Abstract
We analyze the gas mass distribution, the gas kinematics, and the young stellar objects of the California Molecular Cloud L1482 filament. The mean Gaia DR2 YSO distance is
pc. In terms of ...the gas, the line-mass (M/L) profiles are symmetric scale-free power laws consistent with cylindrical geometry. We calculate the gravitational potential and field profiles based on these. Our IRAM 30 m multi-tracer position–velocity diagrams highlight twisting and turning structures. We measure the C
18
O velocity profile perpendicular to the southern filament ridgeline. The profile is regular, confined (projected
r
≲ 0.4 pc), antisymmetric, and, to first order, linear, with a break at
r
∼ 0.25 pc. We use a simple solid-body rotation toy model to interpret it. We show that the centripetal force, compared to gravity, increases toward the break; when the ratio of forces approaches unity, the profile turns over, just before the implied filament breakup. The timescales of the inner (outer) gradients are ∼0.7 (6.0) Myr. The timescales and relative roles of gravity to rotation indicate that the structure is stable, long lived (∼a few times 6 Myr), and undergoing outside-in evolution. This filament has practically no star formation, a perpendicular Planck plane-of-the-sky magnetic field morphology, and 2D “zig-zag” morphology, which together with the rotation profile lead to the suggestion that the 3D shape is a “corkscrew” filament. These results, together with results in other regions, suggest evolution toward higher densities as rotating filaments shed angular momentum. Thus, magnetic fields may be an essential feature of high-mass (
M
∼ 10
5
M
⊙
) cloud filament evolution toward cluster formation.
We report on the analysis of a ∼60-ks XMM–Newton observation of the bright, narrow emission line quasar PG1211+143. Absorption lines are seen in both European Photon Imaging Camera and Reflection ...Grating Spectrometer spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionized outflow velocity of ∼24 000 km s−1. The highest energy lines require a column density of NH∼ 5 × 1023 cm−2, at an ionization parameter of log ξ∼ 3.4. If the origin of this high-velocity outflow lies in matter being driven from the inner disc, then the flow is likely to be optically thick within a radius of ∼130 Schwarzschild radii, providing a natural explanation for the big blue bump (and strong soft X-ray) emission in PG1211+143.
ABSTRACT
We construct full broad‐band models in an analysis of Suzaku observations of nearby Seyfert 1 active galactic nuclei (AGN) (z ≤ 0.2) with exposures >50 ks and with greater than 30 000 counts ...in order to study their iron line profiles. This results in a sample of 46 objects and 84 observations. After a full modelling of the broad‐band Suzaku and Swift‐Burst Alert Telescope data (0.6–100 keV), we find complex warm absorption is present in 59 per cent of the objects in this sample which has a significant bearing upon the derived Fe K region parameters. Meanwhile 35 per cent of the 46 objects require some degree of high column density partial coverer in order to fully model the hard X‐ray spectrum. We also find that a large number of the objects in the sample (22 per cent) require high velocity, high ionization outflows in the Fe K region resulting from Fe xxv and Fe xxvi. A further four AGN feature highly ionized Fe K absorbers consistent with zero outflow velocity, making a total of 14/46 (30 per cent) AGN in this sample showing evidence for statistically significant absorption in the Fe K region.
Narrow Fe Kα emission from distant material at 6.4 keV is found to be almost ubiquitous in these AGN. Examining the 6–7 keV Fe K region we note that narrow emission lines originating from Fe xxv at 6.63–6.70 keV and from Fe xxvi at 6.97 keV are present in 52 and 39 per cent of objects, respectively.
Our results suggest statistically significant relativistic Fe Kα emission is detected in 23 of 46 objects (50 per cent) at >99.5 per cent confidence, measuring an average emissivity index of q = 2.4 ± 0.1 and equivalent width ( EW )=96±10 eV using the relline model. When parametrized with a Gaussian we find an average line energy of 6.32 ± 0.04 keV, σwidth = 0.470 ± 0.05 keV and EW =97±19 eV. Where we can place constraints upon the black hole spin parameter a, we do not require a maximally spinning black hole in all cases.
We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG −02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of ...bare Seyferts allows a consistent and physical modelling of active galactic nuclei due to a weak amount of any intrinsic warm absorption, removing the degeneracy between the spectral curvature due to warm absorption and the red wing of the Fe K region. Through effective modelling of the broad-band spectrum and investigating the presence of narrow neutral or ionized emission lines and reflection from distant material, we obtain an accurate and detailed description of the Fe K line region using models such as laor, kerrdisk and kerrconv.
Results suggest that ionized emission lines at 6.7 and 6.97 keV (particularly Fe xxvi) are relatively common, and the inclusion of these lines can greatly affect the parameters obtained with relativistic models, i.e. spin, emissivity, inner radius of emission and inclination. Moderately broad components are found in all objects, but typically the emission originates from tens of r
g, rather than within <6 r
g of the black hole. Results obtained with kerrdisk line profiles suggest an average emissivity of q ∼ 2.3 at intermediate spin values with all objects ruling out the presence of a maximally spinning black hole at the 90 per cent confidence level. We also present new spin constraints for Mrk 335 and NGC 7469 with intermediate values of a= 0.70+0.12
−0.01 and 0.69+0.09
−0.09, respectively.
Previous studies have shown that chorus wave intensity can be modulated by Pc4‐Pc5 compressional ULF waves. In this study, we present Van Allen Probes observation of ULF wave modulating chorus wave ...intensity, which occurred deep in the magnetosphere. The ULF wave shows fundamental poloidal mode signature and mirror mode compressional nature. The observed ULF wave can modulate not only the chorus wave intensity but also the distribution of both protons and electrons. Linear growth rate analysis shows consistence with observed chorus intensity variation at low frequency (f <∼ 0.3fce), but cannot account for the observed higher‐frequency chorus waves, including the upper band chorus waves. This suggests the chorus waves at higher‐frequency ranges require nonlinear mechanisms. In addition, we use combined observations of Radiation Belt Storm Probes (RBSP) A and B to verify that the ULF wave event is spatially local and does not last long.
Key Points
ULF wave modulation of pitch angle distributions of both electrons and protons and chorus intensity occurs deep in the magnetosphere
This ULF wave shows signatures of fundamental poloidal mode of field line resonance and mirror wave nature
Linear growth rate calculation supports instability below 0.3 fce, while observed chorus at higher frequency requires nonlinear mechanisms
Apolipoprotein L1 gene (APOL1) nephropathy variants in African American deceased kidney donors were associated with shorter renal allograft survival in a prior single‐center report. APOL1 G1 and G2 ...variants were genotyped in newly accrued DNA samples from African American deceased donors of kidneys recovered and/or transplanted in Alabama and North Carolina. APOL1 genotypes and allograft outcomes in subsequent transplants from 55 U.S. centers were linked, adjusting for age, sex and race/ethnicity of recipients, HLA match, cold ischemia time, panel reactive antibody levels, and donor type. For 221 transplantations from kidneys recovered in Alabama, there was a statistical trend toward shorter allograft survival in recipients of two‐APOL1‐nephropathy‐variant kidneys (hazard ratio HR 2.71; p = 0.06). For all 675 kidneys transplanted from donors at both centers, APOL1 genotype (HR 2.26; p = 0.001) and African American recipient race/ethnicity (HR 1.60; p = 0.03) were associated with allograft failure. Kidneys from African American deceased donors with two APOL1 nephropathy variants reproducibly associate with higher risk for allograft failure after transplantation. These findings warrant consideration of rapidly genotyping deceased African American kidney donors for APOL1 risk variants at organ recovery and incorporation of results into allocation and informed‐consent processes.
This study demonstrates that the apolipoprotein L1 nephropathy‐risk genotype in deceased African American kidney donors is associated with shorter allograft survival after engraftment and supports inclusion of this genetic information in the allocation of kidneys for transplantation. See editorial by Ojo and Knoll on page 1457.
We present a broad-band analysis of deep Suzaku observations of nearby Seyfert 1 active galactic nuclei (AGN): Fairall 9, MCG−6-30-15, NGC 3516, 3783 and 4051. The use of deep observations (exposures ...>200 ks) with high signal-to-noise ratio allows the complex spectra of these objects to be examined in full, taking into account features such as the soft excess, reflection continuum and complex absorption components. After a self-consistent modelling of the broad-band data (0.6-100.0 keV, also making use of Burst Alert Telescope data from Swift), the subtle curvature which may be introduced as a consequence of warm absorbers has a measured affect upon the spectrum at energies >3 keV and the Fe K region. Forming a model (including absorption) of these AGN allows the true extent to which broadened disc line emission is present to be examined and as a result the measurement of accretion disc and black hole parameters which are consistent over the full 0.6-100.0 keV energy range.
Fitting relativistic line emission models appears to rule out the presence of maximally spinning black holes in all objects at the 90 per cent confidence level, in particular MCG−6-30-15 at >99.5 per cent confidence. Relativistic Fe K line emission is only marginally required in NGC 3516 and not required in NGC 4051, over the full energy bandpass. None the less, statistically significant broadened 6.4 keV Fe Kα emission is detected in Fairall 9, MCG−6-30-15 and NGC 3783 yielding black hole spin estimates of a= 0.67+0.10
− 0.11, a= 0.49+0.20
− 0.12 and a < −0.04, respectively, when fitted with disc emission models.
Context.
Identifying the most likely sources for high-energy neutrino emission has been one of the main topics in high-energy astrophysics ever since the first observation of high-energy neutrinos by ...the IceCube Neutrino Observatory. Active galactic nuclei with relativistic jets, also known as blazars, have been considered to be one of the main candidates because of their ability to accelerate particles to high energies.
Aims.
We study the connection between radio emission and IceCube neutrino events using data from the Owens Valley Radio Observatory (OVRO) and Metsähovi Radio Observatory blazar monitoring programs.
Methods.
We identify sources in our radio monitoring sample that are positionally consistent with IceCube high-energy neutrino events. We estimate their mean flux density and variability amplitudes around the neutrino arrival time, and compare these with values from random samples to establish the significance of our results.
Results.
We find radio source associations within our samples with 15 high-energy neutrino events detected by IceCube. Nearly half of the associated sources are not detected in the
γ
-ray energies, but their radio variability properties and Doppler boosting factors are similar to the
γ
-ray detected objects in our sample, meaning that they could still be potential neutrino emitters. We find that the number of strongly flaring objects in our statistically complete OVRO samples is unlikely to be a random coincidence (at 2
σ
level).
Conclusions.
Based on our results, we conclude that although it is clear that not all neutrino events are associated with strong radio flaring blazars, observations of large-amplitude radio flares in a blazar at the same time as a neutrino event are unlikely to be a random coincidence.
Observations performed at Metsähovi Radio Observatory at 37 GHz are presented for a sample of 78 radio-loud and radio-quiet narrow-line Seyfert 1 (NLS1) galaxies, together with additional lower and ...higher frequency radio data from RATAN-600, Owens Valley Radio Observatory, and the Planck satellite. Most of the data have been gathered between February 2012 and April 2015 but for some sources even longer light curves exist. The detection rate at 37 GHz is around 19%, which is comparable to other populations of active galactic nuclei presumed to be faint at radio frequencies, such as BL Lac objects. Variability and spectral indices are determined for sources with enough detections. Based on the radio data, many NLS1 galaxies show a blazar-like radio spectra exhibiting significant variability. The spectra at a given time are often inverted or convex. The source of the high-frequency radio emission in NLS1 galaxies, detected at 37 GHz, is most probably a relativistic jet rather than star formation. Jets in NLS1 galaxies are therefore expected to be a much more common phenomenon than earlier assumed.
We report the discovery of a rare new form of long-term radio variability in the light curves of active galaxies (AG)-symmetric achromatic variability (SAV)-a pair of opposed and strongly skewed ...peaks in the radio flux density observed over a broad frequency range. We propose that SAV arises through gravitational milli-lensing when relativistically moving features in AG jets move through gravitational lensing caustics created by subhalo condensates or black holes located within intervening galaxies. The lower end of this mass range has been inaccessible with previous gravitational lensing techniques. This new interpretation of some AG variability can easily be tested and if it passes these tests, will enable a new and powerful probe of cosmological matter distribution on these intermediate-mass scales, as well as provide, for the first time, micro-arcsecond resolution of the nuclei of AG-a factor of 30-100 greater resolution than is possible with ground-based millimeter very-long-baseline interferometry.
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