Dynamical Properties o Dynamical Properties o f Forming Galaxies f Forming Galaxies at Redshift at Redshift z > 5 z > 5 Yoshi Taniguchi Yoshi Taniguchi Research Center for Research Center for Space & Cosmic Evolution Space & Cosmic Evolution Ehime University Ehime University
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Dynamical Properties of Forming Galaxies at Redshift z > 5
Dynamical Properties of Forming Galaxies at Redshift z > 5. Yoshi Taniguchi Research Center for Space & Cosmic Evolution Ehime University. ZOO of Star-Forming Galaxies at High Redshift. LAE LBG ERO DRG BzK SMG ・・・・・・・. z > 5. z < 5. LAEs vs. LBGs. LAE surveys - PowerPoint PPT Presentation
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Dynamical Properties of FDynamical Properties of Forming Galaxiesorming Galaxiesat Redshift at Redshift z > 5z > 5
Yoshi TaniguchiYoshi Taniguchi
Research Center for Research Center for Space & Cosmic EvolutionSpace & Cosmic Evolution
Ehime UniversityEhime University
ZOOZOO of Star-Forming Galaxies of Star-Forming Galaxiesat High Redshiftat High Redshift
LAE surveysLAE surveys may miss weak Lymay miss weak Lyemitters,emitters, but faint cont. doesn’t matterbut faint cont. doesn’t matter
LBG surveysLBG surveys may miss faint continuum sources,may miss faint continuum sources, but w/ or w/o Lybut w/ or w/o Ly doesn’t matter doesn’t matter
LAEs vs. LBGsLAEs vs. LBGs
LAEs tend to beLAEs tend to be younger (larger EW of Lyyounger (larger EW of Ly)) less massive (fainter UV)less massive (fainter UV) ………… ………….. than LBGsthan LBGsBut,But,
not always !not always !
LAEs vs. LBGsLAEs vs. LBGs
LAEs & LBGs are overlappedLAEs & LBGs are overlappedin many physical properties by definitionin many physical properties by definition
Difference between LAEs & LBGsDifference between LAEs & LBGsas a function of redshift & environas a function of redshift & environ
give us hints to understand give us hints to understand SF history in early universeSF history in early universe
But, ……But, ……
LAE to LBG Ratio @ z ~ 3 – LAE to LBG Ratio @ z ~ 3 – 77
SDF
SDF
(Yamada+05, PASJ, 57, 881; Sumiya+08, in prep.)(Yamada+05, PASJ, 57, 881; Sumiya+08, in prep.)
MAHOROBA-11
z=6 sampleby Dow-Hygelund07
HST/ACS Imaging ofHST/ACS Imaging ofLAEs @ z=5.7 & z=4.9LAEs @ z=5.7 & z=4.9in the in the COSMOSCOSMOS Field Field
Morphology of LAEs Morphology of LAEs
HST Treasury Program(Cycle 12 & 13)Scoville et al.
ACS I814
Subaru Intensive Program(S03B , S04B, S05B,…)
Taniguchi et al.Other optical bands
Cosmic Evolution Survey- COSMOS -
COSMOS-20COSMOS-20
12 IB2 NBNB816NB711
119 LAEs @ z=5.7 in COSMOS119 LAEs @ z=5.7 in COSMOS(Murayama et al. 07, ApJS, 172, 523)(Murayama et al. 07, ApJS, 172, 523)
85 LAEs are imaged w/ACS-F814W 85 LAEs are imaged w/ACS-F814W
● Not imaged w/ACS(34 LAEs)
● Detected w/ACS(47 LAEs)
× Not detected w/ACS(38 LAEs)
● Masked out areas
Half-Light Radius (RHalf-Light Radius (RHLHL))(1”=6 kpc @ z = 5.7)
LAEs are more compact LAEs are younger than LBGs ?
(Dow-Hygelund+ 07, ApJ, 660, 47)
RRHLHL vs. z850 mag vs. z850 mag for High-z LAEs and LBGsfor High-z LAEs and LBGs
z~6z~6 Bouwens06 i-dropout (UDF, UDF-P, GOODS-N&S)Bouwens06 i-dropout (UDF, UDF-P, GOODS-N&S) Bunker03 1 LAE @ Bunker03 1 LAE @ z z =5.7=5.7 Bunker04 UDF i-dropoutBunker04 UDF i-dropout Stanway04a 3 LAEsStanway04a 3 LAEs Stanway04b 2 LAEs in GOODS-NStanway04b 2 LAEs in GOODS-N Dow-Hygelund07 22 Dow-Hygelund07 22 z z ~6 (UDF&UDF-P)~6 (UDF&UDF-P)z~5z~5 Rhoads05 1 LAE @ Rhoads05 1 LAE @ z z =5.42=5.42 Overzier06 23 V dropouts in RG (Overzier06 23 V dropouts in RG (z z =5.2) field=5.2) fieldz~4z~4 Overzier08 63 g dropouts in RG (Overzier08 63 g dropouts in RG (z z =4.1) field=4.1) field 13 spectroscopic confirmed LAEs13 spectroscopic confirmed LAEs
Little difference in sizes between LAEs & LBGsLittle difference in sizes between LAEs & LBGsLittle redshift evolution from z=6 to 4 ?Little redshift evolution from z=6 to 4 ?
LAE (Red) LBG (Black)
RRHLHL vs z vs z850 850 Relation Relation for High-z LBGs and LAEsfor High-z LBGs and LAEs
79 LAEs @ z=4.9 in COSMOS79 LAEs @ z=4.9 in COSMOS(Shioya et al. 08, ApJ, submitted)(Shioya et al. 08, ApJ, submitted)
61 LAEs are imaged w/ACS-F814W 61 LAEs are imaged w/ACS-F814W
● Not imaged w/ACS(18 LAEs)
● Detected w/ACS(55 LAEs)
× Not detected w/ACS(6 LAEs)
● Masked out areas
LAE (Red) LBG (Black)
RRHLHL vs z vs z850 850 Relation Relation for High-z LBGs and LAEsfor High-z LBGs and LAEs
?
Little difference in sizeLittle difference in size between LAEs & LBGs @ each zbetween LAEs & LBGs @ each z
Size evolution from z=6 to 4 is weakSize evolution from z=6 to 4 is weak although LAEs @ z=6 are slightly although LAEs @ z=6 are slightly smaller than those @ z =4 – 5smaller than those @ z =4 – 5
RRHLHL vs z vs z850850 Relation Relation for High-z LAEs and LBGsfor High-z LAEs and LBGs
Dynamical Structures of the LAEsDynamical Structures of the LAEs@ @ z=5.7z=5.7 in COMSOS in COMSOS
Disk-like or Spheroidal-like ?Disk-like or Spheroidal-like ?
Azimuthally-averaged profileAzimuthally-averaged profile w/ PSF deconvolutionw/ PSF deconvolution (Hathi et al. 08, arXiv:0710.0007)(Hathi et al. 08, arXiv:0710.0007)
RRHLHL=0.08”=0.08” ~480 pc~480 pc Sersic Sersic nn=0.8=0.8
Dynamical Structures of LAEs Dynamical Structures of LAEs @ z=5.7 in the COSMOS Field@ z=5.7 in the COSMOS Field
Disk-like or Irregular morphologyDisk-like or Irregular morphology for both compact & extended LAEsfor both compact & extended LAEs
Note thatNote that 40% of bright LBGs @ z=2.5 – 5 40% of bright LBGs @ z=2.5 – 5 show disk-like morphology,show disk-like morphology, but 30% show spheroid-like structuresbut 30% show spheroid-like structures (Ravindranath+06)(Ravindranath+06)
Need systematic analysis of dynamical structures of LBGs & LAEs as a function of z
Multiple-component LAEsMultiple-component LAEsin the COSMOS Fieldin the COSMOS Field
Fraction of multiplesFraction of multiples
2/47 = 4 % @ z = 5.72/47 = 4 % @ z = 5.7
8/55 = 15 % @ z = 4.98/55 = 15 % @ z = 4.9
ZOOZOO of Star-Forming Galaxies of Star-Forming Galaxiesat High Redshiftat High Redshift
There There must bemust be overlaps in observational pr overlaps in observational properties between LAEs and LBGs operties between LAEs and LBGs by defiby definitionnition..
However, systematic studies of both populHowever, systematic studies of both populations ations as a function of zas a function of z are absolutely n are absolutely necessary to understand ecessary to understand the whole history the whole history of star formation in early universeof star formation in early universe..