Context. The knowledge of the regular (large scale) component of the Galactic magnetic field gives important information about the structure and dynamics of the Milky Way, and also constitutes a basic tool to determine cosmic ray trajectories. It can also provide clear windows where primordial magnetic fields could be detected. Aims: We aim to

This paper presents the first results from a comparison of Planck dust maps at 353, 545 and 857GHz, along with IRAS data at 3000 (100 μm) and 5000GHz (60 μm), with Green Bank Telescope 21-cm observations of Hi in 14 fields covering more than 800 deg2 at high Galactic latitude. The main goal of this study is to estimate the far-infrared to sub

Using Planck maps of six regions of low Galactic dust emission with a total area of about 140 deg2, we determine the angular power spectra of cosmic infrared background (CIB) anisotropies from multipole ℓ = 200 to ℓ = 2000 at 217, 353, 545 and 857 GHz. We use 21-cm observations of Hi as a tracer of thermal dust emission to reduce the already low

An all sky map of the apparent temperature and optical depth of thermal dust emission is constructed using the Planck-HFI (350μm to 2 mm) andIRAS(100μm) data. The optical depth maps are correlated with tracers of the atomic (Hi) and molecular gas traced by CO. The correlation with the column density of observed gas is linear in the lowest column

We study the contribution of the kinematic Sunyaev-Zel'dovich (kSZ) effect, generated by the warm-hot intergalactic medium, to the cosmic microwave background temperature anisotropies in the five-year Wilkinson Microwave Anisotropy Probe (WMAP) data. We explore the concordance ΛCDM cosmological model, with and without this kSZ contribution, using a

The Arcminute Microkelvin Imager is a pair of interferometer arrays operating with six frequency channels spanning 13.9-18.2GHz, for observations on angular scales of 30arcsec-10arcmin and for declinations greater than -15° the Small Array has a sensitivity of 30mJys-1/2 and the Large Array has a sensitivity of 3mJys-1/2. The telescope is aimed

If the gas in filaments and halos shares the same velocity field as the luminous matter, it will generate measurable temperature anisotropies due to the kinematic Sunyaev-Zel'dovich effect. We compute the distribution function of the KSZ signal produced by a typical filament and show it is highly non-Gaussian. The combined contribution of the

We present an interesting Sunyaev-Zel’dovich (SZ) detection in the first of the Arcminute Microkelvin Imager (AMI) ‘blind’, degree-square fields to have been observed down to our target sensitivity of ?. In follow-up deep pointed observations the SZ effect is detected with a maximum peak decrement greater than eight times the thermal noise. No

Small angular scale (high l) studies of cosmic microwave background (CMB) anisotropies require accurate knowledge of the statistical properties of extragalactic sources at cm-mm wavelengths. We have used a 30 GHz dual-beam receiver (One Centimetre Receiver Array prototype) on the Toruń 32-m telescope to measure the flux densities of 121 sources in

The dust complex G159.6-18.5 in the Perseus region has previously been observed with the COSMOSOMAS experiment on angular scales of ~1°, and was found to exhibit anomalous microwave emission. We present the first high angular resolution observations of this dust complex, performed with the Very Small Array (VSA) at 33GHz, to help increase the

We study the thermal (tSZ) and kinetic Sunyaev-Zel'dovich (kSZ) effect associated with superclusters of galaxies using the MareNostrum (MNU) universe smoothed particle hydrodynamics (SPH) simulation. In particular, we consider superclusters with characteristics (total mass, overdensity and number density of cluster members) similar to those of the

We study the spatial distribution and colours of galaxies within the region covered by the cold spot in the cosmic microwave background recently detected by the Very Small Array interpherometer (VSA) towards the Corona Borealis supercluster (CrB-SC). The spot is in the northern part of a region with a radius ~1° (~5Mpc at the redshift of CrB-SC)

Accurate calibration of data is essential for the current generation of cosmic microwave background (CMB) experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 per cent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver

This paper provides an overview of the Low Frequency Instrument (LFI) programme within the ESA Planck mission. The LFI instrument has been developed to produce high precision maps of the microwave sky at frequencies in the range 27-77 GHz, below the peak of the cosmic microwave background (CMB) radiation spectrum. The scientific goals are described

The European Space Agency's Planck satellite, launched on 14 May 2009, is the third-generation space experiment in the field of cosmic microwave background (CMB) research. It will image the anisotropies of the CMB over the whole sky, with unprecedented sensitivity ({{Δ T}over T} 2 × 10-6) and angular resolution ( 5 arcmin). Planck will provide a

In this paper we present the Low Frequency Instrument (LFI), designed and developed as part of the Planck space mission, the ESA programme dedicated to precision imaging of the cosmic microwave background (CMB). Planck-LFI will observe the full sky in intensity and polarisation in three frequency bands centred at 30, 44 and 70 GHz, while higher

We describe the processing of data from the Low Frequency Instrument (LFI) used in production of the Planck Early Release Compact Source Catalogue (ERCSC). In particular, we discuss the steps involved in reducing the data from telemetry packets to cleaned, calibrated, time-ordered data (TOD) and frequency maps. Data are continuously calibrated

The scientific performance of the Planck Low Frequency Instrument (LFI) after one year of in-orbit operation is presented. We describe the main optical parameters and discuss photometric calibration, white noise sensitivity, and noise properties. A preliminary evaluation of the impact of the main systematic effects is presented. For each of the

The performance of the Planck instruments in space is enabled by their low operating temperatures, 20 K for LFI and 0.1 K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely different

The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since 13 August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. We give an overview of the history of Planck in its first