Une vue d'artiste des galaxies. © vchalup, Adobe Stock

Stars in distant galaxies are more massive than those in the Milky Way

The brilliant physicist in the early 1930s Paul Dirakone of the founders of quantum mechanicswhich enabled him to theoretically discover the existence of antimatter, had advised the very young Subrahmanyan Chandrasekhar to continue his education through a stay in Denmark at the Niels Bohr Institute. It was founded in 1921 for the physicist The Dane Niels Bohr
With his atomic model in 1913 he was one of the founders of quantum theory and because of the influence he would later have on the founders of mechanics…” data-image=”https://cdn.futura-sciences.com/ buildsv6 /images/midioriginal/4/3/e/43e521108b_50141916_bohr-700.jpg” data-url=”https://news.google.com/sciences/personalities/physics-niels-bohr -240/” data-more= ” Read more”>Nils BohrNobel Prize in Physics in 1922 and another brilliant father of the quantum revolution plank and Einstein.

Chandrasekhar was only 20 years old when he used the famous stat discovered by Enrico Fermi
His most famous contributions are in nuclear physics and the creation of…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/f/9/f/f9fe850bca_50141937_fermi-1000 .jpg ” data-url=”https://news.google.com/sciences/personalities/physics-enrico-fermi-241/” data-more=”Read more”>Enrico Fermi and Paul Dirac to model interior behavior Starsalso mobilization in passing the theory of relativity. Then he discovered there was one Dimensions limit for white dwarves. In 1935, the great astrophysicist Arthur Eddington firmly opposed the existence of this limit, not really realizing that it would potentially discredit the young doctor astrophysics by its prestige.

At first glance, a star is a ball of gas, mostly hydrogen. Nuclear fusion reactions of hydrogen at the star’s center release energy. In other words, heat radiating in the form of red, yellow, or blue light… So whether they’re brown dwarfs or red dwarfs, a star’s mass determines its luminosity, that is, the luminosity it radiates in all directions. © CEA Research

The story of this is well known and despite the sense of injustice experienced by Chandrasekhar, the two men will respect each other afterwards and chandraas it is also called, will even write a biography of his elder. It must also be said that Chandrasekhar had sought the opinion of Niels Bohr, who, given his size as a Nobel laureate, had replied that he should not worry and that he absolutely did not understand the reasoning Eddington used to reject Chandra’s calculations which he and his Belgian collaborator, the physicist Léon Rosenfeld, believed to be absolutely correct. Chandrasekhar finally published in the late 1930s a treatise that is still authoritative for the structure of stars.

All this to say that the Niels Bohr Institute has a tradition of excellent astrophysics and that this institute’s recent communication on an article published in is to be taken seriously The Astrophysical Journal and which can also be viewed freely at arXiv.

The stars of 140,000 galaxies across billions of light years

This is a discovery made by analyzing stellar populations in about 140,000 galaxies whose observations are archived in the database of Cosmic Evolution Survey (cosmos), an astronomical investigation to study the formation and evolution of galaxies as a function of both cosmic time (redshift) and the local environment of galaxies. The survey covers an equatorial field of 2 square degrees with spectroscopy and imaging ranging from that invented by Wilhelm Roentgen in 1895
Invention of X-rays
The discovery of…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/d/0/d/d0d21d96c0_50034252_372px-backscatter-x-ray-image-woman-02. jpg” data-url=”https://news.google.com/science/definitions/physics-x-ray-1002/” data-more=”Read more”>X-rays to that of the waves radio thanks to most great telescopes spacecraft and a number of large ground-based telescopes. Over 2 million galaxies have been discovered, covering 75% of the age of The universe’s history begins about 13.7 billion years ago in an extremely dense and hot soup. The laws of physics as we…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/1/5/5/1557798396_80921_universe.jpg” data-url=”https : //news.google.com/sciences/definitions/astronomy-universe-15239/” data-more=”Read more”>universe.

The explosion of very massive stars in gravitational supernovae enriches the interstellar medium with the chemical elements synthesized by nuclear fusion, while the collapse of the stellar core creates a neutron star or black hole. The transition between the collapse of the core and the ejection of the stellar envelope is a challenge for the theoretical understanding of supernovae. A hydraulic experiment designed and carried out at the CEA made it possible to reproduce by analogy one of the phenomena of hydrodynamic instability that facilitates the explosion. This experimental approach is complementary to numerical simulations. Check out this animation experience. This animated film was produced and co-funded by CEA and ERC and directed by Studio Animea. Scientific and technical design: T. Foglizzo, J. Guilet, G. Durand (CEA). © CEA Research

The galaxies studied by the astrophysicist from the University of Copenhagen and the Niels Bohr Institute are far from Earth, only a cross section can be observed…” data-image=”https://cdn.futura-sciences.com/buildsv6/images /midioriginal /7/7/7/777b761907_120668_voie-lactee-galaxie.jpg” data-url=”https://news.google.com/sciences/definitions/universe-voie-lactee-3729/” data-more=” Read more” >Milky Waysometimes several billionlight years. For the first time it was possible for such distant galaxies to compile statistics on the populations of stars in a certain mass range and, above all, to compare them with those that have been determined in the Milky Way for decades. For example, we know that our galaxy is largely dominated by Since their luminosity is very low (at most about 1% that of the Sun), the smallest of them must…” data-image=”https:/ / cdn.futura- sciences.com/buildsv6/images/midioriginal/d/b/d/dbdabe04e7_50034118_gliese-581-dwarf-red-eso.jpg” data-url=”https://news.google.com/sciences/definitions /astronomy-red -dwarf-31/” data-more=”Read more”>Red Dwarfs.

Technically the published article Goal on what in astronomy is the initial mass function (initial mass function or IMF, in English), this is the relationship describing the distribution of stellar masses for a population of newly formed stars, introduced into astrophysics by Edwin Saltpeter in 1955. To measure it, researchers looked at the amount of white light
The wavelengths of visible light range from about 380 nm (violet) to 780 nm (red). The visible spectrum is…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/b/6/9/b697a0c09f_85912_lumiere.jpg” data-url=”https:// news.google.com/science/definitions/physics-light-326/” data-more=”Read more”>bright emitted by galaxies at different wavelengths. Large, massive stars are bluish, while small, low-mass stars sometimes have the color…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/7/ 9/5/7951943cc1_85596_color .jpg” data-url=”https://news.google.com/sciences/definitions/physics-color-4126/” data-more=”Read more”>colour more yellow or red. This means that by comparing the distribution of blue and red in a galaxy, one can determine the distribution of large and small stars.

An effect of the chemical evolution of galaxies?

It now appears that the IMF of distant galaxies is not the same as that of the Milky Way and that they contain more massive stars, with the proportion increasing with increasing distance from our galaxy. This is not necessarily surprising, since the theory of stellar structure and evolution tells us that very massive stars that explode in Excerpt from… data-image=”https://cdn.futura-sciences.com/buildsv6/images /midioriginal/a/9/4/a940132305_50034136_supernova1987a.jpg” data-url=”https://news.google.com/sciences/definitions/universe-supernova-60/” data-more=”Read more”>supernovae After a few million years, SN II produces cores that are heavier than the General
Symbol: H Atomic number:…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/3/8/8/38807f95a1_50010101_equinoxprom-eit-big.jpg” data-url = “https://news.google.com/sciences/definitions/chemistry-hydrogen-14495/” data-more=”Read more”>hydrogen and helium to the left of the Big Bang, nuclei that distribute these explosions in the interstellar medium. Now it forms in the clouds
The amount…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/b/7/e/b7e2382b95_59611_mer-nuages-seblino-camptocamporg-cc-30.jpg” data -url=”https://news.google.com/planete/definitions/climatologie-nuage-14525/” data-more=”Read more”>Clouds Molecules enriched in these heavy nuclei that will form new stars. So over billions of years, galaxies will evolve chemically, and we know that the composition of heavy elements in turn affects the mass of the stars that can form.

Therefore, as foresight is early in astrophysics, one could predict that the IMF of galaxies billions of years ago would likely not be the same as that measured in our galaxy today. But we didn’t have the proof yet, due to a lack of sufficient observation quality.

The mass of the stars says a lot astronomers. If you change the mass, you also change the number of supernovae and black holes who In a figurative sense: the sudden emergence of an idea, a social, economic, political fact.
The term emergence is used in many areas.
Outside…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/4/e/f/4ef87a3a65_50036395_papillon-chrysalis-bernard-schmeltz.jpg” data-url=” https ://news.google.com/planete/definitions/zoologie-emergence-8743/” data-more=”Read more”>emerging massive stars. Therefore, our result means that we have to revise many assumptions, because distant galaxies look very different from ours.
“, explains in the press release of the Niels Bohr Institute Albert Sneppen, PhD student at the Niels Bohr Institute and first author of the published study.

We could only see the tip of the iceberg, and we’ve known for a long time that expecting other galaxies to look like ours wasn’t a particularly good assumption. However, nobody has been able to prove that the other galaxies form different star populations. This study enabled us to do exactly what could open the door to a deeper understanding of how galaxies form and evolve. “, adds Charles Steinhardt, co-author of the study and stationed at Center of the Cosmic Dawn (Dusk).

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