Review of high-contrast imaging systems for current and future ground- and space-based telescopes I: coronagraph design methods and optical performance metrics

The Optimal Optical Coronagraph (OOC) Workshop at the Lorentz Center in September 2017 in Leiden, the Netherlands gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate the emergence and sharing of new ideas. In this first installment of a series of three papers summarizing the outcomes of the OOC workshop, we present an overview of design methods and optical performance metrics developed for coronagraph instruments. The design and optimization of coronagraphs for future telescopes has progressed rapidly over the past several years in the context of space mission studies for Exo-C, WFIRST, HabEx, and LUVOIR as well as ground-based telescopes. Design tools have been developed at several institutions to optimize a variety of coronagraph mask types. We aim to give a broad overview of the approaches used, examples of their utility, and provide the optimization tools to the community. Though it is clear that the basic function of coronagraphs is to suppress starlight while maintaining light from off-axis sources, our community lacks a general set of standard performance metrics that apply to both detecting and characterizing exoplanets. The attendees of the OOC workshop agreed that it would benefit our community to clearly define quantities for comparing the performance of coronagraph designs and systems. Therefore, we also present a set of metrics that may be applied to theoretical designs, testbeds, and deployed instruments. We show how these quantities may be used to easily relate the basic properties of the optical instrument to the detection significance of the given point source in the presence of realistic noise

Infectious Pancreatic Necrosis Virus and its impact on the Irish Salmon Aquaculture and Wild Fish sectors

Infectious pancreatic necrosis (IPN) is an economically significant viral disease of salmonid fish worldwide. Infectious pancreatic necrosis is categorised as a List III disease under Annex A of EU Council Directive 91/67/EEC. List III diseases are present within the EU and up to 2004 were regulated under national control programmes within each member state. The disease was first described in freshwater trout in North America in the 1950’s (Wood et al., 1955) and has been reported in Europe since the early 1970’s (Ball et al., 1971). Initially, IPN was regarded as a serious disease affecting rainbow trout fry and fingerlings (Roberts & Pearson, 2005). However as the salmon farming industry began to expand during the 1970’s, incidence of IPN disease in salmon also increased with the result that IPN is now widespread in the salmon farming industry in both Norway and Scotland. The economic loss due to the disease is large and outbreaks may occur in Atlantic salmon juveniles in fresh-water and in post-smolts after transfer to sea-water. Historically in Ireland, isolations of the IPN virus have been rare and occasional outbreaks have occurred in both rainbow trout and Atlantic salmon facilities. The Marine Institute and its predecessor, the Fisheries Research Centre, have been testing farmed and wild fish for disease pathogens since the mid 1980’s. The first reported clinical outbreak of IPN in Atlantic salmon occurred in 2003. However in 2006 severe outbreaks in a number of freshwater salmon hatcheries occurred which were all linked to imports from a specific single source. To date, clinical outbreaks of IPN in Ireland have been associated with imports of infected ova and their subsequent movement within the country. This report reviews the prevalence of the IPN virus in the Irish salmon farming industry and also in wild fish from selected rivers. It describes the steps taken by the industry to control the disease in 2006 and aims to provide some practical solutions to reduce the prevalence of the virus in farmed and wild fish and to prevent future outbreaks of the disease.Funder: Marine Institut

Molecular differentiation of infectious pancreatic necrosis virus isolates from farmed and wild salmonids in Ireland

peer-reviewedThis study investigated the genotypes and sub-groups of infectious pancreatic necrosis virus (IPNV) present in farmed and wild salmonid fish in Ireland. An 1100-bp portion of the VP2 region of segment A from each of 55 IPNV isolates collected over 2003–2007 was amplified by reverse-transcription–polymerase chain reaction and the product directly sequenced. The nucleotide sequences of each isolate were aligned and compared with each other and with the corresponding sequences of a number of reference isolates. All the 55 sequenced isolates belonged to genogroup 5 (Sp serotype) and could be divided into two subgroups. Irish subgroup 1 consisted of isolates from farmed salmon originating from an Irish salmon broodstock. Irish subgroup 2 consisted of isolates from imported farmed stock and all reported clinical outbreaks of IPN were associated with isolates from subgroup 2. Isolates from wild fish were identical to some isolates from subgroup 2, and therefore are believed to have originated from infected farms. These results highlight the importance of import risk analysis for diseases not listed under current legislation

Pancreas Disease in Farmed Salmon - Health Management and Investigations at Irish Farm Sites 2005-2008

This publication constitutes the final report for the research project ST/05/01 “Site investigations and disease management of the pancreas disease virus in Irish farmed salmon”, funded under the NDP Marine RTDI Programme. Work undertaken within the project included longitudinal studies of rainbow trout and Atlantic salmon at sea following the course of infection, testing for vectors and reservoirs of the virus, molecular studies of the virus and an epidemiological investigation of pancreas disease in Ireland. Results have shown that although pancreas disease is endemic in marine farmed Atlantic salmon, no evidence of infection in rainbow trout farmed at sea was found. Serological and molecular based diagnostic methods were shown to be suitable for the screening of fish stocks for the presence of the virus. For the confirmation of clinical outbreaks, farm data and histopathological results should be included. The results also suggest that horizontal transmission of the virus may be the main route of infection between sites. The project also involved the technology transfer of molecular and serological diagnostic methods for pancreas disease between partners and the final chapter includes practical information on management of, and mitigation against, pancreas disease. Pathologies such as pancreas disease, heart and skeletal muscle inflammation and cardiomyopathy syndrome, pose a serious threat to salmonid farming in Ireland, Scotland and Norway. Most significant among this group of diseases is pancreas disease, a viral disease affecting Atlantic salmon during the marine stage of the production cycle. From the first description of pancreas disease in farmed Atlantic salmon from Scotland in 1976 the disease has now become endemic in Ireland and parts of Norway and continues to be significant in Scotland. The causal agent of pancreas disease, a salmonid alphavirus, has now been characterised and a closely related subtype of the virus is known to cause sleeping disease in farmed rainbow trout on continental Europe and in the United Kingdom. The Irish salmon farming industry has estimated that pancreas disease has resulted in a total loss of turnover of €35 million with €12 million loss of profit in the years 2003-2004. The economic impacts are estimated to be in the range of €100 million per year in Norway. In Scotland, pancreas disease and related pathologies are increasingly responsible for significant losses in marine salmon farms but these have yet to be quantified.Funder: Marine Institut

Fish Health Unit Report of Activities Undertaken in 2018 and 2019

This report summarises the activities undertaken by the Fish Health Unit (FHU) of the Marine Institute (MI) in 2018 and 2019. The services of the FHU, undertaken on behalf of the State, are largely driven by European and national legislation on aquatic animal health. European Council Directive 2006/88/EC on animal health requirements for aquaculture animals lays down rules for the control of aquatic animal health within the EU. The directive is enacted in Irish Law by Statutory Instrument (SI) 261 of 2008. The MI is the Competent Authority (CA) responsible for implementation of aquatic animal health regulation in Ireland as described in these statutes. Aquatic animal health regulations in SI 261 of 2008 apply to finfish farms, shellfish farms, and put and take fisheries, and require that such aquaculture production businesses (APBs) obtain a Fish Health Authorisation (FHA) from the CA prior to operation

EPIC 219217635: A Doubly Eclipsing Quadruple System Containing an Evolved Binary

We have discovered a doubly eclipsing, bound, quadruple star system in the field of K2 Campaign 7. EPIC 219217635 is a stellar image with $Kp = 12.7$ that contains an eclipsing binary (`EB') with $P_A = 3.59470$ d and a second EB with $P_B = 0.61825$ d. We have obtained followup radial-velocity (`RV') spectroscopy observations, adaptive optics imaging, as well as ground-based photometric observations. From our analysis of all the observations, we derive good estimates for a number of the system parameters. We conclude that (1) both binaries are bound in a quadruple star system; (2) a linear trend to the RV curve of binary A is found over a 2-year interval, corresponding to an acceleration, $\dot \gamma = 0.0024 \pm 0.0007$ cm s$^{-2}$; (3) small irregular variations are seen in the eclipse-timing variations (`ETVs') detected over the same interval; (4) the orbital separation of the quadruple system is probably in the range of 8-25 AU; and (5) the orbital planes of the two binaries must be inclined with respect to each other by at least 25$^\circ$. In addition, we find that binary B is evolved, and the cooler and currently less massive star has transferred much of its envelope to the currently more massive star. We have also demonstrated that the system is sufficiently bright that the eclipses can be followed using small ground-based telescopes, and that this system may be profitably studied over the next decade when the outer orbit of the quadruple is expected to manifest itself in the ETV and/or RV curves.Comment: Accepted for publication in MNRA

Review of high-contrast imaging systems for current and future ground- and space-based telescopes I. Coronagraph design methods and optical performance metrics

The Optimal Optical Coronagraph (OOC) Workshop at the Lorentz Center in September 2017 in Leiden, the Netherlands gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate the emergence and sharing of new ideas. In this first installment of a series of three papers summarizing the outcomes of the OOC workshop, we present an overview of design methods and optical performance metrics developed for coronagraph instruments. The design and optimization of coronagraphs for future telescopes has progressed rapidly over the past several years in the context of space mission studies for Exo-C, WFIRST, HabEx, and LUVOIR as well as ground-based telescopes. Design tools have been developed at several institutions to optimize a variety of coronagraph mask types. We aim to give a broad overview of the approaches used, examples of their utility, and provide the optimization tools to the community. Though it is clear that the basic function of coronagraphs is to suppress starlight while maintaining light from off-axis sources, our community lacks a general set of standard performance metrics that apply to both detecting and characterizing exoplanets. The attendees of the OOC workshop agreed that it would benefit our community to clearly define quantities for comparing the performance of coronagraph designs and systems. Therefore, we also present a set of metrics that may be applied to theoretical designs, testbeds, and deployed instruments. We show how these quantities may be used to easily relate the basic properties of the optical instrument to the detection significance of the given point source in the presence of realistic noise.Comment: To appear in Proceedings of the SPIE, vol. 1069

Aquaplan: health management for finfish aquaculture

Lead partner: Marine Institute, Oranmore, Co. Galway. Project Partners: Vet Aqua International, Oranmore, Co. Galway., Global Trust Certification Ltd., Dundalk, Co. Louth. Project duration: 01/10/2008 to 31/10/2011The AquaPlan project brought together key stakeholders from the finfish aquaculture industry and state agencies with the aim of drafting and implementing a national strategic plan for fish health in Ireland. Many countries already have well established comprehensive strategies for managing aquatic animal health which are deemed necessary for the sustainable development of the industry. A range of deliverables were produced by the project which are all essential components of the strategic plan for fish health management.Funder: Ireland's EU structural funds programme 2007-2013, co-funded by the Irish government and the European Union- European Regional Development Fund, Marine Institute. Grant-Aid agreement no. PBA/AF/08/003(01

GILPAT: An Investigation into Gill Pathologies in Marine Reared Finfish

Lead Partner: Marine Institute, Rinville, Oranmore, Co. Galway. Project Partners: Vet-Aqua International, Oranmore, Co. Galway. Coastal & Marine Research Centre (CMRC), University College Cork. Veterinary Sciences Division, Agri-Food & Biosciences Institute (AFBI), Belfast.The aims of the GILPAT project were to take a multidisciplinary approach in order to further understand the underlying causes of gill disease in Irish farmed fish. A specific aim was to establish a pilot zooplankton monitoring programme and use training workshops to enable fish farmers to upskill in areas such as zooplankton sampling and basic identification of the main zooplankton/jellyfish species common to Irish waters. Complimenting this was the development of a number of molecular diagnostic methods for the detection of potential pathogens suspected of being involved in the development of the condition. Together with a comprehensive literature review, epidemiological study, and experimental challenge studies, the project aimed to bring all these elements together with the objective of outlining potential mitigation measures and identifying areas for future research.This project (Grant-Aid Agreement No. PBA/AF/08/002(01)) was carried out under the Sea Change strategy with the support of the Marine Institute and the Marine Research Sub-Programme of the National Development Plan 2007–2013, co-financed under the European Regional Development Fund.Funder: Marine Institut