2K1BC Abstracts


Ali Shafinaz
University of Wales
Cardiff - UNITED KINGDOM
MBI: Millimeter Wave Bolometric Interferometer

MBI is a novel interferometer using bolometers as detectors. The design and expected performances expected performances are presented. Preliminary test results of a 2 telescope prototype are also presented.


Aretxaga Itziar
co-authors: David Hughes (Large Millimetre Telescope Project),
Enrique Gaztanaga, Ed Chapin, James Dunlop
INAOE, Instituto Nacional de Astrofisica, Optica y Electronica
Tonantzintla - MEXICO
Constraints on the accuracy of millimetre - FIR photometric redshifts

More than 150 galaxies have been detected in blank-field millimetre and submillimetre surveys, however their redshift distribution remains uncertain due to the difficulty in identifying their optical-IR counterparts, and subsequently obtaining spectroscopic emission-line redshifts. We will discuss results from a Monte-Carlo analysis of the accuracy with which one can determine redshifts from photometric measurements at millimetre-FIR wavelengths, taking into account the dispersion in colours introduced by including galaxies with a distribution of SEDs, the choice of luminosity function, photometric and absolute calibration errors. The derived redshift distribution of galaxies detected in the current SCUBA and MAMBO surveys (and in the future BLAST, FIRST, ALMA, GBT, LMT surveys) will be presented.


Battistelli Elia Stefano(1),
co-authors: G. Boella(1), F. Cavaliere(1), M. Gervasi(1), A. Passerini(1), G. Sironi(1), M. Zannoni(1),
D. Andreone(2), L. Brunetti(2), V. Lacquaniti(2), S. Maggi(2), R. Steni(2), E. Natale(3), G. Tofani(3),
E. Bava(4), U. Pisani(5), J. R. Thorpe(6), M. De Petris(7)
(1) Università degli Studi di Milano Bicocca - Milan - ITALY
(2) Istituto Elettrotecnico Nazionale Galileo Ferraris – Turin - ITALY
(3) Osservatorio Astrofisico di Arcetri – Florence - ITALY
(4) Department of Electronic - Politecnico – Milan - ITALY
(5) Department of Electronic - Politecnico – Turin - ITALY
(6) Department of Electronic and Electrical Engineering - University of Leeds - Leeds - UK
(7) Department of Physics - University La Sapienza - Rome - ITALY
MASTER: millimetre and sub-millimetre three heterodyne receivers

A system of three heterodyne receivers will be described. Its mixers are based on SIS (superconductor-insulator-superconductor) tunnel junctions which allow a very sensible downconversion of the detectable signal form 94 GHz, 225 GHz and 345 GHz to 1.5 GHz. This will allow the detection of rotational transition lines from diffuse molecular clouds. Current status of a 94 GHz receiver, prototype of MASTER, will also be described. Technical design and cryogenic problems solution will be shown and we will focus our attention on the optical coupling technique based on gaussian beam analysis. Results of preliminary tests and observations at 94 GHz will also be presented.


Benoit Alain
Centre de Recherches sur les Tres Basses Temperatures - CNRS
Grenoble - FRANCE
The Archeops balloon experiment for measuring the CMB anisotropies

Archeops is a telescope dedicated to the observation of CMB anisotropies using bolometers cooled at 100mK. The instrument uses many of the concepts of the Planck satellite experiment but the experiment is supported by a stratospheric balloon. After a technical flight in Trapani (Sicily) in July 1999, we made 7.5 hours of observations on January 29th 2001 during the polar night above Sweden, Finland and Russia. We will discuss the sensitivity of the instrument and the first results.


Bock James
Jet Propulsion Laboratory - Caltech
Pasadena, CA - USA
Spider-Web Bolometers

Bolometers currently offer the highest sensitivity among direct detectors in the far-infrared to millimeter-wave region of the electromagnetic spectrum.  Silicon nitride micromesh ('spider-web') bolometers operating from base temperatures of 300 mK and 100 mK
achieve background-limited performance even under the low astrophysical foregrounds achievable in space-borne photometery, and are the baseline detectors for Planck/HFI and Herschel/SPIRE.  We discuss the recent development of polarization selective bolometers and feedhorn-coupled bolometer arrays.
We are now developing several new bolometer concepts.  High sensitivity detectors, integrated into an efficient, planar waveguide grating, enables ground-based and space-borne spectral line surveys of high-z far-infrared galaxies.  We are developing a flexible array architecture using arrays of slot antennae coupled via low-loss superconducting Nb tranmission line to microstrip filters and antenna-coupled bolometers.  By combining imaging and filtering functions with tranmission line, we are able to realize unique architectures such as a multi-band polarimeter and a planar, dispersive spectrometer.  Microstrip-coupled bolometers have significantly smaller active volume than detectors
with extended absorbers, and can realize higher sensitivity and speed of response.  We present our current development of slot antenna arrays, microstrip filters, Nb microstrip loss, and transition-edge microstrip-coupled bolometers.


Bujakas Victor
co-authors: V.N.Leonov and V.F.Troitsky
Astro Space Center of LPI RAN
Moscow - RUSSIA
The infrared telescope for Submillimetron Mission

The Submillimetron Project for space astronomy is now under consideration in Astro Space Center of P.N.Lebedev Phisical Institute (Russia) and Chalmers University of Technology (Sweden). Within this Project the submillimeter band space telescope will be put in orbit and will operate in 0.3 – 1.5mm wavelengths. The main characteristics of the Mission are described in the talk of Dr. V. Gromov.
In our report we are concentrated in the far infrared telescope with metal mirrors that we proposed as a possible instrument for Submillimetron Mission realisation. The optical diameter of the telescope is 1- meter, it contains primary, second and turning metal mirrors made of special aluminium alloy. A similar telescope, however smaller one, was early developed and used for balloon far infrared studies.
Traditional cooling systems for infrared space telescope mirrors are consumption systems and use liquid helium from a space tank. To increase time of operation and reduce requirements for transport facilities a closed loop system to cool the mirrors of Submillimetron telescope is considered.
To check the possible to use a deeply cooled metal mirror for space telescopes the mirror deformation measurements at low temperatures are needed. The experience of Astro Space Center in ground based cryogenic tests of space equipment was used and the experiment to check the thermal deformation of the main mirror at 80 K o was developed. The main frames of planed experiment are presented in the report.


Carretti Ettore
TESRE - CNR
Bologna - ITALY
The BaR-SPOrt Experiment

BaR-SPOrt is a balloon born experiment at microwave domain (32-90 GHz) aimed to study the polarisation of the diffused Galactic Background as well as of the CMB. Here we present the main scientific goals as well as the observing strategies of the project.


Cartwright John
California Institute of Technology
Pasadena, CA - USA
Polarization Observations with the Cosmic Background Imager

We describe polarization observations of the CMBR with the Cosmic Background Imager, a 13 element interferometer which operates in the 26-36 GHz band from the Atacama site in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a steerable platform which can be rotated about the optical axis to facilitate polarization observations. The CBI employs single mode circularly polarized receivers which sample multipoles from l~600 to l~3500. The instrumental polarization of the CBI was calibrated with observations of 3C279, a bright polarized source which was monitored with the VLA. This work was made possible by NSF grant AST-9802989.


Chapin Edward
INAOE, Instituto Nacional de Astrofisica, Optica y Electronica
Tonantzintla - MEXICO
Telescope simulations of wide-area millimetre and submillimetre surveys

One of the major goals in modern millimetre observational cosmology is to determine the star formation history of the Universe using deep, wide area surveys. In order to facilitate the development of the next generation of instruments, detailed simulations of the expected number counts given different cosmologies, clustering and evolutionary models have been used to create realistic catalogues of galaxies at different wavelengths. We discuss a software telescope simulator which has been developed to incorporate arbitrary bolometer array geometries, instrument characteristics (sensitivity, detector time constants, readout rates) and scan strategies. This simulator is currently using our modeled sky catalogues to evaluate alternative observing strategies for the Balloon-borne Large Aperture Sub-millimeter Telescope (2002) and the Large Millimeter Telescope (2004).


Colafrancesco Sergio
Osservatorio Astronomico di Roma
Monteporzio - ITALY
Non-thermal vs. Thermal SZ effect in galaxy clusters:
theoretical and observational constraints

We present a derivation of the SZ effect produced by a combination of non-thermal relativistic electrons (producing radio halo emission) and thermal non-relativistic electrons (producing X-ray emission) living in the potential wells of galaxy clusters. We discuss the theoretical and observational constrains which can be deduced from the available data on galaxy clusters.


Cortiglioni Stefano
ITESRE - CNR
Bologna - ITALY
The SPOrt Program

The Sky Polarization Observatory (SPOrt) program is aimed to measure the linearly polarized component of the microwave sky emission, which has not been observed at frequencies higher than few GHz. The first opportunity to achieve this goal is to realize an instrument, SPOrt, able to measure directly Q and U Stokes parameters at 22, 32, 60 and 90 GHz, with HPBW=7°, operating onboard the International Space Station for at least 1.5 years. SPOrt has been specifically designed to have a goal sensitivity (on both Q and U) of 3.4-6.3x10-6 K/pixel over more than 80% of the sky, and full sky (on the CMB) sensitivity ~ 0.2x10-6 K. The sensitivity, together with the large frequency/sky coverage, will allow SPOrt for making maps of galactic polarization as well as to put significant upper limits on the CMB polarization on degrees scale.


de Bernardis Paolo
& the BOOMERanG team
Università "La Sapienza"
Rome - ITALY
l-space spectroscopy of the cosmic microwave background

BOOMERanG recently produced a resolved image of the Cosmic Microwave Background (CMB). We briefly describe the payload, which exploits custom bolometric, cryogenic and optical technologies for detection of diffuse millimetric radiation.
We then describe the data analysis used to obtain
    - maximum likelihood maps of the sky at 90, 150, 240 and 410 GHz.
    - the angular power spectrum of the CMB fluctuations.
We pay spacial attention to the search for systematic effects.
In the measured spectrum three peaks are detected, at multipoles 210, 540, 830. This is consistent with predictions of the inflationary theory for the formation of structures in the Universe. The spectral analysis allows to determine, in the framework of this theory and combined with other "prior" cosmological information,  the most important cosmological parameters (curvature, baryon density, dark matter, dark energy etc.), thus giving a very consistent picture of the new cosmology.


Desért F. Xavier
Laboratoire d'Astrophysique, Observatoire de Grenoble
Grenoble - FRANCE
Diabolo and the future of ground based bolometric devices

Ground based bolometric detectors can provide high resolution millimetric images of clusters of galaxies via the SZ effect. We will show early results obtained with the Diabolo photometer (2 by 3 0.1K bolometers at 1 and 2mm) at the 30m IRAM telescope. We will address the next advance that can be expected from the the development of bolometric
cameras containing up to a few thousand pixels.


Devlin Mark
University of Pennsylvania
Philadelphia, PA - USA
Millimeter and Submillimeter Observations from the Atacama Plateau and High Altitude Balloons

A new generation of ground-based and sub-orbital platforms will be operational in the next few years. These new telescopes will operate from the high sites in Chile and Antarctica, airborne, and balloon-borne platforms where the atmosphere is transparent enough to allow sensitive measurements to be made in the millimeter and submillimeter bands. The
telescopes will take advantage of state-of-the-art instrumentation including large format bolometer arrays and spectrometers. I will discuss the results of our observations in the Atacama region of Chile (MAT/TOCO) as well as our future work on the Balloon-borne Large Aperture Telescope (BLAST) and our proposed Atacama Cosmology Telescope (ACT).


Dupac Xavier
CESR
Toulouse - FRANCE
Optimal map-making methods for large CMB timelines

We present optimal map-making methods (both COBE and Wiener) applied to large timelines, thanks to vector-only algorithms.
We test these methods on balloon and satellite experiment simulations.


Encrenaz Pierre
DEMIRM, Observatoire de Paris
Paris - FRANCE
Herschel Space Observatory and Odin preliminary results

Preliminary results with the Odin satellite launched february 21 2001.


Encrenaz Therese
DESPA, Observatoire de Paris
Meudon - FRANCE
Calibrations on planets at millimeter and submillimeter wavelengths

This paper will review our current knowledge of the millimeter and submillimeter spectra of planets, both from an observational and theoretical point of view.
In the case of Mars, which has a very tenuous atmosphere, the mm/submm spectrum is composed of discrete narrow molecular lines of CO, H2O and their isotopes, superimposed over a continuum defined by the surface emissivity and temperature. In the case of Venus, due to its thick CO2 atmosphere, the spectrum is dominated by the pressure-induced CO2
absorption, with some other minor contributions (SO2, H2O). The mm/submm spectra of the giant planets probe their tropospheres. They are dominated by collision-induced absorption, mostly due to H2-H2 and H2-He collisions, with, in the case of Jupiter and Saturn,  additional features due to NH3 and PH3. For all cases, observed and synthetic spectra will be shown, and the various sources of uncertainty will be discussed.


Gaztanaga Enrique
INAOE, Instituto Nacional de Astrofisica, Optica y Electronica
Tonantzintla - MEXICO
Clustering in deep millimetre surveys

Hughes & Gaztanaga 2001 have presented realistic simulations to address key issues confronting existing and forthcoming mm-submm surveys. An important aspect illustrated by the simulations is the effect induced on the counts by the sampling variance of the large-scale galaxy clustering. We find factors of up to $\sim 2-4$ variation (from the mean) in the extracted counts from deep surveys identical in area ($\sim 6$\,arcmin$^{2}$) to the SCUBA surveys of the Hubble Deep Fields (HDF) \cite{h98}.
Here we present a recipe to model the expected degree of clustering as a function of sample area and redshift.


Gear Walter
University of Wales
Cardiff - UNITED KINGDOM
QUEST: Measuring the Polarization of the CMB

no yet available


Giard Martin
CESR
Toulouse - FRANCE
Clusters of Galaxies in SZ surveys and dust contamination

The Sunyaev Zel'dovich Effect (SZE) towards massive clusters of galaxies  will be a powerfull tool to access the very distant Universe in order to study the formation of large-scale structures. I will review the observational problem caused by the contamination of the dust on the line of sight, and how this impacts on the determination of the cluster parameters : peculiar velocity from kinetic SZE, electronic temperature from relativistic thermal SZE. This dust can be either present in the intracluster medium or in the foreground Universe (Our Galaxy and star forming galaxies). I will emphasize this in the perspective of the future
space missions Planck and Hershel.


Gleeson Emily
National University of Ireland Maynooth
Maynooth - Ireland
Electromagnetic Modelling of Few-Moded Winston Cones in the Far-Infrared

Winston cones have traditionally been used as detector feeds in far-infrared cosmological experiments, such as the SuZIE Sunyaev-Zel'dovich experiment on the CSO. We describe the electromagnetic modelling of Winston cones using a rigorous electromagntic mode matching technique. Winston cones are usually designed using ray tracing, which becomes a very poor approximation when the number of spatial modes propagated by the horn is small in number, often the case at the longest wavelengths. Futhermore, the mode matching technique allows more complex structures such as back-to-back Winston cones and the detector cavities to also be modelled.


Gromov Vladimir
Astro Space Center of LPI RAN
Moscow - RUSSIA
Submillimeter and millimeter wave sky mapping in space project Submillimetron

Submillimetron is the international project of the space telescope for astronomical studies at the submillimeter and millimeter wavelengths using free-flying spacecraft and facilities of the Russian segment of the International Space Station. The payload is the 60-cm telescope cooled to liquid helium temperature with arrays of novel type detectors of "Normal-metal Hot-Electron Bolometer" (NHEB). The angular resolution about 1 arcmin, field of view about 1 degree, sensitivity about 10-18 W Hz-1/2, spectral region 0.3 - 1.5 mm.
Possibilities of CMB fluctuation measurements accuracy enhancement by means of foreground sources separation with this instruments are discussed.


Holler Christian
Astrophysics Group, Cavendish Laboratory, Cambridge University
Cambridge - UNITED KINGDOM
Broadband Correlator for AMI

The design and development of the correlator for the Arcminute Microkelvin Imager is introduced. It is a very wideband analogue correlator working in the range 5-13 GHz and could also be used as the second generation correlator for the Very Small Array. Other possible applications include observations of very broad spectral lines. All components are implemented using microstripline and slotline techniques and combined on one single circuit board. The talk will include the basic concept of the instrument and show test results for key components such gas phase shifters and detectors.


Hristov Viktor
California Institute of Technology
Pasadena, CA - USA
Signal Processing of NTD-GE Cryogenic Bolometric Sensors

Design considerations of an AC-biased NTD-GE bolometer signal processing.


Hughes David
INAOE, Instituto Nacional de Astrofisica, Optica y Electronica
Tonantzintla - MEXICO
Guiding cosmological experiments with simulated millimetre wavelength surveys

Improving our understanding of the luminosity and clustering evolution of a high-z population of massive starburst galaxies provides the motivation for conducting cosmological sub-mm and mm surveys. It is therefore important that we quantify the limitations of future
ground-based, airborne and satellite surveys at submm and mm wavelengths and the significance of the results that can be drawn from them. In this paper we present realistic simulated surveys which provide the means to address some key issues confronting existing and forthcoming surveys. We discuss the results from simulations with a range of wavelengths (200um - 3mm), spatial resolutions, and sensitivities. We demonstrate how the measured source-counts could be affected by (and corrected for) resolution and confusion, by the survey sensitivity and noise, and by the sampling variance due to clustering and shot-noise.


Jones Michael
Astrophysics Group, Cavendish Laboratory, Cambridge University
Cambridge - UNITED KINGDOM
Spurious signals in VSA data

The Very Small Array (VSA) is a 14-element compact interferometer for imaging the CMB on degree and sub-degree scales. Commissioning observations revealed a spurious signal on the shortest baselines whose origin is still unclear, but is related to coupling between the antennas. Making use of the individual tracking design of the antennas, which imposes a known fringe frequency on the sky signal, we have used temporal filtering to remove the effects of this signal from the data, with successful results. The same techniques are used to remove the effects of the sun and moon from the data, allowing use of daytime observations.


Keating Brian
Caltech Observational Cosmology
Pasadena, CA - USA
Polarization of the CMB: Large Angular Scales Results From POLAR

The polarization state of the Cosmic Microwave Background Radiation (CMB) has not yet been detected. Theoretical calculations predict its magnitude at large angular scales (7 degrees) is < 1 mK -- an order of magnitude below the large scale anisotropy level of the CMB. Detection of, or an improved upper limit on, the polarization of the CMB at large scales holds great promise for measuring fundamental properties of the standard cosmological model, such as the ionization history of the Universe and the contribution of gravitational waves to the spectrum of primordial density fluctuations. The POLAR (Polarization Observations of Large Angular Regions) project is a ground-based, centimeter-wavelength correlation polarimeter designed to detect the polarization of the CMB at 28, 31, & 33 GHz. The POLAR radiometer has acquired data during the Spring of 2000 from the University of Wisconsin, USA.
The design of the instrument as well as cosmological implications are described. The treatment of polarized galactic synchrotron radiation, and instrumental systematic effects pertinent to correlation polarimeters will also be discussed.


Kreysa Ernst
Max Planck Institute fuer Radioastronomie
Bonn - GERMANY
Bolometer arrays for Astronomy

Recently, new technical developments make it possible to consider mm/submm bolometer arrays of hundreds or even thousands of elements. The manufacture of these devices benefits from the rapid progress in microfabrication technology. However, similar advances will be required in cryogenics, filters, readout electronics and data handling in order to maximize the scientific potential. Even in the optical design of new mm/submm telescopes, the requirement of a large well corrected field will have to be considered. These issues will be discussed in the context of a new dedicated submm telescope to be built at the high altitude ALMA site in Chile.


Lamagna Luca
Università "La Sapienza"
Rome - ITALY
The MAD-4-MITO experiment:
multi-pixel, multi-band ground-based observations of SZ effect

After many years of testing and operation at the Testa Grigia Observatory, the single pixel photometer employed for the first SZ detection over the Coma cluster is going to be upgraded with a new Multi Array of Detectors (MAD). Higher angular resolution, compact optical and mechanical design, low noise readout and flexible observational strategies
are the main characteristics of the system, which will be employed for ground-based observations of the SZ effect from nearby clusters in the 4 MITO bands (140, 220, 270 and 350 GHz).


Lamarre Jean Michel
Institut d'Astrophysique Spatiale, Universite Paris-Sud
Orsay - FRANCE
Planck-HFI: performance requirements and instrument design

The Planck satellite is a project of the European Space Agency based on a wide international collaboration, including United States and Canadian laboratories. It is dedicated to the measurement of the anisotropy of the Cosmic Microwave Background (CMB) with unprecedented sensitivity and angular resolution. Its High frequency Instrument (HFI) is based on the use of bolometers cooled down to 100mK. The sensitivity will be limited by the photon noise of the CMB itself at low frequencies, and of the instrument background at high frequencies. The requirements on the measurement chain are directly related to the strategy of observation used for the satellite. This impacts on all aspects of the instrument design.


Leitch Erik
University of Chicago
Chicago, IL - USA
First Season Results from the Degree Angular Scale Interferometer

We present results from the first season of observation with the Degree Angular Scale Interferometer (DASI), an experiment at the South Pole designed to measure the angular power spectrum of the CMB over the multipole range l=140 to l=900. During the 2000-2001 austral winter, DASI produced sensitive detections of CMB fluctuations over more than 400 square degrees of sky, yielding a new measurement of the power spectrum which strongly suggests a sequence of harmonic peaks. We discuss these results and their implications for cosmological parameters.


Lubin Phil
University of California at Santa Barbara
California – USA
Future Balloon Borne and Ground Based CMB Measurement

In light of the MAP mission and future Planck mission we will discuss some balloon borne and ground based CMB measurements in terms of fundamental detector and background limits.


Macculi Claudio
and BaR SPOrt Collaboration
TESRE - CNR
Bologna - ITALY
BaR SPOrt: Balloon Radiometer for Sky Polarisation Observations

We present a 32 GHz balloon borne polarimeter for direct measurement of Q and U Stokes parameters of the sky with an angular resolution of ~0.5 deg. In this contribution we discuss the instrument design with particular emphasis to the hardware solutions, to reduce the systematics effects in high sensitivity polarisation measurements.


Mandolesi Reno
ITESRE - CNR
Bologna - ITALY
Planck Low Frequency Instrument

no yet available


Masi Silvia
& the BOOMERanG team
Università "La Sapienza"
Rome - ITALY
Diffuse emission from Interstellar Dust at mm wavelengths:
a problem for high sensitivity CMB experiments ?

We present mm-wave observations obtained by the BOOMERanG experiment of Galactic emission at intermediate and high Galactic latitudes, in the bands 90, 150, 240, 410 GHz.
We find that part of this emission is well correlated with extrapolation of the IRAS-DIRBE maps, and is spectrally consistent with thermal emission from interstellar dust (ISD).  We demonstrate that our 410 GHz map is a good dust monitor and we use our measurements
to estimate the limiting effect of ISD in present and future CMB anisotropy observations.


Masi Silvia
& the BOOMERanG team
Università "La Sapienza"
Rome - ITALY
B2K

We describe the B2K experiment: a balloon-borne polarimeter for long duration Antarctic flights aimed to measure the linear polarization of the CMB at subdegree angular scales. We focus on the new hardware, including a new detection system, improved attitude control and a new scan strategy. Forecasted sensitivity, systematic effects, and calibration methods are discussed.


Mauskopf Phil
University of Wales
Cardiff - UNITED KINGDOM
BOLOCAM: A 144 Element Bolometer Array

New developments in millimeter wave detectors allow the possibility of building large format cameras with fully integrated wafer arrays of detectors.  I will describe the design and performance of BOLOCAM, a 144 element camera for millimeter-wave astronomy.  I will describe observations with BOLOCAM at the CSO in Hawaii.
 


Melchiorri Francesco
Università "La Sapienza"
Rome - ITALY
Measurements of CMB polarization

We describe a new technique for measuring CMB polarization from ground around  CMB "bumps".


Mennella Aniello
IFC-CNR
Milan - ITALY
Analysis of thermally-induced effects in Planck Low Frequency Instrument

The Planck mission will provide full-sky maps of the Cosmic Microwave Background with unprecedented angular resolution (~ 10') and sensitivity (DT/T ~ 10-6). This requires cryogenically cooled, high sensitivity instruments as well as an extremely accurate control of systematic errors, which must be kept at micro-K level. In this work we first present an overview of the different types of systematic effects potentially relevant for Planck, and then we focus on those arising from thermal instabilities in the Low Frequency Instrument. Our results show that although it is of crucial importance to assure "in hardware"; a high degree of stability, it is nevertheless possible to reduce the contamination level in the observed maps by proper analysis of the Time Ordered Data.


Morgante Gianluca
TESRE - CNR
Bologna - ITALY
Two Hydrogen Sorption Cryocoolers for the Planck Mission

Two continuous operation 18K/20K sorption cryocoolers are being developed by the Jet Propulsion Laboratory (JPL) as a NASA contribution to the European Space Agency (ESA) Planck mission. The hydrogen sorption coolers will directly cool the Planck Low Frequency Instrument (LFT) HEMT amplifiers to approximately 20K and will provide precooling at 18K to the RAL 4.5K closed-cycle Helium J-T cooler for the High Frequency Instrupment (HFI). The  concept design, the cooler operations and the predicted performances are here presented.


Murphy J.Anthony
National University of Ireland Maynooth
Maynooth - IRELAND
Corrugated Horn Design for PLANCK

We report on the back-to-back feed horn design for the High Frequency Instrument on PLANCK. Single mode Gaussian profiled horns have been developed for the 4 lowest frequency channels (100GHz, 150 GHz, 217 GHz & 353 GHz). These have very pure Gaussian radiation patterns with sidelobe levels reduced well below 30dB. Few moded horn antennas are being proposed for the highest frequency channels (545 GHz & 850 GHz) for non diffraction limited performance with high throughput. The modelling of the horns uses a rigorous electromagntic mode matching technique which is found to give good agreement with theory.


Natale Enzo
CAISMI
Florence - ITALY
HERSCHEL/FIRST: The Far Infrared and Sub-millimeter Space Telescope

The HERSCHEL Space Observatory, formerly known as FIRST, is the fourth cornerstone mission in the "Horizon 2000" long term ESA science program plan. It is a multi user observatory type mission devoted to photometry and spectroscopy in the submillimetre and far-infrared part of the electromagnetic spectrum (60 - 670 um).  It will have a radiatively cooled telescope and carry  three instruments, developed by international consortia,  housed inside a superfluid helium cryostat.
A brief description of the mission together with a review of key scientific objectives are given.


Nati Federico et al.
Università "La Sapienza"
Rome - ITALY
A fast star sensor for balloon borne payloads

We developed a system to reconstruct the attitude of balloon borne spinning experiments, where high accuracy (about 1') and high rotation speed (up to tens of degree per seconds) are required. It is based on a stellar sensor, and gathers togheter hardware simplicity, cheap components, high resolution and sensitivity. It is composed of an optical mirror (diameter 40 cm), an array of 46 fast and sensitive photodiodes, and an ultra-low noise readout electronics.
It was designed for the Archeops experiment, a balloon borne millimetric telescope whose goal is to generate high resolution maps of large regions of the sky, to study the temperature anisotropies of the cosmic background radiation.


O'Sullivan Creidhe
co-authors: J.A. Murphy, S. Withington G. Yassin, E.Atad-Ettedgui,
W. Duncan, D. Henry, W. Jellema and H. van de Stadt
National University of Ireland Maynooth
Maynooth - IRELAND
MM-Wave Optics Design & Verification

Microwave background astronomy requires very high performance millimetre-wave optical systems. However, compact quasi-optics are difficult to design with any confidence using techniques developed for visible wavelengths. In this paper we investigate the performance of existing software design tools (ASAP, CODE V, GLAD) as well as a Gaussian beam mode analysis technique not yet available as commercial software. We have devised a set of test cases and used these to study the underlying methodologies and physics of these packages and we look at their ability to analyse millimetre systems and components. We have used GRASP as our benchmark software.


Palladino Emilia(1),
co-author: S. Colafrancesco(2)
(1) Università "La Sapienza" - Rome - ITALY
(2) Osservatorio Astronomico di Roma - Monteporzio - ITALY
Spatial features of non-thermal SZ effect in galaxy clusters

We investigate the spatial behaviour of the total comptonization parameter $y_{tot}$ evaluated for a galaxy cluster containing two population of electrons: the thermal population, with energy around some KeV and whose trace is evident in the X-ray emission of the ICM (Intra-Cluster Medium), and the relativistic population,  which give rise to the radio halo emission found in several clusters of galaxies. We present the first results obtained from our analysis showing that there are remarkable features in such spatial trend, which might throw a new light in understanding the cluster internal processes.


Pascale Enzo
co-author: A. Boscaleri
IROE - CNR
Florence - ITALY
Attitude Control System for balloon borne experiments

The Pointing System is a key part of any balloon borne experiment. It has to achieve the required attitude stabilization of the telescope during the flight as well as guarantee the post-flight pointing reconstruction. The ACS that has been developed at IROE can reach a high real-time stability in pointing and scanning and it guarantees an attitude solution with an accuracy that is better than 1 arc-minute RMS.


Piacentini Francesco
Università "La Sapienza"
Rome - ITALY
The Boomerang experiment

The Boomerang experiment provided the first high resolution map of the cosmic microwave background radiation with enough sensitivity to detect anisotropies. This result was possible given several innovative technical solution, including bolometers, readout electronics, cold reimaging optics, millimeter-wave filters, cryogenics, scan and attitude reconstruction. Here we describe the instrument in details.


Piccirillo Lucio
University of Wales
Cardiff - UNITED KINGDOM
COMPASS: a 2.6m telescope for CMBR polarization studies

COMPASS (COsmic Microwave Polarization at Small Scale) is an experiment devoted to measure the polarization of the CMBR. Preliminary results from its first observing campaign as well as its design and characteristics are presented.


Puy Denis
Institute of Theoretical Physics, University of Zurich
Zurich - SWITZERLAND
Molecules at millimeter wavelengths

In the last years, progress has been important in the domain of molecules at high redshift. I will present an overview on the molecular content in some systems beyond z=1 and up to z=5 in the millimeter range.


Puy Denis
Institute of Theoretical Physics, University of Zurich
Zurich - SWITZERLAND
SZ effect and Geometry of Galaxy Clusters

We investigate the Sunyaev-Zel'dovich (SZ) effect and the X-ray surface brightness for clusters of galaxies with a non-spherical mass distribution. In particular, we consider the influence of the shape and the finite extension of a cluster as well as of a polytropic thermal profile on the Compton parameter, the X-ray surface brightness and on the determination of the Hubble constant.
We find that the non-inclusion of such effects can induce errors up to 30\% in the various parameters and in particular on the Hubble constant value, when compared with results obtained under the isothermal, infinitely extended and spherical shape assumptions.


Raccanelli Andrea
co-authors: L. A. Reichertz and E. Kreysa
Max Planck Institute fuer Radioastronomie
Bonn - GERMANY
Excess Noise in Cryogenic detectors due to Vibrating 1 K Pots

Temperatures between 4 K and 1 K are obtained by pumping on a 4He bath. In order to reduce the consumption of liquid helium, it is common to pump only on a small volume of He inside a small chamber (1 K pot), continuously replenished from a main bath at 4.2 K, through an impedance. 1 K pots are a necessary cooling step in dilution refrigerators, used to cool many different kind of sensitive detectors to temperatures in the mK range, e.g. gravitational antennas, bolometers for far-infrared radiation or high resolution particle detection. It is known that continuously filled 1K pots are affected by vibrations that are a source of excess noise, and thus can decrease the performance of the detectors.
We present our study on the origin of these vibrations and a solution we have found to eliminate this excess noise from the detectors.


Raljevich Mirko
co-author: D. Urzagasti
Instituto de Investigaciones Fisicas - UMSA
La Paz - BOLIVIA
Chacaltaya Mountain: An option for astrophysical observations

Chacaltaya Mountain is one the most important cosmic rays observatory of the southern hemisphere. Actually there are some experiments set and working there. This place is suitable because it is easy access and the high altitude where the observatory is located (about 5230 m a.s.l.). Here we report the meteorological data like temperature, relative humidity, nuvolosity and velocity and direction of wind at Chacaltaya, that we believe are
important for astrophysical observations.


Reichertz Lothar
Max Planck Institute fuer Radioastronomie
Bonn - GERMANY
Fast Scanning: a new observing technique with detector arrays

Fast scanning is a new observing technique which allows mapping large areas of the sky with any mm/submm telescope in a shorter time than usual. Besides other advantages, it is therefore especially useful in surveys to search for new sources. We will present the principles of electronics and data acquisition and the reconstruction of the original signal in this method as well as first test results.


Rephaeli Yoel
Tel Aviv University
Tel Aviv - ISRAEL
The Sunyaev-Zeldovich Effect: Recent Progress and Future Prospects

The detailed spectral and spatial characteristics of the signature imprinted on the cosmic microwave background (CMB) radiation by Compton scattering of the radiation by electrons in the hot gas in clusters of galaxies - the unyaev - Zeldovich (S-Z) effect - have become major cosmological probes. Very significant progress has been made by the use of sensitive receivers at the BIMA and OVRO interferometric arrays, resulting so far in S-Z images of some 40 (moderately distant) clusters. The current measurement capability, more accurate theoretical description of the effect, and realistic modeling of intracluster gas, have significantly advanced its use as a more precise probe of the Hubble constant and density parameter, as well as cluster masses. I will review recent observational and theoretical progress, discuss how to optimize the scientific yield from S-Z and X-ray measurements, and will outline the projected capabilities of bolometric, multi-frequency arrays that will become operational in the near future.


Reveret Vincent
CEA/Saclay, Service d'Astrophysique
Sacley - FRANCE

A fully sampled bolometer camera for ground submillimeter observations

Accompanying the development of the PACS Photometer camera on the Herschel Space Observatory, CEA/SAp has developed a new type of bolometer array. We present a camera using these CCD-like detectors for ground submillimeter applications. This instrument operating in the 865 microns (350 GHz) atmospheric band, is made of 16 x 16 pixels, providing a 30 arcsec resolution (Nyquist sampling) and a (7.5 x 7.5) arcmin field of view.


Richards Paul
University of California at Berkeley
California – USA
The MAXIMA and MAXIPOLE Experiments

The present status of the MAXIMA experiment to measure the temperature anisotropy of the CMB will be described.  The conversion of MAXIMA into MAXIPOLE to measure the polarization anisotropy will be discussed.


Richards Paul
University of California at Berkeley
California – USA
New Technologies for the Detection of Millimeter and Submillimeter Waves

Voltage biased superconducting bolometers with transition edge sensors are being developed which have favorable properties for large format focal plane arrays.  Absorber coupled bolometers for 1024 pixel close packed arrays and antenna coupled bolometers with integrated band pass filters are being fabricated and tested.  A frequency-domain multiplexer is being developed to read out a row of bolometers through a single SQUID ammeter.


Romeo Giovanni(1),
co-authors: P. de Bernardis(2), G. Di Stefano(1),  S. Masi(2), F. Piacentini(2), F. Pongetti(1), S. Rao(1)
(1) INGV
Rome - ITALY
(2) Università "La Sapienza"
Rome - ITALY

Wide-Sky High-Precision Sun Angle Detector

The Sun position detection is a good way for orientating stratospheric balloons flying during the Antarctic day.
A precision sun angle detector has been developed to orientate the BOOMERANG experiment payload (1998), and will be improved for  BOOMERANG 2k1. The system consists in two separated sections, an almost-analog wide–angle (2p) coarse sensor, used to keep in range the second section, a digital (CCD + DSP) high precision sensor, which offers a range depending of the optical assembly (in BOOMERANG it was p/3) and a precision of 1/40000.


Sandri Maura
TESRE - CNR
Bologna - ITALY
Optical interface of the Planck Low Frequency Instrument

The Low Frequency Instrument (LFI) on board the ESA Planck satellite is coupled to the Planck 1.5 meter off-axis dual reflector telescope by an array of corrugated feed horns. A detailed study of the optical interface devoted to optimize the angular resolution and at the
same time to minimize all the systematics coming from the sidelobes of the radiation pattern has been done. Shapes, locations on the sky, and polarization properties of the beam patterns at the four LFI frequency channels (30, 44, 70, and 100 GHz) have been calculated and reported.


Signore Monique
DEMIRM, Observatoire de Paris
Paris - FRANCE
CMBA and primordial nucleosynthesis

If confirmed, the results on the latest cosmological microwave background anisotropy (CMBA) measurements lead to a higher baryon density (Omega-b) than allowed by the Standard Big Bang Nucleosynthesis (SBBN) theory and observations.
I propose to review several classes of nucleosynthesis models- involving neutrino degeneracy or existence of antimatter regions or .....-which allow larger values of Omega-b than SBBN including the high value suggested by BOOMERANG and MAXIMA.


Silverberg Robert(1),
co-author/s: S. H. Moseley(1), M. M. Freund(1), C. A. Allen(1), G. M Voellmer(1),
D. A. Harper(2), R. F. Loewenstein(2), C. D. Dowell(3), T. G. Phillips(3)
(1) NASA/Goddard Space Flight Center - Greenbelt,MD - USA
(2) Yerkes Observatory, Williams Bay, WI - USA
(3) California Institute of Technology, Pasadena, CA - USA
Arrays of Bolometric Detectors

Large format two-dimensional arrays of detectors are required for many millimeter and submillimeter applications.  We describe the development, fabrication, and testing of bolometric arrays and the plans for using them in both a ground-based and airborne instrument.


Siringo Giorgio
Max Planck Institute fuer Radioastronomie
Bonn - GERMANY
PolKa: a tunable polarimeter for mm/submm wavelenghts

We present a new polarimeter for the mm/submm wavelenghts. Very low insertion losses and the possibility to tune its opearating wavelenght in a wide range make it a versatile instrument. It will be used with the MPIfR bolometer arrays at different wavelenghts (2, 1.3, .85 mm) to produce high-resolution maps of polarization.


Soglasnova Vera A.
co-author: I.A. Maslov
Space Research Institute of Russian Academy of Science
Moscow - RUSSIA
The spectral filters for the astronomical observations
through the atmospheric windows

The study of the cosmic radiation in the mm-submm wavelength region through the separate "windows" of the partly atmospheric transparency with the bolometric cooled receivers is required the spectral filters for the separating these windows. We have developed the set of the bandpass spectral filters for all the atmospheric windows from 2 mm down 0.2 mm with the resolution from 12-40% corresponding to the windows widths. The filters are the freestanding metal meshes with the honeycombs grid of the round holes. The meshes have the transmission maximum (> 90%) near the period of the grid and the bandwidth of the spectral transmission depending on the ratio of the holes diameter to the period of the grid.
The thickness of the meshes is about 15 um and the working field up to 60 mm. The filters easy stand the cryogen temperature and vacuum. Such sort of the meshes are rather elastic to be used also as reflecting surfaces in the cooled Fabry-Perot filters of the mm-wavelength region.


Spergel Martin
York College of the City University of New York
New York - USA
A Center for Cosmic Structure

The proposed "Center for Cosmic Structure", to be funded by NIST, NASA and the NSF will be run by a Consortium of Universities. The Universities will include such institutions as: Princeton, University of Pennsylvania, University of Toronto, York College of the City University of New York, the University of Chile among others. The Center for Cosmic Structure (CCS) will maintain a planned 6 meter telescope in Atacama region of Chile. A Theory group will integrate research product from the MAP satellite, balloons, the proposed 6m telescope, working towards modeling the early galaxy formation.


Stark Anthony
Smithsonian Astrophysical Observatory
Cambridge, MA - U.S.A.
Millimeter and Submillimeter Observations from the South Pole

During the past decade, a year-round observatory has been established at the geographic South Pole by the Center for Astrophysical Research in Antarctica (CARA).  CARA has fielded several millimeter- and submillimeter-wave instruments:  AST/RO (the Antarctic Submillimeter Telescope and Remote Observatory, a 1.7-m telescope),  Python and Viper (Cosmic Microwave Background experiments), SPARO (a submillimeter-wave polarimeter), ACBAR (a multi-channel CMB instrument for Viper) and DASI (the Degree-Angular Scale Interferometer).  These instruments have obtained significant results in observational cosmology, including detections of the 1 degree acoustic peak in the CMB and the Sunyaev-Zel'dovich effect.  The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky.  The atmosphere is dessicated by cold: at the South Pole's average annual temperature of -49 C, the partial pressure of saturated water vapor is only 1.2% of what it is at 0 C.  These low water vapor levels result in exceptionally low values of sky noise.  This is crucial for large-scale observations of faint cosmological sources observed with bolometric instruments---for such observations South Pole is unsurpassed.


Subrahmanyan Ravi
Australia Telescope National Facility (CSIRO)
Narrabri - AUSTRALIA
Cross-talk in close-packed interferometer arrays

Close-packed antenna configurations are important for high-surface-brightness observations in CMB research. The visibilities measured in baselines formed between close antenna elements - in particular, between shadowed elements - of interferometers are often observed to be corrupted. I will show data characterizing the spurious cross-talk and present a model for the spurious correlations.


Tascone Riccardo(1),
co-authors: D. Trinchero(1), M. Baralis(1),  E. Carretti(2), S. Cortiglioni(2)
(1) IRITI-CNR  c/o Politecnico di Torino - Torino - ITALY
(2) ITESRE - CNR - Bologna - ITALY
Millimeter wave passive devices for measurements of the polarized sky emission

The Stokes parameters of the polarized sky emission are detected by a correlation unit, usually called Hybrid Phase Discriminator (HPD). In the millimeter wave range and for rather large bandwidths, heterodyne receivers are not applicable, and the correlation units have to work in the frequency band of the radiometer. The  SPOrt (Sky Polarization Observatory) project will investigate the polarized radiation by means four radiometers at the frequencies 22, 32, 60 and 90 GHz within a 10% bandwidth. This contribution deals with the study of a new configuration of waveguide HPD’s that will be mounted on these radiometers. The configuration presents a high degree of sensitivity for the detection of linearly polarized radiation and is suitable for those technologies that offer a high degree of accuracy. Moreover, the set up allows one to reduce the influence of mechanical tolerances, which are more significant in the higher frequency bands.


Taylor Angela
Cavendish Astrophysics, University of Cambridge
Cambridge - UNITED KINGDOM
The Very Small Array

The Very Small Array (VSA) is a fourteen-element interferometer designed to study the cosmic microwave background on angular scales of 0.14 to 4.5 degrees (angular multipoles l= 100 to 1800). Since mid-2000, the instrument has been making observations of both primordial CMB fluctuations and the Sunyaev-Zeldovich effect in clusters of galaxies from its site in Tenerife. This talk will discuss the current status and results from the telescope.


Terenzi Luca
TESRE - CNR
Bologna - ITALY
Planck-LFI: Sources quick identification

Planck LFI will produce a complete survey of the sky at millimeter wavelenghts. Data stream analysis will provide the possibility to reveal unexpected millimeter sources and to study their flux evolution in time at different frequencies. We describe here the main implications
and discuss data analysis methods. Planck sensitivities typical for this kind of detection are taken into account. We present here preliminary results of our simulation activity.


Thorpe Jim R.(1),
co-authors: D. Andreone(2), L. Brunetti(2), V. Lacquaniti(2), S. Maggi(2), R. Steni(2),
E.S. Battistelli(3), G. Boella(3), F. Cavaliere(3), M. Gervasi(3), A. Passerini(3), G. Sironi(3), M. Zannoni(3),
 E. Natale(4), G. Tofani(4),
E. Bava(5), U. Pisani(6)
(1) Department of Electronic and Electrical Engineering - University of Leeds - Leeds - UK
(2) Istituto Elettrotecnico Nazionale Galileo Ferraris – Turin - ITALY
(3) Università degli studi di Milano Bicocca - Milan - ITALY
(4) Osservatorio Astrofisico di Arcetri – Florence - ITALY
(5) Department of Electronic Engineering- Milan - ITALY
(6) Department of Electronic and Electrical Engineering- Turin - ITALY
Design and Fabrication of Broad-Band Quasi-Optical Heterodyne Detectors for MASTER

The design and fabrication of broad-band 'open-structure' heterodyne detectors for the sensitive down-conversion of millimetre and Submillimetre-Wave signals to the 800 MHz - 1.5 GHz band is described. Details of the chosen quasi-optical coupling structure and methods of non-linear element matching are given. Fabrication processes for the realisation of Nb-AlOx-Nb superconducting tunnel junctions integrated with planar logarithmic antenna structures are provided, together with low-frequency Current-Voltage characteristics.


Tofani Gianni
CAISMI-CNR/Osservatorio Astrofisico di Arcetri
Florence - ITALY
The ALMA project

ALMA project represents a milestone in the contribute given by radioastronomy to the development of Astrophysics. The project, now definitely supported by European, American and Japanise scientific communities, foresees the construction of at least 64 12m radiotelescopes, able to operate in the millimeter/submillimeter spectral range with unsurpassed performances in sensitivity, angular resolution, imaging and spectral capabilities. The programme is now completing the feasibility phase (Phase I), which includes the construction of three antenna prototypes, receiver front end developments, studies on broad band multifunction correlators, simulations on different array configurations etc. The construction phase (phase II) is espected to start in 2002. Science with such a revolutionary telescope covers almostevery field. The main science drivers are the origins of galaxies and
stars: the epoch of first galaxy formation and the evolution of galaxies at later stages including the dust-obscured star-forming galaxies that the HST and VLT cannot see, and all phases of star formation hidden away in dusty molecular clouds.


Valenziano Luca
TESRE - CNR
Bologna - ITALY
The 4K Reference Load for the Planck Low Frequency Instrument

The Planck LFI radiometers will observe continuously the sky and a reference load at T~4K. The design of the 4K Reference Load will be described and test results will be presented.


Villa Fabrizio
TESRE - CNR
Bologna - ITALY
Planck Telescope Performances

The ESA Planck Mission is dedicated to image the Cosmic Microwave Background Anisotropies with uprecedented angular resolution and sensitivity. The two Instruments LFI (Low Frequency Instrument) and HFI (High Frequency Instrument) are coupled to the 1.5m off-axis optimised telescope. The performances of the multi-beam and multi-frequency Planck
telescope optics are discussed.


Wilson Grant
University of Massachusetts - Dept. of Astronomy
Amherst, MA - USA
An Update on The TopHat Experiment

The TopHat Long Duration Balloon (LDB) experiment which launched on January 4, 2001, mapped 6% of the sky in a region centered about the South Celestial Pole. The five spectral bands of the instrument span from 150 to 660 GHz to and are sensitive to CMBR anisotropy and thermal galactic dust emission. Analysis of the data has begun. The parameters of the experiment and observing scheme and preliminary results will be discussed.


Withington Stafford
co-authors: C.Y.Tham and G. Yassin
Astrophysics Group, Cavendish Laboratory, Cambridge University
Cambridge - UNITED KINGDOM
Partially-Coherent Long-Wavelength Optical Simulation Techniques
 for Microwave Background Astronomy

When constructing instruments for microwave-background astronomy, it is essential to control precisely the amount of stray light that is coupled to the detector. Equally, however, it is desirable to maximise the throughput of the telescope. In an attempt to resolve these two conflicting requirements, few-mode waveguide bolometers are being developed. The millimetre and submillimetre-wave fields associated with these detectors are partially coherent, and this complicates the optical design of the telescope considerably. In this paper, we outline a number of techniques for modelling the behaviour of few-moded, long-wavelength, bolometers and optical systems. The techniques are rigorous and applicable to partially-coherent vector fields. We will explain how these techniques can be used to
simulate the behaviour of planar and waveguide bolometers, and how they can be applied to the analysis of large-format imaging arrays.


Yurchenko Vladimir
National University of Ireland Maynooth
Maynooth - IRELAND
Measuring CMB Polarization with ESA PLANCK SubMM-Wave Telescope

We simulated the ESA PLANCK dual-reflector submillimeter-wave telescope designed for measuring the temperature anisotropies and polarization of the CMB radiation. We computed the polarization patterns of the telescope beams from linearly polarized horns. The polarization is generally elliptical except precisely at the beam axis where it remains
linear. To obtain the required orientation of the beam polarization in the sky, we should orient the polarization properly on the horn aperture. We computed the polarization angles for every horn providing the required polarization of the beam in the sky. We also studied the polarization effects of twisting the horns about their axes.


Zannoni Mario
co-authors: E. Battistelli, G. Boella, F. Cavaliere, M. Gervasi, A. Passerini, G. Sironi
Università di Milano - Bicocca
Milan - ITALY
The Milano polarimeter: an instrument to search for large scale polarization of the Cosmic Microwave Background

The expected polarized component of the CMB signal is extremely faint.  On degree angular scales and above it can be in the range of one part to 106 or 107. To detect such an elusive signal a dedicated instrument must be designed. In this contribution we present the new Milano polarimeter, a 33 GHz correlation system able to detect both linear and circular
polarization. It has been designed to operate at large angular scale (7-14 deg) from the ground. In the light of the last observing campaign conducted from Antarctica we have partially redesigned the radiometer to improve its long term stability. The results of  tests of the new system are presented.


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