Observation and Data AnalysisObservation and Data AnalysisActivityActivity

ininSPOrt SPOrt and and BaR-SPOrt BaR-SPOrt Exp.sExp.s

Ettore Ettore Carretti Carretti

Bologna 7-9 January 2004

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

• 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

Why observing CMBP ?Why observing CMBP ?

Polarization

Anisotropy

The The polarized component of the CMBpolarized component of the CMB provides new information on: provides new information on:

• Large angular scales (10°-20°)Large angular scales (10°-20°): can disantangle models with different : can disantangle models with different better than the anisotropybetter than the anisotropy

• Small angular scales Small angular scales (0.2°-0.4°)(0.2°-0.4°): can provide : can provide confirmation of the confirmation of the inflationary frame. inflationary frame. E-mode peaks E-mode peaks correspond to correspond to anisotropy minima and anisotropy minima and viceversa.viceversa.

DASI, WMAP.DASI, WMAP.

Activity in Radio/MW Activity in Radio/MW PolarizationPolarization

The CMBP signal is weekweek (few uK for the E-mode; < 0.3uK for the B-Mode) and calls for:

I.I. Experiment Design AnalysisExperiment Design Analysis to take instrumental errors under control;

II.II. Data AnalysisData Analysis to – Remove residual systematic effects;– Extract relevant scientific information.– Galactic foreground emission study (Synchrotron);

III.III. Identification of low Synchrotron emission regions low Synchrotron emission regions (BaR-SPOrt)(BaR-SPOrt);;

IV.IV. Identification of CalibrationCalibration sources;

V.V. Theoretical studiesTheoretical studies of the relevant astrophysics: Galaxy and CMBP.

Activity in Radio/MW Activity in Radio/MW Polarization:Polarization:

PeoplePeopleBernardi 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

IRA UNI MI-BicoccaUNI FIRENZE

ATNF-CSIRO

MPI-fR Bonn

IEIIT-CNR

I. Design AnalysisI. Design AnalysisExperiment Design AnalysisExperiment Design Analysis to take instrumental errors under

control:• Analysis of instrumental effectsinstrumental effects on data (antenna correlation,

thermal effects, …..).• Definition of SpecsDefinition 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

I. Design Analysis (2)I. Design Analysis (2)

Carretti E. et al. (2004) submitted to A&A

II. Data Analysis: II. Data Analysis: DestripingDestriping• Data AnalysisData 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 versionSbarra C. et al. (2003) A&A, 401, 1215

before…. after destriping

Data Analysis (2)Data Analysis (2)

60

90

• Cosmological parameter Cosmological parameter extraction extraction for the for the forthcoming experiments forthcoming experiments SPOrt and BaR-SPOrt (e.g. SPOrt and BaR-SPOrt (e.g. optical depth optical depth ): in progress.): in progress.

• Measurements of Measurements of Foreground properties: Foreground properties: Angular Power SpectraAngular Power Spectra of of synchrotron emissionsynchrotron emission

• Galactic Foreground Galactic Foreground SeparationSeparation from CMBP from CMBP signalsignal

Tucci M. et al. (2000) NewA, 5, 181

Bruscoli M. et al. (2002) NewA, 7, 171• Power Spectra of Galactic Power Spectra of Galactic

synchrotron synchrotron extrapolated to extrapolated to 60 and 90 GHz and 60 and 90 GHz and compared to compared to CMBP E-ModeCMBP E-Mode

Frequency

32 GHz 1.0

90 GHz 0.05

150 GHz 0.02

About 100 times lowerAbout 100 times lowerthan the CMBP signalthan the CMBP signal

KPrms

III. Observations of Low Emission Areas:III. Observations of Low Emission Areas:the BOOMERanG Patch the BOOMERanG Patch @ 1.4 GHz@ 1.4 GHz

Selected target!Selected target!

•No polarization ObservationsNo polarization Observations in low Galactic in low Galactic emission region existed; emission region existed;

•First detectionFirst detection of diffuse signal at a so low of diffuse signal at a so low emission level (emission level (ATCA-ATNFATCA-ATNF).).

•Mean Emission is found to be: Mean Emission is found to be: IIp p ~ 11.6 mK~ 11.6 mK

•Extrapolations are promising for CMBPExtrapolations are promising for CMBP

Bernardi et al., ApJL, 594, L5, astro-ph/0307363

Activity of observation of low polarized synchrotron emission areas:Activity of observation of low polarized synchrotron emission areas:• Observations of the Observations of the BOOMERanG patch at 2.3 and 5 GHzBOOMERanG patch at 2.3 and 5 GHz

(already performed in June 2003 and December 2003);(already performed in June 2003 and December 2003);• Observations of the Observations of the DASI patch at 1.4 GHzDASI patch at 1.4 GHz (already performed in (already performed in

July 2003)July 2003)• Observations of the Observations of the BaR-SPOrt Northern target at 1.4 GHzBaR-SPOrt Northern target at 1.4 GHz (Low (Low

emission area at RA = 11emission area at RA = 11hh, DEC = 42°), DEC = 42°) Already done with Effelsberg Telescope April 2003.Already done with Effelsberg Telescope April 2003.

Observations: Work in progress…Observations: Work in progress…

I PI

IV. Calibrators: Moon IV. Calibrators: Moon ObservationsObservationsIdentification of CalibrationCalibration sources

• Finding CMBP calibrators is a challengechallenge for Experimenters– no dipole no dipole – no planetsno planets

• Polarized calibrators (as 3C286) are very faint.very faint.• A solution: the Moonthe 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 beamIn progress: Observations at 22, 32 and 90 GHz in next future. Poppi S. et al. (2002) AIP Conf. Proc. 609, 187

V. Theoretical AnalysisV. Theoretical AnalysisTheoretical studiesTheoretical studies of the relevant astrophysics: Galaxy and CMBP.

• Synchrotron emission Synchrotron emission likely represents the most important foreground noise (spinning dust?), but…. lack of datalack of data at high Galactic latitutes and in the MW range:– Development of a polarized synch emission templatesynch emission template– AnalysisAnalysis of the observed data at high Galactic latitudeshigh Galactic latitudes

• Study of re-ionization scenariosStudy of re-ionization scenarios at the epoch of formation of first galaxies.

Bernardi G. et al. (2003) MNRAS, 344, 347 Bernardi G. et al. (2004) MNRAS, submitted

Activity in Radio/MW Activity in Radio/MW PolarizationPolarization

I.I. Experiment Design AnalysisExperiment Design Analysis to take instrumental errors under control;

II.II. Data AnalysisData Analysis to – Remove residual systematic effects;– Extract relevant scientific information.– Galactic foreground emission study (Synchrotron);

III.III. Identification of low Synchrotron emission regions low Synchrotron emission regions (BaR-SPOrt)(BaR-SPOrt);;

IV.IV. Identification of CalibrationCalibration sources;

V.V. Theoretical studiesTheoretical studies of the relevant astrophysics: Galaxy and CMBP.