Winds throughout the Universe

Provided a sufficient supply of gas, black holes may accrete at many times the Eddington rate. If sustained, such accretion may facilitate rapid growth of black holes in the early universe. Such conditions may also help produce some of the higher-mass black hole binary mergers detected by LIGO. However, the dynamics of these systems are strongly affected by both magnetic fields and strong radiative feedback. With particular focus on the role of radiative feedback in super-Eddington accretion, we will present the results of a suite of general relativistic radiation (magneto-)hydrodynamics simulations, and their implications for both the growth of black holes and the feedback of energy to larger scales.

A Deep Chandra HETG study of MCG-6-30-15 Ionized Outflows with a Bayesian Framework

Erika Hoffman (University of Maryland, College Park), Anna Ogorzalek (UMD/NASA GSFC), Chris Reynolds (University of Maryland, College Park)

Ionized outflows of Active Galactic Nuclei (AGN) have potential to explain the physical mechanisms of galaxy-AGN co-evolution. Studying these winds requires careful analysis of X-ray absorption lines and typical studies are not yet optimized to extract the full potential of high-resolution X-ray spectra. Therefore new approaches to analyzing data from instruments like Chandra’s High Energy Transmission Grating (HETG) and XRISM’s microcalorimeter can yield crucial progress.

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Black Hole Spin Gone MAD in Radiatively-inefficient and Luminous Disks

Beverly Lowell, Jonathan Jacquemin-Ide, and Alexander Tchekhovskoy (Northwestern University)

Supermassive black holes (SMBHs) interact with their host galaxies by accreting gas and expelling energy into the surrounding medium in the form of relativistic jets. Jets are thought to be powered by BH spin, but how spin evolves as BHs accrete and launch jets is not understood. I perform 3D general relativistic magnetohydrodynamic (GRMHD) simulations of magnetically arrested disk (MAD) accretion onto BHs. I use simulations of nonradiative disks for a range of spin values (-0.9 a 0.99) and radiation transport two- temperature simulations of luminous disks to discern how the results depend on the Eddington ratio. I show that radiatively-inefficient MADs spin down BHs to low spin values of 0.1. I construct a semi-analytic model and show that the low equilibrium spin emerges due to a powerful magnetic torque on the BH. I show that luminous MADs spin down BHs to a higher equilibrium spin, a = 0.4. This signals a paradigm shift that luminous jetted quasars can spin down BHs to values much lower than the equilibrium spin expected for standard luminous disks, a = 0.998.

ALMA Upgrades Enhancing Kinematic Studies at all Scales

Arielle Moullet, George Privon, Al Wooten, Mark Lacy, Loreto Barcos Munoz and Crystal Brogan (NRAO)

The Atacama Large Millimeter Array has been a key tool in the past decade for the characterization of outflows at different scales, from evolved stars and galactic-scale molecular clouds to quasars. ALMA datacubes of strong molecular transitions enable highly-resolved spectral profile analysis which, often enhanced by high-resolution imaging, allow one to identify and characterize outflow components with projected velocities along the line of sight.

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3D Wind Simulations from Magnetic Massive Stars

Sethupathy Subramnian, Dinshaw S. Balsara (University of Notre Dame) and Marc Gagné (West Chester University)

We study the dynamics of the magnetically channeled winds from massive stars using a full 3D using a code that is uniquely suited to spherical problems. We use high resolution simulations using a GPU-enabled version of our code to study the wind structure from O and OB stars with arbitrary tilt angles between the rotation axis and the axis of the magnetic dipole. The simulations are run up to a quasi-steady state, showing the episodic centrifugal breakout events of the mass outflow, confined by the magnetic field loops that form the closed magnetosphere of the star. The catalogued results provide perspective on how angular momentum varies for different configurations of rotation rate, magnetic field strength and large magnetic tilt angles. We also present a detailed analysis of theta^1 Orionis C. This O7 V star is an oblique magnetic rotator with a rotation period of 15.42 days. The simulations include shock heating, radiative cooling, and inverse Compton cooling. We describe the dynamics of the wind shocks and compare the simulated emission-measure distributions with those extracted from the HETG data analysis. In particular we show that most hotter lines like Si XIV are formed in the magnetically confined wind shocks, while some cooler lines like O VIII are most likely formed in embedded wind shocks. The 3D simulations allow us to show that much of the observed rotational modulation is produced by variations of the line-of-sight absorption in the overlying cool wind.

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Fast Moving Ejections from the High Mass Gamma-ray Binary hosting LS 2883/PSR B1259-63

Jeremy Hale (NASA GSFC/CRESST/CUA), George G. Pavlov (Penn State University), and Oleg Kargaltsev (George Washington University)

LS 2883 is a high mass gamma-ray binary, with an orbital period of about 3.4 years, that hosts the energetic radio pulsar PSR B1259-63. The Be companion star has a decretion disk inclined to the orbital plane of the pulsar, which the pulsar likely interacts with each binary orbit. Additionally, the pulsar itself likely hosts a powerful wind. Here we will report on the latest results from a Chandra monitoring campaign of this source spanning 14 years (from 2009-2023), or 5 orbital cycles, in which high velocity clumps were discovered being launched from the binary. These X-ray emitting clumps have projected velocities of about 10% of the speed of light and show evidence of acceleration over a timescale of about 500 days. I will also discuss our efforts to find similar ejecta in other high mass gamma-ray binaries.

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Tracing Protoplanetary Disk Winds Using Forbidden Emission Lines

Ahmad Nemer (NYU – Abu Dhabi) and Jeremy Goodman (Princeton)

Protoplanetary disk (PPD) winds play an important role in disk dispersal. Constraining disk wind models, along with accretion and jets, is necessary to understand its evolution, and eventually, planet formation. We trace these winds with optical forbidden emission lines of [OI], [SII], [NII], and [NeII] to estimate the wind kinematics and mass loss rates. The emission lines are comprised of multiple components that probably trace a different region in the system. At least one of these components was found to trace an ideal-MHD wind which was not considered in previous models. In addition, disk emission lines were found to be correlated to the accretion luminosity which means that the two processes are related. The correlation between emission lines and the FUV source (accretion) could provide a method for measuring the disk magnetic field.

Time-Dependent Photoionization of Warm Absorbers: High-Resolution Spectra and Response to Flaring Light Curves

Dev Sadula (NASA GSFC), Manuel Bautista (Western Michigan University), Javier Garcia (Caltech), and Timothy Kallman (NASA GSFC)

The nature of the extreme variability of the central ionizing source in Active Galactic Nuclei (AGN) suggests that the outflowing gas may deviate from the commonly approached equilibrium approximation. Hence, we need to consider a time-dependent calculation to describe the ionization states and the transmitted spectra accurately. To see the effects of the variability quantitatively, we carried out a time-dependent photoionization simulation by solving a time-dependent balance equation for level population, internal energy, and radiative transfer simultaneously and self-consistently and developed a time-dependent photoionization modeling code (TDP code). The outflows responsible for the absorption of the X-rays, also known as warm absorbers, are investigated using this newly developed TDP code for various input parameters such as density, the shape of the incident light curve, SED, etc. We simulated the outflow for step and flare incident light curves. We analyzed the high-resolution transmitted model spectra to understand how the ionization structure of the outflow changes over time. The study of the time-resolved spectra could be used in constraining the warm absorber properties such as density and, in turn, the location. This will help to understand the AGN feedback by estimating the kinetic power of the outflow. In this poster, we present the results of how the warm absorber gas responds to the flaring incident ionizing radiation and the transmitted spectrum changes over time.

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Tracking Extreme Variability in the Winds of Mrk 817 with NICER

Ethan Partington and Edward Cackett (Wayne State University)

The AGN STORM 2 collaboration targeted the Seyfert 1 galaxy Mrk 817 for a coordinated, multiwavelength reverberation mapping campaign including HST, Swift, XMM-Newton, NICER, and ground-based observatories. We have continued monitoring for over 30 months, tracking the variability of a dust-free, ionized obscurer consistent with a clumpy disk wind launched from the inner broad line region. Analysis of NICER spectra taken at a two-day cadence attributes variability in the observed X-ray flux to changes in both the column density of the obscurer by at least one order of magnitude on timescales greater than 30 days, and the flux of the unobscured X-ray continuum on shorter timescales. While the X-ray flux of Mrk 817 is typically 10-20% of its historical mean during the campaign, it undergoes two bright epochs of minimal obscuration associated with high unobscured flux. Both epochs can be described by a low column density obscurer which becomes highly ionized (log ξ 2), increasing its transparency. During the first epoch, the observed flux reaches historical brightness for two days. The second epoch lasts at least 60 days, the X-ray flux is twice as bright, and the obscurer may become disrupted, disappearing entirely. We will present the X-ray spectral modeling results from the full campaign of NICER observations, which reveal rapid transitions in the column density of the obscuring wind and its response to the ionizing continuum.

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Winds throughout the Universe

Schedule

Posters

2023 JSI Workshop