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- Bouchet, P., et al.
(författare)
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The Mid-Infrared Instrument for the James Webb Space Telescope, III: MIRIM, The MIRI Imager
- 2015
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Ingår i: Publications of the Astronomical Society of the Pacific. - : IOP Publishing. - 0004-6280 .- 1538-3873. ; 127:953, s. 612-622
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we describe the Mid-Infrared Imager Module (MIRIM), which provides broadband imaging in the 5-27 mu m wavelength range for the James Webb Space Telescope. The imager has a 0 ''.11 pixel scale and a total unobstructed view of 74 '' x 113 '' The remainder of its nominal 113 '' x 113 '' field is occupied by the coronagraphs and the low-resolution spectrometer. We present the instrument optical and mechanical design. We show that the test data, as measured during the test campaigns undertaken at CEA-Saclay, at the Rutherford Appleton Laboratory, and at the NASA Goddard Space Flight Center, indicate that the instrument complies with its design requirements and goals. We also discuss the operational requirements (multiple dithers and exposures) needed for optimal scientific utilization of the MIRIM.
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| 2. |
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| 3. |
- Glasse, A., et al.
(författare)
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The throughput and sensitivity of the JWST mid-infrared instrument
- 2010
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819482211 ; 7731
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Verification Model (VM) of MIRI has recently completed an extensive programme of cryogenic testing, with the Flight Model (FM) now being assembled and made ready to begin performance testing in the next few months. By combining those VM test results which relate to MIRI's scientific performance with measurements made on FM components and sub-assemblies, we have been able to refine and develop the existing model of the instrument's throughput and sensitivity. We present the main components of the model, its correlation with the existing test results and its predictions for MIRI's performance on orbit. © 2010 SPIE.
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| 4. |
- Dehaes, S., et al.
(författare)
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SED for 7 stellar calibrators (Dehaes+, 2011)
- 2011
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Ingår i: VizieR Online Data Catalog. ; 353
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Tidskriftsartikel (refereegranskat)abstract
- This catalogue presents the theoretical spectral energy distributions for 7 stellar calibrators of the ESA Herschel satellite in the wavelength range from 2 to 200 micron. The stellar atmosphere model and theoretical spectrum are generated using the MARCS theoretical stellar atmosphere code (Gustafsson et al., 1975A\ampA....42..407G and further updates; Gustafsson et al. 2003A\ampA...400..709D) and the TURBOSPECTRUM synthetic spectrum code (Plez et al., 1992A\ampA...256..551P). Stellar parameters (and uncertainties thereon) have been derived by Decin et al. (2003A\ampA...400..709D) and are described in the text files added to this catalogue. The line lists used in the spectrum calculation are discussed in Decin (2000, PhD Thesis, Leuven University) and Decin and Eriksson (2007A\ampA...472.1041D). The outermost depth point of the theoretical atmosphere model was taken at log(tau$_lambda$)=-7.2 with lambda being 2.2 micron. The atmosphere model was calculated with a spherically symmetric (parallel for Sirius) geometry, under the assumption of radiative and hydrostatic equilibrium, local thermodynamic equilibrium (LTE) and homogeneous layers. The original theoretical spectrum was calculated at a resolution of Δλ=0.5Å, and then degraded to a resolution of λ/Δλ=5000 applying a gaussian convolution. The wavelength coverage is from 2 to 200 micron. Uncertainties on the theoretical spectrum predictions are discussed in depth in Decin \amp Eriksson (2007A\ampA...472.1041D). Absolute flux calibration is based on Selby (1988A\ampAS...74..127S) K-band (TCS for Sirius) photometry Zero-point is determined on the basis of an ideal ’Vega’, i.e. the K-band photometry of Vega is corrected for a flux excess of 1.29% (cf. Absil et al. 2006A\ampA...452..237A). The determined Selby K-band zeropoint is 4.0517E-10 W/m2/um. The determined TCS K-band zeropoint is 4.4506E-10W/m2/um (for Sirius) The estimated absolute flux uncertainty is 1% These theoretical spectra should be referenced as Decin \amp Eriksson (2007A\ampA...472.1041D). (3 data files).
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| 5. |
- Dehaes, S., et al.
(författare)
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Structure of the outer layers of cool standard stars
- 2011
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 533, s. A107-
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Tidskriftsartikel (refereegranskat)abstract
- Context. Among late-type red giants, an interesting change occurs in the structure of the outer atmospheric layers as one moves to later spectral types in the Hertzsprung-Russell diagram: a chromosphere is always present, but the coronal emission diminishes and a cool massive wind steps in. Aims. Where most studies have focussed on short-wavelength observations, this article explores the influence of the chromosphere and the wind on long-wavelength photometric measurements. The goal of this study is to assess wether a set of standard near-infrared calibration sources are fiducial calibrators in the far-infrared, beyond 50 mu m. Methods. The observational spectral energy distributions were compared with the theoretical model predictions for a sample of nine K- and M-giants. The discrepancies found are explained using basic models for flux emission originating in a chromosphere or an ionised wind. Results. For seven out of nine sample stars, a clear flux excess is detected at (sub)millimetre and/or centimetre wavelengths, while only observational upper limits are obtained for the other two. The precise start of the excess depends upon the star under consideration. For six sources the flux excess starts beyond 210 mu m and they can be considered as fiducial calibrators for Herschel/PACS (60-210 mu m). Out of this sample, four sources show no flux excess in the Herschel/SPIRE wavelength range (200-670 mu m) and are good calibration sources for this instrument as well. The flux at wavelengths shorter than similar to 1 mm is most likely dominated by an optically thick chromosphere, where an optically thick ionised wind is the main flux contributor at longer wavelengths. Conclusions. Although the optical to mid-infrared spectrum of the studied K- and M-type infrared standard stars is represented well by a radiative equilibrium atmospheric model, a chromosphere and/or ionised stellar wind at higher altitudes dominates the spectrum in the (sub)millimetre and centimetre wavelength ranges. The presence of a flux excess has implications on the role of the stars as fiducial spectrophotometric calibrators in these wavelength ranges.
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| 6. |
- Panneman, Daan M., et al.
(författare)
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Cost-effective sequence analysis of 113 genes in 1,192 probands with retinitis pigmentosa and Leber congenital amaurosis
- 2023
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Ingår i: Frontiers in Cell and Developmental Biology. - : Frontiers Media SA. - 2296-634X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are two groups of inherited retinal diseases (IRDs) where the rod photoreceptors degenerate followed by the cone photoreceptors of the retina. A genetic diagnosis for IRDs is challenging since >280 genes are associated with these conditions. While whole exome sequencing (WES) is commonly used by diagnostic facilities, the costs and required infrastructure prevent its global applicability. Previous studies have shown the cost-effectiveness of sequence analysis using single molecule Molecular Inversion Probes (smMIPs) in a cohort of patients diagnosed with Stargardt disease and other maculopathies. Methods: Here, we introduce a smMIPs panel that targets the exons and splice sites of all currently known genes associated with RP and LCA, the entire RPE65 gene, known causative deep-intronic variants leading to pseudo-exons, and part of the RP17 region associated with autosomal dominant RP, by using a total of 16,812 smMIPs. The RP-LCA smMIPs panel was used to screen 1,192 probands from an international cohort of predominantly RP and LCA cases. Results and discussion: After genetic analysis, a diagnostic yield of 56% was obtained which is on par with results from WES analysis. The effectiveness and the reduced costs compared to WES renders the RP-LCA smMIPs panel a competitive approach to provide IRD patients with a genetic diagnosis, especially in countries with restricted access to genetic testing.
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| 7. |
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| 8. |
- Sloot, Frea, et al.
(författare)
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Inventory of current EU paediatric vision and hearing screening programmes
- 2015
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Ingår i: Journal of Medical Screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 22:2, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine the diversity in paediatric vision and hearing screening programmes in Europe. Methods: Themes for comparison of screening programmes derived from literature were used to compile three questionnaires on vision, hearing, and public health screening. Tests used, professions involved, age, and frequency of testing seem to influence sensitivity, specificity, and costs most. Questionnaires were sent to ophthalmologists, orthoptists, otolaryngologists, and audiologists involved in paediatric screening in all EU full-member, candidate, and associate states. Answers were cross-checked. Results: Thirty-nine countries participated; 35 have a vision screening programme, 33 a nation-wide neonatal hearing screening programme. Visual acuity (VA) is measured in 35 countries, in 71% of these more than once. First measurement of VA varies from three to seven years of age, but is usually before age five. At age three and four, picture charts, including Lea Hyvarinen, are used most; in children over four, Tumbling-E and Snellen. As first hearing screening test, otoacoustic emission is used most in healthy neonates, and auditory brainstem response in premature newborns. The majority of hearing testing programmes are staged; children are referred after 1–4 abnormal tests. Vision screening is performed mostly by paediatricians, ophthalmologists, or nurses. Funding is mostly by health insurance or state. Coverage was reported as >95% in half of countries, but reporting was often not first-hand. Conclusion: Largest differences were found in VA charts used (12), professions involved in vision screening (10), number of hearing screening tests before referral (1–4), and funding sources (8).
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