12 research outputs found
PMAS: The Potsdam Multi Aperture Spectrophotometer. II. The Wide Integral Field Unit PPak
PPak is a new fiber-based Integral Field Unit (IFU), developed at the
Astrophysical Institute Potsdam, implemented as a module into the existing PMAS
spectrograph. The purpose of PPak is to provide both an extended field-of-view
with a large light collecting power for each spatial element, as well as an
adequate spectral resolution. The PPak system consists of a fiber bundle with
331 object, 36 sky and 15 calibration fibers. The object and sky fibers collect
the light from the focal plane behind a focal reducer lens. The object fibers
of PPak, each 2.7 arcseconds in diameter, provide a contiguous hexagonal
field-of-view of 74 times 64 arcseconds on the sky, with a filling factor of
60%. The operational wavelength range is from 400 to 900nm. The PPak-IFU,
together with the PMAS spectrograph, are intended for the study of extended,
low surface brightness objects, offering an optimization of total
light-collecting power and spectral resolution. This paper describes the
instrument design, the assembly, integration and tests, the commissioning and
operational procedures, and presents the measured performance at the telescope.Comment: 14 pages, 21 figures, accepted at PAS
Prototype development of the Integral-Field unit for VIRUS
VIRUS is a planned integral-field instrument for the Hobby-Eberly Telescope
(HET). In order to achieve a large field-of-view and high grasp at reasonable
costs, the approach is to replicate integral-field units (IFU) and medium sized
spectrographs many times. The Astrophysical Institute Potsdam (AIP) contributes
to VIRUS with the development and testing of the IFU prototype. This paper
describes the optomechanical design and the manufacture of the fiber-based IFU
subsystem. The initial VIRUS development aims to produce a prototype and to
measure its performance. Additionally, techniques will be investigated to allow
industrial replication of the highly specific fiber-bundle layout. This will be
necessary if this technique is to be applied to the next generation of even
larger astronomical instrumentation.Comment: 11 pages, 13 figures, to be published in SPIE proc. 627
The ERA2 facility: towards application of a fiber-based astronomical spectrograph for imaging spectroscopy in life sciences
Astronomical instrumentation is most of the time faced with challenging
requirements in terms of sensitivity, stability, complexity, etc., and
therefore leads to high performance developments that at first sight appear to
be suitable only for the specific design application at the telescope. However,
their usefulness in other disciplines and for other applications is not
excluded. The ERA2 facility is a lab demonstrator, based on a high-performance
astronomical spectrograph, which is intended to explore the innovation
potential of fiber-coupled multi-channel spectroscopy for spatially resolved
spectroscopy in life science, material sciences, and other areas of research.Comment: 10 pages, 9 figures, SPIE Conference "Astronomical Telescopes and
Instrumentation" 2012, Amsterda
Functional immune responses against SARS-CoV-2 variants of concern after fourth COVID-19 vaccine dose or infection in patients with blood cancer
Summary
Patients with blood cancer continue to have a greater risk of inadequate immune responses following three COVID-19 vaccine doses and risk of severe COVID-19 disease. In the context of the CAPTURE study (NCT03226886) we report immune responses in 80 patients with blood cancer who received a fourth dose of BNT162b2. We measured neutralising antibody titres (NAbT) using a live virus microneutralization assay against wild-type (WT), Delta, Omicron BA.1 and BA.2 and T cell responses against WT and Omicron BA.1 using an activation-induced marker (AIM) assay. The proportion of patients with detectable NAb titres and T cell responses after the fourth vaccine dose increases compared to those after the third vaccine dose. Patients who received B cell-depleting therapies within 12 months before vaccination have the greatest risk of not having detectable NAbT. In addition, we report immune responses in 57 patients with breakthrough infections after vaccination
Development of the wide-field IFU PPak
PPak is a new fiber-bundle, developed at the Astrophysical Institute Potsdam for the existing PMAS 3D-instrument. The intention of PPak is to provide a large integral field-of-view in combination with a large collecting area per fiber for the study of extended low-surface brightness objects. The PPak system consists of a focal reducer lens and a fiber bundle, featuring an innovative design with object, sky and calibration fibers. With a field-of-view of 74 x 65 arcseconds, PPak currently is the world's widest integral field unit that provides a semi-contiguous regular sampling of extended astronomical objects. Its pre-optics and fiber-diameter, combined with the versatility and efficiency of the PMAS spectrograph, allows PPak to make a unique trade-off between total light-collecting power and spectral resolution
Development of the wide-field IFU PPak
PPak is a new fiber-bundle, developed at the Astrophysical Institute Potsdam for the existing PMAS 3D-instrument. The intention of PPak is to provide a large integral field-of-view in combination with a large collecting area per fiber for the study of extended low-surface brightness objects. The PPak system consists of a focal reducer lens and a fiber bundle, featuring an innovative design with object, sky and calibration fibers. With a field-of-view of 74 x 65 arcseconds, PPak currently is the world's widest integral field unit that provides a semi-contiguous regular sampling of extended astronomical objects. Its pre-optics and fiber-diameter, combined with the versatility and efficiency of the PMAS spectrograph, allows PPak to make a unique trade-off between total light-collecting power and spectral resolution