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Astronomical Science As Is Apparent from the Many H Many the from Apparent Is As H Large Avery Has NGC 7793 Distance

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Astronomical Science As Is Apparent from the Many H Many the from Apparent Is As H Large Avery Has NGC 7793 Distance Astronomy in Austria The Messenger NACO Pupil-stabilised Coronography Images from VLTI Wandering in the Redshift Desert No. 137 – September 2009 – September 137 No. The Organisation Astronomy in Austria Sabine Schindler1 a very wide range: from solar physics at of extending international collaborations, Graz1; astroseismology, the late stages of of enhancing public outreach activities stellar evolution, planetary systems, and of increasing the publication rate (see 1 Institute of Astro- and Particle Physics, the interstellar medium, the Milky Way, Figures 2, 3 and 4). Eventually, the ESO University of Innsbruck, Austria structure of galaxies, galaxy clusters, accession document was signed in 2008 the history of astronomy and participation (see the ESO press release of 30 June in the CoRoT and Herschel missions 2008) and ratified in February 2009. Austria officially became the fourteenth at Vienna2; to planetary nebulae, novae, ESO member in June 2009. A brief galaxy structure, galaxy clusters With Austria’s new place in the inter- outline of the recent developments and and astro particle physics at Innsbruck3. national scientific community confirmed scientific highlights of astronomical by its accession to ESO, further devel- research in Austria is presented. Having opment is secured. In Innsbruck a new started from a relatively low level a few Recent developments full professorship was recently filled in years ago, astronomical research is astroparticle physics, in Vienna two new now expanding very rapidly thanks to For many decades it was the goal of full professors for astrophysics are in the accession to ESO. Austrian astronomers to join ESO. For- the process of being appointed and in tunately, accession to ESA was achieved Innsbruck two more astronomy(-related) in 1987, but accession to ESO proved to full professorships are planned, to be Research in astronomy in Austria is con- be more difficult. There were several an nounced in 2010. So from the low state ducted at three universities: the University attempts and a lot of effort spent by the in 2001, with just one full professorship of Vienna at the Institute of Astronomy; scientists to convince the relevant author- in astronomy, with three more filled before the University of Innsbruck at the Institute ities that ESO membership is a must for the ESO accession and the five new ones of Astro- and Particle Physics; and an active astronomical community. Sev- in prospect, there will be nine full profes- the University of Graz at the Institute for eral studies evaluating the quality of the sors within a few years, i.e. an increase Physics. Some additional astronomy or institutes and the scientists were con- by a factor of nine over ten years. This related research is conducted at various ducted. Astronomers have made increas- development allows an optimistic view of other places such as the Institute for ing efforts over recent years to increase the future of Austrian astronomy. Space Research of the Austrian Academy national and international visibility, work- of Sciences in Vienna. In total there are ing towards eventually securing a positive Furthermore, the number of science currently 27 staff members and many result. These efforts included the acquisi- topics being pursued has developed in young people working at the three univer- tion of an increasing number of grants recent years. Previously the Austrian sity institutes. The research topics cover (from national and international sources), strength was mainly in stellar astrophys- Figure 1. The Institute of Astronomy at the University of Vienna. 2 The Messenger 137 – September 2009 50 The Austrian Society for Astronomy and Astrophysics 40 In order to adequately represent the Aus- trian astronomical community in pursu - 30 ing the accession to ESO, the Austrian Society for Astronomy and Astrophysics (ÖGAA) was founded in 2002. This was 20 an important step towards ESO member- ship, but, increasingly, it also serves many other purposes. This society holds 10 an annual meeting, at which all Austrian astronomers meet to present new results Staff 0 and discuss new developments. The PostDoc society performs joint public outreach 2004 2005 2006 2007 2008 PhD activities, keeps in contact with amateur Figure 2. Growth in the total number of personnel at the three university astro- astronomers and supports young people. nomical institutes in Graz, Innsbruck and Vienna over the last five years. While the permanent staff numbers have stayed almost constant, there is a clear increase in the number of postdocs and PhD students. In 2009 an even greater increase in these numbers is expected. Scientific highlights Austrian astronomy can look back on a ics, but there are now several active As in the rest of Europe, the Bachelor/ long history of astrophysics, including the extragalactic groups, along with more Master system was also introduced in Nobel laureate Victor Franz Hess, who connections to other fields such as math- Austria. While the Universities of Graz discovered cosmic rays in 1911. Nowa- ematics and computer science, a natu - and Innsbruck offer a Bachelor of Physics days many modern science topics are ral extension because of the large numer- and a Master of Physics, which include addressed, of which a few recent high- ical simulations performed by some many astrophysics courses, the Univer- lights are selected and presented here. groups. This year has also seen the sity of Vienna offers a Bachelor of Astron- establishment of astroparticle physics in omy and a Master of Astronomy. All Austria (including membership of the three universities also offer a PhD pro- High Energy Stereoscopic System [HESS] gramme, partly in connection with doc- collaboration). torate schools. Figure 3. Number of refereed publications resulting from the three Figure 4. Acquired grants (in €) for the three Austrian university university astronomy institutes in Austria over the last five years. astronomy institutes over the last four years. 140 138 3500000 123 120 3000000 114 10 0 104 2500000 94 80 2000000 60 1500000 40 1000000 20 500000 0 0 2004 2005 2006 2007 2008 2005 2006 2007 2008 The Messenger 137 – September 2009 3 The Organisation Schindler S., Astronomy in Austria Towards a new Maunder Minimum? The current solar activity minimum is longer lasting than previous ones (up to around 1900). Will there be a new pro- longed phase of strongly reduced solar activity like that during the Maunder Mini- mum, which lasted from 1645–1715 and coincided with the peak of the “little Ice Age” in Europe? The activity of the Sun is monitored and “space weather”, which is strongly influenced by solar activity, is studied. Solar activity influences the ioni- sation of the upper atmosphere and the propagation of radio signals and GPS signals can be severely disturbed (see the depiction in Figure 5). Due to the ex-- panding atmosphere, satellite orbits can become unstable and the radiation can endanger human activities in space. At the solar monitoring observatory at Kanzelhöhe, data are taken and used in combination with other observations to predict the upcoming solar activity maxi- mum. The first predictions for the new maximum (2011) were revised and the next maximum is expected to occur two or three years later, and its amplitude is predicted to be lower than the previous In this clumpy gas new stars can form, so Figure 5. The solar wind interacting with the Earth’s one. Applying methods of nonlinear that the star formation rate is increased magnetosphere. It compresses the magnetosphere on the side facing the Sun. This can cause magnetic dynamics, it has been shown that solar considerably by the stripping process, storms and, during strong solar events, such as activity behaves regularly on a longer and in extreme cases the increase in star flares or coronal mass ejections, even power lines on term basis, but is affected by the onset of formation can even be up by a factor of Earth can fail. chaos on smaller scales (Brajša et al., ten (Kronberger et al., 2008). Interestingly 2009). For these calculations solar activ- the stars not only form in the disc, but ity proxies have been used (such as cos- also in the wake behind the galaxy. Many Figure 6. Simulation of a galaxy moving through the mogenic isotopes). of these stars are not bound to the gal- intracluster gas. The interstellar medium is stripped off by ram pressure and forms clumpy structures axy, so that we have found a process that behind the galaxy. In these structures stars, which produces a population of new stars in are no longer bound to the galaxy, can form. Star formation between galaxies While it was thought previously that gal- *DVGHQVLWL\ axy evolution is mainly determined by GLVWULEXWLRQ internal processes, it is now clear that the environment plays an important role. Ram-pressure stripping of galaxies in W 0\U clusters (removal of the interstellar medi- um by the pressure of the intracluster W 0\U medium) in particular has turned out to be much more efficient than previously SF W 0\U thought (Rödiger & Hensler, 2005; N Schindler et al., 2005; Domainko et al., 2006). Therefore numerical simulations of spiral galaxies moving through the intra- W 0\U 6XUURXQGLQJ cluster medium have been performed. It JDVGHQVLWL\ was found that gas is stripped, not simply ´ tJFP dispersed, into the intracluster medium, and it becomes clumpy, due to external Y NPV W 0\U UHODWLYH pressure and radiative heating (Figure 6). 4 The Messenger 137 – September 2009 structure accumulate with age. Important examples are convective overshooting 6'66- and rotational mixing during the central /HR$ /HR,, hydrogen-burning phase that determine /HR, 80D the mass of the helium core, but which are not well understood. The analysis of 6H[WDQV 80L radial and non-radial stellar oscillations 'UDFR can be used to constrain the mass of the helium core.
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