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CCI meets in Potsdam

CCI meeting, May 2015.

CCI meets in Potsdam

22. May 2015. The International Scientific Committee (known internationally by its initials in Spanish) "CCI" held its 73rd meeting at the Leibniz Institute for Astrophysics Potsdam (AIP), Potsdam,...

The CCI is the most important coordinating body of many international collaborations operating the more than 30 telescopes installed at the "Observatorios de Canarias" of the Instituto de Astrofisica de Canarias on the Islands of Tenerife and La Palma.

The kind offer of AIP to host this meeting had been warmly welcomed by the Committee at its 72nd meeting, held in Spain last November. The CCI Secretary Campbell Warden noted that, "This has provided an opportunity for the Members and Associates to learn first hand about the many astronomical projects being developed by AIP, especially future plans to place new telescopes at the Teide Observatory, Tenerife".

Both AIP directors welcomed the participants and Prof. Strassmeier presented an overview of the current AIP projects and concluded that “besides ESO, the Canary Islands are the most important site for AIP’s solar and stellar telescopes, most notably GREGOR and STELLA”.

The first half of the meeting was dedicated to a series of presentations and discussions about major new projects, such as the CTA, and technology developments with the instruments at the existing solar telescopes. During the "business" part of the meeting, the International Time Program was awarded for semesters 15B and 16A, the operation and management of both observatories was reviewed and the Site Managers congratulated on their good stewardship. Finally, the IAC Director, Prof. Rafael Rebolo, informed the members about the EWASS conference  (European Week of Astronomy and Space Science, jointly organized by the EAS and IAC), June 22-26 and invited them to attend the following day's Celebration of the 30th Anniversary of the Observatorios de Canarias and inauguration of several new telescopes at the Teide Observatory.

The meeting was preceded on Monday evening with a unique dinner at the Großer Refraktor at the Telegrafenberg, Wissenschaftspark Albert-Einstein. After the Meeting on Tuesday the participants visited the AIP library, workshops and laboratories.

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Digitizing astronomical photographic plates

5 May 2015. The Leibniz Institute for Astrophysics Potsdam (AIP), in collaboration with Hamburger Sternwarte and Dr. Remeis-Sternwarte Bamberg, is digitizing an archive of astronomical photographic...

The webarchive APPLAUSE (Archives of Photographic PLates for Astronomical USE), hosted by AIP, publishes with a CC0 license, thus this archive is freely accessible.

On 24.05.2015 the first Data Release was published, comprising 25,612 scans of 19,335 photographic plates from the Bamberg, Hamburg and Potsdam archives. The plates contain observations from 1909 to 1976 with and covers 98.9 percent of the sky. Using „PyPlate“, a software developed within the project, 1.66 billion objects were extracted from these plates, giving positions and uncalibrated magnitudes. More than half of these objects were identified using modern astronomical catalogs. The archive additionally provides 26,526 digitized plate covers and logbook entries from 77 logbooks. DR1 contains about half of the currently digitized photoplates.

Data Release 1 consists of 17 terabytes of data, efficiently organized by database catalogs. Not only stars, but also objects of our solar system are among the objects. Additionally, the logbook entries of e.g., temperature or humidity allow to generate time series for the different observatories.

 

Science contact: Dr. Harry Enke, henke@aip.de, +49 331-7499-433

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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Matthias Steinmetz honoured with Foersterpreis 2015

Prof. Dr. Matthias Steinmetz

Matthias Steinmetz honoured with Foersterpreis 2015

29 April 2015. The "Wilhelm-Foerster-Preis 2015" is awarded to Matthias Steinmetz, scientific chairman of the Leibniz Institute for Astrophysics Potsdam (AIP) and director of the research area Extr...

Topics under investigation in his department extend from the structure, dynamics and chemical evolution of the Milky Way over the structure and evolution of galaxies and their massive black holes to the formation of galaxies, clusters of galaxies and the large scale cosmic web. Furthermore, researchers in this area are participating in the development of the next generation of instruments for 8m-class telescopes like the Large Binocular Telescope or ESO's Very Large Telescope and in the establishment of a E-science infrastructure for astronomy.


Matthias Steinmetz's personal research interests focus on the formation and evolution of galaxies, in particular the Milky Way. He has been actively engaged in performing high resolution simulation of the galaxy formation process. He is the principle investigator of the RAdial Velocity Experiment RAVE, a large international collaboration that over the past decade has amassed more than half a Million spectra for stars in the Galaxy.
Matthias Steinmetz is currently president of the German Astronomical Society.

The award ceremony will be held in the Nicolaisaal in Potsdam, at 5 pm on 3 May 2015. The public is welcome to attend. The laudations and the award recipients talk will be in German.

Announcement Urania Potsdam

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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Largest catalogue of X-ray detected astrophysical objects published

28 April 2015. A systematic analysis of all observations performed so far by the X-ray satellite XMM-Newton resulted in the worlds most comprehensive catalogue of X-ray detected celestial objects. ...

Sources that are bright in X-ray light are amongst the most energetic in the Universe. The European Space Agency's highly sensitive XMM-Newton X-ray observatory detects 50-100 X-ray sources in a region of the sky that is the same size as the full moon, and there are around 600 such observations per year. Many of the detections turn out to be objects that have never previously been observed.

Axel Schwope, team lead at the Leibniz Institute for Astrophysics Potsdam (AIP), which is responsible for the source detection software, says: “50 years ago just a handful of X-ray sources were known and scientist entered unchartered territory. Now, with half a million sources, one can make on the one hand a census of the more common objects and on the other hand search for very rare exotic objects.” Iris Traulsen, project scientist at AIP, adds: “Our source detection software is an important tool for those searches. It was continuously improved over the last years, an effort that led to an ever enhanced precision of the detection process.”

The X-ray sources in the XMM-Newton serendipitous source catalogue are objects such as supermassive black holes guzzling the gas and dust that surrounds them in the centres of galaxies, exploding stars and dead stars that have collapsed to tight balls of exotic material that are as dense as the atomic nucleus and rotate up to 1000 times per second. However, new and exotic objects are expected to be found, based on results from previous smaller versions of the catalogue.

Indeed, during the methodical data validation phase, two new extreme binary systems, known as polars were discovered. These systems contain a star like our Sun and the remains of a star that has collapsed into a 'white dwarf'. The two objects orbit each other (much like the Earth and the Moon) and the white dwarf is so dense (1 million times the density of water!) that it strips the outer layers from its companion star through its huge gravitational field. This gas and dust gets caught in the white dwarf's extra-strong magnetic field (ten million times stronger than the Earth's magnetic field) causing it to heat up and radiate strongly in the X-ray domain. In the extreme case, it is possible that so much matter can fall onto the white dwarf that it would no longer be able to support its own weight, therefore such kind of objects are candidates progenitors for type Ia supernova explosions. These explosions allow astronomers to measure the distance to remote objects in the Universe.

Natalie Webb from the Institut de Recherche en Astrophysique et Planétologie (IRAP, Toulouse, France), who is responsible for the XMM-Newton Survey Science Centre that produces the catalogue, enthuses: “This is just the tip of the iceberg – there are many more new and exciting objects waiting to be discovered in the catalogue!”

In order for scientists to make the most of the catalogue, a scientific paper submitted to the European Journal Astronomy and Astrophysics, written by the XMM-Newton Survey Science Centre consortium, describing the catalogue and its products accompanies the release of this prestigious catalogue, along with a new version of the XMM-Newton Survey Science Centre webpages.

Caption: On the map of the sky each dot represents one observation with XMM-Newton. Each of it corresponds to the size of the full moon. The galactic centre and the galactic plane (centre of the map) and our neighbour galaxies, the Magellanic clouds (lower right) were targeted often. Some of the ‘exotic animals in the high-energy zoo’ are also depicted (artists impression).

 

Resources:

IRAP press release

The XMM-Newton Survey Science Centre webpages and catalogue access: http://xmmssc.irap.omp.eu/

The paper describing the catalogue: 'The XMM-Newton serendipitous survey VI. The third XMM-Newton serendipitous source catalogue', S. R. Rosen, N. A. Webb, M. G. Watson et al., A&A.

 

Science contact AIP: Dr. Axel Schwope,+49 331 7499-232, aschwope@aip.de

Media contact AIP: Dr. Janine Fohlmeister, +49 331 7499-383, presse@aip.de

Media contact XMM-Newton Survey Science Centre: Dr. Natalie Webb, Natalie.Webb@irap.omp.eu

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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To flare or not to flare: The riddle of galactic thin–thick disk solved

24 April 2015. A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam ...

We were able to show for the first time that galactic thick disks are not composed only of old stars but must also contain young stars at larger distances from the galactic centre”, explains Minchev. “The flaring seen in groups of stars with the same age is caused mostly by the bombardment of small satellite galaxies. These cosmological car crashes pummel the young disk and cause it to swell and flare.“

To arrive at this new result, the team ran numerical simulations on massive super computers and examined the structure of their simulated galaxies. The scientists grouped stars by common age and looked at where they were located. What they found was that stars of a given age group constituted a disk with flared edges, much like the mouth of a trumpet. This flaring is unavoidable, being caused when the main galaxy collides with smaller galaxies – a generic feature of how scientists believe galaxies form. Since the oldest stars formed in the inner region of the galaxy, for them this flaring occurs closer to the centre, while for the younger stars it occurs at the periphery of the galaxy. When put together, the combination of flaring from all the stars produces the elusive thick disk, as observed.

One of the most fascinating aspects of galaxies is that their stars can be separated into two components: a fluffy thick disk that enshrouds a thin disk. Until now the understanding has been that stars in the thick disk were the oldest. In observations of the Milky Way the oldest stars are found to be closer to the centre, while younger stars are more extended. Scientists agree that this separation is likely due to an “inside-out” formation scenario, wherein the Milky Way forms stars first in its center and later in its outer region, much like how cities grow radially from a medieval center to modern suburbs. Observing the structure of the Milky Way is tricky, since we are located within its disk, roughly half way from the centre. Instead, astronomers have to rely on the stars that surround us and build a model from this limited perspective. Nevertheless, if the Milky Way were similar to other galaxies and its thick disk were composed only of old, centrally concentrated stars, then one would naively expect its thick disk to be short. But in other galaxies the thick disks are observed to be as extended as the galaxies themselves. Minchev’s results resolve this contradiction by requiring that thick disk stars become younger in the disk outskirts.

“With our new understanding of the formation of, and interplay between, galactic thin and thick disks, we have moved much closer to solving one of the most fundamental problems of Galactic astrophysics.”, concludes Ivan Minchev. “Our predictions will soon be tested with data from the Gaia space mission and using high precision instruments, such as MUSE on the Very Large Telescope.”

On the formation of galactic thick disks, Minchev et al. 2015, ApJL, 804, L9.

 

Science contact: Dr. Ivan Minchev,+49 331 7499-454, iminchev@aip.de

Media contact: Dr. Janine Fohlmeister, +49 331 7499-383, presse@aip.de

 

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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