An international team of scientists led by Ivan Minchev of the Leibniz Institute for Astrophysics Potsdam (AIP) has found a way to recover the birth places of stars in our Galaxy. This is one of the major goals in the field of Galactic Archaeology, whose aim is to reconstruct the formation history of the Milky Way.
Stars in galactic discs have long been known to wander away from their birth sites owing to a phenomenon known as “radial migration”. This movement across the Galaxy severely hampers inferences of the Milky Way formation history.
Radial migration is influenced by a number of parameters that are still poorly known: for example, the size and speed of the Galactic bar, the number and shape of spiral arms in the Galactic disc, and the frequency of smaller galaxies colliding with the Milky Way during the past 10 billion years and their respective masses.
To circumvent these obstacles, the scientists devised a way of recovering the Galactic migration history using the ages and chemical composition of stars as “Archaeological artifacts”. They used the well-established fact that star formation in the Galactic disc progresses gradually outwards, following that stars born at a given position at a particular time have a distinct chemical-abundance pattern.
Therefore, if the age and chemical composition (its iron content, for example) of a star can be measured very precisely, it becomes possible to directly infer its birth position in the Galactic disc without additional modeling assumptions.
The team used a sample of about 600 solar-neighborhood stars observed with the high-resolution spectrograph HARPS mounted on the 3.6 m telescope of ESO’s La Silla Observatory in Chile. Thanks to the very precise age and iron abundance measurements, it was found that these stars were born all across the Galactic disc, with older ones coming more from the central parts.
Researches can now use this method for calculation of birth places even for stars not in the original sample. For example, given the age of our Sun of 4.6 billion years and its iron content, it could be estimated that the Sun was born about 2,000 light years closer to the Galactic center than it is currently located.
Minchev comments: “Once in the possession of birth radii, a wealth of invaluable information could be gained about the Milky Way past, even from this small number of stars with precise enough measurements available to us at this time.”
Co-author Friedrich Anders adds: “In the near future, applying this method to the extremely high-quality data from the Gaia mission and ground-based spectroscopic surveys will allow much more exact measurements of the migration history and, thus, the Milky Way past.”
The key areas of research at the Leibniz Institute for Astrophysics Potsdam (AIP) are cosmic magnetic fields and extragalactic astrophysics. A considerable part of the institute's efforts aim at the development of research technology in the fields of spectroscopy, robotic telescopes, and e-science.
The AIP is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory of Potsdam founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP has been a member of the Leibniz Association since 1992.
Ivan Minchev, 0331-7499-259, email@example.com
Dr. Janine Fohlmeister | idw - Informationsdienst Wissenschaft
Massive photons in an artificial magnetic field
14.11.2019 | Faculty of Physics University of Warsaw
A new approach to the hunt for dark matter
14.11.2019 | Johannes Gutenberg-Universität Mainz
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
05.11.2019 | Event News
30.10.2019 | Event News
02.10.2019 | Event News
14.11.2019 | Materials Sciences
14.11.2019 | Physics and Astronomy
14.11.2019 | Information Technology