Test #1! Test #2! Test #2: Results!

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Rebecca Copeland
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1 High-Redshift Galaxies II - Populations (cont d) - Current Redshift Frontier - Gravitational Lensing I will hand back Test #2 HW#10 will be due next Monday. Nov 18, 2015

2 Test #1 Test #2 Test #2: Results

for different redshifts classical LBG: z~3 and higher BX: z~2.0-2.5 BM: z~1.5-2.

3 LBGs vs. BX/BM galaxies LBG LBG BX BM Fine-tuning of LBG technique: Different UGR colors for different redshifts classical LBG: z~3 and higher BX: z~ BM: z~ Tuned to fill the classical redshift desert where few galaxies were known LBG and BX/BM are often lumped together as a population Steidel et al. 2004

4 LBGs: Spectroscopic Confirmation

5 What kind of galaxies are LBGs? Population synthesis modeling & spectra: data fit continuous star formation models with range of ages ( Myrs), masses ( M sun ) and metallicities (0.3 to >1 solar), IMF~Salpeter/Chabrier for >10 M sun Pettini et al. 2000, Shapley et al. 2003, 2005, Erb et al. 2006abc

Properties of Lyman Break Galaxies (z~3) <age> = 320 Myr @ z = 3 <M * > = ~2 x 10 10 M

6 Properties of Lyman Break Galaxies (z~3) <age> = 320 z = 3 <M * > = ~2 x M <E(B-V)> =0.15 A UV ~1.7 "~5 <SFR> ~ 45 M yr -1 Extinction correlates with age young galaxies are much dustier SFR for youngest galaxies average 275 M yr -1 ; oldest average 30 M yr -1 Objects with the highest SFRs are the dustiest objects Shapley et al ApJ 562, 95

7 Composite Spectra: Young versus Old Young LBGs have much weaker Ly# emission, stronger interstellar absorption lines and redder spectral continua dustier Galaxy-scale outflows ( superwinds ), with velocities ~500 km s -1, are present in essentially every case examined in sufficient detail Shapley et al ApJ 562, 95

8 Lyman Break Galaxies: Summary Period of elevated star formation (~100 s M yr -1 ) for ~50 Myr with large dust opacity Superwinds drive out both gas and dust, resulting in more quiescent star formation (10s M yr -1 ) and smaller UV extinction later on Quiescent star formation phase lasts for at least a few hundred Myr; by end at least a few M of stars have formed All phases are observable because of near-constant far-uv luminosity (decreasingly dusty towards older age/lower SFR)

9 Lyman-# emitters (LAEs) (broad-band)-(narrow-band) Spectroscopic follow-up of candidates Tend to be less massive, fainter subpopulation of LBGs [contaminants: lower-z emission line galaxies] 5007Å 3727Å 1216Å Compare signal in narrow-band filter with broad-band signal

10 Lyman-# Blobs (LABs) Giant blobs of Ly-# emission Commonly tens of kpc or more across Winds/outflows driven by star-forming galaxies Ly-# Blob of Hydrogen gas X-ray: AGN X-Ray+optical+IR Lyman-#$ continuum

11 Passively-Evolving Galaxies LBGs are star-forming galaxies Availability of panoramic IR cameras opens possibility of locating non-sf galaxies at high z Termed variously: Extremely Red Objects Distant Red Galaxies depending on selection criterion A break at z=2.5: at 1.4µm Such objects would not be seen in Lyman-break samples for z ~ 1-2: select on I-H color for z > 2: select on J-K color

12 Objects with J-K > 2.3 Surprisingly high surface density: ~0.8/arcmin 2 to K=21 (two fields) ~2/arcmin 2 to K=22 (HDF-S) ~3/arcmin 2 to K=23 (HDF-S) van Dokkum, Franx, Rix et al.

13 Characteristic Properties of Distant Red Galaxies " (Franx et al. 2003, van Dokkum et al. 2004, Foerster-Schreiber et al. 2005, Labbe et al. 2005) Epoch: z~2.5 SED fitting to get M*, SFR,% dust M * ~5x x10 11 M sun Nearly as massive as most massive galaxies today Contain the bulk of stars at those epochs Star-formation rate ~ M sun /yr Dust extinction important A V ~2 mag SFR cross-checked with thermal-ir For SFR ~ e -t/ % " t fit ~500Myr " Mass build-up: SFR x % ~ M sun Reached the epoch when massive galaxies are forming stars at a high rate

14 Distant Red Galaxies: Spectroscopy z=2.43 z=2.43 z=2.43 z=2.71 z=3.52 van Dokkum et al.

15 Redshifted spectra B, z, K bands at z=

16 BzK selection of passive and SF z>1.4 galaxies New apparently less-biased technique for finding all galaxies 1.4<z<2.5 sbzk: star forming galaxies pbzk: passive galaxies (z-k) overlap between different samples is fairly high at same Ks criteria >90% of BX/BM at bright levels (~10 11 M sun, Ks<20) are s-bzk BX/BM are low-obscuration subset of s-bzk less overlap at fainter levels DRGs are more of a mixed bag, include passive galaxies and appear to frequently select AGNs (B-z) Daddi et al ApJ 617, 746

17 Lyman breaks or dropouts at higher z z-dropout Stanway et al. (2003) Traditional dropout technique poorly-suited for z > 6 galaxies: - significant contamination (cool stars, z~2 passive galaxies) - spectroscopic verification impractical below ~few L* i-drop volumes: UDF ( ), GOODS-N/S ( ), Subaru (10 6 ) Mpc 3 flux limits: UDF z<28.5, GOODS z<25.6, Subaru z<25.4

18 Contamination from z~2 Passive Galaxies Addition of a precise opticalinfrared color (z - J) can, in addition to the (i - z) dropout cut, assist in rejecting z~2 passive galaxy contaminants. (i z) 5.7 < z < 6.5 z~2 passive galaxies This contamination is ~10% at z~25.6 but is negligible at UDF limit (z~28.5) (z J)

19 Contamination by Galactic dwarfs - more worrisome UDF z<25.6 L dwarfs E/S0 HST half-light radius R h more effective than broad-band colors Contamination at bright end (z<25.6) is significant (30-40%)

20 Keck spectroscopy of i-drops: 10.5 hrs z AB <25.6 z=5.83 Ly-# L-dwarfs contaminate at bright end

Spectroscopy: The Current Frontier Finkelstein et al.

51 (6 th at z>7) Corresponds to an epoch 700 million years

from HST, only confirmed this one difficult, but possible

21 Spectroscopy: The Current Frontier Finkelstein et al. 2013: LBG with Ly-# emission line ID-ed at z=7.51 (6 th at z>7) Corresponds to an epoch 700 million years after the Big Bang Looked at 43 candidate z~8 galaxies from HST, only confirmed this one difficult, but possible endeavor with new near-ir multi-object spectrographs Nature N&V; Riechers 2013

68 galaxy identified From same sample (4 galaxies), also

22 Spectroscopy: The Current Frontier Oesch et al. 2015: z spec = 7.73 galaxy identified Zitrin et al. 2015: z spec = 8.68 galaxy identified From same sample (4 galaxies), also confirmed one at z spec = 7.47 All are very bright, why sudden, high confirmation rate?

5 µm) implies strong H# and [OIII]+H& emission lines selects

23 Spectroscopy: The Current Frontier Roberts-Borsani et al. 2015: selection based on bright, red Spitzer/IRAC colors (3.6 vs. 4.5 µm) implies strong H# and [OIII]+H& emission lines selects bright, intensely star-forming galaxies " perhaps also high Ly-# escape fraction??

24 The Future: z=10, and beyond "#$%& "#$%&'(%)(*+,(-./.0('#1234%5( 678%%(9:/.(;*&535*)%'(*)(<='$ F++3'(%)(*+,(-./GH(8%?3'%5(I7")"J9()"(9:/-( 8*22%8(%)(*+,(-./GH( K"''31+%(-,L'(+3&%( M"#+5(1%(2"8%( ;"&'3')%&)($3)7(9:-,-( 3&)%8+"I%8( B*C%8(3&;+#53&D(2"8%(5*)*E( N*I*O(%)(*+,(-./GH( P"(+3&%('%%&(*'(183D7)( *'(8*22%80(1#)( I"''31+%(Q*3&)(-,-'(+3&%(

25 Strongly Lensed Candidates '()*&BN+#')%8(+%&'3&DE( 9RS,TU(V7%&D(%)(*+,(-./-( 9R/.,LU(N"%(%)(*+,(-./GU(WX/YGH(Z%&'%5(32*D%'( WX/aWX-( ["&9*+%90(\3%;7%8'(%)(*+,(-./]H(&"(^N `(*)(9://((

26 Massive, Active Galaxies at Very High Redshift Do Massive Galaxies, Supermassive Black Holes, Metals exist very early on? SZ effect: no massive (few times M sun ) galaxy clusters at z>1.5 or so density contrasts not high enough yet, cosmic structure formation not sufficiently mature 9-10 billion years ago At some earlier epochs, halos massive enough to form massive galaxies/ billion solar mass black holes should disappear. How and when? Expectations from hierarchical growth: massive galaxies that do exist early on should grow in the highest-density peaks/over-dense regions or even proto-clusters of galaxies. Evidence? Also, at some early point timescales become short to have formed significant amounts of metals. The first stars (Pop III) are metal-free, and have to pollute their environments to allow dust, CO etc. to form. The most massive halos may be enriched early on. Evidence?

Observed 880 million years after the Big

34 Detect 7 CO lines 7 H 2 O lines H 2 O

27 Observed 880 million years after the Big Bang (current age: 13.8 billion yrs) Big Bang HFLS3 Lines are associated with gas in star-forming regions today A dusty massive starburst galaxy found at z=6.34 Detect 7 CO lines 7 H 2 O lines H 2 O + NH 3 (absorption) OH OH + (absorption) [CI] [CII] Hints of others Highly enriched Gray line is best existing spectrum of nearby starburst Riechers et al. 2013b, Nature

- Almost as much M * as the Milky Way - Similar total mass, already at z=6.

starbursts => massive galaxies exist at z>6 => already chemically enriched, >1

$%+";3)b(53'I%8'3"&(D*'(8%'%8?"38H(73D7(cd\(583?%&(1b(*(2*e"8(2%8D%8( "#$%fgxdh(:/.$

28 - Almost as much M * as the Milky Way - Similar total mass, already at z= x more gas, 2000x higher SFR than MW ~20x higher SFR than extreme nearby starbursts => massive galaxies exist at z>6 => already chemically enriched, >1 billion M sun of dust => rapid enrichment at early epochs ;"2I*;)(B:G,=OI;E0(73D7(?%+";3)b(53'I%8'3"&(D*'(8%'%8?"38H(73D7(cd\(583?%&(1b(*(2*e"8(2%8D%8( "#$%fgxdh(:/.(9:t(z['(i%8(*8;23& -( ((((((((((((((X#')b(')*81#8')'H("&%(*)(9:T(O&"$&(*;8"''(%&h8%('Obi( Riechers et al. 2013b

M100 Herschel/SPIRE ALMA Spectral Energy

Patnaude et al, Optical: ESO/VLT, Infrared:

beyond 500 µm red to Herschel telescope, use to

29 M100 Herschel/SPIRE ALMA Spectral Energy Distribution Credits: X-ray: NASA/CXC/SAO/D.Patnaude et al, Optical: ESO/VLT, Infrared: NASA/JPL/Caltech Flux density wavelength µm - idea: z>3.5 galaxy spectral energy distributions peak beyond 500 µm red to Herschel telescope, use to ID starbursts at the earliest epochs similar to optical color/dropout techniques, only possible since Herschel

30 Enrichment of Typical Very High z Galaxies? Until recently: no dust or ISM detection in normal galaxy beyond z=3.2 (Magdis et al. 2012) ALMA to the rescue: Detection of [CII] 158 µm cooling line in z=5.3 Lyman-break galaxy - SFR UV = 22 M sun /yr typical at z~5 (would be low among classical z~3 LBGs) - SED shows little evidence for old stellar populations or large quantities of dust Even normal galaxies at z>5 (1.1 billion years after the Big Bang) are significantly enriched but: perhaps less than LBGs at z~3 Need to quantify the evolution of metallicity through cosmic time Riechers et al. 2014b

2x2 arcmin 2 Molecular Gas COSMOS/AzTEC-3 (z=5.3) # AzTEC-3: Most Distant Massive Starburst Galaxy 2010-13 (1.

8) M sun ~55% M total (20x Milky Way) SFR: ~1100 M sun /yr or >3 M sun /day (Milky Way: ~2 M sun /yr) # Most Distant Galaxy

31 2x2 arcmin 2 Molecular Gas COSMOS/AzTEC-3 (z=5.3) # AzTEC-3: Most Distant Massive Starburst Galaxy (1.1 billion years after Big Bang) M gas = 5.3 x (# co /0.8) M sun ~55% M total (20x Milky Way) SFR: ~1100 M sun /yr or >3 M sun /day (Milky Way: ~2 M sun /yr) # Most Distant Galaxy Proto-Cluster: 11 star-forming galaxy companions within r~2 Mpc (>10x cosmic average at epoch) Massive galaxies do appear to grow rapidly in massive halos/density peaks at early epochs Riechers, Capak et al. 2010, ApJ Capak, Riechers et al. 2011, Nature

High-Redshift Galaxies - Exploring Galaxy Evolution - Populations - Current Redshift Frontier

Lecture 20; Nov 06, 2017 High-Redshift Galaxies - Exploring Galaxy Evolution - Populations - Current Redshift Frontier Pick up PE #20 Reading: Chapter 9 of textbook I will hand back HW#7 Wednesday: Second