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Matthias Winker new administrative chairman of AIP Board

Matthias Winker

Matthias Winker new administrative chairman of AIP Board

4 August 2015. Matthias Winker is appointed as new administrative chairman at the Leibniz Institute for Astrophysics Potsdam (AIP). Together with the scientific chairman and speaker of the Board, P...

Matthias Winker studied engineering at the Technische Universität Dresden in Germany and science management at the Danube University Krems in Austria. After several line functions at the TU Dresden in science and non-scientific positions he was previously in the managing board of the state secretary of the Saxon Ministry for science and arts and responsible for strategic development, European and international affairs.

Matthias Winker is an expert in science management, in particular science financing, organizational development and human resources as well as European research funding.

As the supervisory body of the institute, the Executive Board of the AIP is accountable to the Board of Trustees for the finances and the fulfilment of the objectives of the foundation.The administrative member of the Executive Board is responsible for the budget and the business transactions of the current administration. The members of the Board work closely and on a basis of mutual trust to achieve the goals of the institute.

Media contact: Dr. Janine Fohlmeister, presse@aip.de, +49 331 7499-802

 

The key topics of 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. Since 1992 the AIP is a member of the Leibniz Association.

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Starry surprise in the bulge: encounter of a halo passerby

Orbit of the high speed star / Visualisation. Credit: AIP / J. Fohlmeister, A. Kunder.

Starry surprise in the bulge: encounter of a halo passerby

21 July 2015. A team led by Andrea Kunder from the Leibniz Institute for Astrophysics Potsdam (AIP) measured the velocity of a sample of 100 old RR Lyrae stars* thought to reside in the Galactic bu...

It took them by surprise, when they found that one of these stars has a space velocity of almost 500 km/s - more than five times the speed expected for normal bulge stars. Since RR Lyrae stars pulsate and all produce roughly the same luminosity, the scientists could use basic physics to measure its exact distance to us and reconstruct the orbit of the star over the last one billion years. They could then get a handle of where the star came from. The results are striking: the star is not a bulge star but an interloper from the halo - as the galactic outskirts are referred to - of the Galaxy and is now moving through the bulge.

“This star with the catalogue name MACHO 176.18833.411 has the largest velocity of any RR Lyrae star in the Galactic bulge known so far, and is travelling at 482 km/s relative to the Galactic rest frame, just below the escape speed of the Galaxy,“ says Andrea Kunder. Stars of such high velocity are rare among bulge stars, and the more precise distance of the RR Lyrae star makes it possible to explore its origin in greater detail. They found that this star, although located now within the bulge and less than 1 kpc from the Galactic center, is actually not confined to the bulge but moves on an elliptical orbit as do stars in the Milky Way halo.

The Milky Ways central region called the bulge is known to roughly resemble a peanut but with a length of 10,000 light years, and is made of old stars, gas and dust. In recent years, astronomers have suspected that the bulge harbours the oldest stars in the Galaxy, and a search to uncover the first stars made in the Milky Way, by probing stars in the bulge, is in full swing.  Andrea Kunder and her team now demonstrate that some old stars in the Milky Way Galaxy’s bulge may not actually be true bulge members, complicating the search for old, bulge stars.

This result is part of a larger study entitled BRAVA-RR, for Bulge RR Lyrae Radial Velocity Assay and  a step forward in attempting to disentangle the oldest stars from the bulge with those from other regions of the Milky Way. It shows that contamination from halo stars is very real when looking at stars in the Milky Way bulge. Interlopers from the Galactic halo pass through the bulge and can be mistaken for bulge stars. The one now found is almost certainly not the only one.

*RR Lyrae stars are variable stars that can be used as standard candles to measure galactic distances. The first star that showed the characteristic periodic pattern was found in the constellation Lyra and gave the population its name. Until now about 38,000 RRLs toward the bulge have been identified from photometric surveys and trace an ancient stellar population.

 

Publication: Andrea Kunder et al.: A high-velocity bulge RR Lyrae variable on a halo-like orbit,
in: Astrophysical Journal Letters (ApJ, 808, L12).

 

 

Caption: The visualization shows one possible orbit of the high speed star over the last billion years (blue). The yellow figure represents the position of the Sun and the red asterisk the current position of the star. Whenever the star moves far out it is pulled back by the gravitational force of the galaxy and passages the central bulge again, where Kunder and her team caught it on high speed. The star moves on an elliptical orbit so large that at its farthest point it is nearly 100,000 light years from the center of the Milky Way. 
(Credit: AIP / J. Fohlmeister, A. Kunder)

 

Science contact: Dr. Andrea Kunder, akunder@aip.de, +49 331 7499-646

Media contact: Kerstin Mork, presse@aip.de, +49 331 7499-803

 

The key topics of 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. Since 1992 the AIP is a member of the Leibniz Association.

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A Dark Matter bridge in our cosmic neighborhood

Current stream of galaxies (detail).

A Dark Matter bridge in our cosmic neighborhood

14. Juli 2015. By using the best available data to monitor galactic traffic in our neighborhood, Noam Libeskind from the Leibniz Institute for Astrophysics Potsdam (AIP) and his collaborators have ...

These dwarf galaxies are often found swarming around larger hosts like our own Milky Way. Since they are dim they are hard to detect, and are thus found almost exclusively in our cosmic neighborhood. A particularly fascinating aspect of their existence is that near the Milky Way and at least two of our closest neighbors - the Andromeda and Centaurus A galaxies - these satellites don’t just fly around randomly, but are instead compressed on to vast, flat, possibly spinning, planes. Such structures are not a naive outcome of the Cold Dark Matter model that most cosmologists believe is responsible for how the universe forms galaxies. These structures are thus a challenge to the current doctrine.

One possibility is that these small galaxies echo the geometry of structure on much greater scales. "This is the first time we have had observational verification that large filamentary super highways are channeling dwarf galaxies across the cosmos along magnificent bridges of Dark Matter" Libeskind says. This cosmic “super highway” gives the speeding satellites an off ramp along which they can be beamed towards the Milky Way, Andromeda and Centaurus A. “The fact that this galactic bridge can affect the dwarf galaxies around us is impressive, given the difference in scale between the two: the planes of dwarfs are around one percent of the size of the galactic bridge to Virgo”.

 

Publication: Noam Libeskind et al. „Planes of satellite galaxies and the cosmic web“ in Monthly Notices of the Royal Astronomical Society and in arXiv.

 

Caption: The figure shows the current stream of galaxies - the flow along in the cosmic super-highway and on the bridge to Virgo, in the region around the Milky Way, Andromeda and Centaurus A (click to enlarge).

Science contact:
Dr. Noam Libeskind, nlibeskind@aip.de, +49 331 7499-641

Media contact:
Kerstin Mork, presse@aip.de, +49 331 7499-803

 

The key topics of 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. Since 1992 the AIP is a member of the Leibniz Association.

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Getty Grant for Einstein Tower

The Einstein Tower on the Telegrafenberg in Potsdam, Germany ( R. Arlt / Leibniz Institute for Astrophysics Potsdam (AIP))

Getty Grant for Einstein Tower

25 June 2015. The Getty Foundation announces a second series of grants for exemplary 20th century buildings as part of its Keeping It Modern initiative. The Einstein Tower receives one of the fourt...

„The Einstein Tower takes a particular role in our efforts to actively maintain our rich science-historical heritage,“ says Prof. Dr. Matthias Steinmetz Chairman of the AIP Board.  „The Getty Grant allows us to develop a sustainable long-term conservation plan and maintain the Einstein Tower as a science-technical landmark, monument and active research facility.“

The solar observatory at the Leibniz Institute for Astrophysics in Potsdam, better known as the Einstein Tower, is architect Erich Mendelsohn’s signature building and a paragon of German expressionism.

As the first solar tower telescope in Europe, the building was intended to support Einstein’s study of relativity, and it continues to function as a research center today. Breaking away from the paradigm of rectangular post and beam architecture, Mendelsohn crafted an organic and sinuous form to reflect the new models of the universe then in development. The use of reinforced concrete to create a smooth, unified skin over the building’s brick substrate was innovative at the time and enabled its expressive plastic form. However, this experimental combination of materials has left the structure vulnerable to water infiltration that threatens the safety of its scientific equipment.

The Getty grant will support an in-depth study of the building’s moisture problems, including the thermal stress of fluctuating seasonal conditions that is a shared concern among concrete buildings in temperate climates.

“Modern architecture is a defining artistic form of the 20th century at considerable risk, often due to the cutting-edge building materials that characterized the movement,” says Deborah Marrow, director of the Getty Foundation. “This new round of Keeping It Modern grants includes some of the finest examples of modern architecture in the world. The grant projects address challenges for the field of architectural conservation and will have impact far beyond the individual buildings to be conserved.”

 

Read more:

Keeping It Modern Press Release

Getty Foundation

 

Contact:

Head of Solar Observatory Einstein Tower: apl. Prof. Dr. Carsten Denker cdenker@aip.de, +49 331 7499-297

Press and Public Outreach: Dr. Janine Fohlmeister, presse@aip.de, +49 331 7499-383

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Emil Popow (1950-2015)

Emil Popow

Emil Popow (1950-2015)

On June 19 2015 our dear colleague Emil Popow passed away. Over a period of more than 40 years, Emil Popow took part in the life of the AIP and made fundamental contributions to the development of ...

Emil Popow was born on December 28, 1950 in Varna, Bulgaria. In September 1967, he began an apprenticeship at the Zentralinstitut für Astrophysik Potsdam (ZIAP) with Jochen Engelbrecht.

After qualifying as a technical assistant Emil Popow worked for the engineering department at ZIAP.  He received his Diploma degree in Physics from the Humboldt University Berlin in 1977.

From 1977 on, Emil Popow made fundamental contributions to the development of photoelectric sensors and charge-coupled devices. In 1992 he started working in the research technology and infrastructure department of AIP and became head of the technical section in 2003. Until 2014 Emil Popow contributed to the development of telescopes and instruments like PMAS, STELLA, the LBT and GREGOR.


We will deeply miss him as our friend and colleague, and we will always remember his great dedication to the institute.

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