We present first comparisons between Light Element Primary Process (LEPP) abundances observed in some ultra metal poor (UMP) stars and nucleosynthesis calculations based on long-time hydrodynamical simulations of core-collapse supernovae and their neutrino-driven wind. UMP star observations indicate Z>38 elements include the contributions of at least two nucleosynthesis components: r-process nuclei that are synthesized by rapid neutron capture in a yet unknown site and LEPP elements (mainly Sr, Y, Zr). We show that neutrino-driven wind simulations can explain the observed LEPP pattern. We explore in detail the sensitivity of the calculated abundances to the electron fraction, which is a key nucleosynthesis parameter but poorly known due to uncertainties in neutrino interactions and transport. Our results show that the observed LEPP pattern can be reproduced in proton- and neutron-rich winds.
Post-starburst (PSB) galaxies may be in rapid transition from star-forming to quiescence and are excellent candidates to constrain active galactic nuclei (AGN) feedback models. We study galactic winds in the stacked spectrum of 560 AGN PSBs and that of a control sample of star-forming galaxies in the Sloan Digital Sky Survey (SDSS). Using a two component (inter-stellar +wind) absorption-line model of the \ion{Na}{i} doublet, and after accounting for the stellar photospheric absorption, we find that the AGN PSBs have a centroid wind velocity shift of $-252^{+64}_{-57}$ km s$^{-1}$ and a maximum…
This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially resolved observations indicate that the majority of the IR emission from 100 pc in many AGN originates from the polar region, contradicting classical torus models. The new model CAT3D-WIND builds upon the suggestion that the dusty gas around the AGN consists of an inflowing disk and an outflowing wind. Here, it is demonstrated that (1) such disk+wind models cove…
Infrared interferometry of local AGN has revealed a warm (~300K-400K) polar dust structure that cannot be trivially explained by the putative dust torus of the unified model. This led to the development of the disk+wind scenario which comprises of a hot (~1000K) compact equatorial dust disk and a polar dust wind. This wind is assumed to be driven by radiation pressure and, therefore, we would expect that long term variation in radiation pressure would influence the dust distribution. In this paper we attempt to quantify if and how the dust distribution changes with radiation pressure. We analy…
Both observational and theoretical evidence point at outflows originating from accretion disks as fundamental ingredients of active galactic nuclei (AGN). These outflows can have more than one component, for example an unbound supersonic wind and a failed wind (FW). The latter is a prediction of the simulations of radiation-driven disk outflows which show that the former is accompanied by an inner failed component, where the flow struggles to escape from the strong gravitational pull of the supermassive black hole. This FW component could provide a physical framework to interpret various pheno…
It has been recently proposed that the broad line region in active galactic nuclei originates from dusty clouds driven from the accretion disk by radiation pressure, at a distance from the black hole where the disk is cooler than the dust sublimation temperature. We test this scenario by checking the consistency of independent broad line region and accretion disk reverberation measurements, for a sample of 11 well studied active galactic nuclei. We show that independent disk and broad line region reverberation mapping measurements are compatible with a universal disk temperature at the Hβ radi…
In most galaxies, the fluxes of rotational H2 lines strongly correlate with star formation diagnostics (such as polycyclic aromatic hydrocarbons, PAH), suggesting that H2 emission from warm molecular gas is a minor byproduct of star formation. We analyse the optical properties of a sample of 309 nearby galaxies derived from a parent sample of 2,015 objects observed with the Spitzer Space Telescope. We find a correlation between the [OI]6300 emission-line flux and kinematics and the H2 S(3)9.665um/PAH11.3um. The [OI]6300 kinematics in Active Galactic Nuclei (AGN) can not be explained only by ga…
We predict the observational signatures of galaxy scale outflows powered by active galactic nuclei (AGN). Most of the emission is produced by the forward shock driven into the ambient interstellar medium (ISM) rather than by the reverse shock. AGN powered galactic winds with energetics suggested by phenomenological feedback arguments should produce spatially extended 1-10 keV X-ray emission of 10^(41-44) erg/s, significantly in excess of the spatially extended X-ray emission associated with normal star forming galaxies. The presence of such emission is a direct test of whether AGN outflows sig…
(Abridged) Infrared high-resolution imaging and interferometry have shown that the dust distribution is frequently elongated along the polar direction of an AGN. To explain these findings, we developed a model scenario for the inner ~30 pc of an AGN. We assume a rotating thick gas disk between about one and ten parsec. External gas accretion adds mass and injects energy via gas compression into this gas disk and drives turbulence. Our disks are assumed to be strongly magnetized via equipartition between the turbulent gas pressure and the energy density of the magnetic field. In a second step, …
We study winds in 12 X-ray AGN host galaxies at z ~ 1. We find, using the low-ionization Fe II 2586 absorption in the stacked spectra, that the probability distribution function (PDF) of the centroid velocity shift in AGN has a median, 16th and 84th percentiles of (-87, -251, +86) km/s respectively. The PDF of the velocity dispersion in AGN has a median, 84th and 16th percentile of (139, 253, 52) km/s respectively. The centroid velocity and the velocity dispersions are obtained from a two component (ISM+wind) absorption line model. The equivalent width PDF of the outflow in AGN has median, 84t…
The broad emission lines (BELs) in active galactic nuclei (AGN) respond to ionizing continuum variations. The time and velocity dependence of their response depends on the structure of the broad-line region: its geometry, kinematics and ionization state. Here, we predict the reverberation signatures of BELs formed in rotating accretion disc winds. We use a Monte Carlo radiative transfer and ionization code to predict velocity-delay maps for representative high- (C$~IV$) and low-ionization (H$α$) emission lines in both high- and moderate-luminosity AGN. Self-shielding, multiple scattering and t…
We present new, deep Chandra X-ray and Giant Metrewave Radio Telescope 610~MHz observations of the spiral-galaxy-rich compact group HCG 16, which we use to examine nuclear activity, star formation and the high luminosity X-ray binary populations in the major galaxies. We confirm the presence of obscured active nuclei in NGC 833 and NGC 835, and identify a previously unrecognized nuclear source in NGC 838. All three nuclei are variable on timescales of months to years, and for NGC 833 and NGC 835 this is most likely caused by changes in accretion rate. The deep Chandra observations allow us to …
Metals in the hot gaseous halos of galaxies encode the history of star formation as well as the feedback processes that eject metals from the galaxies. X-ray observations suggest that massive galaxies have extended distributions of metals in their gas halos. We present predictions for the metal properties of massive galaxies and their gaseous halos from recent high resolution zoom-in simulations that include mechanical and radiation driven feedback from Active Galactic Nuclei (AGN). In these simulations, AGN launch high-velocity outflows, mimicking observed broad absorption line winds. By comp…
We perform simulations to study the effects of active galactic nuclei (AGNs) radiation and wind feedback on the properties of slowly rotating accretion flow at parsec scale. We find that when only radiative feedback is considered, outflows can be produced by the radiation pressure due to Thomson scattering. The mass flux of outflow is comparable to that of inflow. Although strong outflow is present, the luminosity of AGN can be easily super-Eddington. When wind feedback is also taken into account, the mass flux of outflow does not change much. Consequently, the luminosity of the central AGN ca…
Active galactic nuclei (AGN) drive fast winds in the interstellar medium of their host galaxies. It is commonly assumed that the high ambient densities and intense radiation fields in galactic nuclei imply short cooling times, thus making the outflows momentum-conserving. We show that cooling of high-velocity, shocked winds in AGN is in fact inefficient in a wide range of circumstances, including conditions relevant to ultra-luminous infrared galaxies (ULIRGs), resulting in energy-conserving outflows. We further show that fast energy-conserving outflows can tolerate a large amount of mixing wi…
The high-ionization lines of the broad-line region (BLR) of thermal active galactic nuclei (AGNs) show blueshifts of a few hundred km/s to several thousand km/sec with respect to the low-ionization lines. This has long been thought to be due to the high-ionization lines of the BLR arising in a wind of which the far side of the outflow is blocked from our view by the accretion disc. Evidence for and against the disc-wind model is discussed. The biggest problem for the model is that velocity-resolved reverberation mapping repeatedly fails to show the expected kinematic signature of outflow of th…
Accretion disk winds are thought to produce many of the characteristic features seen in the spectra of active galactic nuclei (AGN) and quasi-stellar objects (QSOs). These outflows also represent a natural form of feedback between the central supermassive black hole and its host galaxy. The mechanism for driving this mass loss remains unknown, although radiation pressure mediated by spectral lines is a leading candidate. Here, we calculate the ionization state of, and emergent spectra for, the hydrodynamic simulation of a line-driven disk wind previously presented by Proga & Kallman (2004). To…
Ultraviolet (UV) line driven winds may be an important part of the active galactic nucleus (AGN) feedback process, but understanding their impact is hindered by the complex nature of the radiation hydrodynamics. Instead, we have taken the approach pioneered by Risaliti & Elvis, calculating only ballistic trajectories from radiation forces and gravity, but neglecting gas pressure. We have completely re-written their QWIND code using more robust algorithms, and can now quickly model the acceleration phase of these winds for any AGN spectral energy distribution spanning UV and X-ray wavebands. We…
The warm absorbers observed in more than half of all nearby active galactic nuclei (AGN) are tracers of ionized outflows located at parsec scale distances from the central engine. If the smallest inferred ionization parameters correspond to plasma at a few $10^4$~K, then the gas undergoes a transition from being bound to unbound provided it is further heated to $\sim 10^6$~K at larger radii. Dannen et al. recently discovered that under these circumstances, thermally driven wind solutions are unsteady and even show very dense clumps due to thermal instability. To explore the observational conse…
Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\sim 0.1- 0.2c$ are a common feature in X--ray spectra of luminous AGN, offering a plausible physical origin for the well known connections between the hole and properties of its host. Observability constraints suggest that the winds must be episodic, and detectable only for a few percent of their lifetimes. The most powerful wind feedback, establishing the $M -σ$ relation, is probably not directly observable at all. The…
TeV Gamma Rays and Neutrinos from Winds Driven by Radiatively Inefficient Accretion Flows of Low-Luminosity Active Galactic Nuclei
The University of Osaka（大阪大学）；The Ohio State University（俄亥俄州立大学）；The Pennsylvania State University（宾夕法尼亚州立大学）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）
本研究针对LHAASO探测到的LLAGN NGC 4278宁静期TeV伽马射线，提出RIAF驱动风的新机制，建模重现其辐射，还可推广至Sgr A*，为LLAGN辐射机制提供新解释。
We analyze spatially resolved spectroscopic observations of the Eta Carinae binary system obtained with HST/STIS. Eta Car is enshrouded by the dusty Homunculus nebula, which scatters light emitted by the central binary and provides a unique opportunity to study a massive binary system from different vantage points. We investigate the latitudinal and azimuthal dependence of H$α$ line profiles caused by the presence of a wind-wind collision (WWC) cavity created by the companion star. Using two-dimensional radiative transfer models, we find that the wind cavity can qualitatively explain the obser…
