=== Virginia Trimble - historical introduction === - compact objects: observed, defined, understood - WD: O -> D -> U - NS: D -> U -> O - BH: U -> D -> O === Marta Volonteri - BH formation history === - First black holes: - 100 Msun from PopIII, M ~ 100-600 Msun - 10^3-10^5 Msun from gas dynamics (direct collapse) or stellar dynamics (gas -> dense cluster -> mergers of stars) - initial (z > 20) mass functions very different for three processes: peaked at 10^5 for direct collapse, 10^3 for proto clusters, 10^2 for pop III - seed BHs move toward M-sigma (from low sigma, from low masses); movement can be traced by "plumes"; however AGN see high-mass, more evolved segment - Summary - seed MBHs in biased proto-galaxies - MBHs evolve through mergers and accretion - accretion leads mass and spin evolution - M-sigma at low masses tells the story === Giuseppe Lodato - Early growth of massive black hole seeds from gas collapse in pre-galactic discs === === Marco Spaans - Black holes from run-away growth during gravitational collapse: very high dynamic range studies of fragmentation and collapse === === Jarrett Johnson - BH accretion in first galaxies === - first stars---over a range of masses and metallicities, collapse to BH directly - 10^9 Msun BHs observed within first 10^9 years (z > 6.5?); BH seeds from PopIII provide explanation, but would need sustained Eddington accretion - dense gas around first stars is blown away, so initial accretion can't be efficient; 60 Myr delay - first galaxies at z > 10 from DM minihalos; primordial gas falls in; absent radiative feedback, super-Eddington accretion is possible - pre-galactic Pop III star formation is possible in a few minihalo progenitors of most first galaxies; but otherwise metal enrichment by first supernovae may preclude direct-collapse BH formation === Douglas Spolyar - Dark Stars: a new look at the first stars and seeds for black holes === - first stars: form gently in DM minihalos; structure forms when gas can cool efficiently - hp: DM alters first stars with DM annihilation: dark stars - at high enough density DM heating overwhelms accretion and supports gas cloud - DM: WIMPS (lightest supersymmetric particle, annihilates through weak force, many anomalous signals point to it), axions, KK particles, primordial black holes - dark-star predictions: very luminous (10^6-7 Lsun), cool (10,000 K vs 100,000 K PopIII), leads to very massive PopIII, short lived (but may last if DM captured and halo not disrupted) - but if DM is primordial black holes, eat first stars before they can reach main sequence, forms a mini-quasar === Steinn Sigurdsson - IMBH from Pop III: dynamical history === - look at "local group" in subvolume of cosmological simulation; resimulated it at high resolution - look at subhalos and halo mergers; track those that will form PopIII stars; some make BHs; model loss to kicks after BH mergers - IMBHs can merge to respectable SMBH without accretion; most growth before z = 3 - also get stranded halo IMBHs; potential X-ray and mesolensing detectables - if this happens, they're rich GW sources === Karl Gebhardt - New Observational Results and Models for Black Holes in Globular Clusters === - several stellar clusters with good central stellar kinematics, some with evidence for central BH - contraints on BH in clusters: photometry; kinematics; non-thermal emission - dynamical analysis: evolutionary models, static models - velocity maps with lots of rotation - high central rotation indicates central objects === Julio Chaname - A Search for Intermediate-Mass Black Holes in Galactic Globular Clusters with HST === - detection: look for MBH using accretion-powered luminosity - e.g., X-ray emission from G1 - infrared emission dominated by bright giants and projection effects (line-of-sight measurements) - weighing: proper motions === Holger Baumgardt - Testing the case for an IMBH in Omega Cen === - surface brighness and kinematic data: weak cusp in surface density, central rise in velocity dispersion (compatible with 4x10^4 Msun BH) - however alternative solutions possible for kinematic data: a central cluster of dark remnants, or a radially anisotropic central velocity dispersion - but there's doubt that either alternative would be stable over a Hubble time - different measurement founds different center, which cannot be explained by IMBH wandering - case for IMBH in Omega Cen is still open === R. Michael Rich - M31 G1: The First Intermediate-mass Black Hole in a Globular Cluster === === Albert Kong - Are the X-rays from G1 created by an intermediate-mass black hole? === === Michele Trenti - Intermediate-Mass-Black-Hole Fingerprints in Globular Clusters === - searching for IMBHs in GCs - little gas, little X-rays - sphere of influence is small - velocity evidence is model dependent - proper motion studies provide best evidence, but are expensive - IMBH fingerprints - efficient IMBH heating (large r_core/r_halfmass), but other heating sources possible - less mass segregation toward center when IMBH is present: IMBH gains tightly bound massive star, and three body encounters with binary scatter out incoming stars - to estimate segregation, need good counts, relaxed cluster - NGC2298 example === Tom Maccarone - Accretion constraints on globular cluster black holes === - crossing (1e6 yr), relaxation (1e9 yr), evaporation timescale (x136 rel.) - mass segregation -> BHs may become fully segregated and ejected---or clusters evaporate - IMBH searches - dynamics (rv dispersion, proper motion dispersion, unusual objects/hypervelocity stars) - accretion from interstellar medium, theoretically at Bondi rate; should be easy to see with radio - results: none of examined GCs has right kind of radio source; argues against BHs being common - strongest IMBH case is G1 === Enrico Ramirez-Ruiz - Disruption of stars as probes of intermediate mass black holes === - scale of tidal disruption for WDs relevant to IMBHs - tidal pinching -> shock heating - simulations with realistic equations of state, alpha networks - ignition is possible, radiation from flattened profile is characteristic - most of debris swallowed rapidly, with Eddington luminosities for a few months; faint thermonuclear explosion possible from expelled debris === Kelly Holley-Bockelmann - IMBH retention in globular clusters === - gravitational-wave recoil: any time there's asymmetry in BH mergers - it's hard to retain IMBHs, unless they're very heavy seeds (2000 Mo) to begin with - if they're kicked out, they must be in the halo, invisible - if they're retained, they could be kicked into oscillating at observable offsets (fractions of pc) for 100 Myr also: - SMBHs may also have large offsets - recoil may delay SMBH growth - stellar-mass BHs can also be ejected - how are seed black holes retained in protogalaxies === Steve Zepf - The Mass of the Black Hole in RZ2109 and Its Implications ===