Outflow Properties Research Articles

Discovery of an Accretion Streamer and a Slow Wide-angle Outflow around FU Orionis

We present Atacama Large Millimeter/submillimeter Array 12-m, 7-m, and Total Power Array observations of the FU Orionis outbursting system, covering spatial scales ranging from 160 to 25,000 au. The high-resolution interferometric data reveal an elongated 12CO(2–1) feature previously observed at lower resolution in 12CO(3–2). Kinematic modeling indicates that this feature can be interpreted as an accretion streamer feeding the binary system. The mass infall rate provided by the streamer is significantly lower than the typical stellar accretion rates (even in quiescent states), suggesting that this streamer alone is not massive enough to sustain the enhanced accretion rates characteristic of the outbursting class prototype. The observed streamer may not be directly linked to the current outburst, but rather a remnant of a previous, more massive streamer that may have contributed enough to the disk mass to render it unstable and trigger the FU Orionis outburst. The new data detect, for the first time, a vast, slow-moving carbon monoxide molecular outflow emerging from this object. To accurately assess the outflow properties (mass, momentum, and kinetic energy), we employ 13CO(2–1) data to correct for optical depth effects. The analysis indicates that the outflow corresponds to swept-up material not associated with the current outburst, similar to the slow molecular outflows observed around other FUor and Class I protostellar objects.

Constraining Protoplanetary Disk Winds from Forbidden Line Profiles with Simulation-based Inference

Protoplanetary disks (PPDs) are sites of vigorous hydrodynamic processes, such as accretion and outflows, and ultimately establish the conditions for the formation of planets. The properties of disk outflows are often inferred through the analysis of forbidden emission lines. These lines contain multiple overlapping components, tracing different emission regions with different processes that excite them: a high-velocity component (tracing a jet), a broad low-velocity component (LVC; tracing inner disk wind), and a narrow LVC (tracing the outer disk wind). They are also heavily contaminated by background spectral features. All of these challenges call into question the traditional approach of fitting Gaussian components to the line profiles and cloud the physical interpretation of those components. We introduce a novel statistical technique to analyze emission lines in PPDs. Simulation-based inference is a computationally efficient machine-learning technique that produces posterior distributions of the parameters (e.g., magnetic field, radiation sources, and geometry) of a representative wind model when given a spectrum without any prior assumption about line shapes (e.g., symmetry). In this pathfinder study, we demonstrate that this technique indeed accurately recovers the parameters from simulated spectra without noise and background. Future work will provide an analysis of the observed spectra.

Search for protostellar jets with UWISH2 in the molecular cloud complexes Vulpecula and IRDC G53.2

Abstract Jets and outflows are the early signposts of stellar birth. Using the UKIRT Wide Field Infrared Survey for H2 (UWISH2) at 2.12 μm, 127 outflows are identified in molecular cloud complexes Vulpecula OB1 and IRDC G53.2 covering 12 square degrees of the Galactic plane. Using multi-wavelength datasets, from 1.2 to 70 μm, 79 young stellar objects (YSOs) are proposed as potential driving sources, where, ∼79 % are likely Class 0/I protostars, 17 % are Class II YSOs and the remaining 4 % are Class III YSOs. The outflows are characterized in terms of their length, flux, luminosity and knot-spacing. The identified outflows have a median lobe length of 0.22 pc and 0.17 pc for outflows in Vulpecula OB1 and IRDC G53.2, respectively. Our analysis, from the knot spacing, reveals a typical ejection frequency of ∼1.2 kyr suggesting an intermediate type between the FU-Ori and EX-Ori type of eruptions in both cloud complexes. Furthermore, the physical parameters of the driving sources are obtained by performing radiative transfer modelling to the observed spectral energy distributions (SEDs), which suggest that the outflows are driven by intermediate mass stars. Various observed trends between the outflow properties and the corresponding driving sources, and various interesting outflows and star forming sites, including sites of triggered star formation and protocluster forming clump with clusters of jets, are discussed. The obtained results and the identified jet-bearing protostellar sample will pave the way to understand many aspects of outflows with future high-resolution observations.

Outflows Driven from a Magnetic Pseudodisk

Outflows play a pivotal role in star formation as one of its most visible markers and a means of transporting mass, momentum, and angular momentum from the infalling gas into the surrounding molecular cloud. Their wide reach (at least thousands of astrnomical units) is a contrast to typical disk sizes (∼10–100 au). We employ high-resolution three-dimensional nested-grid nonideal magnetohydrodynamic (MHD) simulations to study outflow properties in the Class 0 phase. We find that no disk wind is driven from the extended centrifugal disk that has weak magnetic coupling. The low-velocity winds emerge instead from the infalling magnetic pseudodisk. Much of the disk actually experiences an infall of matter rather than outflowing gas. Some of the pseudodisk wind (PD-wind) moves inward to regions above the disk and either falls onto the disk or proceeds upward. The upward flow gives the impression of a disk wind above a certain height even if the gas is originally emerging from the pseudodisk. The PD-wind has the strongest flow coming from a disk interaction zone that lies just outside the disk and is an interface between the inwardly advected magnetic field of the pseudodisk and the outwardly diffusing magnetic field of the disk. The low-velocity wind exhibits the features of a flow driven by the magnetic pressure gradient force in some regions and those of a magnetocentrifugal wind in other regions. We interpret the structure and dynamics of the outflow zone in terms of the basic physics of gravity, angular momentum, magnetic fields, and nonideal MHD.

ALMA reveals a compact and massive molecular outflow driven by the young AGN in a nearby ULIRG

ABSTRACT The ultraluminous infrared galaxy F13451+1232 is an excellent example of a galaxy merger in the early stages of active galactic nucleus (AGN) activity, a phase in which AGN-driven outflows are expected to be particularly important. However, previous observations have determined that the mass outflow rates of the warm ionized and neutral gas phases in F13451+1232 are relatively modest, and there has been no robust detection of molecular outflows. Using high-spatial resolution Atacama Large Millimeter/submillimeter Array CO(1–0) observations, we detect a kiloparsec-scale circumnuclear disc, as well as extended (r ∼ 440 pc), intermediate-velocity (300 < |v| < 400 km s−1) cold molecular gas emission that cannot be explained by rotational disc motions. If interpreted as AGN-driven outflows, the mass outflow rates associated with this intermediate-velocity gas are relatively modest ($\dot{M}_\mathrm{out}=22$–27 M⊙ yr−1); however, we also detect a compact (rout < 120 pc), high-velocity (400 < v < 680 km s−1) cold molecular outflow near the primary nucleus of F13451+1232, which carries an order of magnitude more mass ($\dot{M}_\mathrm{out}$ ∼ 230 M⊙ yr−1) than (and several times the kinetic power of) the previously detected warmer phases. Moreover, the similar spatial scales of this compact outflow and the radio structure indicate that it is likely accelerated by the small-scale (r ∼ 130 pc) AGN jet in the primary nucleus of F13451+1232. Considering the compactness of the nuclear outflow and intermediate-velocity non-rotating gas that we detect, we argue that high-spatial resolution observations are necessary to properly quantify the properties of AGN-driven outflows and their impacts on host galaxies.

GRB 220304A: Another Gamma-Ray Burst Dominated by Thermal Radiation

We report a recently detected long-duration gamma-ray burst (GRB) event by Fermi-GBM, GRB 220304A. The spectral analysis of the burst by the Band function shows that both the time-integrated and time-resolved spectra are very narrow, with low-energy spectral index 〈α〉 = −0.05 ± 0.30 and high-energy spectral index 〈β〉 = −3.53 ± 0.30. It is reminiscent of GRB 090902B, a special GRB with photosphere radiation characteristics. Then, we perform spectral analysis using the Planck function (blackbody, BB) and the multicolor BB model. It is found that the spectra within −1 ∼ 3 s is well fit by the BB model, indicating that the observation within the first 4 s is a pure thermal event. Apart from that most of the spectra can be well modeled as a multicolor BB. We conclude that GRB 220304A is a GRB dominated by thermal radiation. We also find that the spectral widths of the time-resolved spectrum of the burst gradually increase with time. Based on the Amati relation, we infer the redshift to be 0.23, the physical properties of the relativistic outflow, and find that the relationship between the bulk Lorentz factor and the isotropic luminosity Γ–L iso,52 still exists.

Revealing Multiple Nested Molecular Outflows with Rotating Signatures in HH270mms1-A with ALMA

We present molecular line observations of the protostellar outflow associated with HH270mms1 in the Orion B molecular cloud with ALMA. The 12CO (J = 3−2) emissions show that the outflow velocity structure consists of four distinct components of low (≲10 km s−1), intermediate (∼10–25 km s−1) and high (≳40 km s−1) velocities in addition to the entrained gas velocity (∼25–40 km s−1). The high- and intermediate-velocity flows have well-collimated structures surrounded by the low-velocity flow. The chain of knots is embedded in the high-velocity flow or jet, which is the evidence of episodic mass ejections induced by time-variable mass accretion. We could detect the velocity gradients perpendicular to the outflow axis in both the low- and intermediate-velocity flows. We confirmed the rotation of the envelope and disk in the 13CO and C17O emission and found that their velocity gradients are the same as those of the outflow. Thus, we concluded that the velocity gradients in the low- and intermediate-velocity flows are due to the outflow rotation. Using observational outflow properties, we estimated the outflow launching radii to be 67.1–77.1 au for the low-velocity flow and 13.3–20.8 au for the intermediate-velocity flow. Although we could not detect the rotation in the jets due to the limited spatial resolution, we estimated the jet launching radii to be (2.36–3.14) × 10−2 au using the observed velocity of each knot. Thus, the jet is driven from the inner disk region. We could identify the launching radii of distinct velocity components within a single outflow with all the prototypical characteristics expected from recent theoretical works.

Spin-induced offset stream self-crossing shocks in tidal disruption events

Abstract Tidal disruption events occur when a star is disrupted by a supermassive black hole, resulting in an elongated stream of gas that partly falls back to the pericenter. Due to apsidal precession, the returning stream may collide with itself, leading to a self-crossing shock that launches an outflow. If the black hole spins, this collision may additionally be affected by Lense-Thirring precession that can cause an offset between the two stream components. We study the impact of this effect on the outflow properties by carrying out local simulations of collisions between offset streams. As the offset increases, we find that the geometry of the outflow becomes less spherical and more collimated along the directions of the incoming streams, with less gas getting unbound by the interaction. However, even the most grazing collisions we consider significantly affect the trajectories of the colliding gas, likely promoting subsequent strong interactions near the black hole and rapid disc formation. We analytically compute the dependence of the offset to stream width ratio, finding that even slowly spinning black holes can cause both strong and grazing collisions. We estimate that the self-crossing shock luminosity is lower for an offset collision than an aligned one since radiation energy injected by the shock is significantly lower for more offset collisions. We find that the deviation from outflow sphericity may cause significant variations in the efficiency at which X-ray radiation from the disc is reprocessed to the optical band, depending on the viewing angle, and increase the degree of the observed polarization. These potentially observable features hold the promise of constraining the black hole spin from tidal disruption events.

JWST reveals widespread AGN-driven neutral gas outflows in massive z ~ 2 galaxies

ABSTRACT We use deep JWST/NIRSpec R ∼ 1000 slit spectra of 113 galaxies at $1.7 < z < 3.5$, selected from the mass-complete Blue Jay survey, to investigate the prevalence and typical properties of neutral gas outflows at cosmic noon. We detect excess Na id absorption (beyond the stellar contribution) in 46 per cent of massive galaxies (log M*/M⊙ > 10), with similar incidence rates in star-forming and quenching systems. Half of the absorption profiles are blueshifted by at least 100 km s−1, providing unambiguous evidence for neutral gas outflows. Galaxies with strong Na id absorption are distinguished by enhanced emission line ratios consistent with AGN ionization. We conservatively measure mass outflow rates of 3–100 M⊙ yr−1; comparable to or exceeding ionized gas outflow rates measured for galaxies at similar stellar mass and redshift. The outflows from the quenching systems (log(sSFR)[yr−1] ≲ −10) have mass loading factors of 4–360, and the energy and momentum outflow rates exceed the expected injection rates from supernova explosions, suggesting that these galaxies could possibly be caught in a rapid blowout phase powered by the AGN. Our findings suggest that AGN-driven ejection of cold gas may be a dominant mechanism for fast quenching of star formation at z ∼ 2.

Multiphase characterization of AGN winds in five local type-2 quasars

We present MEGARA integral field unit (IFU) observations of five local type-2 quasars (QSO2s, z ∼ 0.1) from the Quasar Feedback (QSOFEED) sample. These active galactic nuclei (AGN) have bolometric luminosities of 1045.5 − 46 erg s−1 and stellar masses of ∼1011 M⊙. The LR-V grating of MEGARA allows us to explore the kinematics of the ionized gas through the [O III]λ5007 Å emission line. The nuclear spectra of the five QSO2s, extracted in a circular aperture of ∼1.2″ (∼2.2 kpc) in diameter, matching the resolution of these seeing-limited observations, show signatures of high velocity winds in the form of broad (full width at half maximum, 1300 ≤ FWHM ≤ 2240 km s−1) and blueshifted components. We found that four out of the five QSO2s present outflows that we can resolve with our seeing-limited data, and they have radii ranging from 3.1 to 12.6 kpc. In the case of the two QSO2s with extended radio emission, we found that it is well aligned with the outflows, suggesting that low-power jets might be compressing and accelerating the ionized gas in these radio-quiet QSO2s. In the four QSO2s with spatially resolved outflows, we measured ionized mass outflow rates of 3.3–6.5 M⊙ yr−1 when we used [S II]-based densities, and of 0.7–1.6 M⊙ yr−1 when trans-auroral line-based densities were considered instead. We compared them with the corresponding molecular mass outflow rates (8–16 M⊙ yr−1), derived from CO(2–1) ALMA observations at 0.2″ resolution. The cold molecular outflows carry more mass than their ionized counterparts. However, both phases show lower outflow mass rates than those expected from observational scaling relations where uniform assumptions on the outflow properties were adopted. This might be indicating that the AGN luminosity is not the only driver of massive outflows and/or that these relations need to be rescaled using accurate outflow properties (i.e., electron density and radius). We did not find a significant impact of the outflows on the global star formation rates when considering the energy budget of the molecular and ionized outflows together. However, spatially resolved measurements of recent star formation in these targets are needed in order to evaluate this fairly, considering the dynamical timescales of the outflows, of 3–20 Myr for the ionized gas and 1–10 Myr for the molecular gas.

ALMA-IMF. IX. Catalog and Physical Properties of 315 SiO Outflow Candidates in 15 Massive Protoclusters

We present a catalog of 315 protostellar outflow candidates detected in SiO J = 5 − 4 in the ALMA-IMF Large Program, observed with ∼2000 au spatial resolution, 0.339 km s−1 velocity resolution, and 2–12 mJy beam−1 (0.18–0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ∼0.3 M ⊙, 4 M ⊙ km s−1, and 1045 erg, respectively. Median outflow lifetimes are 6000 yr, yielding median mass, momentum, and energy rates of Ṁ = 10−4.4 M ⊙ yr−1, Ṗ = 10−3.2 M ⊙ km s−1 yr−1, and Ė = 1 L ⊙. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (∼3σ–5σ), and no correlations above 3σ with clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass—which has been previously described in the literature—may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15%–30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force−bolometric luminosity relationship in the literature, and our data extend this relationship up to L ≥ 106 L ⊙ and Ṗ ≥ 1 M ⊙ km s−1 yr−1. Our lack of correlation with clump L/M is inconsistent with models of protocluster formation in which all protostars start forming at the same time.

Investigating the impact of quasar-driven outflows on galaxies at z ∼ 0.3–0.4

Aims. We present a detailed study of the kinematics of 19 type 2 quasars (QSO2s) with redshifts in the range 0.3 < z < 0.41 and [OIII] luminosities of L[OIII] > 108.5 L⊙. We aim to advance our understanding of the active galactic nucleus (AGN) feedback phenomenon by correlating outflow properties with (i) young stellar populations (YSPs) with ages < 100 Myr, (ii) the optical morphology and the environment of the galaxies, and (iii) the radio luminosity. Methods. We characterized the ionized gas kinematics using the [OIII]λ5007 Å emission line profiles detected in intermediate spectral resolution (R ∼ 1500–2500) optical spectra of the QSO2s. To do this, we employed three different outflow detection methods: multicomponent parametric, flux-weighted nonparametric, and peak-weighted nonparametric. Results. We detect ionized outflows in 18 of the 19 QSO2s using the parametric analysis, and in all of them using the nonparametric methods. We find higher outflow masses using the parametric analysis (average log MOF(M⊙) = 6.47 ± 0.50), and higher mass rates and kinetic powers with the flux-weighted nonparametric method (MOF = 4.0 ± 4.4 M⊙ yr−1 and Ekin = 41.9 ± 0.6 erg s−1). However, when we use the parametric method and the maximum outflow velocities (vmax), we measure the highest outflow mass rates and kinetic energies (MOF = 23 ± 35 M⊙ yr−1 and log(Ekin) = 42.9 ± 0.6 erg s−1). We do not find any significant correlation between the outflow properties and the previously mentioned AGN and galaxy-wide properties. Conclusions. Four of the five QSO2s without a YSP of age < 100 Myr show highly disturbed kinematics, whereas only 5 out of the 14 QSO2s with YSPs show similarly asymmetric [OIII] profiles. Despite the small sample size, this might be indicative of negative feedback. The lack of a correlation between the outflow properties and the galaxies optical morphologies might be due to their different dynamical timescales (millions of years in the case of the outflows versus billions of years in the case of galaxy mergers). Last, the small radio luminosity range covered by our sample, log(L5 GHz) = [22.1, 24.7] W Hz−1, may impede the detection of any correlation between radio emission and outflow properties.

A new discovery space opened by eROSITA

Context.In the context of an evolutionary model, the outflow phase of an active galactic nucleus (AGN) occurs at the peak of its activity, once the central supermassive black hole (SMBH) is massive enough to generate sufficient power to counterbalance the potential well of the host galaxy. This outflow feedback phase plays a vital role in galaxy evolution.Aims.Our aim in this paper is to apply various selection methods to isolate powerful AGNs in the feedback phase, trace and characterise outflows in these AGNs, and explore the link between AGN luminosity and outflow properties.Methods.We applied a combination of methods to the Spectrum Roentgen Gamma (SRG) eROSITA Final Equatorial Depth survey (eFEDS) catalogue and isolated ∼1400 candidates atz > 0.5 out of ∼11 750 AGNs (∼12%). Furthermore, we narrowed down our selection to 427 sources that have 0.5 < z < 1. We tested the robustness of our selection on the small subsample of 50 sources with available good quality SDSS spectra at 0.5 < z < 1 and, for which we fitted the [OIII] emission line complex and searched for the presence of ionised gas outflow signatures.Results.Out of the 50 good quality SDSS spectra, we identified 23 quasars (∼45%) with evidence of ionised outflows based on the presence of significant broad and/or shifted components in [OIII]λ5007 Å. They are on average more luminous (logLbol ∼ 45.2 erg s−1) and more obscured (NH ∼ 1022cm−2) than the parent sample of ∼427 candidates, although this may be ascribed to selection effects affecting the good quality SDSS spectra sample. By adding 118 quasars at 0.5 < z < 3.5 with evidence of outflows reported in the literature, we find a weak correlation between the maximum outflow velocity and the AGN bolometric luminosity. On the contrary, we recovered strong correlations between the mass outflow rate and outflow kinetic power with the AGN bolometric luminosity.Conclusions.About 30% of our sample have kinetic coupling efficiencies,Ė/Lbol> 1%, suggesting that the outflows could have a significant effect on their host galaxies. We find that the majority of the outflows have momentum flux ratios lower than 20 which rules out an energy-conserving nature. Our present work points to the unequivocal existence of a rather short AGN outflow phase, paving the way towards a new avenue to dissect AGN outflows in large samples within eROSITA and beyond.

Magnetic support, wind-driven accretion, coronal heating, and fast outflows in a thin magnetically arrested disc

ABSTRACT Accretion discs properties should deviate from standard theory when magnetic pressure exceeds the thermal pressure. To quantify these deviations, we present a systematic study of the dynamical properties of magnetically arrested discs (MADs), the most magnetized type of accretion disc. Using an artificial cooling function to regulate the gas temperature, we study MADs of three different thermal thicknesses, hth/r = 0.3, 0.1, and 0.03. We find that the radial structure of the disc is never mostly supported by the magnetic field. In fact, thin MADs are very near Keplerian. However, as discs gets colder, they become more magnetized and the largest deviations from standard theory appear in our thinnest disc with hth/r = 0.03. In this case, the disc is much more extended vertically and much less dense than in standard theory because of vertical support from the turbulent magnetic pressure and wind-driven angular momentum transport that enhances the inflow speed. The thin disc also dissipates a lot of thermal energy outside of z/r = ±0.03 and a significant fraction of this dissipation happens in mildly relativistic winds. The enhanced dissipation in low-density regions could possibly feed coronae in X-ray binaries (XRBs) and active galactic nuclei (AGNs). Wind-driven accretion will also impact the dynamical evolution of accretion discs and could provide a mechanism to explain the rapid evolution of changing-look AGN and the secular evolution of XRBs. Finally, our MAD winds have terminal velocities and mass-loss rates in good agreement with the properties of ultrafast outflows observed in AGN.

Dissecting a 30 kpc galactic outflow at z ~ 1.7

ABSTRACT We present the spatially resolved measurements of a cool galactic outflow in the gravitationally lensed galaxy RCS0327 at z ≈ 1.703 using VLT/MUSE IFU observations. We probe the cool outflowing gas, traced by blueshifted Mg ii and Fe ii absorption lines, in 15 distinct regions of the same galaxy in its image-plane. Different physical regions, 5 – 7 kpc apart within the galaxy, drive the outflows at different velocities (Vout ∼ −161 to −240 km s−1), and mass outflow rates ($\dot{M}_{out} \sim 183$ – 527 ${\rm M}_{\odot }\, \mathrm{yr}^{-1}$). The outflow velocities from different regions of the same galaxy vary by 80 km s−1, which is comparable to the variation seen in a large sample of star-burst galaxies in the local universe. Using multiply lensed images of RCS0327, we probe the same star-forming region at different spatial scales (0.5–25 kpc2), we find that outflow velocities vary between ∼ −120 and −242 km s−1, and the mass outflow rates vary between ∼37 and 254 ${\rm M}_{\odot }\, \mathrm{yr}^{-1}$. The outflow momentum flux in this galaxy is ≥ 100% of the momentum flux provided by star formation in individual regions, and outflow energy flux is ≈ 10% of the total energy flux provided by star formation. These estimates suggest that the outflow in RCS0327 is energy driven. This work shows the importance of small scale variations of outflow properties due to the variations of local stellar properties of the host galaxy in the context of galaxy evolution.

Complex AGN feedback in the Teacup galaxy

Context. The z ∼ 0.1 type-2 QSO J1430+1339, known as the “Teacup”, is a complex galaxy showing a loop of ionised gas ∼10 kpc in diameter, co-spatial radio bubbles, a compact (∼1 kpc) jet, and outflow activity. Its closeness offers the opportunity to study in detail the intricate interplay between the central supermassive black hole (SMBH) and the material in and around the galaxy, both the interstellar medium (ISM) and circumgalactic medium (CGM). Aims. We characterise the spatially resolved properties and effects of the galactic ionised gas outflow and compare them with those of the radio jet and with theoretical predictions to infer its acceleration mechanism. Methods. We used VLT/MUSE optical integral field spectroscopic observations to obtain flux, kinematic, and excitation maps of the extended (up to ∼100 kpc) ionised gas and to characterise the properties of stellar populations. We built radial profiles of the outflow properties as a function of distance from the active nucleus, from kiloparsec up to tens of kiloparsec scales, at ∼1 kpc resolution. Results. We detect a velocity dispersion enhancement (≳300 km s−1) elongated over several kiloparsecs perpendicular to the radio jet, the active galactic nucleus (AGN) ionisation lobes, and the fast outflow, similar to what is found in other galaxies hosting compact, low-power jets, indicating that the jet strongly perturbs the host ISM during its passage. We observe a decreasing trend with distance from the nucleus for the outflow properties (mass outflow rate, kinetic rate, momentum rate). The mass outflow rate drops from around 100 M⊙ yr−1 in the inner 1–2 kpc to ≲0.1 M⊙ yr−1 at 30 kpc. The mass outflow rate of the ionised outflow is significantly higher (∼1–8 times) than the molecular one, in contrast with what is often quoted in AGN. Based on energetic and morphological arguments, the driver of the multi-phase outflow is likely a combination of AGN radiation and the jet, or AGN radiation pressure on dust alone. The outflow mass-loading factor is ∼5–10 and the molecular gas depletion time due to the multi-phase outflow is ≲108 yr, indicating that the outflow can significantly affect the star formation and the gas reservoir in the galaxy. However, the fraction of the ionised outflow that is able to escape the dark matter halo potential is likely negligible. We detect blue-coloured continuum emission co-spatial with the ionised gas loop. Here, stellar populations are younger (≲100–150 Myr) than in the rest of the galaxy (∼0.5–1 Gyr). This constitutes possible evidence for star formation triggered at the edge of the bubble due to the compressing action of the jet and outflow (“positive feedback”), as predicted by theory. All in all, the Teacup constitutes a rich system in which AGN feedback from outflows and jets, in both its negative and positive flavours, co-exist.

CLASSY VII Lyα Profiles: The Structure and Kinematics of Neutral Gas and Implications for LyC Escape in Reionization-era Analogs* * Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Lyα line profiles are a powerful probe of interstellar medium (ISM) structure, outflow speed, and Lyman-continuum escape fraction. In this paper, we present the Lyα line profiles of the Cosmic Origins Spectrograph (COS) Legacy Archive Spectroscopic SurveY, a sample rich in spectroscopic analogs of reionization-era galaxies. A large fraction of the spectra show a complex profile, consisting of a double-peaked Lyα emission profile in the bottom of a damped, Lyα absorption trough. Such profiles reveal an inhomogeneous ISM. We successfully fit the damped Lyα absorption and the Lyα emission profiles separately, but with complementary covering factors, a surprising result because this approach requires no Lyα exchange between high-N H i and low-N H i paths. The combined distribution of column densities is qualitatively similar to the bimodal distributions observed in numerical simulations. We find an inverse relation between Lyα peak separation and the [O iii]/[O ii] flux ratio, confirming that the covering fraction of Lyman-continuum-thin sightlines increases as the Lyα peak separation decreases. We combine measurements of Lyα peak separation and Lyα red peak asymmetry in a diagnostic diagram, which identifies six Lyman-continuum leakers in the COS Legacy Archive Spectrocopy SurveY (CLASSY) sample. We find a strong correlation between the Lyα trough velocity and the outflow velocity measured from interstellar absorption lines. We argue that greater vignetting of the blueshifted Lyα peak, relative to the redshifted peak, is the source of the well-known discrepancy between shell-model parameters and directly measured outflow properties. The CLASSY sample illustrates how scattering of Lyα photons outside the spectroscopic aperture reshapes Lyα profiles because the distances to these compact starbursts span a large range.

Magnetic field effects on nucleosynthesis and kilonovae from neutron star merger remnants

ABSTRACT We investigate the influence of parametric magnetic field configurations of a hypermassive neutron star (HMNS) on the outflow properties, nucleosynthesis yields, and kilonova light curves. We perform three-dimensional dynamical space–time general-relativistic magnetohydrodynamic simulations, including a neutrino leakage scheme, microphysical finite-temperature equation of state, and an initial poloidal magnetic field. We find that varying the magnetic field strength and falloff impacts the formation of magnetized winds or mildly relativistic jetted outflows, which in turn has profound effects on the outflow properties. All of the evolved configurations collapse to a black hole ∼38–40 ms after coalescence, where the ones forming jetted outflows seem more effective at redistributing angular momentum, which result in earlier collapse times. Larger mass ejecta rates and radial velocities of unbound material characterize the systems that form jetted outflows. The bolometric light curves of the kilonovae and r-process yields that are produced by the post-merger remnant system change considerably with different magnetic field parameters. We conclude that the magnetic field strength and falloff have robust effects on the outflow properties and electromagnetic observables. This can be particularly important as the total ejecta mass from our simulations (≃10−3 M⊙) makes the ejecta from HMNS a compelling source to power kilonova through radioactive decay of r-process elements.

Direct Collapse to Precursors of Supermassive Black Hole Seeds: Radiation-feedback-generated Outflows

We use high-resolution zoom-in cosmological simulations to model outflow triggered by radiation and thermal drivers around the central mass accumulation during direct collapse within the dark matter (DM) halo. The maximal resolution is 1.3 × 10−5 pc, and no restrictions are put on the geometry of the inflow/outflow. The central mass is considered prior to the formation of the supermassive black hole seed at a redshift of z ∼ 15.9 and can constitute either a supermassive star (SMS) of ∼105 M ⊙ surrounded by a growing accretion disk or a self-gravitating disk. The radiation transfer is modeled using the ray-tracing algorithm. Due to the high accretion rate of ∼1 M ⊙ yr−1 determined by the DM halo, accretion is mildly supercritical, resulting in mildly supercritical luminosity that has only a limited effect on the accretion rate, with a duty cycle of ∼0.9. We observe a fast development of hot cavities, which quickly extend into polar funnels and expand dense shells. Within the funnels, fast winds, ∼103 km s−1, are mass-loaded by the accreting gas. We follow the expanding shells to ∼1 pc, when the shell velocity remains substantially (∼5 times) above the escape speed. The ionization cones formed by the central UV/X-ray completely ionize the cavities. Extrapolating the outflow properties shows that the halo material outside the shell will have difficulty stopping it. We therefore conclude that the expanding wind-driven shell will break out of the central parsec and will reach the halo virial radius. Finally, the anisotropic accretion flow on subparsec scales will attenuate the UV/soft X-rays on the H2. Hence, the formation of funnels and powerful outflows around, e.g., SMSs can have interesting observational corollaries.

Accurate systemic redshifts and outflow speeds for extremely red quasars (ERQs)

ABSTRACT Extremely Red Quasars (ERQs) are thought to represent a brief episode of young quasar and galactic evolution characterized by rapid outflows and obscured growth due to dusty environments. We use new redshift measurements from CO and narrow Ly α emission-lines to better constrain outflow velocities from previous line measurements. We present sample of 82 ERQs, and the analysis confirms that ERQs have a higher incidence of large C iv blueshifts, accompanied by large Rest Equivalent Width (REW) and narrower line Full Width at Half-Maximum (FWHM) than blue quasars. We find that strong blueshifts (>2000 km s−1) are present in 12/54 (22.2 per cent) of ERQs with the most robust redshift indicators. At least 4 out of 15 ERQs in the sample also have blueshifts in their H β and low-ionization ultraviolet lines ranging from −500 to −1500 km s−1. ERQs with strong C iv blueshifts are substantially offset in C iv REW and FWHM from typical blue quasars in the same velocity range. ERQs have average values of REW = 124 Å and FWHM = 5274 km s−1, while blue quasars have REW = 24 Å and FWHM = 6973 km s−1. The extreme nature of the outflows in ERQs might explain some of their other spectral properties, such as the large C iv REWs and peculiar wingless profiles owing to more extended broad-line regions participating in outflows. The physical reasons for the extreme outflow properties of ERQs are unclear; however, larger Eddington ratios and/or softer ionizing spectra incident on the outflow gas cannot be ruled out.