A5079016405- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Quantum chaos and dynamical systems
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
- Planetary Science and Exploration
- Astronomical Observations and Instrumentation
- Geomagnetism and Paleomagnetism Studies
- Superconducting and THz Device Technology
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Fluid Dynamics and Turbulent Flows
- Adaptive optics and wavefront sensing
- Advanced X-ray Imaging Techniques
University of Toronto
2015-2024
Canadian Institute for Theoretical Astrophysics
2015-2024
Perimeter Institute
2024
Herzberg Institute of Astrophysics
2015-2020
Queen's University
2020
Northwestern University
2016
University of Alberta
2013
Teledyne e2v (United Kingdom)
2012
University of California, Berkeley
1985-2005
Center for Astrophysics Harvard & Smithsonian
2005
We present a series of high-resolution cosmological simulations galaxy formation to z=0, spanning halo masses ~10^8-10^13 M_sun, and stellar ~10^4-10^11. Our include fully explicit treatment both the multi-phase ISM (molecular through hot) feedback. The feedback inputs (energy, momentum, mass, metal fluxes) are taken directly from population models. These sources feedback, with zero adjusted parameters, reproduce observed relation between mass up M_halo~10^12 M_sun (including dwarfs,...
The Feedback In Realistic Environments (FIRE) project explores feedback in cosmological galaxy formation simulations. Previous FIRE simulations used an identical source code (FIRE-1) for consistency. Motivated by the development of more accurate numerics - including hydrodynamic solvers, gravitational softening, and supernova coupling algorithms exploration new physics (e.g. magnetic fields), we introduce FIRE-2, updated numerical implementation GIZMO code. We run a suite compare against...
view Abstract Citations (781) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Accretion Disk Winds from Active Galactic Nuclei Murray, N. ; Chiang, J. Grossman, S. A. Voit, G. M. We present a dynamical model in which the broad absorption lines seen some quasar spectra form smooth nonspherical wind an accretion disk. On inner edge of this wind, at r ‚âç 1016 cm for 108 Msun black hole, entrained dense gas blocks soft X-rays but transmits...
We investigate large-scale galactic winds driven by momentum deposition. Momentum injection is provided (1) radiation pressure produced the continuum absorption and scattering of photons on dust grains (2) supernovae (momentum important even if supernova energy radiated away). Radiation can be a starburst or active nucleus (AGN) activity. argue that momentum-driven are an efficient mechanism for feedback during formation galaxies. show above limiting luminosity, deposition from star expel...
We consider the structure of marginally Toomre-stable starburst disks under assumption that radiation pressure on dust grains provides dominant vertical support against gravity. This is particularly appropriate when disk optically thick to its own IR radiation, as in central regions ULIRGs. Because radiates at Eddington limit, Schmidt-law for star formation changes optically-thick with rate per unit area scaling Sigma_g/kappa, where Sigma_g gas surface density and kappa mean opacity. show...
Future surveys for transiting extrasolar planets are expected to detect hundreds of jovian-mass and tens terrestrial-mass planets. For many these newly discovered planets, the intervals between successive transits will be measured with an accuracy 0.1 100 minutes. We show that timing measurements allow detection additional in system (not necessarily transiting) by their gravitational interaction planet. The transit-time variations depend on mass planet, some cases produce a measurable...
Photoionization heating from ultraviolet (UV) radiation incidents on the atmospheres of hot Jupiters may drive planetary mass loss. Observations stellar Lyman-α (Lyα) absorption have suggested that Jupiter HD 209458b is losing atomic hydrogen. We construct a model escape includes realistic and cooling, ionization balance, tidal gravity, pressure confinement by host star wind. show loss takes form hydrodynamic (Parker) wind, emitted planet's dayside during lulls in When winds are suppressed...
We present an analysis of the galaxy-scale gaseous outflows from Feedback in Realistic Environments (FIRE) simulations. This suite hydrodynamic cosmological zoom simulations resolves formation star-forming giant molecular clouds to z = 0, and features explicit stellar feedback model on small scales. Our reveal that high-redshift galaxies undergo bursts star followed by powerful gusts galactic eject much interstellar medium temporarily suppress formation. At low redshift, however,...
Feedback from massive stars is believed to play a critical role in driving galactic super-winds that enrich the IGM and shape galaxy mass function mass-metallicity relation. In previous papers, we introduced new numerical methods for implementing stellar feedback on sub-GMC through scales simulations. This includes radiation pressure (UV IR), SNe (Type-I & II), winds ('fast' O-star 'slow' AGB winds), HII photoionization. Here, show these mechanisms drive with outflow rates as high ~10-20...
Feedback from massive stars is believed to play a critical role in shaping the galaxy mass function, structure of interstellar medium (ISM), and low efficiency star formation, but exact form feedback uncertain. In this paper, first series, we present test novel numerical implementation stellar resulting momentum imparted ISM by radiation, supernovae, winds. We employ realistic cooling find that large fraction gas cools <100K, so becomes highly inhomogeneous. Despite this, our simulated...
Star formation is slow in the sense that gas consumption time much longer than dynamical time. It also inefficient; star local galaxies takes place giant molecular clouds (GMCs), but fraction of a GMC converted to stars very small, ∼ 5%. In luminous starbursts, lifetime shorter main-sequence even most massive stars, so supernovae can play no role disruption. We investigate disruption GMCs across wide range from normal spirals densest starbursts; we take into account effects H ii pressure,...
The exosolar planet HD 80606b has a highly eccentric (e = 0.93) and tight (a 0.47 AU) orbit. We study how it might arrive at such an orbit avoided being tidally circularized until now. presence of stellar companion to the host star suggests possibility that Kozai mechanism tidal dissipation combined draw inward well after formed: oscillations produce periods extreme eccentricity in orbit, occurs during these small pericenter distances leads gradual orbital decay. call this migration "Kozai...
We use cosmological simulations from the FIRE (Feedback In Realistic Environments) project to study baryon cycle and galaxy mass assembly for central galaxies in halo range $M_{\rm halo} \sim 10^{10} - 10^{13} M_{\odot}$. By tracing cosmic inflows, galactic outflows, gas recycling, merger histories, we quantify contribution of physically distinct sources material growth. show that situ star formation fueled by fresh accretion dominates early growth all masses, while re-accretion previously...
We present multiple ultrahigh resolution cosmological hydrodynamic simulations of M⋆ ≃ 104–6.3 Mȯ dwarf galaxies that form within two Mvir = 109.5–10 dark matter halo initial conditions. Our rely on the Feedback in Realistic Environments (fire) implementation star formation feedback and were run with high enough force mass to directly resolve structure ∼200 pc scales. The resultant sit versus relation required match Local Group stellar function via abundance matching. They have bursty...
The conversion of gas into stars is a fundamental process in astrophysics and cosmology. Stars are known to form from the gravitational collapse dense clumps interstellar molecular clouds, it has been proposed that resulting star formation rate proportional either amount mass above threshold surface density, or volume density. These star-formation prescriptions appear hold nearby clouds our Milky Way Galaxy's disk as well distant galaxies where rates often much larger. inner 500 pc Galaxy,...
We use a sample of the 13 most luminous WMAP Galactic free-free sources, responsible for 33% free- free emission Milky Way, to investigate star formation. The contains 40 forming complexes; we combine this with giant molecular cloud (GMC) catalogs in literature, identify host GMCs 32 complexes. estimate formation efficiency epsilon_GMC and rate per free-fall time epsilon_ff. find that ranges from 0.002 0.2, an ionizing luminosity-weighted average = 0.08, compared 0.005. Turning time, values...
We demonstrate that the observed distribution of "hot Neptune"/"super-Earth" systems is well reproduced by a model in which planet assembly occurs situ, with no significant migration post-assembly. This achieved only if amount mass rocky material ∼50–100 M⊕ interior to 1 AU. Such reservoir implies radial solid takes place, and it before stage final assembly. The not reproduces general versus period but also detailed statistics multiple sample. furthermore cores this size are likely meet...
We present numerical methods for including stellar feedback in galaxy-scale simulations. include heating by SNe (I & II), gas recycling and shock-heating from O-star AGB winds, HII photoionization, radiation pressure photons. The energetics time-dependence are taken directly evolution models. implement these simulations with pc-scale resolution, modeling galaxies SMC-like dwarfs MW analogues to massive z~2 starburst disks. Absent feedback, cools collapses without limit. With the ISM reaches...
We use simulations with realistic models for stellar feedback to study galaxy mergers. These high resolution (1 pc) follow formation and destruction of individual GMCs star clusters. The final starburst is dominated by in situ formation, fueled gas which flows inwards due global torques. resulting density results rapid formation. self gravitating, forms massive (~10^10 M_sun) subsequent super-starclusters (masses up 10^8 M_sun). However, contrast some recent simulations, the bulk new stars...
Galactic outflows of low ionization, cool gas are ubiquitous in local starburst galaxies, and the majority galaxies at high redshift. How these arise is still question. Hot from supernovae has long been suspected as primary driver, but this mechanism suffers its tendency to destroy latter accelerated. We propose a modification supernova scenario that overcomes difficulty. Star formation observed take place clusters; given galaxy, bulk star found ~20 most massive clusters. show that, for L*...
The star formation rate (SFR) in the Central Molecular Zone (CMZ, i.e. central 500 pc) of Milky Way is lower by a factor >10 than expected for substantial amount dense gas it contains, which challenges current theories. In this paper, we quantify physical mechanisms could be responsible. On scales larger disc scale height, low SFR found to consistent with episodic due secular instabilities or possibly variations inflow along Galactic bar. CMZ marginally Toomre-stable when including and...
Coalescing black hole (BH) binaries forming in the dense core of globular clusters (GCs) are expected to be one brightest sources gravitational wave (GW) radiation for next generation ground-based laser interferometers. Favorable conditions merger initiated by Kozai resonance which interaction with a third distant object, typically another BH, induces quasi-periodic variations inner BH binary eccentricity. In this paper we perform high precision N-body simulations long term evolution...
Following the first two annual intensity mapping workshops at Stanford in March 2016 and Johns Hopkins June 2017, we report on recent advances theory, instrumentation observation that were presented these meetings some of opportunities challenges identified looking forward. With preliminary detections CO, [CII], Lya low-redshift 21cm, a host experiments set to go online next few years, field is rapidly progressing all fronts, with great anticipation for flood new exciting results. This...
We study the implementation of mechanical feedback from supernovae (SNe) and stellar mass loss in galaxy simulations, within Feedback In Realistic Environments (FIRE) project. present FIRE-2 algorithm for coupling feedback, which can be applied to any hydrodynamics method (e.g. fixed-grid, moving-mesh, mesh-less methods), black hole as well feedback. This ensures manifest conservation mass, energy, momentum, avoids imprinting 'preferred directions' on ejecta. show that it is critical...
We study the interaction of feedback from active galactic nuclei (AGN) and a multiphase interstellar medium (ISM), in simulations including explicit stellar feedback, cooling, accretion-disc winds, Compton heating. examine radii ∼0.1–100 pc around black hole (BH), where accretion rate on to BH is determined AGN-powered winds radiation couple ISM. conclude: (1) by exchange angular momentum between gas stars gravitational instabilities. This produces rates ∼0.03–1 M⊙ yr−1, sufficient power...