Andromeda's Parachute: A Bright Quadruply Lensed Quasar at z=2.377

We present Keck Cosmic Web Imager spectroscopy of the four putative images of the lensed quasar candidate J014709+463037 recently discovered by Berghea et al. (2017). The data verify the source as a quadruply lensed, broad absorption-line quasar having z_S = 2.377 +/- 0.007. We detect intervening absorption in the FeII 2586, 2600, MgII 2796, 2803, and/or CIV 1548, 1550 transitions in eight foreground systems, three of which have redshifts consistent with the photometric-redshift estimate reported for the lensing galaxy (z_L ~ 0.57). By virtue of their positions on the sky, the source images probe these absorbers over transverse physical scales of ~0.3-21 kpc, permitting assessment of the variation in metal-line equivalent width W_r as a function of sight-line separation. We measure differences in W_r,2796 of <40% across all sight-line pairs subtending 7-21 kpc, suggestive of a high degree of spatial coherence for MgII-absorbing material. W_r,2600 is observed to vary by >50% over the same scales across the majority of sight-line pairs, while CIV absorption exhibits a wide range in W_r,1548 differences of ~5-80% within transverse distances less than ~3 kpc. J014709+463037 is one of only a handful of z > 2 quadruply lensed systems for which all four source images are very bright (r = 15.4-17.7 mag) and are easily separated in ground-based seeing conditions. As such, it is an ideal candidate for higher-resolution spectroscopy probing the spatial variation in the kinematic structure and physical state of intervening absorbers.Comment: Submitted to ApJL. 9 pages, 3 figures. Uses aastex61 forma

Andromeda's Parachute: A Bright Quadruply Lensed Quasar at z = 2.377

We present Keck Cosmic Web Imager spectroscopy of the four putative images of the lensed quasar candidate J014710+463040 recently discovered by Berghea et al. The data verify the source as a quadruply lensed, broad absorption-line quasar having ${z}_{{\rm{S}}}=2.377\,\pm \,0.007$. We detect intervening absorption in the Fe ii λλ2586, 2600, Mg ii λλ2796, 2803, and/or C iv λλ1548, 1550 transitions in eight foreground systems, three of which have redshifts consistent with the photometric-redshift estimate reported for the lensing galaxy (z L ≈ 0.57). The source images probe these absorbers over transverse physical scales of ≈0.3–22 kpc, permitting assessment of the variation in metal-line equivalent width ${W}_{{\rm{r}}}$ as a function of sight-line separation. We measure differences in ${W}_{{\rm{r}},2796}$ of 50% over the same scales across the majority of sight-line pairs, while C iv absorption exhibits a wide range in ${W}_{{\rm{r}},1548}$ differences of ≈5%–80% within transverse distances of lesssim3 kpc. These spatial variations are consistent with those measured in intervening absorbers detected toward lensed quasars drawn from the literature, in which ${W}_{{\rm{r}},2796}$ and ${W}_{{\rm{r}},1548}$ vary by ≤20% in 35 ± 7% and 47 ± 6% of sight lines separated by 2 quadruply lensed systems for which all four source images are very bright (r = 15.4–17.7 mag) and are easily separated in ground-based seeing conditions. As such, it is an ideal candidate for higher-resolution spectroscopy probing the spatial variation in the kinematic structure and physical state of intervening absorbers

Neonicotinoids thiamethoxam and clothianidin adversely affect the colonisation of invertebrate populations in aquatic microcosms

Surface waters are sometimes contaminated with neonicotinoids: a widespread, persistent, systemic class of insecticide with leaching potential. Previous ecotoxicological investigations of this chemical class in aquatic ecosystems have largely focused on the impacts of the neonicotinoid imidacloprid; few empirical, manipulative studies have investigated the effect on invertebrate abundances of two other neonicotinoids which are now more widely used: clothianidin and thiamethoxam. In this study, we employ a simple microcosm semi-field design, incorporating a one-off contamination event, to investigate the effect of these pesticides at field-realistic levels (ranging from 0 to 15 ppb) on invertebrate colonisation and survival in small ephemeral ponds. In line with previous research on neonicotinoid impacts on aquatic invertebrates, significant negative effects of both neonicotinoids were found. There were clear differences between the two chemicals, with thiamethoxam generally producing stronger negative effects than clothianidin. Populations of Chironomids (Diptera) and Ostracoda were negatively affected by both chemicals, while Culicidae appeared to be unaffected by clothianidin at the doses used. Our data demonstrate that field-realistic concentrations of neonicotinoids are likely to reduce populations of invertebrates found in ephemeral ponds, which may have knock on effects up the food chain. We highlight the importance of developing pesticide monitoring schemes for European surface waters

Molecular and atomic gas in dust lane early-type galaxies - I : Low star-formation efficiencies in minor merger remnants

In this work we present IRAM-30m telescope observations of a sample of bulge-dominated galaxies with large dust lanes, which have had a recent minor merger. We find these galaxies are very gas rich, with H2 masses between 4x10^8 and 2x10^10 Msun. We use these molecular gas masses, combined with atomic gas masses from an accompanying paper, to calculate gas-to-dust and gas-to-stellar mass ratios. The gas-to-dust ratios of our sample objects vary widely (between ~50 and 750), suggesting many objects have low gas-phase metallicities, and thus that the gas has been accreted through a recent merger with a lower mass companion. We calculate the implied minor companion masses and gas fractions, finding a median predicted stellar mass ratio of ~40:1. The minor companion likely had masses between ~10^7 - 10^10 Msun. The implied merger mass ratios are consistent with the expectation for low redshift gas-rich mergers from simulations. We then go on to present evidence that (no matter which star-formation rate indicator is used) our sample objects have very low star-formation efficiencies (star-formation rate per unit gas mass), lower even than the early-type galaxies from ATLAS3D which already show a suppression. This suggests that minor mergers can actually suppress star-formation activity. We discuss mechanisms that could cause such a suppression, include dynamical effects induced by the minor merger.Peer reviewe

Biological and chemical induction of systemic resistance in the barley powdery mildew pathosystem

Systemic acquired resistance (SAR) provides plants with a broad spectrum resistance to a variety of phytopathogens (fungi, bacteria and viruses). In dicotyledons the systemic resistance can be induced by both biological and chemical activators. At present it is unclear whether SAR exists in monocotyledons, however, induced resistance has been well reported. The barley-powdery mildew interaction ($\textit{Blumeria graminis f.sp. hordei, Bgh}$) was used as a test system. The effects of various biological ($\textit{Pseudomonas syringae subspecies and Xanthomonas translucens subspecies}$) and chemical (Bion$^{®}$, INA, SA and Paraquat) inducers have been analysed. Local pre-infiltration with some but not all of the bacterial strains tested led to lower systemic powdery mildew growth. The bacteria which were able to multiply quickly within barley were also able to provide protection against fungal infection. The degree of chemical resistance induced varied depending on the chemical inducer used, Bion$^{®}$ was the most effective of those tested. By using a combination of metabolite and expression analyses a hypothesis was developed concerning the mechanisms and signalling cascades involved in the development of the systemic resistance. Phenylpropanoid biosynthesis does not appear to be involved in the induced resistance observed in the course of this study. Little influence was found on the accumulation of soluble phenolic compounds following the individual local pre-treatments, whilst alterations were observed after $\textit{Bgh}$ infection. This was in agreement with the obtained expression data for PAL and CHS. In contrast three different pathogenesis-related (PR) proteins displayed differential regulation. PR-1, PR-2 and PR-3 are commonly used as markers for SAR in dicotyledons, it was shown here that Bion$^{®}$ and a $\textit{Pseudomonas syringae}$ subspecies resulted in induced PR-gene expression in barley. Paraquat led to primed expression, whilst the remaining bacteria induced local PR transcript accumulation and primed systemic expression. In some but not all systemic leaves lipoxygenase, as a marker for JA biosynthesis, was primed or induced as well as some JA dependent genes. It was hypothesised that Bion$^{®}$ mediates its systemic effects through JA signalling, whilst another signal is required for local responses possibly SA. The bacterial strains tested appear to involve a variety of signalling mechanisms which respond with differing speed and intensity. Local triggering includes reactive oxygen species (ROS) accumulation, at later time points JA and other signalling molecules induce defence responses. Paraquat pretreatment sensitised the barley plants to respond quicker and stronger to subsequent pathogen attack without having the cost of pre-emptively producing defence proteins. JA signalling is suggested to be responsible for local events whilst another signalling molecule must contribute to the systemic responses, possibly ROS. Local Paraquat pre-treatment of barley plants had a massive effect by reducing redox genes in systemic leaves as shown by differential gene expression. The results pointed out, that the systemic induced resistance in monocotyledons involves several different signalling cascades and induces various defence mechanisms. In some parameters it resembles SAR of dicotyledons but not in others. Thus the systemic induced resistance seems to be of higher complexity in monocotyledons than in dicotyledons and requires further investigation