20 Mars 2006Visions en Astronomie Infrarouge INSTRUMENTAL PROSPECTS IN INFRARED AND SUBMILLIMETER ASTRONOMY Jean-Loup Puget Institut d'Astrophysique Spatiale, Université Paris Sud, Orsay

20 Mars 2006Visions en Astronomie Infrarouge Specificities of thermal infrared astronomy the earth atmosphere is opaque from 13 µm to 350 µm (and still mostly opaque up 800 µm) thermal emission of the atmosphere and of the telescope is a severe limitation to sensitivity increasing very steeply beyond 2 µm in the range 10 µm to 1mm the diffraction limit is from 20 to 2000 times what it is in the V band: CONFUSION limits the sensitivity detector array technology progress have been slower than in the optical and near infrared (although major progress were made on individual detectors and related technology like cryogenic systems)

20 Mars 2006Visions en Astronomie Infrarouge how to overcome these limitations observing from space allow your telescope: –to be above the atmosphere –to be cooled uses large telescopes and interferometers near and thermal IR adaptive optics and interferometry on the long wavelengths side –in atmospheric windows – in very high altitude sites (JCMT, CSO, IRAM, ALMA) the far infrared remains the most difficult; space interferomers still require a lot of developments and will not be available before a long time

20 Mars 2006Visions en Astronomie Infrarouge (D. Scott) Cosmic background from radio to gamma rays CMB CIB

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge The HDF seen by ISO (7 and 15  m) ISOCAM team Orange: 15  m Green: 7  m

20 Mars 2006Visions en Astronomie Infrarouge Fast progress in mid IR detectors and cryogenic telescopes: SPITZER the Si-As BIB arrays used in MIPS allow to get – deep surveys comparable to optical ones –spectra of galaxies at redshifts beyond 3 with an 85 cm telescope ! very efficient He cryostat in space have been built through very efficient passive cooling large telescopes (2 to 3.5 m) for Herschel- Planck can be cooled down below 50 K also with passive cooling

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge Typical galaxy spectrum

20 Mars 2006Visions en Astronomie Infrarouge Source Counts Lagache, Dole, Puget, 2003, MNRAS

20 Mars 2006Visions en Astronomie Infrarouge z < 0.3 z < 2 z < 1.3 z < 1 z < 0.8 Predictions for Redshifts Lagache, Dole, Puget et al, 2004, ApJS, 154 For S 24 2 galaxies bimodal contribution: 0.3 < z < 1 (11 to 13 µm features) peaks at 0.5 mJy 1.6 < z < 2.5 (6 to 9 µm features) peaks at 0.2 mJy min contribution 1.1 < z < 1.6

20 Mars 2006Visions en Astronomie Infrarouge PAH at z~2 Normalized Redshift Distribution in GOODS CDFS : -Ks sample of ~3000 sources (black) -MIPS 24um sample (red), identified at 94% in Ks: ~730 sources: -36% spectroscopic -21% COMBO % photo-z -~30% of Spitzer sources are at z>  m PAH Redshifted at z~2 and Observed at 24  m ! K. Caputi et al., 2005b, submitted

20 Mars 2006Visions en Astronomie Infrarouge Lutz et al, 2005, ApJ PAHs at z~ Submm Galaxies at z~2.8 observed w/ IRS -~2hrs of integration -6.2 & 7.7 (& 8.6) PAHs -Luminosities: 1.3 to Lo -SFR>2000Mo/yr M82+linear AGN continuum

20 Mars 2006Visions en Astronomie Infrarouge ISO 170  m surveys The FIRBACK survey

20 Mars 2006Visions en Astronomie Infrarouge Confusion two types: if you detect sources S>Smin keep the probability to have not separable sources directly linked to N(S>Smin) keep good signal to noise in you beam due to fluctuations of the weaker sources the far infrared and submillimeter is a special case: the second criteria is often coming from sources much weaker than Smin

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge Deep cosmological surveys reveal in K band (K<21.5) MIPS-24µm reveal about galaxies per sq deg 10 per Herschel beam at 550 µm 250 gal per PLANCK beam ! Stacking 24 µm sources in long wavelengths maps possible if you have excellent/stable pointing and effective PSF limited by number of sources and clustering of sources (cannot do stacking when your angular resolution gets smaller than the correlation scale of the source population you study)

20 Mars 2006Visions en Astronomie Infrarouge Stacking Analysis 160 Not physically relevant but illustrative: 80<S 24 <83  Jy 330 sources CDFS [z>1.5 ?] Dole, Lagache, Puget, 2005, astro-ph/

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge beat the confusion: future steps in the stacking game if you can get photometric redshifts for your mid infrared sources such that –galaxies in a redshift and mid IR flux band (typically dz/z~10- 20%) have a long wavelength distribution symetrical with respect to the mean you get from stacking –a large enough number of sources per long wavelength beam such that statistical fluctuations are getting small enough you can then remove these galaxies from the long wavelength maps and be left with a CIB containing only the structures associated with the redshift >2.5 for example in a Planck map at 550 µm with µm galaxies per beam, the error in the removal is the dispersion of the colors divided by about 15

20 Mars 2006Visions en Astronomie Infrarouge Instrumentation: other coming steps at millimeter and submillimeter wavelengths detectors close to quantum limits are being built –for Herschel – Planck arrays in the far infrared are still being developped –Si detectors are very successful up to 35 µm –Ge photoconductors have met many problems –bolometer arrays will fly on Herschel-PACS –arrays of TES (transition edge supra-conductor detectors) multiplexed, planar antenna detection

20 Mars 2006Visions en Astronomie Infrarouge Polarization sensitive bolometers Andrew Lange, Jamie Bock,Caltech-JPL

20 Mars 2006Visions en Astronomie Infrarouge Performances JPL data P100P143P217P353 # in focal plane req  ms6,34,4 8,46,34,4 average  ms 5,22,52,31,21,910,34,53,24,2 Avg dark NEP aW/rt H z 11,313,611,429,830,49,110,314,012,6 NEP/BLIP 0,810,800,540,480,210,991,031,270,84 NET goal  K rt s ,48, Avg NET  K rt s ,45, (min,max) ,09,45,05, UWC data xpol resp. 3,52%5,96%2,21%5,48% (min,max) 1,9 % 5,2 % 3,6 % 8,9 % 2,5 % 3,4 % 4,2 % 7,0 % optical eff. 35%32%26%29%19%32%40%34%23% (min,max) 35 % 36 % 31 % 33% 24%24% 28 % 27 % 30 % 16 % 21 % 25 % 37 % 34 % 44 % 31 % 36 % 21 % 24 % Planck bolometers performances: dark NEP below the photon noise at mm wavelengths

20 Mars 2006Visions en Astronomie Infrarouge Stabilisation PID2 N - thermometer PID2 N 8 nK Hz- 1/2 (+0.014) 30 space qualified dilution cooler (Alain Benoit CRTBT)

20 Mars 2006Visions en Astronomie Infrarouge integrating sphere C S2 CS 1 mirror polariser + crosstalk sources on rocker HFI CQM

20 Mars 2006Visions en Astronomie Infrarouge CMB spectra: temperature, E and B polarization 3 observables : T, E, B B polarization power spectrum is 5 orders of magnitude weaker than T for tensor/scalar =0.1 ! E > 0 E < 0 B > 0 B < 0 WMAP PLANCK dedicated polarization mission

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge Observatories –ISOCAM 15 µm 6 arc sec (32*32 array) –ISOPHOT 160 µm 90 arc sec (4 individual pixels) –SPITZER-MIPS 24 µm 5.6 arcsec (128*128 array) 160 µm (2*20 array) –JCMT-SCUBA 850 µm –IRAM PdB –HERSCHEL 550 µm All sky Surveys –IRAS 1.5 arcmin/0.5 Jy at 100 µm, 30 arcsec/0.5Jy at 12 µm –COBE 40 arc minutes –ASTRO-F –PLANCK 550 µm, 5 arc minutes

20 Mars 2006Visions en Astronomie Infrarouge redshift ranges contributing to the CIB Wavelength (µm)z 50% z 20% - z 80% – – – – – – – 5.5

20 Mars 2006Visions en Astronomie Infrarouge

20 Mars 2006Visions en Astronomie Infrarouge CIB SED Lagache, Dole, Puget, 2003, MNRAS long wavelengths emissivity 1.5 to 2

20 Mars 2006Visions en Astronomie Infrarouge PAHs at z~1.8 to 2.6 Yan et al, 2005, ApJ in press  m galaxies targetted w/ IRS (52 total) -6 MIR features detections: 1.8 < z < & 7.7, 8.6, 11.3 PAHs (+Si abs) -Luminosities: 0.6 to Lo

20 Mars 2006Visions en Astronomie Infrarouge Cosmic Infrared Background 24  m –Down to 60  Jy –75% resolved –By integration of the source counts, is nWm -2 sr  m –Down to 15 mJy –~23% resolved 160  m –Down to 45 mJy –~7% resolved References –Papovich et al., 2004 –Dole et al., 2004

20 Mars 2006Visions en Astronomie Infrarouge Papovich, Dole et al, 2004, ApJS 24  m Differential Source Counts Dole et al, 2004a, ApJS

20 Mars 2006Visions en Astronomie Infrarouge Planck planned capabilities

20 Mars 2006Visions en Astronomie Infrarouge One year mission CMB performances beam size arcmi n 9,57,15555 n pixels 1,65E+062,95E+065,94E+06 system sensitivity to T  K rt s 28,816,426,193,94,22,6 system sensitivity to Q,U  K rt s 43,838,158,9262 avg time/pixel s 19,210,75,3  T/pixel KK 6,65,  T/T/pixel ,41,94,215,  T/T/pixel bluebook ,52,24,814,  (Q,U)/pixel KK 10,011,625,6114  (Q,U)/T/pixel ,74,39,441,9  (Q,U)/T/pixel bluebook ,29,829,8

20 Mars 2006Visions en Astronomie Infrarouge Comparison CIB in optical/IR Energy in the extragalactic background :  < 6  m: 2  W m -2 sr -1  > 6  m: W m -2 sr -1 => E(Far-IR) / E(opt) ~1 – 1.25 Local Universe: –E(Far-IR) / E(opt) = 0.4 !!! Conclusion: –Strong increase of the IR ouput energy with z Questions: –stars or massive black holes as the main energy source –role of IR galaxies in the building of galaxies as we see them today –does the emerging picture fits or not in the standard model of hierarchical structure formation

20 Mars 2006Visions en Astronomie Infrarouge Updated 2004 LDP Model Lagache, Dole, Puget, et al, 2004, ApJS 7.5% 3%