Context. We discuss the formation of stellar mass black holes via protoneutron star (PNS) collapse. In the absence of an earlier explosion, the PNS collapses to a black hole due to the continued mass ...accretion onto the PNS. We present an analysis of the emitted neutrino spectra of all three flavors during the PNS contraction. Aims. Special attention is given to the physical conditions which depend on the input physics, e.g. the equation of state (EoS) and the progenitor model. Methods. The PNSs are modeled as the central object in core collapse simulations using general relativistic three-flavor Boltzmann neutrino transport in spherical symmetry. The simulations are launched from several massive progenitors of \(40\) M\(_\odot\) and \(50\) M\(_\odot\). Results. We analyze the electron-neutrino luminosity dependencies and construct a simple approximation for the electron-neutrino luminosity, which depends only on the physical conditions at the electron-neutrinosphere. In addition, we analyze different \((\mu,\tau)\)-neutrino pair-reactions separately and compare the differences during the post-bounce phases of failed core collapse supernova explosions of massive progenitors. We also investigate the connection between the increasing \((\mu,\tau)\)-neutrino luminosity and the PNS contraction during the accretion phase before black hole formation. Conclusions. Comparing the different post bounce phases of the progenitor models under investigation, we find large differences in the emitted neutrino spectra. These differences and the analysis of the electron-neutrino luminosity indicate a strong progenitor model dependency of the emitted neutrino signal.
SUMMARY
In earthquake swarms, seismic energy is released gradually by many earthquakes without a dominant event, which offers detailed insight into the processes on activated faults. The swarm of May ...2018 that occurred in West Bohemia/Vogtland region included more than 4000 earthquakes with ML = 〈0.5, 3.8〉 and its character showed significant changes during the two weeks duration: what started as a pure earthquake swarm ended as a typical main shock–aftershock sequence. Based on precise double-difference relocations, four fault segments differing in strikes and dips were identified with similar dimensions. First, two segments of typical earthquake swarm character took place, and at the end a fault segment hosting a main shock–aftershock sequence was activated. The differences were observable in the earthquakes spatio-temporal evolutions (systematic versus disordered migration of the hypocentres), b-values (>1.3 for the swarm, <1 for the main shock–aftershocks), or the smoothness of seismic moment spatial distribution along the fault plane. Our findings can be interpreted by local variations of fault rheology, differential stress and/or smoothness of the faults surface, possibly related to the crustal fluids circulating along the fault plane and their interplay with the seismic cycle.
Abstract
Safe insertion of the Veress needle during laparoscopy relies on the surgeons’ technical skills in order to stop needle insertion just in time to prevent overshooting in the underlying ...organs. To reduce this risk, a wide variety of Veress needle systems were developed with safety mechanisms that limit the insertion speed, insertion depth or decouple the driving force generated by the surgeon’s hand on the needle
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The aim of this study is to evaluate current surgeons’ perceptions related to the use of Veress needles and to investigate the relevance of preventing overshooting of Veress needles among members of the European Association of Endoscopic Surgery (EAES). An online survey was distributed by the EAES Executive Office to all active members. The survey consisted of demographic data and 14 questions regarding the use of the Veress needle, the training conducted prior to usage, and the need for any improvement. A total of 365 members residing in 58 different countries responded the survey. Of the responding surgeons, 36% prefer the open method for patients with normal body mass index (BMI), and 22% for patients with high BMI. Of the surgeons using Veress needle, 68% indicated that the reduction of overshoot is beneficial in normal BMI patients, whereas 78% indicated that this is beneficial in high BMI patients. On average, the members using the Veress needle had used it for 1448 (SD 3031) times and felt comfortable on using it after 22,9 (SD 78,9) times. The average years of experience was 17,6 (SD 11,1) and the surgeons think that a maximum overshoot of 9.4 (SD 5.5) mm is acceptable before they can safely use the Veress needle. This survey indicates that despite the risks, Veress needles are still being used by the majority of the laparoscopic surgeons who responded. In addition, the surgeons responded that they were interested in using a Veress needle with an extra safety mechanism if it limits the risk of overshooting into the underlying structures.
Abstract
We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14–195 keV luminosities LX ≥ 1041.5 erg s−1, redshift z ≤ 0.015, being accessible for observations ...with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended O iiiλ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H ii) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS. We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density (Σ) profiles for H ii and H2 in their inner ∼500 pc, showing that H ii emission presents a steeper radial gradient than H2. This can be attributed to the different excitation mechanisms: ionization by AGN radiation for H ii and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ ΣH ii ≤ 35.9) M⊙ pc−2, and (0.2 ≤ ΣH2 ≤ 13.9)× 10−3 M⊙ pc−2, while the ratios between the H ii and H2 masses range between ∼200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity.
The Arctic is warming at almost four times the global rate. An estimated sixty percent of greenhouse‐gas‐induced Arctic warming has been offset by anthropogenic aerosols, but the contribution of ...aerosols to radiative forcing (RF) represents the largest uncertainty in estimating total RF, largely due to unknown preindustrial aerosol abundance. Here, sulfur isotope measurements in a Greenland ice core show that passive volcanic degassing contributes up to 66 ± 10% of preindustrial ice core sulfate in years without major eruptions. A state‐of‐the‐art model indicates passive volcanic sulfur emissions influencing the Arctic are underestimated by up to a factor of three, possibly because many volcanic inventories do not include hydrogen sulfide emissions. Higher preindustrial volcanic sulfur emissions reduce modeled anthropogenic Arctic aerosol cooling by up to a factor of two (+0.11 to +0.29 W m−2), suggesting that underestimating passive volcanic sulfur emissions has significant implications for anthropogenic‐induced Arctic climate change.
Plain Language Summary
Sulfate aerosols are particles in the atmosphere that have a net cooling effect on the climate. One of the most uncertain aspects of climate modeling is the abundance of sulfate aerosols during the preindustrial era. Without knowing the amount of sulfate aerosols during the preindustrial, it is difficult to estimate how much anthropogenic sulfate aerosols have offset warming from anthropogenic greenhouse gases. In this study, we examine preindustrial sulfate aerosols in a Greenland ice core. We find that sulfate aerosols from passive (i.e., non‐eruptive) volcanic degassing contribute almost two thirds of preindustrial Arctic sulfate aerosols in years without major volcanic eruptions. We compare this result to a state‐of‐the‐art global model and find that most climate models use a volcanic emissions inventory that underestimates preindustrial passive volcanic sulfur emissions. That volcanic inventory only includes one type of sulfur emission (sulfur dioxide), but studies have shown that volcanoes emit hydrogen sulfide, which can also form sulfate aerosols. We show that higher emissions of volcanic sulfur during the preindustrial era decrease the estimated cooling effect of anthropogenic aerosols during the industrial era. Thus, the underestimate of preindustrial volcanic emissions in current climate models has significant implications for anthropogenic climate change in the Arctic.
Key Points
Sulfur isotopes in a Greenland ice core show that passive volcanic degassing contributes 66% of preindustrial Arctic sulfate
The volcanic inventory used by most climate models underestimates passive degassing, possibly due to missing hydrogen sulfide emissions
Elevated preindustrial passive volcanic degassing reduces the estimated cooling effect of anthropogenic sulfate in the Arctic
ABSTRACT
We have analysed Chandra/High Energy Transmission Gratings spectra of the X-ray emission line gas in the Seyfert galaxy NGC 4151. The zeroth-order spectral images show extended H- and ...He-like O and Ne, up to a distance r ∼ 200 pc from the nucleus. Using the first-order spectra, we measure an average line velocity ∼−230 km s−1, suggesting significant outflow of X-ray gas. We generated cloudy photoionization models to fit the first-order spectra; the fit required three distinct emission line components. To estimate the total mass of ionized gas and the mass outflow rates, we applied the model parameters to fit the zeroth-order emission line profiles of Ne ix and Ne x. We determined the total mass of ≈5.4 × 105 M⊙. Assuming the same kinematic profile as that for the O iii gas, derived from our analysis of Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra, the peak X-ray mass outflow rate was ≈1.8 M⊙ yr−1, at r ∼ 150 pc. The total mass and mass outflow rates are similar to those determined using O iii, implying that the X-ray gas is a major outflow component. However, unlike the optical outflows, the X-ray outflow rate does not drop off at r > 100 pc, which suggests that it may have a greater impact on the host galaxy.
Background
Laparoscopic removal of cryptorchid testes has been routinely reported through enlarged parainguinal incisions in dorsally recumbent horses. Outcomes following removal through an extended ...umbilical incision have not been previously reported.
Objective
To describe the surgical technique of removing cryptorchid testes in dorsally recumbent horses through an enlarged umbilical portal after laparoscopic intra‐abdominal castration.
Study design
Retrospective case series.
Methods
Medical records were reviewed for horses that underwent laparoscopic removal of unilateral or bilateral cryptorchid testes from January 2006 to December 2016. Horses were placed under general anaesthesia, positioned in dorsal recumbency and then tilted into Trendelenburg position. Cryptorchid testes were castrated by ligating loop application and/or electrosurgery. The umbilical portal incision was extended along the linea alba for testes removal. All descended testes were removed by routine closed castration with the scrotal incision left to heal by second intention. Perianaesthetic laboratory values, surgical procedure descriptions, surgery and anaesthesia times, and in‐hospital perioperative complications were recorded.
Results
A total of 79 horses, aged 1‐14 years, with unilateral or bilateral cryptorchidism were included: 90 cryptorchid testes were successfully removed through an enlarged umbilical portal incision. Sixty‐eight horses were unilaterally cryptorchid and 11 were bilaterally cryptorchid. Two horses had minor post‐operative complications related to the extended umbilical portal incision.
Main limitations
Retrospective nature of the study, no control population for comparison and no follow‐up after hospital discharge.
Conclusion
An extended umbilical portal incision is a successful alternative to extending a parainguinal incision for testis removal after laparoscopic castration.
ABSTRACT
We use Hubble Space Telescope/Space Telescope Imaging Spectrograph long-slit G430M and G750M spectra to analyse the extended O iii λ5007 emission in a sample of 12 nearby (z < 0.12) luminous ...(Lbol > 1.6 × 1045 erg s−1) QSO2s. The purpose of the study is to determine the properties of the mass outflows of ionized gas and their role in active galactic nucleus feedback. We measure fluxes and velocities as functions of radial distances. Using cloudy models and ionizing luminosities derived from O iii λ5007, we are able to estimate the densities for the emission-line gas. From these results, we derive masses of O iii-emitting gas, mass outflow rates, kinetic energies, kinetic luminosities, momenta, and momentum flow rates as a function of radial distance for each of the targets. For the sample, masses are several times $10^{3}$–$10^{7}\, {\rm M_{\odot }}$ and peak outflow rates are from 9.3 × 10−3 to $10.3\, {\rm M_{\odot }}\, {\rm yr^{-1}}$. The peak kinetic luminosities are (3.4 × 10−8)–(4.9 × 10−4) of the bolometric luminosity, which does not approach the (5.0 × 10−3)–(5.0 × 10−2) range required by some models for efficient feedback. For Mrk 34, which has the largest kinetic luminosity of our sample, in order to produce efficient feedback there would have to be 10 times more O iii-emitting gas than that we detected at its position of maximum kinetic luminosity. Three targets show extended O iii emission, but compact outflow regions. This may be due to different mass profiles or different evolutionary histories.
We have used narrowband O iii λλ4959, 5007 and H +N ii λλ6548, 84 Hubble Space Telescope (HST) images of nine luminous (LO iii > 1042 erg s−1) type 2 QSOs with redshifts 0.1 < z < 0.5 in order to ...constrain the geometry of their extended narrow-line regions (ENLRs), as recent ground-based studies suggest that these regions become more spherical at high luminosities due to destruction of the torus. We instead find elongated ENLRs reaching 4-19 kpc from the nucleus and bipolar ionization cones in O iii/(H +N ii) excitation maps indicating that the torus survives these luminosities, allowing the escape of 10 times higher ionizing photon rates along the ionization axis than perpendicular to it. The exceptional HST angular resolution was key to our success in arriving at these conclusions. Combining our measurements with previous ones based on similar HST data, we have revisited the relation between the ENLR radius Rmaj and LO iii over the range 39 < log(LO iii) < 43.5 (L in erg s−1): log(Rmaj) = (0.51 0.03) log(LO iii)−18.12 0.98. The radius of the ENLR keeps increasing with LO iii in our data, implying that the ENLR can extend to distances beyond the limit of the galaxy if gas is present there-e.g., from active galactic nucleus (AGN) outflows or interactions, seen in six objects of our sample. We attribute the flattening previously seen in this relation to the fact that the ENLR is matter-bounded, meaning that ionizing photons usually escape to the intergalactic medium in luminous AGNs. Estimated ionized gas masses of the ENLRs range from 0.3 to 2 × 108 M , and estimated powers for associated outflows range from <0.1% to a few percent of the QSO luminosity.
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