already died before the galaxy was observed.

“Taken together, all these observations show that JADES-GS-z14-0 is different from the types of galaxy predicted to exist in the early universe by theoretical models and computer simulations,” the researchers said.

“Given the observed luminosity of a source, we can predict how it will grow over cosmic time. So far, we have not found a suitable analogue among the hundreds of other galaxies we have observed at high redshifts in our survey.”

“Because the region of sky we searched to find JADES-GS-z14-0 is relatively small, its discovery has a significant impact on the predicted number of luminous galaxies seen in the early universe, as discussed in a separate, concurrent JADES study.”

“Webb’s observations will enable astronomers to discover many more such luminous galaxies over the next decade, and perhaps sooner.”

“We’re excited to see the incredible diversity of galaxies present in Cosmic Dawn!”

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Stefano Carniani others2024. A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z ∼ 14. arXiv:2405.18485

Source: www.sci.news