In-flight calibration and verification of the Planck-LFI instrument

In this paper we discuss the Planck-LFI in-flight calibration campaign. After a brief overview of the ground test campaigns, we describe in detail the calibration and performance verification (CPV) phase, carried out in space during and just after the cool-down of LFI. We discuss in detail the functionality verification, the tuning of the front-end and warm electronics, the preliminary performance assessment and the thermal susceptibility tests. The logic, sequence, goals and results of the in-flight tests are discussed. All the calibration activities were successfully carried out and the instrument response was comparable to the one observed on ground. For some channels the in-flight tuning activity allowed us to improve significantly the noise performance.Comment: Long technical paper on Planck LFI in flight calibration campaign: 109 pages in this (not final) version, 100 page in the final JINST versio

Mission-level performance verification approach for the Euclid space mission

ESA's Dark Energy Mission Euclid will map the 3D matter distribution in our Universe using two Dark Energy probes: Weak Lensing (WL) and Galaxy Clustering (GC). The extreme accuracy required for both probes can only be achieved by observing from space in order to limit all observational biases in the measurements of the tracer galaxies. Weak Lensing requires an extremely high precision measurement of galaxy shapes realised with the Visual Imager (VIS) as well as photometric redshift measurements using near-infrared photometry provided by the Near Infrared Spectrometer Photometer (NISP). Galaxy Clustering requires accurate redshifts (∆z/(z+1)<0.1%) of galaxies to be obtained by the NISP Spectrometer. Performance requirements on spacecraft, telescope assembly, scientific instruments and the ground data-processing have been carefully budgeted to meet the demanding top level science requirements. As part of the mission development, the verification of scientific performances needs mission-level end-to-end analyses in which the Euclid systems are modeled from as-designed to final as-built flight configurations. We present the plan to carry out end-to-end analysis coordinated by the ESA project team with the collaboration of the Euclid Consortium. The plan includes the definition of key performance parameters and their process of verification, the input and output identification and the management of applicable mission configurations in the parameter database

# 2003. The American Astronomical Society. All rights reserved. Printed in U.S.A. DUST TEMPERATURES IN THE INFRARED SPACE OBSERVATORY ATLAS OF

We examine far-infrared and submillimeter spectral energy distributions for galaxies in the Infrared Space Observatory Atlas of Bright Spiral Galaxies. For the 71 galaxies where we had complete 60–180 lm data, we fitted blackbodies with 1 emissivities and average temperatures of 31 K or 2 emissivities and average temperatures of 22 K. Except for high temperatures determined in some early-type galaxies, the temperatures show no dependence on any galaxy characteristic. For the 60–850 lm range in eight galaxies, we fitted blackbodies with 1, 2, and (with variable) emissivities to the data. The best results were with the emissivities, where the temperatures were 30 K and the emissivity coefficient ranged from 0.9 to 1.9. These results produced gas-to-dust ratios that ranged from 150 to 580, which were consistent with the ratio for the Milky Way and which exhibited relatively little dispersion compared with fits with fixed emissivities

An Infrared Space Observatory Atlas Of Bright Spiral Galaxies

In this first paper in a series we present an atlas of infrared images and photometry from 1.2 to 180 lm for a sample of bright spiral galaxies. The atlas galaxies are an optically selected, magnitude-limited sample of 77 spiral and S0 galaxies chosen from the Revised Shapley-Ames Catalog (RSA). The sample is a representative sample of spiral galaxies and includes Seyfert galaxies, LINERs, interacting galaxies, and peculiar galaxies