Forty Years of X-Raying Narrow-Line Seyfert 1 Galaxies

Forty years after the discovery of Narrow-Line Seyfert 1 Galaxies (NLS1s), and 20 years since the discovery of the remarkable ultrasoft soft X-ray emissions of NLS1s, strategic publications improved the understanding of the Seyfert phenomenon more generally. New theoretical models emerged from the observations and stimulated the discussions on the innermost regions of AGN. NLS1s are an amazing class of AGN for X-ray, optical and multiwavelength science

EROSITA: AGN SCIENCE, BACKGROUND DETERMINATION, AND OPTICAL FOLLOW-UP SPECTROSCOPY

More than 20 years after the highly impacting ROSAT all-sky survey in the soft X-ray spectral range, we are close to the next major X-ray all/sky surveys with eROSITA. eROSITA will be the primary instrument on-board the Russian “Spectrum–Roentgen–Gamma” (SRG) satellite which will be launched from Baikonur in 2014 and placed in an L2 orbit. It will perform the first imaging all-sky survey in the medium energy X-ray range up to 10 keV with an unprecedented spectral and angular resolution. The eROSITA all sky X-ray survey will take place in a very different context than the ROSAT survey. There is now a wealth of complete, ongoing and planned surveys of the sky in broad range of wavelengths from the gamma, X-ray to the radio. A significant amount of science can be accomplished through the multi-frequency study of the eROSITA AGN and cluster sample, including optical confirmation and photometric redshift estimation of the eROSITA extended sources and AGNs. Optical spectroscopy has been, and will for the foreseeable future be, one of the main tools of astrophysics allowing studies of a large variety of astronomical objects over many fields of research. The fully capitalize on the eROSITA potential, a dedicated spectroscopic follow-up program is needed. 4MOST is the ideal instrument to secure the scientific success of the eROSITA X-ray survey and to overcome the small sample sizes together with selection biases that plagued past samples. The aim is to have the instrument commissioned in 2017, well matched to the data releases of eROSITA and Gaia. The design and implementation of the 4MOST facility simulator aimed to optimize the science output for eROSITA is described in necessary details

Quo vadis, Pep? Plant elicitor peptides at the crossroads of immunity, stress, and development

Peps were discovered as endogenous peptides triggering plant defence. Here we additionally highlight first studies showing their connection to plant stress resistance and developmen

Partial Covering Interpretation of the X-Ray Spectrum of the NLS1 1H 0707-495

The X-ray spectrum of 1H 0707-495 obtained with XMM-Newton showing a deep flux drop at ~7 keV (Boller et al. 2002) is studied based on the partial covering concept. The previously inferred extreme iron overabundance can be reduced down to ~3x solar if the hard component gradually steepens at high energies. The spectral shape supports that 1H 0707-495 is an AGN analogue of the galactic black-hole binaries in the soft state. Interpreting the soft excess as the emission from an optically-thick disk, the minimum black hole mass M is estimated to be 2 x 10^6 solar masses from the intrinsic luminosity corrected for partial covering. Based on the slim disk model, the observed disk temperature implies that the luminosity is close to the Eddington limit. The rapid and large flux variations with little change in the spectral shape can also be explained, if not all, as due to changes in the partial covering fraction. Partial covering may account for the large variability characteristics of NLS1.Comment: Accepted for publication in PASJ (2004). 9 page

Experimental tests of pseudo-complex General Relativity

Based on previous publications exploring pseudo-complex General Relativity (pc-GR) we present a selection of observable consequences of pc-GR and possible ways to experimentally access them. Whenever possible we compare the results to Einstein's GR and differences are worked out in detail. We propose experimental tests to check the predictions of pc-GR for the orbital frequency of test particles, the gravitational redshift effect and the last stable orbit. We will show that the orbital frequency of test particles at a given radius in pc-GR is in general lower compared to standard GR. Also the effect of frame dragging is modified (weakened) in pc-GR. Concerning the gravitational redshift of a radiation emitting object we find that it is also lower in pc-GR than in standard GR. Eventually the classical concept of a last stable orbit has to be modified in pc-GR.Comment: submitted for publication to the Monthly Notices of the Royal Astronomical Societ

Genotype x Environment Interactions of Winter Wheat

Winter wheat cultivars for organic farming have to be adapted to highly variable environments. Yield and yield stability, the nutritional value and the bread making quality are here of major importance. Particularly, seed quality, tillering capacity, regeneration ability after harrowing, weed suppression ability, resistance or tolerance against diseases and improved nutrient use efficiency (NUE) under limited nutrient conditions need to be improved by specific breeding efforts (Kunz et al., 2006; Löschenberger et al., 2008). Ten winter wheat cultivars were grown in 2007 in two organic systems of the DOK long-term experiment in CH-Therwil. Eight of these cultivars were tested in 2008 at three organic farms in different pedo-climatic environments in Switzerland to observe genotype x environment interactions under different organic conditions. In contrast to the DOK site on a fertile loess soil, the on-farm sites were located on sandy or sandy-loamy sites with lower inherent yield potential. We assessed grain yield, yield components and parameters related to baking quality and NUE. Grain yield at the on-farm sites ranged between 2.2 t ha-1 and 2.8 t ha-1 and was much lower than at the DOK sites ( 3.7 t ha-1 to 4.2 t ha-1) (Hildermann et al., 2009). Cultivars and sites significantly affected grain yield. Genotype x environment interactions were significant across the three on-farm sites; however they were not significant across all five organically managed sites. Calculated across the on farm sites, there was a tendency towards higher yields of the organically bred cultivars. This effect was statistically significant at the lowest yielding site, where yield of the organically bred cultivars was 14% higher than yields of the conventionally bred cultivars. However, at the DOK sites and averaged across all five organic sites, the organically bred cultivars could not outperform the conventionally bred cultivars. Similar to the grain yield, the total gluten content increased from the on-farm sites to the DOK sites. Irrespective of the site, the gluten index of the cultivars Scaro, Antonius and Caphorn was stable. In contrast, the gluten index of the cultivars Sandomir, CCP and Titlis highly varied between the tested environments. Yield was significantly correlated with grain N yield (r = 0.93) and nitrogen (N) utilization efficiency (NUtE) (r = 0.72). Genotype x environment interactions were not significant for grain N yield, however strongly significant for NUtE (p < 0.01). The conventionally bred cultivars strongly responded to environmental conditions and showed a low NUtE under at low N supply. In contrast, NUtE of the organically bred cultivars Scaro and Sandomir was stable across all test environments. Beside high yields, cultivars suitable for organic farming should achieve high baking quality and nutrient use efficiency under nutrient limited conditions. Among the tested cultivars, the organically bred cultivar Scaro revealed such a performance across all tested sites

Lack of arginine- and polyphosphate-storage pools in a vacuole-deficient mutant (end1) of Saccharomyces cerevisiae

AbstractYeast cells accumulate large amounts of arginine and polyphosphate in their vacuoles and utilize these compounds as endogenous nitrogen or phosphate sources under conditions of starvation. We examined a vacuoleless mutant, end1, and found that it stored virtually no arginine or polyphosphate when grown on a medium with arginine as the sole nitrogen source. When starved of nitrogen or phosphate it stopped growing much faster than the wildtype. Unlike the wildtype, end1 showed no accumulation of polyphosphate and, concomitantly, of arginine after a period of phosphate starvation. The results support the concept that vacuoles contain the main reserves of nitrogen and phosphate in fungi

Statistical Properties of Narrow-Line Seyfert 1 galaxies

The number of publications considering Narrow-Line Seyfert 1 galaxies has increased dramatically in recent years. Especially after the launch of the X-ray missions ROSAT and ASCA, Narrow-Line Seyfert 1s have become very popular. In these proceedings I will give an overview of how they are distributed over the electromagnetic spectrum. I will describe what we know about them at radio, infrared, optical, and X-ray bands, and how they differ and how they are similar to Broad-Line Seyfert 1s. Finally I will introduce a method to find them with high probability.Comment: Invited talk presented at the Joint MPE,AIP,ESO workshop on NLS1s, Bad Honnef, Dec. 1999, to appear in New Astronomy Reviews; also available at http://wave.xray.mpe.mpg.de/conferences/nls1-worksho