Observation and Data Analysis Activity in SPOrt and BaR-SPOrt Exp.s

1. Observation and Data Analysis Activity in SPOrt and BaR-SPOrt Exp.s Ettore Carretti Bologna 7-9 January 2004

2. CMB photons had last interaction with free electrons about 300000 years after the Big Bang. • They are then carrying the picture of an Universe 50000 times younger, 1000 times hotter and 109 times denser than today. • Statistic properties of such a picture are determined by the plasma physics pre-recombination (acoustic oscillations), by the physics of the early universe (early fluctuations spectrum) and both by the expansion and the geometry of the universe on large scales. • This picture represents the only straight way to investigate the Early Universe and it allows to study its properties. 13.7 Billion years The Science Context • Most of information we have about formation, evolution and destiny of the Universe come from investigations of the Cosmic Microwave Background (CMB) • Anisotropy • Polarization • Spectrum

3. Why observing CMBP ? • The polarized component of the CMB provides new information on: • Large angular scales (10°-20°): can disantangle models with different t better than the anisotropy • Small angular scales (0.2°-0.4°): can provide confirmation of the inflationary frame. • E-mode peaks correspond to anisotropy minima and viceversa. • DASI, WMAP. Anisotropy Polarization

4. Activity in Radio/MW Polarization The CMBP signal is week (few uK for the E-mode; < 0.3uK for the B-Mode) and calls for: • Experiment Design Analysis to take instrumental errors under control; • Data Analysis to • Remove residual systematic effects; • Extract relevant scientific information. • Galactic foreground emission study (Synchrotron); • Identification of low Synchrotron emission regions (BaR-SPOrt); • Identification of Calibration sources; • Theoretical studies of the relevant astrophysics: Galaxy and CMBP.

5. IRA UNI MI-Bicocca UNI FIRENZE ATNF-CSIRO MPI-fR Bonn IEIIT-CNR Activity in Radio/MW Polarization:People Bernardi Gianni Dottorando Carretti Ettore Ricercatore Casarini Luciano Dottorando Cecchini Stefano I Ricercatore Cortiglioni Stefano Ricercatore Macculi Claudio Assegno di Ric. Sbarra Carla Ricercatore ex Art. 23 Sezione di Bologna

6. I. Design Analysis Experiment Design Analysis to take instrumental errors under control: • Analysis of instrumental effects on data (antenna correlation, thermal effects, …..). • Definition of Specs for all components of the system to take systematics under control w.r.t. the wanted signal (CMBP) • Instrument clean enough to match data reduction software requirements Carretti E. et al. (2001) NewA, 6, 173 Carretti E. et al. (2004) submitted to A&A

7. I. Design Analysis (2) Carretti E. et al. (2004) submitted to A&A

8. II. Data Analysis: Destriping • Data Analysis to • Remove residual systematic effects; • Extract relevant scientific information • Instabilities on time scales larger than the signal modulation period generate stripes on the map: Destriping software. • fast iterative version Sbarra C. et al. (2003) A&A, 401, 1215 before…. after destriping

9. Tucci M. et al. (2000) NewA, 5, 181 Bruscoli M. et al. (2002) NewA, 7, 171 Data Analysis (2) • Cosmological parameter extraction for the forthcoming experiments SPOrt and BaR-SPOrt (e.g. optical depth t): in progress. • Measurements of Foreground properties: Angular Power Spectra of synchrotron emission • Galactic Foreground Separation from CMBP signal 60 90 • Power Spectra of Galactic synchrotron extrapolated to 60 and 90 GHz and compared to CMBP E-Mode

10. III. Observations of Low Emission Areas: the BOOMERanG Patch @ 1.4 GHz Bernardi et al., ApJL, 594, L5, astro-ph/0307363 Selected target! • No polarization Observations in low Galactic emission region existed; • First detection of diffuse signal at a so low emission level (ATCA-ATNF). • Mean Emission is found to be: Ip ~ 11.6 mK • Extrapolations are promising for CMBP About 100 times lower than the CMBP signal

11. PI I Observations: Work in progress… • Activity of observation of low polarized synchrotron emission areas: • Observations of the BOOMERanG patch at 2.3 and 5 GHz (already performed in June 2003 and December 2003); • Observations of the DASI patch at 1.4 GHz (already performed in July 2003) • Observations of the BaR-SPOrt Northern target at 1.4 GHz (Low emission area at RA = 11h, DEC = 42°) • Already done with Effelsberg Telescope April 2003.

12. IV. Calibrators: Moon Observations Identification of Calibration sources • Finding CMBP calibrators is a challenge for Experimenters • no dipole • no planets • Polarized calibrators (as 3C286) are very faint. • A solution: the Moon • Observation at 8.3 GHz (MEDICINA) • Polarized intensity is really high: • - Peak at  10 K on arcmin scale • -  5 mK integrated on 7° SPOrt beam • In progress: • Observations at 22, 32 and 90 GHz in next future. Poppi S. et al. (2002) AIP Conf. Proc. 609, 187

13. Bernardi G. et al. (2003) MNRAS, 344, 347 Bernardi G. et al. (2004) MNRAS, submitted V. Theoretical Analysis Theoretical studies of the relevant astrophysics: Galaxy and CMBP. • Synchrotron emission likely represents the most important foreground noise (spinning dust?), but…. lack of data at high Galactic latitutes and in the MW range: • Development of a polarized synch emission template • Analysisof the observed data at high Galactic latitudes • Study of re-ionization scenariosat the epoch of formation of first galaxies.

14. Activity in Radio/MW Polarization • Experiment Design Analysis to take instrumental errors under control; • Data Analysis to • Remove residual systematic effects; • Extract relevant scientific information. • Galactic foreground emission study (Synchrotron); • Identification of low Synchrotron emission regions (BaR-SPOrt); • Identification of Calibration sources; • Theoretical studies of the relevant astrophysics: Galaxy and CMBP.