A Unified Picture of Short and Long Gamma-ray Bursts from Compact Binary Mergers
First theoretical framework that connects the underlying physics of binary systems to GRB observations. It provides a first-pricinples explanation for the origin of the constant power GRB prompt emission and decaying extended emission for the first time. Massive post-merger accretion disks, which arise from unequal-mass NS-NS mergers, inevitably produce long GRBs such as 211211A. At the same time, both meta-stable NSs and newly formed BHs remain viable candidates as central engines for standard short GRBs.
Read more in: Unified Picture of GRBs from Binary Mergers
First numerical simulations that track the evolution of a black hole-neutron star merger from pre-merger to r>1e11 cm. The disk that forms after a merger of mass ratio q=2 ejects massive disk winds (3e-2−5e−2 Msol). The resulting jets feature excessive duration compared to typical short gamma-ray bursts (sGRBs). This provides a natural explanation for long sGRBs such as GRB 211211A. The jet-wind interaction leads to a power-law angular energy distribution by inflating an energetic cocoon which emits strong wide-angle emission.
Read more in: Seconds-long GRB emissionHours-ling cocoon emission
A new class of noninspiral GW sources-the end states of massive stars-that can produce the brightest simulated stochastic GW burst signal in the LVK bands known to date, and could be detectable in LVK run A+. Some dying massive stars launch bipolar relativistic jets, which inflate a turbulent energetic bubble-cocoon-inside of the star, which emits quasi-isotropic GW emission in the LVK band, ~10-100 Hz, over a characteristic jet activity timescale ~10-100 s.
Read more in: Jetted and Turbulent Stellar Deaths: New LVK-detectable Gravitational-wave Sources
GRMHD simulations of outflows from black holes to the photosphere
First 3D general-relativity magnetohydrodynamic simulations that span over six orders of magnitude in space and time. The simulations shift the evolution paradigm by revealing inevitable misalignment between the jet and the black hole rotational axis. As a result, the jet wobbles, implying lower intrinsic GRB rates and can naturally explain the long-standing mystery of quiescent times in GRB lightcurves.
Read more in: Black Hole to Photosphere: 3D GRMHD Simulations of Collapsars Reveal Wobbling and Hybrid Composition Jets
Shocked jets in CCSNe can power FBOTs
Relativistic jets in hydrogen-rich collapsing stars can naturally explain the multi-wavelength fast blue optical transient (FBOT) observables: The jet-star interaction forms a cocoon which powers cooling emission during the first few weeks. The cocoon-CSM interaction generates synchrotron self-absorbed emission in the radio bands, featuring a steady rise on a month timescale. After a few months the relativistic outflow decelerates, enters the observer’s line of sight, peaks in radio and decays thereafter. The cocoon becomes optically thin to X-rays ∼ day after the collapse, allowing X-ray photons to diffuse from the central engine to the observer.
Read more in: Shocked jets in CCSNe can power the zoo of fast blue optical transients
The propagation of relativistic jets in expanding media
Comprehensive analytic model of relativistic jet propagation in expanding homologous media, covering the entire jet evolution as well as a range of configurations that are relevant to binary mergers. These include low- and high-luminosity jets, unmagnetized and mildly magnetized jets, time-dependent luminosity jets, and Newtonian and relativistic head velocities. The model provides simple analytic formulae (calibrated by 3D simulations) for the jet head propagation and breakout times.
Read more in: The propagation of relativistic jets in expanding media
O. Gottlieb, B. D. Metzger, E. Quataert, D. Issa, T. Martineau, F. Foucart, M. D. Duez, L. E. Kidder, H. P. Pfeiffer, M. A. Scheel,
A Unified Picture of Short and Long Gamma-ray Bursts from Compact Binary Mergers,
ApJL, 958, 33 (2023).
O. Gottlieb, D. Issa, J. Jacquemin-Ide, M. Liska, F. Foucart, A. Tchekhovskoy, B. D. Metzger, E. Quataert, R. Perna, D. Kasen, M. D. Duez, L. E. Kidder, H. P. Pfeiffer, M. A. Scheel,
Large-scale Evolution of Seconds-long Relativistic Jets from Black Hole-Neutron Star Mergers, ApJL, 954, 21 (2023)
O. Gottlieb, D. Issa, J. Jacquemin-Ide, M. Liska, A. Tchekhovskoy, F. Foucart, D. Kasen, R. Perna, E. Quataert, B. D. Metzger,
Hours-long Near-UV/Optical Emission from Mildly Relativistic Outflows in Black Hole-Neutron Star Mergers,
ApJL, 953, 11 (2023)
O. Gottlieb, H. Nagakura, A. Tchekhovskoy, P. Natarajan, E. Ramirez-Ruiz, J. Jacquemin-Ide,
N. Kaaz, V. Kalogera, Jet-Inflated Cocoons in Dying Stars: New LIGO-Detectable Gravitational Wave Sources, ApJL,
951, 30 (2023)
O. Gottlieb, S. Moseley, T. Ramirez-Aguilar, A. Murguia-Berthier, M. Liska, A. Tchekhovskoy, On the jet-ejecta interaction in 3D GRMHD simulations of binary neutron star merger aftermath, ApJL, 933, 2 (2022)
O. Gottlieb, M. Liska, A. Tchekhovskoy, O. Bromberg, A. Lalakos, D. Giannios, P. Mosta, Black hole to photosphere: 3D GRMHD simulations of collapsars reveal wobbling and hybrid composition jets, ApJL, 933, 9 (2022)
Equal contribution authors: K. P. Mooley*, A. T. Deller*, O. Gottlieb*,
E. Nakar, G. Hallinan, S. Bourke, D. A. Frail, A., Horesh, A. Corsi, K. Hotokezaka,
Superluminal motion of a relativistic jet in the neutron star merger GW170817,
Nature, 561, 355 (2018)