Collapsar Gamma-ray Bursts Grind their Black Hole Spins to a Halt

The spin of a newly formed black hole (BH) at the center of a massive star evolves from its natal value due to two competing processes: accretion of gas angular momentum that increases the spin, and extraction of BH angular momentum by outflows that decreases the spin. Ultimately, the final, equilibrium spin is set by the balance between both processes. In order for the BH to launch relativistic jets and power a $\gamma$-ray burst (GRB), the BH magnetic field needs to be dynamically important. Thus, we consider the case of a magnetically arrested disk (MAD) driving the spin evolution of the BH. By applying the semi-analytic MAD BH spin evolution model of Lowell et al. (2023) to collapsars, we show that if the BH accretes $\sim 20\%$ of its initial mass, its dimensionless spin inevitably reaches small values, $a \lesssim 0.2$. For such spins, and for mass accretion rates inferred from collapsar simulations, we show that our semi-analytic model reproduces the energetics of typical GRB jets, $L_{\rm jet}\sim10^{50}\,\,{\rm erg\,s^{-1}}$. We show that our semi-analytic model reproduces the nearly constant power of typical GRB jets. If the MAD onset is delayed, this allows powerful jets at the high end of the GRB luminosity distribution, $L_{\rm jet}\sim10^{52}\,\,{\rm erg\,s^{-1}}$, but the final spin remains low, $a \lesssim 0.3$. These results are consistent with the low spins inferred from gravitational wave detections of binary BH mergers. In a companion paper, Gottlieb et al. (2023), we use GRB observations to constrain the natal BH spin to be $a \simeq 0.2$

Collapsar Black Holes are Born Slowly Spinning

Collapsing stars constitute the main black hole (BH) formation channel, and are occasionally associated with the launch of relativistic jets that power $\gamma$-ray bursts (GRBs). Thus, collapsars offer an opportunity to infer the natal (before spin-up/down by accretion) BH spin directly from observations. We show that once the BH saturates with large-scale magnetic flux, the jet power is solely dictated by the BH spin and mass accretion rate. Recent core-collapse simulations by Halevi et al. 2022 and GRB observations favor stellar density profiles that yield a typical BH accretion rate, $\dot{m} \approx 10^{-2} {\rm M_\odot~s^{-1}}$, which is weakly dependent on time. This leaves the BH spin as the main factor that governs the jet power. By comparing the resultant jet power to characteristic GRB luminosities, we find rapidly spinning BHs produce jets with excessive power, so that the majority of BHs associated with jets are born slowly spinning with a dimensionless spin $a \simeq 0.2$, or $a \simeq 0.5$ for wobbling jets. This result could be applied to the entire core-collapse BH population, unless an anti-correlation between the stellar magnetic field and angular momentum is present. In a companion paper (Jacquemin-Ide et al. 2023), we show that regardless of the natal spin, the extraction of BH rotational energy ultimately leads to inevitable spin-down to $a \lesssim 0.2$. These results are consistent with recent gravitational wave observations of BH mergers that indicate low spins. We verify our results by carrying out the first 3D general relativistic magnetohydrodynamic simulations of collapsar jets with characteristic GRB energies, powered by slowly spinning BHs. We find that jets of typical GRB power do not retain their energy during the propagation in the star, providing the first numerical indication that many jets might fail to generate a GRB

Winds and Disk Turbulence Exert Equal Torques on Thick Magnetically Arrested Disks

The conventional accretion disk lore is that magnetized turbulence is the principal angular momentum transport process that drives accretion. However, when dynamically important magnetic fields thread an accretion disk, they can produce mass and angular momentum outflows that also drive accretion. Yet, the relative importance of turbulent and wind-driven angular momentum transport is still poorly understood. To probe this question, we analyze a long-duration ($1.2 \times 10^5 r_{\rm g}/c$) simulation of a rapidly rotating ($a=0.9$) black hole (BH) feeding from a thick ($H/r\sim0.3$), adiabatic, magnetically arrested disk (MAD), whose dynamically-important magnetic field regulates mass inflow and drives both uncollimated and collimated outflows (e.g., "winds" and "jets", respectively). By carefully disentangling the various angular momentum transport processes occurring within the system, we demonstrate the novel result that both disk winds and disk turbulence extract roughly equal amounts of angular momentum from the disk. We find cumulative angular momentum and mass accretion outflow rates of $\dot{L}\propto r^{0.9}$ and $\dot{M}\propto r^{0.4}$, respectively. This result suggests that understanding both turbulent and laminar stresses is key to understanding the evolution of systems where geometrically thick MADs can occur, such as the hard state of X-ray binaries, low-luminosity active galactic nuclei, some tidal disruption events, and possibly gamma ray bursts.Comment: 15 pages, 6 figures. Submitted to ApJ. Comments welcom

Jets with a Twist: Emergence of FR0 Jets in 3D GRMHD Simulation of Zero Angular Momentum Black Hole Accretion

Spinning supermassive black holes (BHs) in active galactic nuclei (AGN) magnetically launch relativistic collimated outflows, or jets. Without angular momentum supply, such jets are thought to perish within $3$ orders of magnitude in distance from the BH, well before reaching kpc-scales. We study the survival of such jets at the largest scale separation to date, via 3D general relativistic magnetohydrodynamic simulations of rapidly spinning BHs immersed into uniform zero-angular-momentum gas threaded by weak vertical magnetic field. We place the gas outside the BH sphere of influence, or the Bondi radius, chosen much larger than the BH gravitational radius, $R_\text{B}=10^3R_\text{g}$. The BH develops dynamically-important large-scale magnetic fields, forms a magnetically-arrested disk (MAD), and launches relativistic jets that propagate well outside $R_\text{B}$ and suppress BH accretion to $1.5\%$ of the Bondi rate, $\dot{M}_\text{B}$. Thus, low-angular-momentum accretion in the MAD state can form large-scale jets in Fanaroff-Riley (FR) type I and II galaxies. Subsequently, the disk shrinks and exits the MAD state: barely a disk (BAD), it rapidly precesses, whips the jets around, globally destroys them, and lets $5-10\%$ of $\dot{M}_\text{B}$ reach the BH. Thereafter, the disk starts rocking back and forth by angles $90-180^\circ$: the rocking accretion disk (RAD) launches weak intermittent jets that spread their energy over a large area and suppress BH accretion to $\lesssim 2 \% ~ \dot{M}_\text{B}$. Because BAD and RAD states tangle up the jets and destroy them well inside $R_\text{B}$, they are promising candidates for the more abundant, but less luminous, class of FR0 galaxies

Jet-Inflated Cocoons in Dying Stars: New LIGO-Detectable Gravitational Wave Sources

Long Gamma-Ray Bursts (LGRBs), the most powerful events in the Universe, are generated by jets that emerge from dying massive stars. Highly beamed geometry and immense energy make jets promising gravitational wave (GW) sources. However, their sub-Hertz GW emission is outside of ground based GW detectors' frequency band. Using a 3D general-relativistic magnetohydrodynamic simulation of a dying star, we show that jets inflate a turbulent, energetic bubble-cocoon that emits strong quasi-spherical GW emission within the ground-based GW interferometer band, $100-600$ Hz, over the characteristic jet activity timescale, $\approx 10-100$ s. Our prediction for the source amplitude makes this the first non-inspiral GW source detectable by current interferometers out to hundreds of Mpc, with $\approx 0.1 - 3$ detectable events expected during LIGO/Virgo/Kagra's observing run O4. These GWs are likely accompanied by detectable energetic core-collapse supernova and cocoon electromagnetic emission, making jetted stellar explosions promising multi-messenger sources.Comment: For movies of the simulation, see https://oregottlieb.com/gw.htm

Absorption lines from magnetically driven winds in X-ray binaries II: high resolution observational signatures expected from future X-ray observatories

In our self-similar, analytical, magneto-hydrodynamic (MHD) accretion-ejection solution, the density at the base of the outflow is explicitly dependent on the disk accretion rate - a unique property of this class of solutions. We had earlier found that the ejection index $p >\sim 0.1 (\dot{M}_{acc} \propto r^p )$ is a key MHD parameter that decides if the flow can cause absorption lines in the high resolution X-ray spectra of black hole binaries. Here we choose 3 dense warm solutions with $p = 0.1, 0.3, 0.45$ and carefully develop a methodology to generate spectra which are convolved with the Athena and XRISM response functions to predict what they will observe seeing through such MHD outflows. In this paper two other external parameters were varied - extent of the disk, $\rm{r_o|_{max}} = 10^5, \, 10^6 \,\, \rm{r_G}$, and the angle of the line of sight, $i \sim 10 - 25^{\circ}$. Resultant absorption lines (H and He-like Fe, Ca, Ar) change in strength and their profiles manifest varying degrees of asymmetry. We checked if a) the lines and ii) the line asymmetries are detected, in our suit of synthetic Athena and XRISM spectra. Our analysis shows that Athena should detect the lines and their asymmetries for a standard 100 ksec observation of a 100 mCrab source - lines with equivalent width as low as a few eV should be detected if the 6-8 keV counts are larger than $10^4 - 10^5$ even for the least favourable simulated cases.Comment: 18 pages, 13 figures in the main body and 3 figures in the appendix. Accepted for publication in MNRA

Large-scale Evolution of Seconds-long Relativistic Jets from Black Hole-Neutron Star Mergers

We present the first numerical simulations that track the evolution of a black hole-neutron star (BH-NS) merger from pre-merger to $r\gtrsim10^{11}\,{\rm cm}$. The disk that forms after a merger of mass ratio $q=2$ ejects massive disk winds ($3-5\times10^{-2}\,M_\odot$). We introduce various post-merger magnetic configurations, and find that initial poloidal fields lead to jet launching shortly after the merger. The jet maintains a constant power due to the constancy of the large-scale BH magnetic flux, until the disk becomes magnetically arrested (MAD), where the jet power falls off as $L_j\sim t^{-2}$. All jets inevitably exhibit either excessive luminosity due to rapid MAD activation when accretion rate is high, or excessive duration due to delayed MAD activation, compared to typical short gamma-ray burst (sGRBs). This provides a natural explanation to long sGRBs such as GRB 211211A, but also raises a fundamental challenge to our understanding of jet formation in binary mergers. One possible implication being the necessity of higher binary mass ratios or moderate BH spins to launch typical sGRB jets. For post-merger disks with a toroidal magnetic field, dynamo processes delay jet launching such that the jets break out of the disk winds after several seconds. We show for the first time that sGRB jets with initial magnetization $\sigma_0>100$ retain significant magnetization ($\sigma\gg1$) at $r>10^{10}\,{\rm cm}$, emphasizing the importance of magnetic processes in the prompt emission. The jet-wind interaction leads to a power-law angular energy distribution by inflating an energetic cocoon, whose emission is studied in a companion paper.Comment: For movies of the simulations, see https://oregottlieb.com/bhns.htm

Jets et vents émis et accélérés magnétiquement par les disques d'accrétion turbulents

We observe Accretion disks around several astrophysical objects across different length scales and at very different wavelengths. Accretion disks are detected around several objects: newborn stars, compact objects in binary systems, white dwarfs in binary systems, supermassive black holes, etc. In all cases, the accretion disk has a considerable impact on the emission properties of the object. Signatures of outflows, be it jets or winds, are often observed around accretion disks. Outflow ejection from accretion disks seems to be a ubiquitous process. Moreover, it is possible to measure a correlation between the outflow emission and the accretion signatures, showing that both processes are interrelated.Disks around compact objects, like X-ray binaries and dwarf novae, are subject outbursts, powerful events where the luminosity of the system increases by several orders of magnitude. Outbursts are incredibly useful as they allow us to constrain the secular evolution of the accretion disk system. Hence, we can measure the long-term effects of accretion on the system.Accretion is the consequence of angular momentum transport in the accretion disk system. When angular momentum is removed from the system, the matter, prived from its rotational support, falls into the central object. Angular momentum can be transported radially through turbulent torques or evacuated from the system by an outflow.Historically both processes have been studied separately: (1) effective 2D models have been used to study the vertical laminar torque imposed by an outflow, (2) while 3D shearing box simulations have been used to model turbulent torques. Nonetheless, both processes appear naturally in the presence of a large-scale vertical magnetic field.Shearing box models excel at modeling the turbulence but can not accurately compute the dynamics of the outflow. In contrast, effective 2D models accurately compute the dynamics of the outflow, but they cannot resolve the 3D turbulence. Thanks to numerical improvements, it is now possible to accurately compute both torques. Indeed, 3D global simulations can accurately compute the dynamics of the outflow while resolving the turbulence. These 3D global simulations show a very different structure to the 2D effective models and point towards not understood physics. Moreover, these recent simulations show that it is possible to compute outflows with a weak magnetic field. In contrast, with self-similar solutions where no weakly magnetized solutions have been computed.However, 3D global simulations prove difficult to compare with observations due to how numerically expensive they are. Hence, 2D effective models are still useful for comparison with observations and thus need to be educated by 3D global simulations.In this manuscript, we attempt to bridge the gap between 2D effective models and global simulations. We focus on self-similar models, which are a kind of 2D effective model. First, we compute new weakly magnetized self-similar models. We analyze their properties and compare them with state-of-the-art numerical simulations of weakly magnetized accretion disks. Second, we compute global simulations of accretion disk emitting magnetized outflows. We analyze the global simulations and understand why their vertical structure is different from the one computed in 2D effective models. We then constraint the secular evolution in the system and examine how it evolves as a function of the magnetic field strength.Finally, using the insight from our 3D global simulations, we construct a new turbulence model that will lead to more accurate 2D effective models.Les disques d'accrétion sont observés à différentes échelles spatiales et à différentes longueurs d'onde au voisinage d'une grande variété d'objets astrophysiques : étoiles en formation, binaires comprenant un objet compact ou une naine blanche, trous noirs supermassifs,... Ces disques ont un impact considérable sur les propriétés radiatives de l'objet. Par ailleurs, plusieurs observations suggèrent la présence d'écoulements, jets ou vents, émanant du disque. Ces écoulements sont extrêmement répandus et semblent être intrinsèquement liés aux disques d'accrétion. De plus, il est maintenant possible de mesurer une corrélation entre les propriétés de l'écoulement et de l'accrétion, illustrant l'interdépendance de ces deux phénomènes.Les disques autour d'objets compacts (binaires X ou novae naines), en particulier, sont extrêmement variables : la luminosité du système peut augmenter de plusieurs ordres de grandeur lors de "sursauts". Ces sursauts sont extrêmement utiles pour contraindre l'évolution séculaire du disque d'accrétion, et peuvent permettre de mesurer sur le long terme l'impact de l'accrétion sur le système.L'accrétion résulte d'un transport de moment cinétique dans le disque. Lorsque la matière accrétante perd du moment cinétique, elle perd son inertie centrifuge et tombe vers l'objet central. Le transport radial de moment cinétique peut avoir lieu par l'intermédiaire d'un couple turbulent, ou peut être dû à un écoulement emportant au loin le moment cinétique du système. Historiquement, ces deux processus ont été étudiés séparément. Des modèles 2D effectifs ont été utilisés afin d'étudier le couple laminaire dû à la présence de l'écoulement , tandis que des simulations 3D locales, avec cisaillement, ont permis de modéliser le couple turbulent. Cependant, ces deux processus résultent de la présence d'un champ magnétique vertical ordonné, à grande échelle. Les simulations locales 3D capturent parfaitement la turbulence, mais sont incapables de modéliser précisément la dynamique de l'écoulement. A l'inverse, les modèles 2D effectifs capturent cette dynamique, mais ne peuvent résoudre la turbulence (qui est intrinsèquement tridimensionnelle). De plus, l'amélioration des performances des supercalculateurs permet maintenant d'étudier à la fois les couples laminaire et turbulent dans une même simulation globale 3D. De telles simulations montrent des différences importantes par rapport aux modèles 2D effectifs, indiquant que la physique de ces disques reste mal comprise. De plus, ces simulations ont montré qu'il était possible de produire des écoulements à faible champ magnétique, ce qui entre en contradiction avec les prédictions des modèles auto-similaires. Malgré tout, les simulations 3D globales sont numériquement coûteuses, rendant leur comparaison avec les modèles 2D difficile. Ceux-ci restent un outil utile pour l'interprétation des observations, à condition qu'ils soient éduqués par des simulations 3D.Dans cette thèse, nous cherchons à combler le fossé entre modèles 2D effectifs et simulations globales 3D. Nous étudions des modèles auto-similaires, qui sont un cas particulier de modèle effectif 2D. Tout d'abord, nous découvrons de nouvelles solutions auto-similaires faiblement magnétisées. Nous analysons leurs propriétés, et les comparons avec les simulations de disques faiblement magnétisés les plus récentes. Ensuite, nous réalisons des simulations globales de disques d'accrétion avec écoulements. Nous analysons en particulier leur structure verticale, et expliquons les raisons derrière la différence avec les modèles effectifs 2D. Nous étudions également l'évolution séculaire du système, et détaillons la dépendance de cette évolution avec l'intensité du champ magnétique. Enfin, à partir de la compréhension acquise de ces simulations 3D, nous construisons un nouveau modèle de turbulence, qui conduira à la mise en place de modèles effectifs 2D plus précis

Jets et vents émis et accélérés magnétiquement par les disques d'accrétion turbulents

We observe Accretion disks around several astrophysical objects across different length scales and at very different wavelengths. Accretion disks are detected around several objects: newborn stars, compact objects in binary systems, white dwarfs in binary systems, supermassive black holes, etc. In all cases, the accretion disk has a considerable impact on the emission properties of the object. Signatures of outflows, be it jets or winds, are often observed around accretion disks. Outflow ejection from accretion disks seems to be a ubiquitous process. Moreover, it is possible to measure a correlation between the outflow emission and the accretion signatures, showing that both processes are interrelated.Disks around compact objects, like X-ray binaries and dwarf novae, are subject outbursts, powerful events where the luminosity of the system increases by several orders of magnitude. Outbursts are incredibly useful as they allow us to constrain the secular evolution of the accretion disk system. Hence, we can measure the long-term effects of accretion on the system.Accretion is the consequence of angular momentum transport in the accretion disk system. When angular momentum is removed from the system, the matter, prived from its rotational support, falls into the central object. Angular momentum can be transported radially through turbulent torques or evacuated from the system by an outflow.Historically both processes have been studied separately: (1) effective 2D models have been used to study the vertical laminar torque imposed by an outflow, (2) while 3D shearing box simulations have been used to model turbulent torques. Nonetheless, both processes appear naturally in the presence of a large-scale vertical magnetic field.Shearing box models excel at modeling the turbulence but can not accurately compute the dynamics of the outflow. In contrast, effective 2D models accurately compute the dynamics of the outflow, but they cannot resolve the 3D turbulence. Thanks to numerical improvements, it is now possible to accurately compute both torques. Indeed, 3D global simulations can accurately compute the dynamics of the outflow while resolving the turbulence. These 3D global simulations show a very different structure to the 2D effective models and point towards not understood physics. Moreover, these recent simulations show that it is possible to compute outflows with a weak magnetic field. In contrast, with self-similar solutions where no weakly magnetized solutions have been computed.However, 3D global simulations prove difficult to compare with observations due to how numerically expensive they are. Hence, 2D effective models are still useful for comparison with observations and thus need to be educated by 3D global simulations.In this manuscript, we attempt to bridge the gap between 2D effective models and global simulations. We focus on self-similar models, which are a kind of 2D effective model. First, we compute new weakly magnetized self-similar models. We analyze their properties and compare them with state-of-the-art numerical simulations of weakly magnetized accretion disks. Second, we compute global simulations of accretion disk emitting magnetized outflows. We analyze the global simulations and understand why their vertical structure is different from the one computed in 2D effective models. We then constraint the secular evolution in the system and examine how it evolves as a function of the magnetic field strength.Finally, using the insight from our 3D global simulations, we construct a new turbulence model that will lead to more accurate 2D effective models.Les disques d'accrétion sont observés à différentes échelles spatiales et à différentes longueurs d'onde au voisinage d'une grande variété d'objets astrophysiques : étoiles en formation, binaires comprenant un objet compact ou une naine blanche, trous noirs supermassifs,... Ces disques ont un impact considérable sur les propriétés radiatives de l'objet. Par ailleurs, plusieurs observations suggèrent la présence d'écoulements, jets ou vents, émanant du disque. Ces écoulements sont extrêmement répandus et semblent être intrinsèquement liés aux disques d'accrétion. De plus, il est maintenant possible de mesurer une corrélation entre les propriétés de l'écoulement et de l'accrétion, illustrant l'interdépendance de ces deux phénomènes.Les disques autour d'objets compacts (binaires X ou novae naines), en particulier, sont extrêmement variables : la luminosité du système peut augmenter de plusieurs ordres de grandeur lors de "sursauts". Ces sursauts sont extrêmement utiles pour contraindre l'évolution séculaire du disque d'accrétion, et peuvent permettre de mesurer sur le long terme l'impact de l'accrétion sur le système.L'accrétion résulte d'un transport de moment cinétique dans le disque. Lorsque la matière accrétante perd du moment cinétique, elle perd son inertie centrifuge et tombe vers l'objet central. Le transport radial de moment cinétique peut avoir lieu par l'intermédiaire d'un couple turbulent, ou peut être dû à un écoulement emportant au loin le moment cinétique du système. Historiquement, ces deux processus ont été étudiés séparément. Des modèles 2D effectifs ont été utilisés afin d'étudier le couple laminaire dû à la présence de l'écoulement , tandis que des simulations 3D locales, avec cisaillement, ont permis de modéliser le couple turbulent. Cependant, ces deux processus résultent de la présence d'un champ magnétique vertical ordonné, à grande échelle. Les simulations locales 3D capturent parfaitement la turbulence, mais sont incapables de modéliser précisément la dynamique de l'écoulement. A l'inverse, les modèles 2D effectifs capturent cette dynamique, mais ne peuvent résoudre la turbulence (qui est intrinsèquement tridimensionnelle). De plus, l'amélioration des performances des supercalculateurs permet maintenant d'étudier à la fois les couples laminaire et turbulent dans une même simulation globale 3D. De telles simulations montrent des différences importantes par rapport aux modèles 2D effectifs, indiquant que la physique de ces disques reste mal comprise. De plus, ces simulations ont montré qu'il était possible de produire des écoulements à faible champ magnétique, ce qui entre en contradiction avec les prédictions des modèles auto-similaires. Malgré tout, les simulations 3D globales sont numériquement coûteuses, rendant leur comparaison avec les modèles 2D difficile. Ceux-ci restent un outil utile pour l'interprétation des observations, à condition qu'ils soient éduqués par des simulations 3D.Dans cette thèse, nous cherchons à combler le fossé entre modèles 2D effectifs et simulations globales 3D. Nous étudions des modèles auto-similaires, qui sont un cas particulier de modèle effectif 2D. Tout d'abord, nous découvrons de nouvelles solutions auto-similaires faiblement magnétisées. Nous analysons leurs propriétés, et les comparons avec les simulations de disques faiblement magnétisés les plus récentes. Ensuite, nous réalisons des simulations globales de disques d'accrétion avec écoulements. Nous analysons en particulier leur structure verticale, et expliquons les raisons derrière la différence avec les modèles effectifs 2D. Nous étudions également l'évolution séculaire du système, et détaillons la dépendance de cette évolution avec l'intensité du champ magnétique. Enfin, à partir de la compréhension acquise de ces simulations 3D, nous construisons un nouveau modèle de turbulence, qui conduira à la mise en place de modèles effectifs 2D plus précis

Jets et vents émis et accélérés magnétiquement par les disques d'accrétion turbulents

We observe Accretion disks around several astrophysical objects across different length scales and at very different wavelengths. Accretion disks are detected around several objects: newborn stars, compact objects in binary systems, white dwarfs in binary systems, supermassive black holes, etc. In all cases, the accretion disk has a considerable impact on the emission properties of the object. Signatures of outflows, be it jets or winds, are often observed around accretion disks. Outflow ejection from accretion disks seems to be a ubiquitous process. Moreover, it is possible to measure a correlation between the outflow emission and the accretion signatures, showing that both processes are interrelated.Disks around compact objects, like X-ray binaries and dwarf novae, are subject outbursts, powerful events where the luminosity of the system increases by several orders of magnitude. Outbursts are incredibly useful as they allow us to constrain the secular evolution of the accretion disk system. Hence, we can measure the long-term effects of accretion on the system.Accretion is the consequence of angular momentum transport in the accretion disk system. When angular momentum is removed from the system, the matter, prived from its rotational support, falls into the central object. Angular momentum can be transported radially through turbulent torques or evacuated from the system by an outflow.Historically both processes have been studied separately: (1) effective 2D models have been used to study the vertical laminar torque imposed by an outflow, (2) while 3D shearing box simulations have been used to model turbulent torques. Nonetheless, both processes appear naturally in the presence of a large-scale vertical magnetic field.Shearing box models excel at modeling the turbulence but can not accurately compute the dynamics of the outflow. In contrast, effective 2D models accurately compute the dynamics of the outflow, but they cannot resolve the 3D turbulence. Thanks to numerical improvements, it is now possible to accurately compute both torques. Indeed, 3D global simulations can accurately compute the dynamics of the outflow while resolving the turbulence. These 3D global simulations show a very different structure to the 2D effective models and point towards not understood physics. Moreover, these recent simulations show that it is possible to compute outflows with a weak magnetic field. In contrast, with self-similar solutions where no weakly magnetized solutions have been computed.However, 3D global simulations prove difficult to compare with observations due to how numerically expensive they are. Hence, 2D effective models are still useful for comparison with observations and thus need to be educated by 3D global simulations.In this manuscript, we attempt to bridge the gap between 2D effective models and global simulations. We focus on self-similar models, which are a kind of 2D effective model. First, we compute new weakly magnetized self-similar models. We analyze their properties and compare them with state-of-the-art numerical simulations of weakly magnetized accretion disks. Second, we compute global simulations of accretion disk emitting magnetized outflows. We analyze the global simulations and understand why their vertical structure is different from the one computed in 2D effective models. We then constraint the secular evolution in the system and examine how it evolves as a function of the magnetic field strength.Finally, using the insight from our 3D global simulations, we construct a new turbulence model that will lead to more accurate 2D effective models.Les disques d'accrétion sont observés à différentes échelles spatiales et à différentes longueurs d'onde au voisinage d'une grande variété d'objets astrophysiques : étoiles en formation, binaires comprenant un objet compact ou une naine blanche, trous noirs supermassifs,... Ces disques ont un impact considérable sur les propriétés radiatives de l'objet. Par ailleurs, plusieurs observations suggèrent la présence d'écoulements, jets ou vents, émanant du disque. Ces écoulements sont extrêmement répandus et semblent être intrinsèquement liés aux disques d'accrétion. De plus, il est maintenant possible de mesurer une corrélation entre les propriétés de l'écoulement et de l'accrétion, illustrant l'interdépendance de ces deux phénomènes.Les disques autour d'objets compacts (binaires X ou novae naines), en particulier, sont extrêmement variables : la luminosité du système peut augmenter de plusieurs ordres de grandeur lors de "sursauts". Ces sursauts sont extrêmement utiles pour contraindre l'évolution séculaire du disque d'accrétion, et peuvent permettre de mesurer sur le long terme l'impact de l'accrétion sur le système.L'accrétion résulte d'un transport de moment cinétique dans le disque. Lorsque la matière accrétante perd du moment cinétique, elle perd son inertie centrifuge et tombe vers l'objet central. Le transport radial de moment cinétique peut avoir lieu par l'intermédiaire d'un couple turbulent, ou peut être dû à un écoulement emportant au loin le moment cinétique du système. Historiquement, ces deux processus ont été étudiés séparément. Des modèles 2D effectifs ont été utilisés afin d'étudier le couple laminaire dû à la présence de l'écoulement , tandis que des simulations 3D locales, avec cisaillement, ont permis de modéliser le couple turbulent. Cependant, ces deux processus résultent de la présence d'un champ magnétique vertical ordonné, à grande échelle. Les simulations locales 3D capturent parfaitement la turbulence, mais sont incapables de modéliser précisément la dynamique de l'écoulement. A l'inverse, les modèles 2D effectifs capturent cette dynamique, mais ne peuvent résoudre la turbulence (qui est intrinsèquement tridimensionnelle). De plus, l'amélioration des performances des supercalculateurs permet maintenant d'étudier à la fois les couples laminaire et turbulent dans une même simulation globale 3D. De telles simulations montrent des différences importantes par rapport aux modèles 2D effectifs, indiquant que la physique de ces disques reste mal comprise. De plus, ces simulations ont montré qu'il était possible de produire des écoulements à faible champ magnétique, ce qui entre en contradiction avec les prédictions des modèles auto-similaires. Malgré tout, les simulations 3D globales sont numériquement coûteuses, rendant leur comparaison avec les modèles 2D difficile. Ceux-ci restent un outil utile pour l'interprétation des observations, à condition qu'ils soient éduqués par des simulations 3D.Dans cette thèse, nous cherchons à combler le fossé entre modèles 2D effectifs et simulations globales 3D. Nous étudions des modèles auto-similaires, qui sont un cas particulier de modèle effectif 2D. Tout d'abord, nous découvrons de nouvelles solutions auto-similaires faiblement magnétisées. Nous analysons leurs propriétés, et les comparons avec les simulations de disques faiblement magnétisés les plus récentes. Ensuite, nous réalisons des simulations globales de disques d'accrétion avec écoulements. Nous analysons en particulier leur structure verticale, et expliquons les raisons derrière la différence avec les modèles effectifs 2D. Nous étudions également l'évolution séculaire du système, et détaillons la dépendance de cette évolution avec l'intensité du champ magnétique. Enfin, à partir de la compréhension acquise de ces simulations 3D, nous construisons un nouveau modèle de turbulence, qui conduira à la mise en place de modèles effectifs 2D plus précis