MAXIMA is a balloon-borne platform for measuring the anisotropy of the Cosmic
Microwave Background (CMB). It has measured the CMB power spectrum with a
ten-arcminute FWHM beam, corresponding to a detection of the power spectrum out
to spherical harmonic multipole l~1000. The spectrum is consistent with a flat
Universe with a nearly scale-invariant initial spectrum of adiabatic density
fluctuations. Moreover, the MAXIMA data are free from any notable non-Gaussian
contamination and from foreground dust emission. In the same region, the WMAP
experiment observes the same structure as that observed by MAXIMA, as evinced
by analysis of both maps and power spectra. The next step in the evolution of
the MAXIMA program is MAXIPOL, which will observe the polarization of the CMB
with comparable resolution and high sensitivity over a small patch of the sky.Comment: To appear in New Astronomy Reviews, Proceedings of the CMBNET
  Meeting, 20-21 February, 2003, Oxford, U

Adrian T Lee

Andrew H Jaffe

Bahman Rabii

Balbi

Bond

Brad Johnson

Celeste Winant

Cyburt

de Bernardis

Esposito

George F Smoot

Halverson

Hanany

Huan Tran

Jaffe

Jeff Collins

Jiun-Huei Proty Wu

Julian Borrill

Matthew Abroe

Paul Richards

Pedro Ferreira

Radek Stompor

Santos

Shaul Hanany

Stompor

Tom Renbarger

Tomotake Matsumura

New Astronomy Reviews

arXiv

Crossref

Recent results from the MAXIMA experiment

MAXIMA is a balloon-borne platform for measuring the anisotropy of the Cosmic Microwave Background (CMB). It has measured the CMB power spectrum with a ten-arcminute FWHM beam, corresponding to a detection of the power spectrum out to spherical harmonic multipole l~1000. The spectrum is consistent with a flat Universe with a nearly scale-invariant initial spectrum of adiabatic density fluctuations. Moreover, the MAXIMA data are free from any notable non-Gaussian contamination and from foreground dust emission. In the same region, the WMAP experiment observes the same structure as that observed by MAXIMA, as evinced by analysis of both maps and power spectra. The next step in the evolution of the MAXIMA program is MAXIPOL, which will observe the polarization of the CMB with comparable resolution and high sensitivity over a small patch of the sky

Jaffe, AH

Abroe, M

Borrill, J

Collins, J

Ferreira, Pedro

Hanany, S

Johnson, B

Lee, AT

Matsumura, T

Rabii, B

Renbarger, T

Richards, P

Smoot, GF

Stompor, R

Tran, H

Winant, C

Wu, JHP

ORA - Oxford University Research Archive

Recent Results from the MAXIMA Experiment

Ferreira, P

Spiral - Imperial College Digital Repository

arXiv:astro-ph/0306504v1  24 Jun 2003Recent Results from the MAXIMAExperimentAndrew H. Jaffe a Matthew Abroe b Julian Borrill c,dJeff Collins e Pedro Ferreira f Shaul Hanany b Brad Johnson bAdrian T. Lee e Tomotake Matsumura b Bahman Rabii eTom Renbarger b Paul Richards e George F. Smoot d,eRadek Stompor c,d,e Huan Tran e Celeste Winant eJiun-Huei Proty Wu gaImperial College LondonbUniversity of MinnesotacNational Energy Resource Supercomputing CenterdLawrence Berkeley National LaboratoryeUniversity of California, BerkeleyfUniversity of OxfordgNational Taiwan UniversityAbstractMAXIMA is a balloon-borne platform for measuring the anisotropy of the CosmicMicrowave Background (CMB). It has measured the CMB power spectrum with aten-arcminute FWHM beam, corresponding to a detection of the power spectrumout to spherical harmonic multipole ℓ ∼ 1000. The spectrum is consistent witha flat Universe with a nearly scale-invariant initial spectrum of adiabatic densityfluctuations. Moreover, the MAXIMA data are free from any notable non-Gaussiancontamination and from foreground dust emission. In the same region, the WMAPexperiment observes the same structure as that observed by MAXIMA, as evincedby analysis of both maps and power spectra. The next step in the evolution of theMAXIMA program is MAXIPOL, which will observe the polarization of the CMBwith comparable resolution and high sensitivity over a small patch of the sky.1 IntroductionIn 2000, MAXIMA-I (Hanany et al., 2000) [along with BOOMERANG-98(de Bernardis et al., 2000), with which it shares considerable personnel andPreprint submitted to Elsevier Science 2 February 2008technology] was one of the first CMB experiments to detect anisotropy overa range of angular scales from several degrees down to a resolution of ten ar-cminutes. The pattern of temperature anisotropy, with a characteristic scale ofroughly one degree, was as expected from a flat Universe with a nearly scale-invariant initial power spectrum of adiabatic perturbations, as predicted by,for example, Inflation. This was confirmed in a combined analysis (Jaffe et al.,2001) and by comparison with the many other experiments that have followed,including the recent results from WMAP (see other contributions to this vol-ume).In this Proceedings, we will give an overview of the MAXIMA experimentalprogram, report on results to date from MAXIMA, including cosmologicalresults from the analysis of primary anisotropy as well as efforts to detectdepartures from a Gaussian distribution and contributions from foregroundemission. We will discuss comparisons with results from the WMAP experi-ment, and ongoing plans to use MAXIMA as a CMB polarimeter: MAXIPOL.The MAXIMA program has so far resulted in ten letters and journal paperspublished by the team, several works in progress, many conference proceed-ings, and three Ph.D. theses (with more coming), in addition to the manyworks by other authors using the results. These publications contain far moreinformation than can be reproduced here.2 MAXIMA: Hardware and StrategyMAXIMA is a balloon-borne platform carrying a focal plane of spider-webbolometers cooled to 100 mK. It observes the CMB at 150, 240 and 410 GHzwith a resolution of better than ten arcminutes at all frequencies. The tele-scope is an off-axis Gregorian mount with a 1.3 meter primary mirror. Thebolometers have a Noise-Equivalent Temperature (NET) of 80–90µK√sec at150 GHz.MAXIMA flew on August 2, 1998. The scan strategy was designed to revisitthe same area of sky over a wide variety of timescales to allow for a robustinvestigation of possible systematic errors as well as reduction of the effects of“1/f noise”. The primary mirror chops at 0.45 Hz over about ±2◦ in azimuth atfixed elevation. The gondola simultaneously scans in azimuth at 0.02 Hz overan angular scale designed to result in a roughly 10◦×10◦ patch of sky. The ele-vation of the detector was shifted in mid-flight to cover the same area. Duringthe same flight, observations of Jupiter and the CMB dipole were carried outfor calibration and beam mapping (Jupiter only). The approximately threehours spent observing a field of approximately 120 square degrees resulted ina noise per beam of tens of µK.23 Primary CMB Anisotropy: Maps, Power Spectra and Cosmolog-ical ParametersThe primary scientific results from MAXIMA are in the form of CMB mapsand power spectra (Hanany et al., 2000; Lee et al., 2001). They were producedby the MADCAP (Borrill, 1999) program implementing a Bayesian/maximumlikelihood CMB data analysis algorithm (Bond et al., 1998, 2000).Fig. 1. Map of the MAXIMA-1 field. The temperature in µK is given by the colorbarto the right. The central square was used for subsequent analysis.This power spectrum was then used to estimate the cosmological parame-ters within the paradigm of big-bang models with adiabatic initial conditionsdescribed by a nearly power-law spectrum of primordial perturbations (i.e., so-called inflationary models). The data prefer a flat Universe (Ωtot ≃ 0.9±0.2 at95% confidence) with a nearly scale-invariant spectrum of initial density fluc-tuations (ns ≃ 1.08+0.22−0.12) and a baryon density as determined from big-bangnucleosynthesis (Ωbh2 ≃ 0.33 ± 0.13). These are all consistent with expecta-tions from the inflationary paradigm and with determinations of the parame-ters from other ground- and balloon-based experiments (e.g., Halverson et al.,2002; Pearson et al., 2002; Grainge et al., 2002) and from the WMAP satellite3Fig. 2. CMB Power spectrum from MAXIMA-1, from Lee et al. (2001). The filledcircles give the maximum-likelihood solution and errorbars (decorrelated using thetechnique of Bond et al. (1998)); the crosses and errorbars give an estimate of thepower spectrum from two independent maps given by different combinations ofMAXIMA detectors. The curve is a best-fit model from Stompor et al. (2001).(Spergel et al., 2003).In addition to the work by the MAXIMA team itself, these data have alsobeen used to test the details of quintessence or dark energy (Balbi et al., 2001)and Big-Bang nucleosynthesis (Esposito et al., 2001; Cyburt et al., 2002), aswell as more exotic models with massive neutrinos, nontrivial topology, extradimensions, isocurvature fluctuations, topological defects, etc. There remainsno compelling evidence from these data for anything beyond the “standardcosmology” discussed above.44 Foregrounds & Non-GaussianityThus far, no departure from Gaussianity have been detected at a level that issignficant or would affect these results. Indeed, in the main analysis describedin the previous section, we assume that the data are as simple as possible:uncontaminated by foreground emission and with both signal and noise well-described by Gaussian statistics. These assumptions can be tested and anydepartures from them can be quantified.The question of non-Gaussianity is discussed elsewhere in these Proceedings(Heavens 2003) as well as in greater detail in Wu et al. (2001), which considers82 (not independent) pixel-based tests, and in Santos et al. (2002, 2003), whichcalculate the cosmological bispectrum (3-point function in harmonic space).Thus far, no significant departures from Gaussianity have been detected.The MAXIMA field was chosen to be well off of the Galactic plane and ina region of particularly low dust contrast. Nonetheless, in Jaffe et al. (2003),we show that there is a small amount of emission correlated with the pat-tern of dust morphology. The amplitude of the correlated emission is barelydetectable, but as expected from extrapolations of the dust spectrum downto the 150-400 GHz observed by MAXIMA. This emission has no significanteffect on the power spectrum or cosmological parameters.5 MAXIMA and WMAPIn February, 2003, data from the WMAP satellite became available, provid-ing a benchmark against which the last few years’ ground- and balloon-basedCMB results can be tested, down to WMAP’s resolution of 13 arcminutes.We will provide a full comparison of the MAXIMA data with that from theWMAP satellite in Abroe et al (forthcoming). Here, we concentrate on thecomparison of publicly-available data from both teams. In Figure 3 we com-pare power spectra. As is evident from this figure, the field probed by theMAXIMA data shows structure with the same statistical properties as, andwith higher resolution than, the all-sky WMAP data. This comparison is borneout by a side by side visual comparison of the maps of the MAXIMA region(Figure 4), and with a more detailed comparison of the overlapping portionof the two datasets as well as MAXIMA data from other campaigns (Abroeet al, forthcoming).5Fig. 3. MAXIMA-1 and WMAP power spectra. The filled green circles are the MAX-IMA data from Lee et al. (2001); the error bars without symbols are the WMAPdata, rebinned to the same ℓs as MAXIMA, weighted by the inverse variance. Thesolid curve is the best fit from the WMAP team.6 MAXIPOLThe next step in the evolution of the MAXIMA program is MAXIPOL. Itconsists of the MAXIMA hardware with additions to make it sensitive to thepolarization of the CMB. A wire grid is placed in front of the detector horns,and a half-wave plate is rotated at 2 Hz in front (see Figure 5). This meansthat a single detector can observe polarization states rotated around a full180◦ on timescales much shorter than the drift in detector gain, and addinganother timescale over which we can monitor for systematic effects.MAXIPOL should have a polarization sensitivity (in Cℓ) comparable to thatof WMAP and other recent experiments. It achieves this by combining the6Fig. 4. MAXIMA (left) and WMAP (right) maps of the MAXIMA-1 region. Bothmaps have been Wiener filtered and smoothed for presentations. Note that theMAXIMA map has a resolution of about 10 arcminutes, the WMAP map about 13arcminutes.Fig. 5. Diagram of the MAXIPOL polarizer, feed horn and bolometer.high-resolution MAXIMA optics and the cooled MAXIMA bolometers with avery deep “exposure” of a small area of sky (a few square degrees).The MAXIPOL team is happy to report that on 24 May, 2003, just prior to thesubmission of these proceedings, the MAXIPOL instrument was successfullylaunched for a twenty-five hour flight from Fort Sumner, New Mexico.7 ConclusionsThe MAXIMA program has measured the temperature anisotropy of the Cos-mic Microwave Background over angular scales from ten degrees to ten arcmin-utes, and over a factor of several in frequency. It has used these measurementsto determine the CMB power spectrum and the parameters of the cosmolog-ical. It will soon be able to detect the polarization of the CMB, which willallow a strong check on the underlying cosmological paradigm as well as thedetermination of the parameters to higher precision. Similar technology willbe used in the forthcoming Planck satellite mission as well as future ground-7and balloon-based detectors.ReferencesBalbi, A., et al, Feb. 2001. Implications for Quintessence Models fromMAXIMA-1 and BOOMERANG-98. Astrophys. J. Lett.547, L89–L92.Bond, J. R., Jaffe, A. H., Knox, L., Feb. 1998. Estimating the power spectrumof the cosmic microwave background. Phys. Rev. D57, 2117–2137.Bond, J. R., Jaffe, A. H., Knox, L., Apr. 2000. Radical Compression of CosmicMicrowave Background Data. Astrophys. J.533, 19–37.Borrill, J., 1999. Madcap - the microwave anisotropy dataset computa-tional analysis package. http://www.nersc.gov∼borrill/cmb/madcap.html;astro-ph/9911389.Cyburt, R. H., Fields, B. D., Olive, K. A., Apr. 2002. Primordial nucleosyn-thesis with CMB inputs: probing the early universe and light element as-trophysics. Astroparticle Physics 17, 87–100.de Bernardis, P. et al, Apr. 2000. A flat Universe from high-resolution mapsof the cosmic microwave background radiation. Nature404, 955–959.Esposito, S., et al, Feb. 2001. Testing standard and degenerate big bang nucle-osynthesis with BOOMERANG and MAXIMA-1. Phys. Rev. D63, 43004.Grainge, K., et al, Dec. 2002. The CMB power spectrum out to l=1400 mea-sured by the VSA. In: 6 pages with 5 figures, submitted as a letter toMNRAS.Halverson, N. W., et al, Mar. 2002. Degree Angular Scale Interferometer FirstResults: A Measurement of the Cosmic Microwave Background AngularPower Spectrum. Astrophys. J.568, 38–45.Hanany, S., et al, Dec. 2000. MAXIMA-1: A Measurement of the CosmicMicrowave Background Anisotropy on Angular Scales of 10′-5◦. Astrophys.J. Lett.545, L5–L9.Jaffe, A. H., et al, Apr. 2001. Cosmology from MAXIMA-1, BOOMERANG,and COBE DMR Cosmic Microwave Background Observations. PhysicalReview Letters 86, 3475–3479.Jaffe, A. H., et al, Jan. 2003. Determining Foreground Contamination inCMB Observations: Diffuse Galactic Emission in the MAXIMA-I Field.astro-ph/0301077.Lee, A. T., et al, Nov. 2001. A High Spatial Resolution Analysis of theMAXIMA-1 Cosmic Microwave Background Anisotropy Data. Astrophys.J. Lett.561, L1–L5.Pearson, T. J., et al, May 2002. The Anisotropy of the Microwave Backgroundto l = 3500: Mosaic Observations with the Cosmic Background Imager ,astro-ph/0205388.Santos, M. G., et al, Jun. 2002. Estimate of the Cosmological Bispectrumfrom the MAXIMA-1 Cosmic Microwave Background Map. Physical Review8Letters 88, 241302.Santos, M. G., et al, May 2003. Multiple methods for estimating the bispec-trum of the cosmic microwave background with application to the MAXIMAdata. Mon. Not. R. Astr. Soc.341, 623–643.Spergel, D. N., et al, Feb. 2003. First Year Wilkinson Microwave AnisotropyProbe (WMAP) Observations: Determination of Cosmological Parameters.astro-ph/0302209.Stompor, R., et al, Nov. 2001. Cosmological Implications of the MAXIMA-1High-Resolution Cosmic Microwave Background Anisotropy Measurement.Astrophys. J. Lett.561, L7–L10.Wu, J. H., et al., Dec. 2001. Tests for Gaussianity of the MAXIMA-1 CosmicMicrowave Background Map. Physical Review Letters 87, 251303.9

Oxford University Research Archive

MAXIMA is a balloon-borne platform for measuring the anisotropy of the Cosmic
Microwave Background (CMB). It has measured the CMB power spectrum with a
ten-arcminute FWHM beam, corresponding to a detection of the power spectrum out
to spherical harmonic multipole l~1000. The spectrum is consistent with a flat
Universe with a nearly scale-invariant initial spectrum of adiabatic density
fluctuations. Moreover, the MAXIMA data are free from any notable non-Gaussian
contamination and from foreground dust emission. In the same region, the WMAP
experiment observes the same structure as that observed by MAXIMA, as evinced
by analysis of both maps and power spectra. The next step in the evolution of
the MAXIMA program is MAXIPOL, which will observe the polarization of the CMB
with comparable resolution and high sensitivity over a small patch of the sky

Oxford University Research Archive (ORA)

Recent results from the MAXIMA experiment

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ORA - Oxford University Research Archive

Spiral - Imperial College Digital Repository

Oxford University Research Archive

Oxford University Research Archive (ORA)