1 / 64

High Redshift Starbursts

High Redshift Starbursts. Mauro Giavalisco Space Telescope Science Institute and the GOODS team STScI/ESO/ST-ECF/JPL/SSC/Gemini/Boston U./U. Ariz./U. Fla./U. Hawai/UCLA/UCSC/IAP/Saclay/Yale/AUI. The Quest for the Early Galaxies. Giavalisco 2002 ARA&A Ellis 1997 ARA&A.

eliot
Télécharger la présentation

High Redshift Starbursts

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. High Redshift Starbursts Mauro Giavalisco Space Telescope Science Institute and the GOODS team STScI/ESO/ST-ECF/JPL/SSC/Gemini/Boston U./U. Ariz./U. Fla./U. Hawai/UCLA/UCSC/IAP/Saclay/Yale/AUI

  2. The Quest for the Early Galaxies Giavalisco 2002 ARA&A Ellis 1997 ARA&A During the mid-90’s, with improved instrumentation, the commissioning of the 8-m class telescopes, and the repair of HST, a number of influential deep galaxy surveys (CFRS, LBGS, HDF) uncovered two important pieces of evidence: • Normal, luminous galaxies (the bright end of the Hubble sequence) were essentially in place by z~1 • Massive (M*) galaxies formed prior to z~1 • The universe was well populated with star-forming galaxies at z~3 • At z~1 these must be old and/or massive or both. Are these the progenitors of the bright galaxies? Earlier suggestions that the bulk of galaxies formation occurred at z<1 and that “essentially no galaxies are to be expected at redshifts z>1” (1993, actual quote) were dismissed.

  3. Lilly et al. 1995 Abraham et al. 1996

  4. Star-forming galaxies at z~3 (Lyman Break Galaxiess) Steidel, Giavalisco, Dickinson, Pettini & Adelberger 1996

  5. Efficient star formation at z>2.5 Steidel, Adelberger, Giavalisco, Dickinson & Pettini 1999

  6. Galaxy morphology at z~3 • Smaller • Regulars, • Irregulars, • Merging, • Spheroids? • Disks? • No Hubble Seq. • No l-dependence Giavalisco et al. 1994; Giavalisco et al. 1996; Steidel, Giavalisco, Dickinson & Adelberger 1996; Lowenthal et al. 1997; Dickinson 1998; Giavalisco 1998; Papovich, Giavalisco, Dickinson, Conselice & Ferguson 2003 Papovich, Dickinson, Giavalisco, Conselice & Ferguson 2004

  7. UV-star formation rates Some rates are relatively low, ~ today’s spirals; others are prodigiously high Metallicity ~1/10 to ~ solar Still an open issue

  8. The birth of the GOODS • No Hubble Sequence apparently observed at z>2. When and how did it form? • What kind of galaxies are LBGs • Bursting dwarfs? Massive? • What did they evolve into? How much stellar mass did they contribute? • Up to which redshift are there LBGs? When did SF on galactic scale start? • Are there other (non LBG selectable, I.e. non star-forming or very obscured) galaxies at z>2? • How does star formation occur and evolve?

  9. The GOODS Treasury/Legacy Mission Aim:to establish deep reference fields with public data sets from X-ray through radio wavelengths for the study of galaxy and AGN evolution of the broadest accessible range of redshift and cosmic time. GOODS unites the deepest survey data from NASA’s Great Observatories (HST, Chandra, SIRTF), ESA’s XMM-Newton, and the great ground-based observatories. Primary science goals: • The star formation and mass assembly history of galaxies • The growth distribution of dark matter structures • Supernovae at high redshifts and the cosmic expansion • Census of energetic output from star formation and supermassive black holes • Measurements or limits on the discrete source component of the EBL Raw data public upon acquisition; reduced data released as soon as possible

  10. GOODS Space HST Treasury (PI: M. Giavalisco) B, V, i, z (3, 2.5, 2.5, 5 orbits) 400 orbits Δθ= 0.05 arcsec, or ~0.3 kpc at 0.5<z<5 0.1 sq.degree 45 days cadence for Type Ie Sne at z~1 SIRTF Legacy (PI: M. Dickinson) 3.6, 4.5, 5.8, 8, 24 μm 576 hr 0.1 sq.degree Chandra (archival): 0.5 to 8 KeV Δθ < 1 arcsec on axis XMM-Newton (archival) GOODS Ground ESO, institutional partner (PI C. Cesarsky), CDF-S Full spectroscopic coverage in CDF-S Ancillary optical and near-IR imaging Keck, access through GOODS’ CoIs Deep spectroscopic coverage Subaru, access through GOODS’ CoI Large-area BVRI imaging NOAO support to Legacy & Treasury Very deep U-band imaging Gemini Optical spectroscopy, HDF-N Near-IR spectroscopy, HDF-S ATCA, ultra deep (5-10 mJy) 3-20 cm imaging, of CDF-S VLA, ultra deep HDF-N (+Merlin, WSRT) JCMT + SCUBA sub-mm maps of HDF-N A Synopsis of GOODS

  11. GOODS/ACS B = 27.5 V = 27.9 i = 27.0 z = 26.7 HDF/WFPC2 B = 27.9 V = 28.2 I = 27.6 ∆m ~ 0.3-0.6 AB mag; S/N=10 Diffuse source, 0.5” diameter Add ~ 0.9 mag for stellar sources In ~2-3 months we will release a new stack of ~15 orbits in the z band, as well as ~50% and ~30% more exp. time in the i and V bands, in both fields, plus source catalogs (GOODS++)

  12. Unattenuated Spectrum Spectrum Attenuated by IGM B435 V606 z850 GOODS galaxies at High Redshift B435V606i775z850 • Theory predicts that dark matter structures form at z~20-30 • It does not clearly predict galaxies, because we do not fully understand star formation • Empirical information on • galaxy evolution needed to • the highest redshifts • GOODS yielded the deepest and largest quality samples • of LBGs at z~4 to ~6 z~4

  13. LBG color selection B-dropouts, z~4 V-dropouts, z~5

  14. ACS/grism, Keck/LRIS & VLT/FORS2 observations confirm z=5.83 S123 #5144: m(z) = 25.3 Galaxies at z~6 (~6.8% of the cosmic age) Dickinson et al. 2003

  15. Observed redshift distribution #24 Z=5.78 Z=6.24? Curves from full numerical simulations Giavalisco et al. 2004, 2005 V Z=5.83 Spectra from Bunker et al. 2003; Stanway et al. 2003; Vanzella et al. 2004 and the GOODS Team

  16. LBG luminosity function Apparently, very little evolution in the UV luminosity function

  17. The history of the cosmic star formation activity: We find that at z~6 the cosmic star formation activity was nearly as vigorous as it was at its peak, between z~2 and z~3. NOTE: soon, nearly all GOODS will have three times the original exposure time in z band, and ~50% more in i band (thanks to the Sne program). Measure at z~6 will significantly improve. a=-1.6 assumed Giavalisco et al. 2004 Giavalisco et al. 2005, in prep.

  18. Still uncertainty on measures • LF still not well constrained • Clean z~6 color selection still missing • Cosmic variance still not understood • Will use SST data to refine z~6 sample • Will triple exp time in GOODS See also Bunker et al. 2004 Bouwens et al. 2004

  19. SFR from X-ray emission Lehmert et al 2005 See also Giavalisco 2002, ARA&A

  20. Star formation rates z~4 B-band dropouts Dust obscuration correction: Calzetti starburst obscuration law B&C synthetic SED Similar to what observed at z~3

  21. SIRTF Imaging 20.0 20.7 1.66 23.4 0.11 26.3 0.21 25.6 1.35 23.6 GOODS sensitivity 5-σ limiting flux μJy 5-σ limiting AB mag

  22. PAH + continuum (24 mm) Far IR (GTO) Optical + near-IR + nebular lines UV Stellar mass & star formation Mass: Rest-frame near-IR (e.g., rest-frame K-band at z~3), provides best photometric measure of total stellar content • Reduces range of M/L(l) for different stellar populations • Minimizes effects of dust obscuration Star formation: Use many independent indicators for to calibrate star formation (obscured & open) in “ordinary” starbursts (e.g. LBGs) at z > 2. • mid- to far-IR (SIRTF/MIPS); rest-frame UV (e.g, U-band); radio (VLA, ATCA); sub-mm (SCUBA, SEST); nebular lines (spectroscopy) Stellar mass fitting Measuring star formation

  23. Rest-optical & -IR at z~6 • SST IRAC detections of z~6 galaxies => stellar population & dust fitting possible ch1, 3.6mm lrest=5300A ch2, 4.5mm lrest=6600A Dickinson et al in prep

  24. Luminosity Density versus Color and Redshift Papovich et al. 2003 U- and B- dropouts have similar UV-Optical color-magnitude "trends”. Rest-frame UV luminosity density roughly comparable at z ~ 3 and 4. Increase of ~33% in the rest-frame B-band luminosity density from z ~ 4 to 3. UV-Optical color reddens from z ~ 4 to 3, which implies an increase in the stellar-mass/light ratio. Suggests that the stellar mass is increasing by > 33% growth in B-band luminosity density. increase of ~33%

  25. Implications for Galaxy Evolution Dickinson, Papovich, Ferguson, & Budavari 2003

  26. Implications for Galaxy Evolution Dickinson, Papovich, Ferguson, & Budavari 2003 Stellar mass is building up We still need to know how this growth depends on the total mass Total mass of individual galaxies seems to evolve less rapidly: bottles form first, wine is added later GOODS; Papovich et al. 2004

  27. Morphology of Lyman Break Galaxies at z~4 Sersic profile fits and Sersic indices: [Ravindranath et al. 2005] Irregulars: (n < 0.5) Disks: (0.5 > n > 1.0)

  28. Morphology of Lyman Break Galaxies at z~4 Bulges (n > 3.0) Central compact component / point sources? (n = 5.0)

  29. LBG morphology: light profiles We measured the light profiles and parametrized them with the Sersic index Ravindranath et al. 2005

  30. Morphology of LBG Theory predicts that when they form undisturbed, galaxies are disks. Images show a distribution of morphology. Both spheroid-like and disk-like morphology are observed. Ravindranath et al. 2005 z=0 disks z=0 spheroids

  31. Morphology of LBG: the GINI and M20 coefficients mergers spheroids Both spheroids and disk, as well as “transitional morphologies, observed. Major mergers estimated at 15-25%, both at z~4 and z~1.4 (in agreement with kinematics of close pairs with DEIMOS-DEEP –Lin et al. 2005) Lotz, Madau, Giavalisco, Conselice & Ferguson 2005

  32. Local galaxies at high redshift Statistics calibrated using local galaxies Lotz et al. 2005

  33. LBG morphology Lotz et al. 2005

  34. LBG morphology Lotz et al. 2005

  35. LBG morphology Lotz et al. 2005

  36. Infrequent “morphological k-correction” WFPC2 (HDF) and NIC3 J and H images Internal color dispersion consistent with relatively young and homogeneous stellar population Dickinson 1998 Papovich, Giavalisco, Dickinson, Conselice & Ferguson 2004 Papovich, Dickinson, Giavalisco Conselice & Ferguson 2004

  37. The Evolution of galaxy size • First measures at these redshifts • Testing key tenets of the theory • Galaxies appear to grow hierarchically R~H(z)-2/3 Standard ruler R~H(z)-1 Ferguson et al. 2003

  38. Galaxy Clustering at High Redshift • Galaxies at high redshifts have “strong” spatial clustering, I.e. they are more clustered than the z~0 halos “de-evolved back” at their redshift. • High-redshift galaxies are biased, I.e. they occupy only the most massive portion of the mass spectrum (today, the bias of the mix is b~1). • Important: • evolution of clustering with redshift contains information on how the mass spectrum gets populated with galaxies as the cosmic time goes on. • Clustering of star-forming galaxies contains information on relationship between mass and star formation activity

  39. Clustering of star-forming galaxies at z~3 r0=3.3+/- 0.3 Mpc h-1 g = -1.8 +/- 0.15 Steidel et al. 2003 Adelberger et al. 1998 Giavalisco et al. 1998

  40. Strong clustering, massive halos g=1.55 r0 =3.6 Mpc h-1 Porciani & Giavalisco 2002 Adelberger et al. 2004

  41. local galaxies m*>2.5E10 MO m*>1.0E11 MO LBGs K20 EROs sub-mm SDSS QSOs Somerville 2004

  42. Clustering segregationmass drives LUV (SFR) GOODS Ground Lee et al. 2005 Adelberger et al. (1998, 2004) Giavalisco et al. (1998) Giavalisco & Dickinson (2001)

  43. Clustering segregation at z~4 and 5 Clustering segregation is detected In the GOODS ACS sample at z~4 Consistent with other measures, e.g. Ouchi et al. 2004 Lee et al. 2005

  44. Halo sub-structure at z~4 We are observing the structure within the halo. Break observed at ~10 arcsec Note: 10 arcsec at z~4 is about ~350 kpc. See also Hamana et al. 2004 Lee et al. 2005

  45. The Halo Occupation Distribution at z~4 Consistent with Hamana et al. 2004 and Bullock et al. 2001 <Ng>=(M/M1)a M>Mmin 1-s 2-s Lee et al. 2005

  46. The Halo Occupation Distribution at z~0 a = 0.89 +/- 0.05 M1 = (4.74 +/- 0.50) x 1013 MO Mmin = 6.10 x 1012 MO From SDSS data Zehavi et al. 2004

  47. Halos and Galaxies at z~3-5 Halo substructure: we observe an excess of faint galaxies around bright ones. massive halos contain more than one LBG “Bright Centers”: z_850<24.0 “Faint centers”: 24.0< z_850 <24.7 “Satellites”: z_850 >25.0 Lee et al. 2005

  48. Halos and Galaxies at z~3-5 Clustering scaling in good agreement with hierarchical theory Implied halo mass in the range 5x1010 – 1012 MO 1-σ scatter between mass and SFR smaller that 100% Giavalisco & Dickinson 2001 Porciani & Giavalisco 2002 Lee et al. 2004, in prep.

  49. EROs, orUV-faint galaxies at z~2-3 Galaxies selected from near-IR photometry [(J-K)>2.3] A fraction would NOT be selected by LBG criteria (UV selection) However, overlap with LBG not quantified and likely significant (see Adelberger et al. 2004). They appear in general more evolved, I.e. more massive (larger clustering), with larger stellar mass, more metal rich, and more dust obscured) than LBGs. Occurrence of AGN also seems higher. At z~3 these galaxies have about 50% of the volume density of LBGs (highly uncertaint). However; they possibly contribute about up to 100% of the LBG stellar mass density, because they have higher M/L ratios Van Dokkum et al. 2004

More Related