Monsters in Early Universe

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Kerrie Collins
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1 Monsters in Early Universe Myungshin Im Dept. of Physics and Astronomy Astronomy Program Seoul National University

2 History of the Universe Early Universe Unexplored Epoch of the Cosmic History

3 Theoretical Story of Early Universe I Proton (+) Cosmic Microwave Background (Nobel Prizes) + + H Photons (N) Electron (-) - - He H H Dark Age ~3x10 5 yrs ~3x10 8 yrs Proto- Galactic Gas H H First Stars (~100 M ) Re-ionization of the Universe H + Proto- Galactic Gas - + H Black Holes (~10 M ) + - ~(3-10)x10 8 yrs Proto- Galactic Gas - + Supernovae ( 超新星, GRB) ~3-6 Myr H + - Heavy elements (Ingredients of life!)

4 Theoretical Story of Early Universe II Supermassive Black Holes (~ M ) ~1x10 9 yrs Quasar (> L ) Galaxy Cluster ~2x10 9 yrs Quasar + Galaxy

5 Is This Story Right? Monsters in the Universe can answer the question! Enormous Explosion: Gamma Ray Burst (GRB) Ghosts of Star: Supermassive Black Holes The Most Massive Astronomical Object: Proto-clusters of Galaxies

6 Gamma Ray Bursts: The Most Energetic Event in the Universe γ-ray: high energy photons (> 100 kev, nuclear bomb) Discovered first by spy satellites (1973) Duration of sec Luminosity: ~10 54 erg/sec The Sun: 2 x erg/sec Galaxy ~ erg/sec All galaxies in the Universe ~ erg/sec

Optical Afterglow Can be as bright as 6 mag

5 billion years old) GRB 071010B (Urata,

7 Optical Afterglow Can be as bright as 6 mag (Naked-eye burst) even at billions of light-years away GRB can be studied at very high redshift (early universe ~ 0.5 billion years old) GRB B (Urata, Huang, Im, et al. 2009; Lee, Im, et al. 2010) ΔT=0.5 days ΔT=5.5 days ΔT=8.5 days

8 Origin of GRB Long GRB (> 2 sec): Hypernova (Extreme Supernova; e.g., Woosley & Bloom 2006) First stars (Belczynski et al. 2010; 10x) Short GRB (< 2 sec): Neutron star-neutron star merging, neutron star-black hole merging (e.g., Nakar 2007)

GRBs at High Redshift GRB 090423 (z ~ 8.2; Tanvir et al. 2009, Salvattera et al. 2009) GRB 100905A (z ~ 7.5; Im et al. 2011, prep) GRB 080930 (z ~ 6.

9 GRBs at High Redshift GRB (z ~ 8.2; Tanvir et al. 2009, Salvattera et al. 2009) GRB A (z ~ 7.5; Im et al. 2011, prep) GRB (z ~ 6.8; Greiner et al. 2009) GRB (z ~ 6.29; Kawai et al. 2006; Totani et al. 2006) Age (Gyr) GRB A at z ~ 7.5 Lyman break (13.6 kev ~ nm)

10 GRBs in Early Universe GRBs in early universe long GRB? No! All three GRBs at z > 6.5 Short GRBs! Great Mystery. BZ process? (Blandford- Znajek 1977) Short

11 Supermassive Black Holes (SMBH) What are they? - Black Holes with masses ~ M Where are they? - Centers of massive spheroids/bulges or quasars Elliptical galaxy Bulges of Spirals Quasars/AGNs

12 Quasars Lee, Im, et al Looks like a star (QUAsi-StellAR radio sources) Shines via accretion of matters around SMBHs Highest redshift QSO at z=6.43 (Willott et al. 2009)

13 Mass of BH When Did They Appear? AKARI points (Our result) Quasar Cliff? Present day Early Universe M SMBHs are stilll forming at z ~ 6 (0.95 Gyr) What Happened before? Quasar Cliff?

14 Growth of SMBHs E= ε M c 2, L = de/dt ~ ε dm/dt c 2 dm/dt = L(Edd)/c 2 / ε = M/τ, where τ ~ 4.5 x 10 7 (ε/0.1) yrs M(t) = M(seed) exp(t/τ), exponential growth Between z=15 to z=6, only 0.5 Gyr difficult to make SMBHs Volonteri & Rees (2006) ε=0.1 Super-critical ε=0.2 ε=0.4 Sijacki, Springel, & Haehnelt (2009) Age

15 Galaxy Clusters The most massive, gravitationally bound object in the Universe (~10 15 M ) member galaxies

16 Recent proto-cluster studies Abundance: Sensitive to cosmological parameters, initial conditions Search for proto-clusters (Miley et al. 2004; Overzier et al. 2008, Matsuda et al. 2011; Kajisawa et al. 2006; Capak et al. 2011, ; 1 < z < 5.3)

17 Proto-clusters in Early Universe Discovered a proto-cluster at z=3.7 (t ~ 1.7 billion years) Mass: M Also proto-clusters at z=3.1 (Matsuda, Yamada et al.), z=4.1 (Miley et al. 2004), z=5.3 (Capak et al. 2011) Kang & Im (2009)

18 Implication Ph.D Thesis Kang, E. (2010) Too many massive proto-clusters at high redshift! another mystery

19 What Have We Learned? Death of First Stars - GRB Theory Observation? Long GRB Short GRB Why? Supermassive BH Growth Theory Observation? ~1 Gyr Rapid Growth How? Proto-clusters in Early Universe Theory Observation? Rare 100x more Strange

20 Summary Extreme Objects in Early Universe GRB, SMBH, and Proto-clusters Current results present challenges to theoretical/observational studies Exciting era to study the first objects in the universe

Gamma-Ray Astronomy. Astro 129: Chapter 1a

Gamma-Ray Astronomy. Astro 129: Chapter 1a Gamma-Ray Bursts Gamma-Ray Astronomy Gamma rays are photons with energies > 100 kev and are produced by sub-atomic particle interactions. They are absorbed by our atmosphere making observations from satellites