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Galaxy formation from infrared to submm. Michael Rowan-Robinson Imperial College London. 1. Extragalactic infrared and submillimetre surveys 2. Radiative transfer models for extragalactic infrared sources 3. Models for source-counts and background radiation, from
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Galaxy formation from infrared to submm Michael Rowan-Robinson Imperial College London 1. Extragalactic infrared and submillimetre surveys 2. Radiative transfer models for extragalactic infrared sources 3. Models for source-counts and background radiation, from submm to ultraviolet MAGPOP Summer School
Extragalactic infrared and submillimetre surveys Michael Rowan-Robinson Imperial College London most of the starlight ever generated in the universe is emitted at infrared wavelengths, ~ 50% is absorbed by dust and reemitted at far infrared and submillimetre wavelengths Dole et al 2006 MAGPOP Summer School
the infrared and submillimetre bands 1 micron - 1 mm - a few terrestial windows MAGPOP Summer School
Pre-IRAS, IRAS • Pre-IRAS: • 1969: Caltech 2 Micron Survey (Neugebauer and Leighton) – circumstellar dust shells, BN object • 1976: The AFGL Survey at 4.2, 11, 19.8 and 27.4 mm • (Price and Walker) – cds, HII regions • IRAS: • 1984: IRAS all sky survey at 12, 20, 60, 100 mm • - 30,000 infrared galaxies (measured redshifts of 12000 with S(60)>0.6 Jy - PSCz) • - ir cirrus • - ULIRGS, HLIRGS • - AGN dust tori • - ir dipole, large scale structure MAGPOP Summer School
IRAS Horsehead Nebula MAGPOP Summer School
IRAS all-sky survey MAGPOP Summer School
Infrared galaxy populations with IRAS we were able to identify the main infrared galaxy populations - quiescent galaxies (ir cirrus) - starburst galaxies (prototype M82) - extreme starbursts (prototype A220) - AGN dust tori but the IRAS survey was not deep enough (z ~ 0.3) to study the cosmological evolution of these populations, though 60 mm source-counts showed that evolution is present, at a comparable rate to that seen in radio-galaxies and quasars an important insight was that as infrared luminosity increased, the proportion of interactions and mergers increased MAGPOP Summer School
ISO ISO, launched 1996, reached z~1, + spectroscopy MAGPOP Summer School
ISO surveys • CAM Deep Surveys • Fadda et al, 2001, AA, astro-ph/011412 • Franceschini et al, 2002, AA, astro-ph/0108292 • Elbaz et al, 2002, AA 384, 848 • ELAIS Survey at 6.7, 15, 90, 175 mm • Oliver et al, 2000, MN 316, 749 • Serjeant et al, 2000, MN 316, 768 • Efstathiou et al, 2000, MN 319, 1169 • Serjeant et al, 2001, MN 322, 262 • Lari et al, 2001, MN 325, 1173 • Gruppioni et al, 2002, MN 341, L1 • Rowan-Robinson et al, 2004, MN 351, 1290 • ISO HDF-N and HDF-S surveys • Oliver et al, 2002, MN 332, 546 • Mann et al, 2002, MN 332, 549 • FIRBACK 175 mm survey • Dole et al, 2001, AA 372, 264 MAGPOP Summer School
ISO surveys • * main result was very strong increase in star-formation rate • in galaxies between z = 0 and 1 (factor ~10) (Rowan-Robinson • et al 1997, Flores et al 1999), confirming the result from optical • surveys (Lilley et al 1996, Madau et al 1996) and that the rate • estimated from optical data without correction for extinction is • severely underestimated. • problems of screen model for extinction correction • issue of consistency between estimates of star-formation rate • from uv, Ha, radio, far infrared • sfr = 2.2 x 10-10 L60 = 2.5x10-8 LHa = 4.5x10-10 L2800A MAGPOP Summer School
Dust extinction in local galaxies <AV> ~ 0.3 in local galaxies (Rowan-Robinson, 2003, MN 344, 13) MAGPOP Summer School
comparison of star-formation rate estimates Daddi et al 2007 MAGPOP Summer School
impact of JCMT HDFN at 850 mm Hughes et al 1998 blank field surveys at 850 mm showed that we were able to survey the whole universe to z = 5 with ultraluminous ir galaxies SHADES MAGPOP Summer School
Submillimetre surveys • Hubble Deep Field North • Hughes et al 1998 • Hawaii surveys • Barger et al 1998, 1999, Cowie et al 2002, • Wang et al 2004 • CUDSS survey • Eales et al 1999, Webb et al 2003, • Clements et al 2004, Ashby et al 2006 • UK 8 mJy survey (200 sq arcmin) • Scott et al 2001, Fox et al 2001, • Ivison et al 2002, Almaini et al 2003 • SHADES (0.5 sq deg) • Mortier et al 2005, Coppin et al 2006, • Ivison et al 2007, Aretxaga et al 2007 MAGPOP Summer School
submillimetre associations and galaxy redshift distribution Chapman et al, 2005, ApJ 622, 772 • poor spatial resolution of JCMT means that reliable optical or infrared associations can only be made if have millimetre • interferometry or radio associations • why don’t we see submm • galaxies at z > 4 ? • is this a selection effect ? MAGPOP Summer School
Near-ir Surveys • 2MASS all-sky survey at J, H, K (to 15.8, 15.1, 14.3 mag.) • – http://www.ipac.caltech.edu/2mass/ • UKIDDS survey of 7500 sq deg in JHK (K=18.3) • -http://www.ukidss.org/ • FIR Surveys • SPITZER surveys (GTO - various, FLS - 4 sq deg, SWIRE - 49 sq deg, GOODS - 0.1 sq deg, AEGIS - 1 sq deg, COSMOS - 1 sq deg) • at 3.6, 4.5, 5.6, 8, 24, 70, 160 mm • - http://ssc.spitzer.caltech.edu/ • ASTRO-F all-sky survey in 6 bands at 9-180 mm • - http://www.akari.org.uk MAGPOP Summer School
2MASS • 2MASS provides a better picture of galaxy distribution at z<0.03 MAGPOP Summer School
Layered SPITZER Surveys • Wide–shallowFLS GTO-shallow SWIRE • greatest volume 4 8.5 49 sq deg • rare luminous objects • large-scale structure • Confusion-limitedGTO-deep GOODS-IRAC • maximum information 2.5 sq deg 300 sq arcmin on faintest resolved sources • Ultra-deepGTO-ultra GOODS-24mm • confusion distribution150 300 sq arcmin MAGPOP Summer School
M51Sombrero combined 3.6, 8 and 24 mm images (SINGS consortium) MAGPOP Summer School
M82N2207/IC2163Stefan’s Quintet MAGPOP Summer School
SPITZER SWIRE survey 49 sq deg in 6 areas, at 3.6, 4.5, 5.8, 8, 24, 70, 160 mm MAGPOP Summer School
ELAIS N1: 9 sq. deg SWIRE 3.6 mm survey in ELAIS-N1 MAGPOP Summer School
Photometric redshifts method based on fixed galaxy and AGN templates, two passes through data to help identify QSOs and AGN dust tori, and selected priors Rowan-Robinson et al 2007 MAGPOP Summer School
Photometric redshifts SWIRE-VVDS sample (with VVDS team, PI LeFevre) VIRMOS-VLT Deep Survey spectra >1000 sources ~3% rms in (1+z) <1% outliers red: gals, blue QSOs ~ IRAC 3.6 and 4.5 mm big help in reducing outliers z = 1 MAGPOP Summer School 2 3 4
Photometric redshifts All SWIRE Catalogue VVDS: 9 optical bands N1,N2: 5 optical bands Lockman: 3-4 optical bnds CDFS: 3 optical bands XMM-LSS: 5 optical bands red: galaxies, blue QSOs SWIRE Photometric Redshift Catalogue contains over 1 million redshifts, 10% have z >2, 4% have z > 3, 20% detected at 24 mm, 1% at 70 or 160 mm z = 1 MAGPOP Summer School 2 3 4
rms, % outliers, as function of number of bands MAGPOP Summer School
Redshift distributions left: Suburu XDS, R<27.5 below: ELAIS-N1, r<23.5: for optically blank sources use 3.6-8 mm for phot-z >=3 bands from U-8mm MAGPOP Summer School
Lir/Lopt • for galaxies with an ir excess, we fit ir templates (cirrus, M82, A220, AGN dust • torus) and estimate Lir (reasonably accurate if have 70 mm detection) • for cirrus galaxies, Lir/Lopt is a measure of optical depth of ism • for star-forming galaxies, Lir/Lopt is the specific star formation rate MAGPOP Summer School
Lir/Lopt for starbursts MAGPOP Summer School
star-forming ellipticals • * Lir/Lopt (specific star formation rate) versus Lopt (~ M•) for galaxies with elliptical galaxy template fits * includes objects like Arp 220, whose star formation is heavily obscured • Black: cirrus • Red: M82 starburst • Green: A220 starburst MAGPOP Summer School
ultraluminous cirrus gals(L), star-forming ellipticals(R) MAGPOP Summer School
Japanese mission, 68 cm cooled telescope, first all-sky far • infrared survey since IRAS, 90 and 140 mm, sensitivity • probably comparable to IRAS FSS, but much better spatial • resolution, so in principle may be able to construct deeper • all-sky sample than PSCz AKARI MAGPOP Summer School
HERSCHEL 3.6 m passively cooled telecope operating at 50-500 mm layered survey will be carried out by SPIRE and PACS teams in guaranteed time, widest area 70 sq deg in 9 areas MAGPOP Summer School
PLANCK PLANCK will carry out a shallow all-sky extragalactic point-source survey, which will detect many high-z very luminous submm galaxies MAGPOP Summer School
Radiative transfer models for extragalactic infrared sources • radiative transfer models for ir sources • cirrus models for local quiescent galaxies • models for starburst, UKIRGs, HLIRGs • applications to Spitzer galaxies, submm galaxies • IRS spectra and their interpretation MAGPOP Summer School
ingredients for models for seds of infrared sources • model for interstellar grains [ Mathis et al 1977, Draine and Lee 1984, Rowan-Robinson 1992, Desert et al 1990, Siebenmorgen and Krugel 1992, Dwek 1998] • assumed density distribution for dust [r ~r-b, HII region physics (Yorke 1977, Efstathiou et al 2000)] • dust geometry [ spherically symmetric, axisymmetric (Efstathiou and RR 1990, 1991, 1995, Pier and Krolik 1992, Granato et al 1994, 1997, Silva et al 1998), clumpy [Rowan-Robinson 1995, Hoenig et al 2006] • radiative transfer code [Rowan-Robinson 1980, Efstathiou and RR 1990, Pier and Krolik 1992, Krugel and Siebenmorgen 1994, Granato et al 1997, Silva et al 1998, Popescu et al 2000, Hoenig et al 2006] MAGPOP Summer School
Radiative transfer models for infrared sources • spherically symmetric dust clouds • - first accurate code 1980 (R-R, ApJS 234, 111) • - circumstellar dust shells 1981-3 • starbursts and ULIRGs (RRE, 1993, MN 263, 675; ERRS, 2000) • cirrus galaxies (ERR, 2003) • axially symmetric dust clouds • - first accurate code 1990 (Efstathiou and R-R, MN 245, 275) • - protostars 1991 • - AGN dust tori 1995 MAGPOP Summer School
the radiative transfer equation The intensity of radiation In(r,q) satisfies the equation dIn/ds = - n(r) Cn,ext In + n(r) Cn,abs Bn [T(r)] + n(r) |4p Cn,sc (q’) In (q’) dw/4p where Cn,abs= pa2Qn,abs, Cn,sc= pa2Qn,scz(q’) Cn,ext = Cn,abs + |4p Cn,sc (q’) dw/4p MAGPOP Summer School
interstellar dust grains size 50 A - 0.1 mm (and larger ?) composition: amorphous C graphite amorphous silicates crystalline silicates SiC PAHs Brownlee particle MAGPOP Summer School
discovery of PAHs Leger and Puget, 1984, AA 137, L5 MAGPOP Summer School
IRAS - cirrus south celestial pole MAGPOP Summer School
Cirrus models for local galaxies • assume optically thin ism, extinction AV (<1, 0.4-0.9) • BC starburst models, age t*, exponential decay time t • characterise galaxies by single mean intensity, y = bolometric intensity/solar neighbourhood intensity (~2-5) • for local galaxies, t* = 0.25 Gyr, t = 5-11 Gyr • (Efstathiou and Rowan-Robinson 2003, MN 343, 322) MAGPOP Summer School
IRAS - star forming regions LMC constellation Orion MAGPOP Summer School
IRAS - ultraluminous infrared galaxies Arp 220 Soifer et al, 1984, ApJ 283, L1: the remarkable infrared galaxy Arp 220 MAGPOP Summer School
Models for starburst galaxies • Eftstathiou, R-R, Seibenmorgen, 2000, • MN 313, 734 • embedded phase, t < 107 yrs • expanding neutral shell, t = 107-108 years • at 108 yrs, indistinguishable from cirrus MAGPOP Summer School
galaxy sed model fits from GRASIL(Silva et al 1998) MAGPOP Summer School
seds of ultraluminous infrared galaxies L:ISO R:SPITZER MAGPOP Summer School
IRAS - AGN dust tori Miley et al, 1984, ApJ 278, L79: A 25 mm component in 3C390.3 MAGPOP Summer School
Infrared templates (Rowan-Robinson 2001) MAGPOP Summer School