Duilia de Mello

Some results presented are unpublished. If you need to referto this work contact me. Don’t use it without emailingme before, please, duilia@ipanema.gsfc.nasa.gov

Steidel et al. 1999

Extinction corrected

LBGs

| | | | 8.8 6 3.3 1.6 Gyr Duilia de Mello

Lyman Break Technique

UV dropouts – z~2.6-3.4 [UV is detected in the optical]Steidel et al. 2004, Shapley et al. 2003, Pettini et al. 2000

Rest-frame 1000 1200 1450 1925

LBGs spectra are similar to starbursts at low-z starbursts.

What are their morphologies?

Are they the building blocksof larger galaxies?

Need a large sample of LBGs!Deep images with high resolution.

Giavalisco et al. 2004

HSTACS (B, V, i, z)Multi-epoch2 fields SouthNorth (CDF-SHDF-N) –316 arcmin2

0.03”/pixSpatial resolution 0.1’’

B-dropouts : LBGs at z = 4

Ravindranath et al. (2005; in preparation)

Steidel et al. 1999

Extinction corrected

LBGs

| | | | 8.8 6 3.3 1.6 Gyr Duilia de Mello

Rest-frame UV

• 1500 Å at z~0.5 is observed at 2250 Å

• 0.8 2700

• 1.0 3000

• 1.2 3300

1500 Å at z=1

• WFPC2 (F300W) observations of GOODS/HST are shallow but cover large area.

• WFPC2 (F300W) observations of the Ultra Deep Field (UDF) - Deep but cover small area.

Magnitude_Auto (F300W)

UDF

GOODS

84 700 s orient 310238 400 s orient 314= 323 100 s

278.9 ks

Resolution = 0.06”/pixel

de Mello, Wadadekar, Casertano, Gardner 2005 (submitted)

Photometric Redshifts

Templates: early- to late-type Coleman et al.Starbursts Kinney et al.

E Sbc Scd

Im Starburst Starburst

Dahlen et al. 2005, Mobasher et al. 2004

Coleman et al. 80, Kinney et al. 96

Results – GOODS shallow U-band

E Sbc Scd Im Sb1 Sb2

E Sbc Scd Im Sb1 Sb2

Gallery of starbursts with spectroscopicredshifts:

Late-types, Interacting, Tidal tails,Compacts,tadpoles

zphot=0.36 zphot=0.42 zphot=0.57

zphot=1.12 zphot=0.55 zphot=0.69

zphot=0.7 zphot=1.12 zphot=1.31

Results – GOODS shallow U-band

• 35% are starbursts (81/227 – 43 stars)

• 75% of starbursts have tidal tails or peculiarities/interaction

• 50% of starbursts have another galaxy within 5x5”

• 36% of starbursts show tadpole morphology

Blue are starbursts Circles HDF-N Triangles CDF-S

Luminous blueCompact galsBlue nucleated,Compact narrowemission line,Small blue galsBershady etal 00

Blue are starbursts Circles HDF-N Triangles CDF-S

Bluest are mostly Starbursts, #2 is Im

BluestObjects

CompactsTidal tailsTadpolesBut...

BluestObjects

CompactsTidal tailsTadpolesBut...Are we lookingat the SFregion shapeor overallMorphology?

BluestObjects

CompactsTidal tailsTadpolesBut...Are we lookingat the SFregion shapeor overallMorphology?Is GOODS goodEnough?? Depth Of ACS and WFPC2 enough??

Results – GOODS deep U-band

E-Sa

SB1

SB2

1. E2. Sbc3. Scd4. Im5. Starburst 16. Starburst 2

Cyan 0.2<z<0.6Yellow 0.6<z<0.8Green 0.8<z<1.0Magenta 1.0<z<1.2

Scd/Sdm/IrrSab/SbcE/S0

Locals:

Measured on rest-frame B band

Papovich et al 05

At 0.8<z<1.2 mostof objects are: -compact, LSB, tadpoles

- Have spectraltypes of starbursts

- and have small and have small sizes rsizes rhh~2kpc~2kpc

LBGs at z~4<rh>~1.7kpcFerguson etal. 2004 – measuredat rest-frame UV1200-2000Å

Young clusters (Antennae)Intermediate 0.25-1GyrOld Globulars

B-V

V-I

108 – 1010 yr

New Starburst99Vazquez &Leitherer 05

Cyan 0.2<z<0.6Yellow 0.6<z<0.8Green 0.8<z<1.0Magenta 1.0<z<1.2

• UV-selected galaxies at intermediate-z when seen in redder wavelenghts are:- spirals, peculiars, compact, tadpoles, lsb, and

even early-types ! • Majority of them have spectral types of starbursts,

have neighbors, show signs of interaction. Bluest are compact, tadpole.

• At 0.8<z<1.2 most of UV-selected objects are compact, LSB, blue dots, tadpole, with small sizes rh~2kpc, and spectral types of starbursts.

• When compared to clusters and models, most of the UV-selected have mixed ages ranging from 108 to 1010 yr.

• Next: increase UV sample: GALEX, UDF ACS-UV

BluestObjects

CompactsTidal tailsTadpolesBut...Are we lookingat the SFregion shapeOr overallMorphology?Is GOODS goodEnough?? Depth Of ACS and WFPC2 problem??

Zphot=1.28

Zphot=1.48

Zphot=1.74

Local Universe – multiwavelength view (K-correction)

• Late-type (Sc and later) are similar in the optical and UV (star-forming regions dominate).

• Early-type spirals (Sa-Sbc) tend to be classified as later-types in the UV (disk dominates).

• Ellipticals retain smooth profile, but appear more compact.

Morphological K-correction (ACS/SBC, WFPC2, NICMOS)Teplitz et al. 2005 in preparation

FUV NUV300 I874 H160 FUV NUV300 I874 H160

z0.09

0.321

0.321

0.475

0.555

0.682

HDF-N

Comparison of Structural Parameters from GOODS and HUDF:

Ravindranath et al. (2005; in preparation)

Triangles are LBGsBlue z=3Green z=4Red z=5

Dots are all galaxies

GOODS depth is goodEnough for bright LBGs

Results – GOODS shallow U-band

• 95 objects with spectroscopy

• Objects of all types (35% Starbursts)

• 66% of the starbursts have tidal effects and/or close companions, but only

• 33% of the other types have tidal effects

Cyan 0.2<z<0.6Yellow 0.6<z<0.8Green 0.8<z<1.0Magenta 1.0<z<1.2

LBGs are moreluminous withMB ~ -23 ± 1

Cyan 0.2<z<0.6Yellow 0.6<z<0.8Green 0.8<z<1.0Magenta 1.0<z<1.2

Scd/Sdm/IrrSab/SbcE/S0

Locals:

CAS in the ACS

1134 galaxies identified in the ACS field within0.24<z<1.3 RAB<24 – Mobasher et al. 2003

65% are late-types (C=2.65, A=0.27)21% are early-types (C=2.35, A=0.23)14% are starbursts (C=2.53, A=0.33)

UV selected galaxies are on average moreasymmetric (C=2.63, A=0.35)

AAS Atlanta 2004

Chandra=460 arcmin2

Duilia de Mello

Which objects cause the decline in the SFR density?

| | | | 8.8 6 3.3 1.6 Gyr

Connolly et al. 97Lilly et al. 96

Fading dwarfs or decline in SF in disks?

Duilia de Mello

Steidel et al. 1999

Multi-wavelength: B, V, i, z (3700 – 11000 Å)

Multi-epoch: every 45 days (5 epochs)

Area: 316 arcmin2 – two fields

Resolution: 0.03”/pixel – spatial resolution 0”.11

Duilia de Mello

Models – Starburst99

Vazquez & Leitherer 2005

Young clustersIntermediateOld Globulars

NGC4038/39 Whitmore et al. 99

solar metal.20% solar2% solar

• 88% of the two GOODS ACS fields

• 741 WFPC2 images: 30 GOODS-S, 25 GOODS-N drizzled images.

• Source Extractor (1.5σ sky threshold – 5 contiguous pixels)

• Match WFPC2 and ACS catalogs (1.5”): 130 objects in the GOODS-S and 138 in the GOODS-N, total of 268 objects

U-dropouts : LBGs at z = 3

<----------->3"Ravindranath et al. (2005; in preparation)

V-dropouts : LBGs at z = 5

Ravindranath et al. (2005; in preparation)