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The image of the CMB

• Mapping the CMB is very important, since the properties of the image of the CMB are determined by:

1) The physical processes happening in the early Universe

2) The large scale geometry of the Universe

3) The expansion history of the Universe

Long Duration Balloon Flights• NASA-National Scientific Balloons

Facility (based in Palestine-Texas), provides circum-Antarctic long-duration balloon flights during the Antarctic summer. 37 km for 7-14 days.

• This enables long integrations, wide sky coverage and extensive tests for systematic effects, through the repetition of measurements under different experimental conditions:

• Different locations: control ground spillover

• Different day: control Sun in the far sidelobes

• “day” vs “night”observations have different scan directions on the same area, producing crosslinked maps.

William Field, McMurdo, Ross-Sea167o 5.76’E ; 77o 51.76’ S

The launch: Dec. 29, 1998

The launch: Dec. 29, 1998

CMB anisotropy results:

images of the early Universe

The sky scan• The image of the sky is obtained by

slowly scanning in azimuth (+30o) at constant elevation

• The optimal scan speed is between 1 and 2 deg/s in azimuth

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crosslink in BOOMERanG LDB scans (1 scan/hour shown)

elev. = 45o

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R ight Ascension (hours)

• The scan center constantly tracks the azimuth of the lowest foreground region

• Every day we obtain a fully crosslinked map.

BOOMERanG: the MAP• 1998:

BOOMERanG mapped the temperature fluctuations of the CMB at sub-horizon scales (<1O).

• The signal was well above the noise:

2 indep. det.at 150 GHz

The next BIG step: CMB polarization measurements

Velocity fields in the early Universe

The Polarization-sensitive BOOMERanG: B2K

• BOOMERanG can give an important contribution to CMB polarization research

• We have modified the focal plane after the anisotropy flight of 1998 to accomodate Polarization Sensitive Bolometers (PSB).

• We have flown the instrument in Jan. 2003 to detect E-modes

• We plan to fly it again to detect E and B modes polarization of the foreground from ISD at high galactic latitudes.

06/01/2003

BOOM03 Flight

11.7 days of good data

Launched:

January 6, 2003

From:

McMurdo Station,

Antarctica

Measurements OKfor 11.6 days

BOOMERanG landed near Dome Fuji (h=3700m) after 14 days of flight. The data have been recovered immediately . The payload has been recovered in Jan 2004.

BOOMERANG / B2K

Polarization measurements

Preliminary results

Optimal CMB anoisotropy maps obtained with IGLS, the Rome pipeline (Natoli et al. 2001). The anisotropy signal is much larger than the instrument noise. This is the CMB map with highest S/N ever.For the polarization signal the problem is harder.

Rods show measured polarization (signal + noise)

Deep region: polarization signal similar to the noise

Shallow region: polarization signal smaller than the noise

Next BOOMERANG: B2K5

• We plan to re-fly B2K with an upgraded focal plane, to go after foreground cirrus dust polarization.

• This information is essential for all the planned B-modes experiments (e.g. BICEP, Dome-C etc.) and is very difficult to measure from ground.

• The BOOMERanG optics can host an array of >100 PSB at >350 GHz.

30’ 30’ 30’

30’

B2K

B2K5

16 detectors128 detectors

Higher resolution images of the early Universe

Shading light on the dark ages

OLIMPO

OLIMPOAn arcmin-resolution

survey of the sky at mm and sub-mm

wavelengths

(http://oberon.roma1.infn.it/olimpo)

Silvia Masi Dipartimento di Fisica

La Sapienza, Roma

and

the OLIMPO team

30’

CMB anisotropy SZ clusters Galaxies

mm-wave sky vs OLIMPO arrays

150 GHz 220 GHz 340 GHz 540 GHz

Olimpo: list of Science Goals• Sunyaev-Zeldovich effect

– Measurement of Ho from rich clusters – Cluster counts and detection of early clusters ->

parameters ()

• Distant Galaxies – Far IR background– Anisotropy of the FIRB– Cosmic star formation history

• CMB anisotropy at high multipoles– The damping tail in the power spectrum– Complement interferometers at high frequency

• Cold dust in the ISM– Pre-stellar objects– Temperature of the Cirrus / Diffuse component

OLIMPO(http://oberon.roma1.infn.it/olimpo)

Test flight from Trapani (Italy) (July 2005)

Long Duration Balloon flight from polar regions(Peterzen et al. ESA Symposium 2003 – St. Gallen)

Svalbard LDB tests

Test launch July 24, 2004

Feasibility of LDB flight from Svalbard proven

More than 40 days at float

IRIDIUM telemetry module for OLIMPO succesfully tested

Solar panels/charge control tested

Forecasted OLIMPO LDB scientific balloon flight in Summer 2006

BOOMERANG launch movie (10 min.)

Click on the black frame to start

Possible Synergies on LDBs• Technical subsystems:

– Attitude control (ACS) and reconstruction – Power control (solar panels for daylight flights: experience with

BOOM and OLIMPO)– Telemetry (Iridium-based global telemetry for moderate data

rates: experience with Pegaso – G.Romeo, 2400 bps; new parallel system for higher throughput under development for OLIMPO)

• Stratospheric background radiance from – Archeops star sensor data– B2K star camera data– Models

Il Sistema di Puntamento

(Arc min) 90GHz (K) 150GHz (K) 240GHz (K) 400GHz (K)

1 62 56 121 209

2 124 112 242 418

3 186 168 364 628

Errore introdotto da un pendolamento della gondola

E. Pascale, Nov.2000

Se il puntamento non è preciso, la foto viene sfuocata: si perdono le informazioni a piccola scala

Attitude Control System (ACS)

Boomerang ha un beam di 10 minuti d’arco. L’ACS deve garantire:

La ricostruzione della linea di vista entro 1 arc-min rms

Sensori di posizione

Scansioni in azimut a velocità costante

Massimizzare la copertura di cielo

Controllare effetti sistematici:

•Gradienti di temp. sulle strutture

•Residuo atmosferico

Hardware di puntamento

Minimizzare i pendolamentiper ridurre il segnale indotto dalla modulazione

dell’atmosferaE. Pascale, Nov.2000

Pendulation Damper (UCB)

E. Pascale, A. Boscaleri, Nov.2000

Connette la Gondola al Pallone

Scansioni in azimut tramite la torsione Sulla catena di volo e la rotazione di una Ruota di inerzia

Il Pivot

Ava Hristov

Movim

ento di elevazione: Inner frame

ruotato Tram

ite un attuatore lineare

I sensori di posizioneBOMERanG conta un volo di test, notturno, nel 1997 e quello

ANTARTICO, diurno, del ’98Ci vogliono quindi due serie di sensori

Tipo volo Sensori Grossolani Sensori Fini

Notturno Magnetometro Flux Gate (1)(4)

(alta sensibilità, scarsa accuratezza)

Star Tracker (1)(3)

(determina completamente la soluzione attitudinale entro 2 arc-min rms)

Diurno Coarse Sun Sensor (2)(4)

(Sei foto-resistenze, accuratezza ~ 1°)

CCD bilineare solare (2)(4)

(~ 1 arc-min rms)

Entrambe GPS Differenziale: assetto entro 10’ Giroscopio a tre assi (3)

(10 arc-sec rms)

Puntamento in Elevazione: Encoder assoluto ottico a 16bit (20 Arc sec)

Puntamento in Azimut

(1) – IROE(2) – “La Sapienza” (3) – Caltech (4) - ING

Il Controllo

Un sistema completamente digitale permette grande versatilità

Raggi Cosmici possono indurre errori nell’elettronica

Due CPU 386 ridondanti:

• acquisiscono i sensori

• controllano i motori (controller PWM)

Un Watch Dog in pochi ms commuta il controllo fra le due CPU nel caso una fosse ferma per un evento da CR

Interfaccia comandi tdress – gondola

Elettronica di potenza motori

E. Pascale, A. Boscaleri Nov. 2000

BOOMERanG Scan Strategy

Abbiamo una sovrapposi-zione ottimale sulla regione di cielo osservata

3 4 5 6

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crosslink in BOOMERanG LDB scans (1 scan/hour shown)

elev. = 45o

0-11h

12-23h

de

clin

atio

n (

de

gre

es)

R ight Ascension (hours)

P.de Bernardis Oct.2000

Esploriamo il cielo con scansioni lineari in azimut tutto l’esperimento è ruotato d i +30°, 1 o 2°/s. Il centro della scansione traccia l’azimuth a minore foreground

PerformancePerformance

Volo Anntartico:Volo Anntartico:Il Sensore Solare provvede un misura precisa e ripetibile di azimut ed elevazione della navicella, tuttavia il segnale è difficile da calibrare essendo dipendente sia dall’azimut che dall’elevazione del Sole (accuratezza arc-min rms)

Per questo si integrano i tre giroscopi sul SS.

Il Giroscopio di roll fornisce il rollio ignoto al SS

Attitude reconstruction: migliore di 3 arc-min rms

Volo di test:Volo di test:La telecamera stellare fornisce la posizione della navicella negli angoli di azimut,

elevazione e rollio entro 2 ar-min rms a 5 Hz

Su questa vengono integrati i tre giroscopi per la rimozione degli offset

Attitude reconstruction: migliore di 0.5 arc-min rms

E. Pascale, Nov. 2000

Archeops Star Sensor• A linear array of 46 photodiodes in the

focus of a 40cm f/5 telescope.

• Heavily baffled.

• Red filter to maximize stars to atmosphere ratio.

• Attitude reconstruction: better than 1 arcmin.

• See Nati et al. RSI 74, 4169, 2003.

The polar-night flight of Archeops

Stars Great night-time performance: 1300 stars/circle

Poor day-time performance: payload reflections and large-scaleatmospheric diffusion of sun light. (stars are around ten ADU !)

During the Trapani flight we got also day-time data:

Poor day-time performance: payload reflections and large-scaleatmospheric diffusion of sun light. (stars are around ten ADU !)

Scattered sunlight

one azimuth rotation