среда, 8 января 2020 г.

2,400-year-old pendants unearthed in Assos excavations


Archaeological excavations in Assos, one of the most important port cities of antiquity have unearthed 2,400-year-old pendants made from bone, shaped in human and animal figures.

2,400-year-old pendants unearthed in Assos excavations
Credit: AA
The pendants date back to the fourth century BC, said Nurettin Arslan, professor at Çanakkale Onsekiz Mart University (ÇOMÜ) Faculty of Arts and Sciences Department of Archaeology and head of Assos excavations, in an interview with the state-run Anadolu Agency.

The ancient city is located in the Turkish province of Çanakkale (Greek Dardanellia) on the coast of the Adramyttian Gulf (Turkish: Edremit Körfezi)..


“There are two objects used as jewellery among those produced in the bone workshop to the west of the agora, one shaped as an animal and the other as a human. These must be part of jewellery which people used as necklaces in the ancient period,” Arslan said.

The professor also said that during the excavations, coins from the Byzantine and the Ottoman eras were revealed.

“The largest group of coins uncovered in Assos are Byzantine (Eastern Roman) coins, because the layers we are working on are mainly from the Byzantine period. These works show us that the Byzantine ruins in Assos archaeological site is a well-preserved centre,” the professor said.

2,400-year-old pendants unearthed in Assos excavations
Credit: AA
The findings show that there was intense settlement in Assos between the fifth and seventh centuries. The settlement gradually decreased until the 12th century and eventually became a “small fortress” in the acropolis, Arslan said.

“Since there is no settlement later on, we can say that the data related to urban planning, lifestyle functions of houses and daily life in the early Byzantine period are very valuable,” he said.


The professor underlined that one of the most archaic discoveries of the excavation works was stone axes made of granite.

“This stone axe was found on the surface in the necropolis area, but similar discoveries were made by Turkish archaeologists in the American excavations and during the 1990s,” he said.

“We have four axes dating back to the Chalcolithic period, to 5000 BC. These axes are important such as they are traces showing that the settlement of Assos dates back to 5000 BC,” he added.

The city was founded from 1000 to 900 BC by Aeolian colonists from Lesbos, who specifically are said to have come from Methymna.

It was the first ancient city where U.S. archaeologists excavated in the 1800s. It was excavated in 1981 after a long break.

Source: Hurriyet Daily News [December 30, 2019]



* This article was originally published here

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’


The 2,500-year-old tomb of a Scythian warrior has been found in the ‘Siberian Valley of the Kings’ in Russia.

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’
The skeletal remains of the 2,500-year-old Scythian warrior was found buried with a bronze battle axe, arrows,
an iron knife and fragments of a bow [Credit: Igor Pieńkos]
Buried with his weapon and golden ornaments, the warrior discovered by archaeologists from Jagiellonian University in Krakow was found in an untouched grave in an area known for both its rich burial sites and notorious grave-robbing.


The so-called ‘Siberian Valley of the Kings’, named after its Egyptian counterpart, is located in the Asian part of the Russian Federation.

It earned its name due to the numerous giant kurgan tombs, often full of treasures of thought to belong to royalty.

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’
The warrior discovered by archaeologists from Jagiellonian University in Kraków was found in an untouched grave
in an area known for both its rich burial sites and notorious grave-robbing [Credit: Igor Pieńkos]
The archaeological site of Chinge-Tey where Poles uncovered the new treasures is operated together with the State Hermitage Museum in Sankt Petersburg and Korean Seoul University, reports the Science in Poland website (Nauka w Polsce).

Dr. Lukasz Oleszczak, the Polish expedition’s head, told PAP: "For our research we chose an inconspicuous, almost invisible kurgan with a diameter of about 25 m.

“We hoped that it remained unnoticed by the robbers."

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’
The so-called ‘Siberian Valley of the Kings’, named after its Egyptian counterpart, is located
in the Asian part of the Russian Federation [Credit: Igor Pieńkos]
Of the two tombs they found only one was robbed, while the other was untouched.

He added: "Inside was a young warrior’s skeleton with full equipment. There area around his head was decorated with a pectoral made of gold sheet, a glass bead, a gold spiral for adorning the braid.”


Archaeologists also found the Scythian buried with a sharpening stone and his weapon – a bronze battle-axe with a stylized eagle's head, arrows, an iron knife, fragments of an bow – presenting an array of items a warrior roaming the Siberian wilderness would need.

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’
Of the two tombs they found only one was robbed, while the other was untouched
[Credit: Igor Pieńkos]
Dr. Oleszczak said: "Other well-preserved items were made of organic materials. Among them there is a leather quiver, arrow spars, the axe’s shaft and a belt.”

The findings date back to the 7th or 6th century BC. Scythians were nomad people from Central Asia, who expanded into Eastern Europe through their love of combat and war.

Their achievements were described by the Greek historian Herodotus.

2,500-year-old Scythian warrior grave found in Siberian ‘Valley of the Kings’
The new treasures were discovered at the archaeological site of Chinge-Tey
[Credit: Igor Pieńkos]
The Scythians buried their dead in kurgans, some resembling hills visible from afar.


The grave found this year was surrounded by a shallow trench. Inside archaeologists uncovered several dozen fragments of ceramic vessels and animal bones, mainly of cows, horses, goats or sheep.

Most probably they are traces of religious ceremonies and rituals, such as funeral wakes.

The Polish archaeologists will continue their work in Chinge-Tey, as there is still one grave they found, but were unable to fully examine.

Author: Joanna Jasinka | Source: The First News [December 31 2019]



* This article was originally published here

Restoring the Rimini Altarpiece to new splendour


The Liebieghaus Skulpturensammlung has launched a large-scale conservation project that will focus on one of the collection’s most important works over the next few years. The Rimini Altarpiece, one of the most comprehensive and best-preserved late medieval figural groups in alabaster, will undergo a range of conservation and restoration treatments, including state-of-the-art laser technology. An in-depth technical analysis of the artwork will also be carried out.

Restoring the Rimini Altarpiece to new splendour
Master of the Rimini Altarpiece: Crucifixion altarpiece from Rimini, Southern Netherlands, c. 1430
(overall view before restoration) [Credit: Liebieghaus Skulpturensammlung]


The Liebieghaus has acquired a special laser to ensure that the highly sensitive material can be cleaned as gently and effectively as possible, and has also been able to gain the support of the research laboratory of the Louvre in Paris which will assist in the precise analysis of the stone’s material composition.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: detail [Credit: Liebieghaus Skulpturensammlung]
A special conservation studio has been set up for the project at the museum that is on view to visitors and will be complemented by an educational display explaining the ongoing work, an accompanying film and regular updates on the results of the analyses and conservation-restoration work that will be published on the Liebieghaus website, allowing the public to follow each step of the project firsthand. The project is set to run for three years and is supported by the Ernst von Siemens Kunststiftung within the framework of “Kunst auf Lager”.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: detail [Credit: Liebieghaus Skulpturensammlung]
“It had long been a major concern of ours to dedicate a proper, in-depth research and restoration project to the Rimini Altarpiece in order to return this world-renowned masterpiece in our collection to its original state as much as is possible. I’m particularly delighted that we’ve been able to make the whole exciting process and the resulting insights directly accessible to the public on site at the Liebieghaus,” says Philipp Demandt, director of the Liebieghaus.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: detail [Credit: Liebieghaus Skulpturensammlung]


“Looking at the Rimini Altarpiece from the conservation perspective, it is immediately apparent that there’s a huge discrepancy between its tremendous significance to art history and its present, unsatisfactory condition. As alabaster is one of the most fragile types of stone, the material poses a considerable challenge for our conservators. Many of the usual methods for stone restoration cannot be applied here, so the first step is to carry out a series of tests to ensure the most gentle treatment possible,” explains the head of sculpture conservation, Harald Theiss. “The successful restoration of key works in museum collections is, at times, more important than new acquisitions,” adds Dr Martin Hoernes, General Secretary of the Ernst von Siemens Kunststiftung.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: detail [Credit: Liebieghaus Skulpturensammlung]
The last large-scale conservation-restoration treatment of the ensemble of 18 alabaster figures and figural groups took place in the late 1960s. In addition to the layers of dirt and discoloured coatings, the conservation materials used at that time have, with time, penetrated right into the substance of the stone, where they are increasingly hardening and becoming brittle, so action is urgently needed. Another difficulty is that during the last restoration treatment the original appearance of the central Crucifixion group was substantially altered by lengthening the arms of the cross.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: after and before laser treatment
[Credit: Liebieghaus Skulpturensammlung]
This intervention also caused a loss of stability, to the extent that it is almost impossible to move the object without considerable risk, even for routine activities at the museum. It also means that the work cannot be lent to other museums, for example, despite frequent requests from abroad. A detailed art-technical examination of the ensemble will also be carried out within the framework of this project, as no such analysis has been undertaken before. It will include a precise analysis of the condition of the material and a systematic examination of the figures for traces of the original polychrome paintwork.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: detail view after laser treatment
[Credit: Liebieghaus Skulpturensammlung]


Acquired in 1913, the Rimini Altarpiece with its white alabaster figures is one of the key works at the Liebieghaus Skulpturensammlung and one of the best-known objects from the museum’s Medieval Department worldwide. Its uniqueness and great significance to art history is underlined by the fact that the work has lent its name to the attribution of many alabaster sculptures from the early 15th century, both within Germany and beyond: for instance, the designation ‘Master of the Rimini Altarpiece’ is listed as the artist’s name in museums and art collections from Warsaw, Berlin and Munich to Barcelona, Paris and London and even in New York and Los Angeles. Its popularity is not only due to the exquisite craftsmanship of the figures, but also to the fact that it is one of the largest and best-preserved examples of a figural group made out of alabaster from the late Middle Ages.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece after and before 1967 [Credit: Liebieghaus Skulpturensammlung]
The centre of the ensemble was formed out of several blocks, depicting the Crucifixion of Christ flanked by six apostles on either aside. Carved in the round and originally partially painted, the works were once part of an altarpiece in the church of Santa Maria delle Grazie in Rimini. They were not made in Italy, however, but in a workshop that specialised in alabaster in the Southern Netherlands, possibly in Bruges, around 1430.

Restoring the Rimini Altarpiece to new splendour
Rimini Altarpiece: mapping of damages [Credit: Liebieghaus
Skulpturensammlung]


The extremely idealised works adhere for the great part to the characteristic design aesthetic of the International Gothic style, which prevailed across Europe between approximately 1380 and 1430. The realistic depiction of some of the anatomical and physiognomic details, especially the unsparing portrayal of the broken and contorted limbs of the thieves indicates a change in style, however.


A new interest in working from nature is evident that can also be observed in Netherlandish painting from this period, for example, in the work of Jan van Eyck, Robert Campin and Rogier van der Weyden, and paved the way for the art of the following decades.

Source: Liebieghaus Skulpturensammlung [December 27, 2019]



* This article was originally published here

2020 January 8 Galaxies in the River Image Credit &...



2020 January 8

Galaxies in the River
Image Credit & Copyright: Star Shadows Remote Observatory, PROMPT, CTIO

Explanation: Large galaxies grow by eating small ones. Even our own galaxy engages in a sort of galactic cannibalism, absorbing small galaxies that are too close and are captured by the Milky Way’s gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus, The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531 (right of center), a struggle the smaller galaxy will eventually lose. Seen edge-on, spiral NGC 1532 spans about 100,000 light-years. Nicely detailed in this sharp image, the NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51.

∞ Source: apod.nasa.gov/apod/ap200108.html



* This article was originally published here

Cors y Gedol Prehistoric Burial Chamber, Dyffryn Ardudwy, North Wales, 4.1.20.

Cors y Gedol Prehistoric Burial Chamber, Dyffryn Ardudwy, North Wales, 4.1.20.



* This article was originally published here

Wind conditions influence water circulation and CO2 concentrations in the Southern Ocean


The sea encircling Antarctica acts as a huge mixer for water from all the ocean basins - and this circulating pattern influences the exchange of carbon dioxide (CO2) between the ocean and the atmosphere. A study by an international team of researchers, led by Dr. Torben Struve from the University of Oldenburg's Institute for Chemistry and Biology of the Marine Environment (ICBM), has now established that this complex equilibrium of water masses reacts highly sensitively to wind conditions over the Southern Ocean.

Wind conditions influence water circulation and CO2 concentrations in the Southern Ocean
An international team of scientists led by the University of Oldenburg, Germany, used measurements on fossil skeletons
 of the cold-water coral Desmophyllum dianthus to reveal that significant changes in deep-water circulation occurred
in the Drake Passage, a narrow strait between Antarctica and South America, around six to seven thousand years ago.
The scientists see indications that these changes also influenced CO2 levels in the atmosphere - and suggest
that future climate change could lead to increased release of CO2 from the deep waters of the
Southern Ocean into the atmosphere [Credit: Andrew Margolin]
The study, which is published in the scientific journal Proceedings of the National Academy of Sciences, used measurements on fossil coral skeletons to reveal that significant changes in deep-water circulation occurred in the Drake Passage, a narrow strait between Antarctica and South America, around six to seven thousand years ago. The scientists see indications that these changes also influenced CO2 levels in the atmosphere - and suggest that future climate change could lead to increased release of CO2 from the deep waters of the Southern Ocean into the atmosphere.

"The Southern Ocean connects all the world's oceans. It's one of the few places on Earth where water from great depths comes to the surface and at the same time surface water sinks to the depths," explained lead author Struve. The marine region around Antarctica is therefore critical for the global conveyor belt of ocean currents, which distributes heat, nutrients, salt and CO2 over great distances.

However, until now, it had not been clear whether the current flowing in the Southern Ocean had changed significantly since the last ice age ended about 12,000 years ago. Previous studies by climate researchers had shown that there have been several shifts in the strong westerly winds blowing around Antarctica during the current interglacial period.


These winds drive the Antarctic Circumpolar Current (ACC), a cold ocean current that extends from the surface to the ocean floor and which connects the Atlantic, Indian and Pacific Oceans. Importantly, the winds also stimulate the upwelling of deep ocean waters towards the ocean surface. The study set out to determine how the currents in the Southern Ocean reacted to these changes in the atmosphere.

To answer this question, Struve and his colleagues from Imperial College London, University College London and the University of Edinburgh, analysed fossil cold-water corals from the Drake Passage, some of which were several thousand years old. The corals were collected from different water depths at three locations in the Drake Passage during two expeditions with the US research vessel Nathaniel B. Palmer.

"This area is notorious for its poor weather conditions - simply collecting the samples was a challenge," Struve explained.

The cold-water corals store certain trace elements, such as neodymium, in their calcareous skeletons, and therefore record a chemical fingerprint of the water they grew in.


Analyses of the neodymium fingerprints in the coral samples showed that there was an abrupt change in the chemical composition of the water about 7,000 years ago, which lasted for about 1,000 years. On the basis of several findings, the team concluded that increased amounts of CO2-rich deep water from the Pacific Ocean penetrated the Drake Passage at that time, presumably driven by a northwards shift of the Southern Hemisphere westerly winds.

"This was a surprising result for us. We hadn't expected the Southern Ocean to react so sensitively during an interglacial period," said Struve. "This study highlights the invaluable contribution of cold water coral fossils to understanding past climate change. They provide unique records of the chemical composition of seawater - often in regions of the ocean where other types of archives are scarce," co-author Dr. Kirsty Crocket of the University of Edinburgh underlined.

The study also sheds light on a series of other climate changes that occurred around the same time. In particular, atmospheric CO2 levels, which had dropped slightly in the preceding 2,000 years, began to rise once more. Struve and his colleagues suspect that a key source for this phenomenon was an increase in the amount of CO2-rich Pacific deep water in the Southern Ocean.


"This is important because when deep waters upwell to the surface of the Southern Ocean, some of the stored CO2 is able to escape to the atmosphere", explained co-author Dr. David Wilson. And then, as the winds shifted southwards once more, this upwelling increased and larger amounts of CO2 were released into the atmosphere.

It is not yet clear how rising global temperatures will affect the ocean currents encircling Antarctica. However, current climate scenarios indicate that the Southern Hemisphere westerly winds will move further south towards Antarctica. This scenario could lead to stronger mixing of water masses in the Southern Ocean and more upwelling - which the team of researchers suspects could in turn result in larger amounts of CO2 being released from the deep ocean.

Source: University of Oldenburg [December 30, 2019]



* This article was originally published here

Astronomers Spot Distant Galaxy Group Driving Ancient Cosmic Makeover

EGS77 is the farthest galaxy group identified to date. It dates back to a time when the universe was only 680 million years old, or less than 5 percent of its current age of 13.8 billion years.  Credit: Nasa's Goddard Space Flight Center 

Maunakea, Hawaii – An international team of astronomers funded in part by NASA has found the farthest galaxy group identified to date. With the help of W. M. Keck Observatory on Maunakea, Hawaii, the team confirmed the trio of galaxies called EGS77 dates to a time when the universe was only 680 million years old, or less than 5% of its current age of 13.8 billion years. 

More significantly, observations show the galaxies are participants in a sweeping cosmic makeover called reionization. The era began when light from the first stars changed the nature of hydrogen throughout the universe in a manner akin to a frozen lake melting in the spring. This transformed the dark, light-quenching early cosmos into the one we see around us today.

“The young universe was filled with hydrogen atoms, which so attenuate ultraviolet light that they block our view of early galaxies,” said James Rhoads at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who presented the findings on Jan. 5 at the 235th meeting of the American Astronomical Society in Honolulu. “EGS77 is the first galaxy group caught in the act of clearing out this cosmic fog.” 

While more distant individual galaxies have been observed, EGS77 is the farthest galaxy group to date showing the specific wavelengths of far-ultraviolet light revealed by reionization. This emission, called Lyman alpha light, is prominent in all members of EGS77.

In its infancy, the universe was a hot, opaque plasma. After expanding and cooling for about 380,000 years, the universe formed the first atoms — more than 90% of them hydrogen. Hundreds of millions of years later, this gas formed the first stars and galaxies. But the very presence of this abundant gas poses challenges for spotting galaxies in the early universe.  

In its earliest phase, the universe was a glowing plasma of particles, including electrons, protons, atomic nuclei, and light. Atoms could not yet exist. The universe was in an ionized state, similar to the gas inside a lighted neon sign or fluorescent tube.

This illustration of the EGS77 galaxy group shows the galaxies surrounded by overlapping bubbles of hydrogen ionized by ultraviolet light from their stars. By transforming light-quenching hydrogen atoms to ionized gas, UV starlight is thought to have formed such bubbles throughout the early universe, gradually transitioning it from opaque to completely transparent. Credit: Nasa's Goddard Space Flight Center

After the universe expanded and cooled for about 380,000 years, electrons and protons combined into the first atoms — more than 90% of them hydrogen. Hundreds of millions of years later, this gas formed the first stars and galaxies. But the very presence of this abundant gas poses challenges for spotting galaxies in the early universe. 

Hydrogen atoms readily absorb and quickly re-emit far-ultraviolet light known as Lyman alpha emission, which has a wavelength of 121.6 nanometers. When the first stars formed, some of the light they produced matched this wavelength. Because Lyman alpha light easily interacted with hydrogen atoms, it couldn’t travel far before the gas scattered it in random directions.  

“Intense light from galaxies can ionize the surrounding hydrogen gas, forming bubbles that allow starlight to travel freely,” said team member Vithal Tilvi, a researcher at Arizona State University in Tempe. “EGS77 has formed a large bubble that allows its light to travel to Earth without much attenuation. Eventually, bubbles like these grew around all galaxies and filled intergalactic space, reionizing the universe and clearing the way for light to travel across the cosmos.”

EGS77 was discovered as part of the Cosmic Deep And Wide Narrowband (Cosmic DAWN) survey, for which Rhoads serves as principal investigator. The team imaged a small area in the constellation Boötes using a custom-built filter on the National Optical Astronomy Observatory’s Extremely Wide-Field InfraRed Imager (NEWFIRM), which was attached to the 4-meter Mayall telescope at Kitt Peak National Observatory near Tucson, Arizona.

This animation shows EGS77’s place in cosmic history, flies to the galaxies, and illustrates how ultraviolet light from their stars create bubbles of ionized hydrogen around them.  Credit: Nasa's Goddard Space Flight Center 

Because the universe is expanding, Lyman alpha light from EGS77 has been stretched out during its travels, so astronomers actually detect it at near-infrared wavelengths. We can’t see these galaxies in visible light now because that light started out at shorter wavelengths than Lyman alpha and was scattered by the fog of hydrogen atoms.

To help select distant candidates, the researchers compared their images with publicly available data of the same region taken by NASA’s Hubble and Spitzer space telescopes. Galaxies appearing brightly in near-infrared images were tagged as possibilities, while those appearing in visible light were rejected as being too close.  

The team confirmed the distances to EGS77’s galaxies by using the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) on the Keck I telescope at the W. M. Keck Observatory on Maunakea, Hawaii. The three galaxies all show Lyman alpha emission lines at slightly different wavelengths, reflecting slightly different distances. The separation between adjacent galaxies is about 2.3 million light-years, or slightly closer than the distance between the Andromeda galaxy and our own Milky Way. 

A paper describing the findings, led by Tilvi, has been submitted to The Astrophysical Journal.

“While this is the first galaxy group identified as being responsible for cosmic reionization, future NASA missions will tell us much more,” said co-author Sangeeta Malhotra at Goddard. “The upcoming James Webb Space Telescopeis sensitive to Lyman alpha emission from even fainter galaxies at these distances, and may find more galaxies within EGS77.” 

Astronomers expect that similar reionization bubbles from this era will be rare and hard to find. NASA’s planned Wide Field Infrared Survey Telescope (WFIRST) may be able to uncover additional examples, further illuminating this important transition in cosmic history.




About MOSFIRE

MOSFIRE (Multi-Object Spectrograph for Infrared Exploration) is a highly-efficient instrument that can take images or up to 46 simultaneous spectra. Using a sensitive state-of-the-art detector and electronics system, MOSFIRE obtains observations fainter than any other near infrared spectrograph. MOSFIRE is an excellent tool for studying complex star or galaxy fields, including distant galaxies in the early Universe, as well as star clusters in our own Galaxy. MOSFIRE obtained first light in April 2012 and was made possible by funding provided by the National Science Foundation and astronomy benefactors Gordon and Betty Moore. It is currently the most in-demand instrument at the W. M. Keck Observatory.


About W. M. Keck Observatory

The W. M. Keck Observatory telescopes are among the most scientifically productive on Earth. The two, 10-meter optical/infrared telescopes on the summit of Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems.

Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c) 3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. 

The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community.  We are most fortunate to have the opportunity to conduct observations from this mountain.




* This article was originally published here

Romano-Celtic Hut Circles, Cors y Gedol, Dyffryn Ardudwy, North Wales, 4.1.20.

Romano-Celtic Hut Circles, Cors y Gedol, Dyffryn Ardudwy, North Wales, 4.1.20.



* This article was originally published here

Giant magnetic ropes seen in Whale Galaxy's halo


Using the National Science Foundation's Karl G. Jansky Very Large Array radio telescope, a team of astronomers has captured for the first time an image of large-scale, coherent, magnetic fields in the halo of a faraway spiral galaxy, confirming theoretical modeling of how galaxies generate magnetic fields and potentially increasing knowledge of how galaxies form and evolve.

Giant magnetic ropes seen in Whale Galaxy's halo
Composite image of the galaxy NGC 4631, the "Whale Galaxy," revealing large magnetic structures
[Credit: Jayanne English of the University of Manitoba, with NRAO VLA radio data
from Silvia Carolina Mora-Partiarroyo and Marita Krause
of the Max-Planck Institute for Radio Astronomy]
The international consortium, led by scientists from the Max Planck Institute for Radio Astronomy in Bonn, Germany, and including astronomers from the NSF-funded National Radio Astronomy Observatory in Charlottesville, Virginia, reported the results in the journal Astronomy & Astrophysics.


"To understand how stars like the sun and planets like Earth came to be, we must understand how galaxies, such as our Milky Way, form and evolve," said Matthew Benacquista, a project director in NSF's division of Astronomical Sciences. "This project is an attempt to measure galactic magnetic fields and learn how they influence the way that interstellar gases are ejected from galaxy disks and contribute to galaxy formation and evolution."


The spiral galaxy, identified as NGC 4631 or the "Whale Galaxy," is seen edge-on in the image, with its disk of stars shown in pink. The field lines are shown in green and blue, extending beyond the disk into the galaxy's extended halo. Green indicates filaments with their magnetic field pointing roughly toward the viewer, and blue indicates filaments with their magnetic fields pointing away. This phenomenon, with the field alternating in direction, has never been seen before in the halo of a galaxy.

Source: National Science Foundation [December 31, 2019]



* This article was originally published here

Porth Dafarch Prehistoric Settlement and Hut Circles, Holy Island, Anglesey, North Wales 5.1.20.

Porth Dafarch Prehistoric Settlement and Hut Circles, Holy Island, Anglesey, North Wales 5.1.20.



* This article was originally published here

Hubble views a galaxy with an active centre


This swirling mass of celestial gas, dust and stars is a moderately luminous spiral galaxy named ESO 021-G004, located just under 130 million light-years away.

Hubble views a galaxy with an active centre
Spiral Galaxy ESO 021-G004 [Credit: ESA/Hubble & NASA, D. Rosario et al.]
This galaxy has something known as an active galactic nucleus. While this phrase sounds complex, this simply means that astronomers measure a lot of radiation at all wavelengths coming from the center of the galaxy.

This radiation is generated by material falling inward into the very central region of ESO 021-G004, and meeting the behemoth lurking there—a supermassive black hole.


As material falls toward this black hole it is dragged into orbit as part of an accretion disk; it becomes superheated as it swirls around and around, emitting characteristic high-energy radiation until it is eventually devoured.

The data comprising this image were gathered by the Wide Field Camera 3 aboard the NASA/ESA Hubble Space Telescope.

Source: NASA's Goddard Space Flight Center [December 31, 2019]



* This article was originally published here

Bryn Celli Ddu Prehistoric Burial Chamber in Early Morning Winter Sun, Anglesey, North Wales,...

Bryn Celli Ddu Prehistoric Burial Chamber in Early Morning Winter Sun, Anglesey, North Wales, 3.1.20.



* This article was originally published here

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