4MOST: the 4-metre multi-object spectroscopic telescope project in the assembly, integration and test phase

4MOST is a new high-multiplex, wide-field spectroscopic survey facility under construction for ESO's 4m-VISTA telescope at Paranal, Chile. Its key specifications are: a large field of view of 4.4 square degrees, a high multiplex fibre positioner based on the tilting spine principle that positions 2436 science fibres in the focal surface of which 1624 fibres go to two low-resolution optical spectrographs (R = λ/Δλ ~ 6500) and 812 fibres transfer light to the high-resolution optical spectrograph (R ~ 20,000). Currently, almost all subsystems are completed and full testing in Europe will be finished in spring 2023, after which 4MOST will be shipped to Chile. An overview is given of instrument construction and capabilities, the planned science of the consortium and the recently selected community programmes, and the unique operational scheme of 4MOST

4MOST : the 4-metre multi-object spectroscopic telescope project in the assembly, integration, and test phase

4MOST is a new high-multiplex, wide-field spectroscopic survey facility under construction for ESO's 4m-VISTA telescope at Paranal, Chile. Its key specifications are: a large field of view of 4.4 square degrees, a high multiplex fibre positioner based on the tilting spine principle that positions 2436 science fibres in the focal surface of which 1624 fibres go to two low-resolution optical spectrographs (R = λ/Δλ ~ 6500) and 812 fibres transfer light to the high-resolution optical spectrograph (R ~ 20,000). Currently, almost all subsystems are completed and full testing in Europe will be finished in spring 2023, after which 4MOST will be shipped to Chile. An overview is given of instrument construction and capabilities, the planned science of the consortium and the recently selected community programmes, and the unique operational scheme of 4MOST

Left ventricular free wall rupture as a result of delayed presentation of an inferior ST-elevation myocardial infarction due to fear of COVID-19: case report.

BackgroundLeft ventricular free wall rupture (LVFWR) is a rare complication after myocardial infarction and usually occurs 1 to 4 days after the infarct. Over the past decade, the overall incidence of LVFWR has decreased given the advancements in reperfusion therapies. However, during the COVID-19 pandemic, there has been a significant delay in hospital presentation of patients suffering myocardial infarctions, leading to a higher incidence of mechanical complications from myocardial infarctions such as LVFWR.Case presentationWe present a case in which a patient suffered a LVFWR as a mechanical complication from myocardial infarction due to delay in seeking care over fear of contracting COVID-19 from the medical setting. The patient had been having chest pain for a few days but refused to seek medical care due to fear of contracting COVID-19 from within the medical setting. He eventually suffered a cardiac arrest at home from a massive inferior myocardial infarction and found to be in cardiac tamponade from a left ventricular perforation. He was emergently taken to the operating room to attempt to repair the rupture but he ultimately expired on the operating table.ConclusionsThe occurrence of LVFWR has been on a more significant rise over the course of the COVID-19 pandemic as patients delay seeking care over fear of contracting COVID-19 from within the medical setting. Clinicians should consider mechanical complications of MI when patients present as an out-of-hospital cardiac arrest, particularly during the COVID-19 pandemic, as delay in seeking care is often the exacerbating factor

4MOST: 4-metre multi-object spectroscopic telescope

International audienceThe 4MOST consortium is currently halfway through a Conceptual Design study for ESO with the aim to develop a wide-field ( < 3 square degree, goal < 5 square degree), high-multiplex ( < 1500 fibres, goal 3000 fibres) spectroscopic survey facility for an ESO 4m-class telescope (VISTA). 4MOST will run permanently on the telescope to perform a 5 year public survey yielding more than 20 million spectra at resolution R&tilde;5000 (lambda=390-1000 nm) and more than 2 million spectra at R~20,000 (395-456.5 nm and 587-673 nm). The 4MOST design is especially intended to complement three key all-sky, space-based observatories of prime European interest: Gaia, eROSITA and Euclid. Initial design and performance estimates for the wide-field corrector concepts are presented. Two fibre positioner concepts are being considered for 4MOST. The first one is a Phi-Theta system similar to ones used on existing and planned facilities. The second one is a new R-Theta concept with large patrol area. Both positioner concepts effectively address the issues of fibre focus and pupil pointing. The 4MOST spectrographs are fixed configuration two-arm spectrographs, with dedicated spectrographs for the high- and low-resolution fibres. A full facility simulator is being developed to guide trade-off decisions regarding the optimal field-of-view, number of fibres needed, and the relative fraction of high-to-low resolution fibres. The simulator takes mock catalogues with template spectra from Design Reference Surveys as starting point, calculates the output spectra based on a throughput simulator, assigns targets to fibres based on the capabilities of the fibre positioner designs, and calculates the required survey time by tiling the fields on the sky. The 4MOST consortium aims to deliver the full 4MOST facility by the end of 2018 and start delivering high-level data products for both consortium and ESO community targets a year later with yearly increments