Detection of interstellar oxidaniumyl: Abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334

Aims. We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin. Methods. The characteristic hyperfine pattern of the H2O+ ground-state rotational transition, and the lack of other known low-energy transitions in this frequency range, identifies the feature as H2O+ absorption against the dust continuum background and allows us to derive the velocity profile of the absorbing gas. By comparing this velocity profile with velocity profiles of other tracers in the DR21 star-forming region, we constrain the frequency of the transition and the conditions for its formation. Results. In DR21, the velocity distribution of H2O+ matches that of the [Cii] line at 158 μm and of OH cm-wave absorption, both stemming from the hot and dense clump surfaces facing the Hii-region and dynamically affected by the blister outflow. Diffuse foreground gas dominates the absorption towards Sgr B2. The integrated intensity of the absorption line allows us to derive lower limits to the H2O+ column density of 7.2 × 1012 cm−2 in NGC 6334, 2.3 × 1013 cm−2 in DR21, and 1.1 × 1015 cm−2 in Sgr B2

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

GRB 160410A: the first Chemical Study of the Interstellar Medium of a Short GRB

Short Gamma-Ray Bursts (SGRBs) are produced by the coalescence of compact binary systems which are remnants of massive stars. GRB 160410A is classified as a short-duration GRB with extended emission and is currently the farthest SGRB with a redshift determined from an afterglow spectrum and also one of the brightest SGRBs to date. The fast reaction to the Neil Gehrels Swift Observatory alert allowed us to obtain a spectrum of the afterglow using the X-shooter spectrograph at the Very Large Telescope (VLT). The spectrum shows a number of absorption features at a redshift of z=1.7177, in addition, we detect two intervening systems at z=1.581 and z=1.444. The spectrum shows ly-alpha in absorption with a column density of log N(HI)=21.3+/-0.3 cm$^{-2}$ which, together with FeII, CII, SiII and OI, allow us to perform the first study of chemical abundances in a SGRB host galaxy. We determine a metallicity of [Fe/H]=-2.7+/-0.3, significantly lower than observed for any long GRB host. We find no evidence for extinction in the afterglow spectral energy distribution (SED). The environment has a low degree of ionisation and the CIV and SiIV lines are completely absent. We do not detect an underlying host galaxy down to deep limits. Additionally, we present the spectrum of GRB 201221D, another high-z short GRB that shows absorption lines at z=1.045 but whose environment seems to be more similar to the one of short GRBs as derived from the SED fitting to the host photometry

Responses to the ‘Arabellions’: The EU in Comparative Perspective — Introduction

This article introduces the themes of this special issue which is devoted to the reactions by external actors including the EU to the events unfolding in the Arab world beginning in December 2010. In particular, we look at the balancing act by external actors between their desire for stability, on the one hand, and their normative principles toward human rights and democracy, on the other. We compare the action (and inaction) of the European Union (EU) with other international and regional players, including the United States, Russia, Turkey and Israel. The contributions assess the response of these actors to the Arabellions events and analyse changes in their approaches to the Arab region. We ask three questions: (1) How have external actors assessed the 'Arabellions' and what role did they see for themselves in this context? (2) Which goals and instruments did external actors pursue toward the MENA region? In particular, how did they deal with conflicting goals, such as support for human rights and democracy, on the one hand, and concerns about security and stability, on the other? (3) How can we explain the varying responses of external actors to the Arabellions