A5067562686- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Phytochemistry Medicinal Plant Applications
- Natural product bioactivities and synthesis
- Natural Compound Pharmacology Studies
- Plant-derived Lignans Synthesis and Bioactivity
- Biological Activity of Diterpenoids and Biflavonoids
- Traditional and Medicinal Uses of Annonaceae
- Phytochemical compounds biological activities
- Astro and Planetary Science
- Phytochemistry and Biological Activities
- Synthesis of Organic Compounds
- Bioactive natural compounds
- Plant biochemistry and biosynthesis
- Astronomy and Astrophysical Research
- Chemical synthesis and alkaloids
- Plant Diversity and Evolution
- Infectious Diseases and Mycology
- Oral Health Pathology and Treatment
- Plant Toxicity and Pharmacological Properties
- Botanical Research and Applications
- Sesquiterpenes and Asteraceae Studies
- Biochemical and biochemical processes
Flatiron Health (United States)
2023-2025
Flatiron Institute
2023-2025
Columbia University
2023-2025
Northwestern University
2021-2024
Tel Aviv University
2017-2022
Center for Excellence in Education
2022
Fundação Oswaldo Cruz
2000-2001
Instituto de Pesquisas Jardim Botânico do Rio de Janeiro
1994
Universidade de São Paulo
1973-1993
Institut für Forensische Genetik
1993
Merging neutron stars offer an exquisite laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of electromagnetic counterpart EM170817 to gravitational waves (GW170817) detected from merging stars. By synthesizing a panchromatic dataset, we demonstrate that are long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma-rays seen dissimilar classical short gamma-ray bursts with...
The short Gamma-Ray Burst, GRB170817A, that followed the binary neutron star merger gravitational waves signal, GW170817, is not a usual sGRB. It weaker by three orders of magnitude than weakest sGRB seen before and its spectra, showing hard early signal softer thermal spectrum, unique. We show, first, $\gamma$-rays must have emerged from at least mildly relativistic outflow, implying jet was launched following merger. then show observations are consistent with predictions shock breakout:...
Short Gamma-Ray Bursts (SGRBs) are believed to arise from compact binary mergers (either neutron star-neutron star or black hole-neutron star). If so their jets must penetrate outflows that ejected during the merger. As a jet crosses ejecta it dissipates its energy, producing hot cocoon which surrounds it. We present here 3D numerical simulations of propagation in mergers' and we calculate resulting emission. This emission consists two components: cooling emission, leakage thermal energy...
After being launched, GRB jets propagate through dense media prior to their breakout. The jet-medium interaction results in the formation of a complex structured outflow, often referred as "structured jet". underlying physics that sets post-breakout jet morphology has never been explored systematically. Here we use suite 3D simulations follow evolution hydrodynamic long and short gamma-ray bursts (GRBs) after breakout study structure induced by interaction. Our feature Rayleigh-Taylor...
We present the first relativistic MHD numerical simulation of a magnetic jet that propagates through and emerges from dynamical ejecta binary neutron star merger. Generated by magnetized rotation merger remnant, produces an energetic cocoon expands at mildly velocities breaks out ejecta. show if has low-mass ($\sim10^{-7} M_\odot$) high-velocity ($v\sim0.85$ c) tail, shock breakout will generate $γ$-ray emission is comparable to observed short GRB170817A accompanied recent gravitational wave...
For the first $\sim3$ years after binary neutron star merger event GW 170817 radio and X-ray radiation has been dominated by emission from a structured relativistic off-axis jet propagating into low-density medium with n $< 0.01\,\rm{cm^{-3}}$. We report on observational evidence for an excess of at $\delta t>900$ days merger. With $L_x\approx5\times 10^{38}\,\rm{erg\,s^{-1}}$ 1234 days, recently detected represents $\ge 3.2\,\sigma$ (Gaussian equivalent) deviation universal post jet-break...
Long-duration $\gamma$-ray bursts (GRBs) accompany the collapse of massive stars and carry information about central engine. However, no 3D models have been able to follow these jets from their birth by a black-hole (BH) photosphere. We present first such general-relativity magnetohydrodynamic simulations, which span over 6 orders magnitude in space time. The collapsing stellar envelope forms an accretion disk, drags inwardly magnetic flux that accumulates around BH, becomes dynamically...
ABSTRACT Evidence is mounting that recent multiwavelength detections of fast blue optical transients (FBOTs) in star-forming galaxies comprise a new class transients, whose origin yet to be understood. We show hydrogen-rich collapsing stars launch relativistic jets near the central engine can naturally explain entire set FBOT observables. The jet–star interaction forms mildly shocked jet (inner cocoon) component, which powers cooling emission dominates high velocity signal during first few...
Abstract The recent detections of the ∼10 s long γ -ray bursts (GRBs) 211211A and 230307A followed by softer temporally extended emission (EE) kilonovae point to a new GRB class. Using state-of-the-art first-principles simulations, we introduce unifying theoretical framework that connects binary neutron star (BNS) black hole–NS (BH–NS) merger populations with fundamental physics governing compact GRBs (cbGRBs). For binaries large total masses, M tot ≳ 2.8 ⊙ , remnant created promptly...
Abstract We present the first numerical simulations that track evolution of a black hole–neutron star (BH–NS) merger from premerger to r ≳ 10 11 cm. The disk forms after mass ratio q = 2 ejects massive winds (3–5 × −2 M ⊙ ). introduce various postmerger magnetic configurations and find initial poloidal fields lead jet launching shortly merger. maintains constant power due constancy large-scale BH flux until becomes magnetically arrested (MAD), where falls off as L j ∼ t . All jets inevitably...
Abstract Spinning supermassive black holes (BHs) in active galactic nuclei magnetically launch relativistic collimated outflows, or jets. Without angular momentum supply, such jets are thought to perish within 3 orders of magnitude distance from the BH, well before reaching kiloparsec scales. We study survival at largest scale separation date, via 3D general magnetohydrodynamic simulations rapidly spinning BHs immersed into uniform zero-angular-momentum gas threaded by a weak vertical...
Relativistic jets reside in high-energy astrophysical systems of all scales. Their interaction with the surrounding media is critical as it determines jet evolution, observable signature, and feedback on environment. During its motion ambient inflates a highly pressurized cocoon, which under certain conditions collimates strongly affects propagation. Recently, Bromberg et al. (2011) derived general simplified (semi)analytic solution for evolution cocoon case an unmagnetized that propagates...
ABSTRACT The interaction of gamma-ray burst (GRB) jets with the dense media into which they are launched promote growth local hydrodynamic instabilities along jet boundary. In a companion paper, we study evolution (unmagnetized) jets, finding that mixing jet–cocoon material gives rise to an interface layer, termed (JCI), contains significant fraction system energy. We find angular structure + JCI, when reach homologous phase, can be approximated by flat core (the jet) power-law function JCI)...
Abstract The gravitational waves from the first binary neutron star merger, GW170817, were accompanied by a multiwavelength electromagnetic counterpart, γ -rays to radio. accompanying seem at confirm association of mergers with short gamma-ray bursts (sGRBs). common interpretation was that we see an emission sGRB jet seen off-axis. However, closer examination subluminous and peculiar radio afterglow inconsistent this simple interpretation. Here present results 3D 2D numerical simulations...
We present a suite of the first 3D GRMHD collapsar simulations, which extend from self-consistent jet launching by an accreting Kerr black hole (BH) to breakout star. identify three types outflows, depending on angular momentum, $ l $, collapsing material and magnetic field, B BH horizon: (i) Subrelativistic outflow (low high $), (ii) Stationary accretion shock instability (SASI; low (iii) Relativistic jets (high $). In absence jets, free-fall stellar envelope provides good estimate for...
X-shaped radio galaxies (XRGs) produce misaligned jet pairs and make up $\lesssim10\%$ of galaxies. XRGs are thought to emerge in featuring a binary supermassive black hole ($\rm SMBH$), $\rm SMBH$ merger, or large-scale ambient medium asymmetry. We demonstrate that XRG morphology can naturally form without such special, preexisting conditions. Our 3D general-relativistic magnetohydrodynamic (GRMHD) simulation for the first time follows magnetized rotating gas from outside sphere influence...
Abstract Short γ -ray burst (sGRB) jets form in the aftermath of a neutron star merger, drill through disk winds and dynamical ejecta, extend over four to five orders magnitude distance before breaking out ejecta. We present first 3D general-relativistic magnetohydrodynamic sGRB simulations span this enormous scale separation. They feature three possible outcomes: jet+cocoon, cocoon, neither. Typical break ejecta if (i) bound ejecta’s isotropic equivalent mass along pole at time BH formation...