Less metal, more X-rays: New research unlocks key to high luminosity of black holes | Aliens are Real

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Less metals, more X-rays!
Α Hubble Space Telescope image of the galaxy NGC 922, showing the regions with intense star formation (red colour). The purple contours show the X-ray emission, based on observations with the Chandra X-ray Observatory. The location of the bright ULXs is indicated by the circles, that occupy regions of intense star-forming activity.

A recent article published in the Monthly Notices of the Royal Astronomical Society, led by Dr. Kostas Kouroumpatzakis, of the Institute of Astrophysics at the Foundation for Research and Technology, Hellas (IA-FORTH), and the University of Crete, provides new insights into the connection between the X-ray luminosity of accreting black holes and neutron stars and the composition of the stellar populations they are associated with. This research was conducted at the Institute of Astrophysics of FORTH and the University of Crete.


This work showed for the first time that different regions of a galaxy have very different amounts of metals while hosting young stellar populations of very similar ages. The key result, however, is that metal-poor regions have higher X-ray luminosity.

This study focuses on the nearby galaxy NGC922 (Figure 1), a so-called “ring galaxy,” which features an impressive ring of stars and gas formed after the head-on collision between a dwarf and a larger spiral galaxy. The stars produced by the encounter have effectively the same age, allowing us to explore the formation rate of stellar remnants such as back holes and neutron stars.

By using spectroscopic data from the ESO telescopes this work shows for the first time that there are significant variations in the metallicity (i.e. the amount of elements heavier than hydrogen and helium) between different regions of this galaxy. Furthermore, these data combined with observations from the Hubble Space Telescope showed that the same regions, despite their different metallicity, host young stellar populations of very similar ages. The stars are just born: they are younger than ~10 million years.

“The key result from this work, however, comes from the X-ray emission in these regions as measured with the Chandra X-ray Observatory, which probes the black-hole and neutron-star populations left after the massive stars end their lives, often found in binary stellar systems” says Dr. K. Kouroumpatzakis. “The regions with lower metallicity have higher X-ray luminosity.” In fact, some of these regions host a number of Ultraluminous X-ray sources, puzzling sources producing luminosities exceeding by far the typical luminosity of accreting black holes and neutron stars (commonly known as X-ray binaries) seen in our Galaxy.

Although a similar trend had been observed when comparing different galaxies, this is the first time that it is measured within the same galaxy. It is therefore possible to unambiguously disentangle the role of metallicity from the effect of the age of stellar populations.

These results are of key importance for understanding the effect of metallicity in the formation and evolution of X-ray binary systems. “This is a very active area of study because it provides crucial information for the formation of binary systems of massive stellar remnants such as those producing gravitational wave events, and because X-ray binary systems may have played an important role in the early Universe (when it was only ~3% of its current age) affecting the subsequent formation of galaxies,” concluded Dr. Kouroumpatzakis.

This study combined data for the nearby galaxy NGC922 from NASA’s Chandra X-ray observatory (X-ray data), the Hubble Space Telescope (optical imaging), the Wide-Field Infrared Survey Explorer (WISE; infrared), and the New-Technology Telescope (NTT) of the European Southern Observatory (ESO; optical spectra). It was supported by the European Research Council and the Marie Skłodowska-Curie RISE Action.


Astronomers identify nearly 3,000 candidate stars of a nearby star-forming galaxy


More information:
K Kouroumpatzakis et al, Metallicity and X-ray luminosity variations in NGC 922, Monthly Notices of the Royal Astronomical Society (2020). DOI: 10.1093/mnras/staa3290

Citation:
Less metal, more X-rays: New research unlocks key to high luminosity of black holes (2021, June 23)
retrieved 2 July 2021
from https://phys.org/news/2021-06-metal-x-rays-key-high-luminosity.html

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What is Unidentified flying object (UFO)
A unidentified flying article (UFO) is any flying marvel that can’t promptly be distinguished or clarified. Most UFOs are recognized or explored as regular items or wonders. The term is generally utilized for guaranteed perceptions of extraterrestrial shuttle airplane, and was authored as an an-acronym by Project Blue Book project head Edward J. Ruppelt. Numerous UFOs are portrayed as being flying saucers, as is displayed in the picture to one side.

Studies and examinations have been directed by different governments around the world, alongside private people and associations. In the United States, considers started in the last part of the 1940s and have included Project Grudge, Project Sign and Project Blue Book. The last was finished in 1969-70 after the Condon Committee formally reasoned that the subject neglected to justify further examination. In any case, an unpublicized study named the Advanced Aerospace Threat Identification Program was subsidized by the U.S. government from 2007-2012, and a replacement program named the Unidentified Aerial Phenomena Task Force is at present operational.

Unidentified lights and flying items have been accounted for in the skies for quite a bit of mankind’s set of experiences. Doubters including different researchers, and associations like the Committee for Skeptical Inquiry, express that the whole subject can be clarified as ordinary items or wonders, while Ufologists recommend different problematic hypotheses. Public surveying demonstrates an impressive bit of the U.S. populace feels that their administration is retaining data regarding the matter.

The subject of UFOs has been, and is right now, famous in overall culture in anecdotal motion pictures, TV and other media. UFO reports are additionally the subject of proceeding with discussion and news announcing.

Early history before the 20th century
Unexplained aeronautical perceptions have been accounted for since forever. Some were without a doubt galactic in nature. These may incorporate comets, brilliant meteors, at least one of the five planets that can be promptly seen with the unaided eye, planetary conjunctions, or environmental optical wonders, for example, parhelia and lenticular mists. A model is Halley’s Comet, which was recorded first by Chinese cosmologists in 240 BC and conceivably as ahead of schedule as 467 BC. Such sightings from the beginning of time frequently were treated as powerful signs, heavenly messengers, or other strict omens. Some momentum day UFO specialists have seen similitudes between some strict images in middle age canvases and UFO reports however the accepted and emblematic character of such pictures is recorded by craftsmanship students of history putting more regular strict translations on such pictures.

Julius Obsequens was a Roman author who is accepted to have lived in the fourth century AD. The solitary work related with his name is the Liber de prodigiis (Book of Prodigies), totally separated from an exemplification, or edited version, composed by Livy; De prodigiis was built as a record of the miracles and signs that happened in Rome somewhere in the range of 249 and 12 BCE. A part of Obsequens’ work that has propelled a lot of interest in certain circles is that references are made to things traveling through the sky. These have been deciphered as reports of UFOs, however may similarly also portray meteors, and, since Obsequens, most likely, writes in the fourth century, that is, approximately 400 years after the occasions he depicts, they scarcely qualify as observer accounts.

On April 14, 1561, occupants of Nuremberg portrayed the presence of a huge dark three-sided object. As per witnesses, there were additionally many circles, chambers and other odd-molded articles that moved inconsistently overhead.

The 1566 heavenly wonder over Basel was a progression of mass sightings of divine marvels above Basel, Switzerland. Heavenly marvels were said to have “battled” together as various red and torpedoes in the sky. In the fifteenth and sixteenth hundreds of years, numerous pamphlets composed of “wonders” and “sky displays”.

On January 25, 1878, the Denison Daily News printed an article in which John Martin, a neighborhood rancher, had detailed seeing a huge, dim, round object looking like an inflatable flying “at magnificent speed”. Martin, as indicated by the news account, said it gave off an impression of being about the size of a saucer from his viewpoint, one of the principal employments of “saucer” in relationship with a UFO.

In April 1897, a great many individuals detailed seeing “carriers” in different pieces of the United States. Many marked affirmations. Scores of individuals even detailed conversing with the pilots. Thomas Edison was asked his assessment, and said, “You can take it from me that it’s anything but an unadulterated phony.”

20th century and after
The three soonest known pilot UFO sightings, of 1,305 comparative sightings classified by NARCAP, occurred in 1916 and 1926. On January 31, 1916, a UK pilot close to Rochford announced a column of lights, taking after lit windows on a rail line carriage, that rose and vanished. In January 1926 a pilot revealed six “flying sewer vent covers” between Wichita, Kansas, and Colorado Springs, Colorado. In late September 1926 an airmail pilot over Nevada said he had been compelled to land by a gigantic, wingless, tube shaped item.

On August 5, 1926, while going in the Humboldt Mountains of Tibet’s Kokonor district, Russian pioneer Nicholas Roerich announced that individuals from his campaign saw “something significant and sparkly mirroring the sun, similar to an enormous oval moving at incredible speed. Intersection our camp the thing altered in its course from south to southwest. Also, we perceived how it vanished in the serious blue sky. We even had the opportunity to take our field glasses and saw particularly an oval structure with glossy surface, one side of which was splendid from the sun.” Another portrayal by Roerich was of a “sparkly body flying from north to south. Field glasses are within reach. It’s anything but a tremendous body. One side gleams in the sun. It is oval fit. Then, at that point it some way or another turns toward another path and vanishes in the southwest.”

In the Pacific and European venues during World War II, “foo contenders” (metallic circles, wads of light and different shapes that followed airplane) were accounted for and every so often captured by Allied and Axis pilots. Some proposed Allied clarifications at the time included St. Elmo’s shoot, the planet Venus, fantasies from oxygen hardship, or German unmistakable advantages.

In 1946, in excess of 2,000 reports were gathered, principally by the Swedish military, of unidentified ethereal articles over the Scandinavian countries, alongside disengaged reports from France, Portugal, Italy and Greece. The items were alluded to as “Russian hail” (and later as “phantom rockets”) since it was thought the strange articles were conceivably Russian trial of caught German V1 or V2 rockets. Albeit most were believed to be such regular wonders as meteors, more than 200 were followed on radar by the Swedish military and considered to be “genuine actual items”. In a 1948 highly confidential report, Swedish specialists informed the USAF Europe that some with respect to their agents accepted these specialty to be extraterrestrial in beginning.