223 research outputs found
Confirmation of and Variable Energy Injection by a Near-Relativistic Outflow in APM 08279+5255
We present results from multi-epoch spectral analysis of XMM-Newton and
Chandra observations of the broad absorption line (BAL) quasar APM 08279+5255.
Our analysis shows significant X-ray BALs in all epochs with rest-frame
energies lying in the range of ~ 6.7-18 keV. The X-ray BALs and 0.2-10 keV
continuum show significant variability on timescales as short as 3.3 days
(proper time) implying a source size-scale of ~ 10 r_g, where r_g is the
gravitational radius. We find a large gradient in the outflow velocity of the
X-ray absorbers with projected outflow velocities of up to 0.76 c. The maximum
outflow velocity constrains the angle between the wind velocity and our line of
sight to be less than ~ 22 degrees. We identify the following components of the
outflow: (a) Highly ionized X-ray absorbing material (2.9 < logxi < 3.9) and a
column density of log N_H ~ 23 outflowing at velocities of up to 0.76 c. (b)
Low-ionization X-ray absorbing gas with log N_H ~ 22.8. We find that flatter
spectra appear to result in lower outflow velocities. Based on our spectral
analysis of observations of APM 08279+5255 over a period of 1.2 years (proper
time) we estimate the mass-outflow rate and efficiency of the outflow to have
varied between 16(-8,+12) M_solar yr^-1 and 64(-40,+66) M_solar yr^-1 and
0.18(-0.11,+0.15) to 1.7(-1.2+1.9), respectively. Assuming that the outflow
properties of APM 08279+5255 are a common property of most quasars at similar
redshifts, our results then imply that quasar winds are massive and energetic
enough to influence significantly the formation of the host galaxy, provide
significant metal enrichment to the interstellar medium and intergalactic
medium, and are a viable mechanism for feedback at redshifts near the peak in
the number density of galaxy mergers.Comment: 27 pages, includes 12 figures, accepted for publication in Ap
Evidence for ultra-fast outflows in radio-quiet AGNs: III - location and energetics
Using the results of a previous X-ray photo-ionization modelling of
blue-shifted Fe K absorption lines on a sample of 42 local radio-quiet AGNs
observed with XMM-Newton, in this letter we estimate the location and
energetics of the associated ultra-fast outflows (UFOs). Due to significant
uncertainties, we are essentially able to place only lower/upper limits. On
average, their location is in the interval ~0.0003-0.03pc (~10^2-10^4 r_s) from
the central black hole, consistent with what is expected for accretion disk
winds/outflows. The mass outflow rates are constrained between ~0.01-1
M_{\odot} yr^{-1}, corresponding to >5-10% of the accretion rates. The average
lower-upper limits on the mechanical power are log\dot{E}_K~42.6-44.6 erg
s^{-1}. However, the minimum possible value of the ratio between the mechanical
power and bolometric luminosity is constrained to be comparable or higher than
the minimum required by simulations of feedback induced by winds/outflows.
Therefore, this work demonstrates that UFOs are indeed capable to provide a
significant contribution to the AGN cosmological feedback, in agreement with
theoretical expectations and the recent observation of interactions between AGN
outflows and the interstellar medium in several Seyferts galaxies.Comment: 5 pages, 3 figures, accepted for publication in MNRA
The variability of the warm absorber in I Zwicky 1 as seen by XMM-Newton
We present new XMM-Newton observations of the intriguing warm absorber in I
Zwicky 1. This luminous and nearby narrow-line Seyfert 1 galaxy shows ionized
absorption by two components of outflowing gas; a low and a high-ionization
phase with log ~0 and log ~2 respectively. Detailed modelling of
these data reveal a complex and variable multi-phase warm absorber. However, we
find the changes in the ionization state of the gas not to be straightforwardly
correlated with the variability of the intrinsic continuum source, in apparent
contrast with photoionization equilibrium. The observed variability hints
instead at a close connection between the two gas components, possibly both
directly connected to the accretion disc activity. We thus suggest a
phenomenological model capable of explaining these observations, consisting of
a clumpy outflow where the high and the low-ionization components are closely
linked. Changes in ionization over the years are mainly driven by the different
densities of the clumps crossing the observer's line-of-sight, in which the
`skin' layer facing the source accounts for the more ionized component.Comment: 10 pages, 7 figures. Accepted for publication in MNRA
Tormund's return: Hints of quasi-periodic eruption features from a recent optical tidal disruption event
Quasi-periodic eruptions (QPEs) are repeating thermal X-ray bursts associated
with accreting massive black holes, the precise underlying physical mechanisms
of which are still unclear. We present a new candidate QPE source, AT 2019vcb
(nicknamed Tormund by the ZTF collaboration), which was found during an
archival search for QPEs in the XMM-Newton archive. It was first discovered in
2019 as an optical tidal disruption event (TDE) at , and its X-ray
follow-up exhibited QPE-like properties. Our goals are to verify its robustness
as QPE candidate and to investigate its properties to improve our understanding
of QPEs. We performed a detailed study of the X-ray spectral behaviour of this
source over the course of the XMM-Newton archival observation. We also report
on recent Swift and NICER follow-up observations to constrain the source's
current activity and overall lifetime, as well as an optical spectral
follow-up. The first two Swift detections and the first half of the 30 ks
XMM-Newton exposure of Tormund displayed a decaying thermal emission typical of
an X-ray TDE. However, the second half of the exposure showed a dramatic rise
in temperature (from 53 to 114 eV) and 0.2-2 keV luminosity (from
to erg s). The late-time NICER
follow-up indicates that the source is still X-ray bright more than three years
after the initial optical TDE. Although only a rise phase was observed,
Tormund's strong similarities with a known QPE source (eRO-QPE1) and the
impossibility to simultaneously account for all observational features with
alternative interpretations allow us to classify Tormund as a candidate QPE. If
confirmed as a QPE, it would further strengthen the observational link between
TDEs and QPEs. It is also the first QPE candidate for which an associated
optical TDE was directly observed, constraining the formation time of QPEs.Comment: Accepted for publication in A&A, 20 pages, 17 figure
Overcoming barriers to the effective management of severe asthma in Italy
Introduction: People with severe asthma (SA) often have poor disease control and quality of life, and are at high risk of exacerbations, lung function decline and asthma-related death. The present expert opinion article aimed to identify unmet needs in the management of SA in Italy, and propose possible solutions to address these needs. Methods: At five multidisciplinary events in Italy, attendees identified factors that interfered with the effective management of SA and suggested how these barriers could be overcome. A core group of 12 Italian experts (pulmonologists, general practitioners, allergists, payers and patients) identified the main issues and proposed possible solutions based on the results from the meetings and relevant articles from the literature. Results and Conclusions: We reviewed the gap between real-world practice and guide-lines, oral corticosteroid overuse, SA-related mortality, and barriers to effective SA treat-ment. Common themes were lack of awareness about SA among both patients and clinicians, and lack of networking/information exchange between those involved in the treatment of SA. Participants agreed on the need to implement patient education and create multidisciplinary groups of specialists to improve SA management through multidisciplinary educational initiatives, meetings with local experts, development of a flow chart for referral/connection with local experts and specialized centers. Clinical instruments that might help specialists improve SA management included referral networks, integrated care pathways, phenotyping and treatment algorithms, exacerbation tracking, and examination of electronic medical records for patients with uncontrolled asthma. The following actions need to be implemented in Italy: i) maximize the use of advanced therapies, eg, biologics; ii) increase/improve education for physicians and patients; iii) improve multidisciplinary communication and care coordination; iv) introduce regional and local protocols for SA diagnosis and treatment; and v) change the structure of healthcare services to reduce specialist waiting times and facilitate access to biologic therapies
The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180
We present joint \textit{XMM-Newton} and \textit{NuSTAR} observations of the
`bare' narrow line Seyfert 1 Ton S180 (), carried out in 2016 and
providing the first hard X-ray view of this luminous galaxy. We find that the
0.4--30 keV band cannot be self-consistently reproduced by relativistic
reflection models, which fail to account simultaneously for the soft and hard
X-ray emission. The smooth soft excess prefers extreme blurring parameters,
confirmed by the nearly featureless nature of the RGS spectrum, while the
moderately broad Fe K line and the modest hard excess above 10 keV appear to
arise in a milder gravity regime. By allowing a different origin of the soft
excess, the broadband X-ray spectrum and overall spectral energy distribution
(SED) are well explained by a combination of: (a) direct thermal emission from
the accretion disc, dominating from the optical to the far/extreme UV; (b)
Comptonization of seed disc photons by a warm ( keV) and
optically thick () corona, mostly contributing to the soft X-rays;
(c) Comptonization by a standard hot ( keV) and
optically thin () corona, responsible for the primary X-ray
continuum; and (d) reflection from the mid/outer part of the disc. The two
coronae are suggested to be rather compact, with R. Our SED analysis implies that Ton S180 accretes
at super-Eddington rates. This is a key condition for the launch of a wind,
marginal (i.e., 3.1 significance) evidence of which is indeed found in
the RGS spectrum.Comment: 20 pages, 12 figures. Accepted for publication MNRA
Coordinated X-ray and UV absorption within the accretion disk wind of the active galactic nucleus PG 1126-041
Context. Accretion disk winds launched close to supermassive black holes (SMBHs) are a viable mechanism providing feedback between the SMBH and the host galaxy. Aims. We aim to characterize the X-ray properties of the inner accretion disk wind of the nearby active galactic nucleus PG 1126-041 and to study its connection with the UV-absorbing wind. Methods. We performed a spectroscopic analysis of eight XMM-Newton observations of PG 1126-041 taken between 2004 and 2015, using both phenomenological models and the most advanced accretion disk wind models available. For half of the data set, we were able to compare the X-ray analysis results with the results of quasi-simultaneous, high-resolution, spectroscopic UV observations taken with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Results. The X-ray spectra of PG 1126-041 are complex and absorbed by ionized material, which is highly variable on multiple timescales, sometimes as short as 11 days. Accretion disk wind models can account for most of the X-ray spectral complexity of PG 1126-041, with the addition of massive clumps, represented by a partially covering absorber. Variations in column density (NH ∼ 5-20 7times;1022 cm-2) of the partially covering absorber drive the observed X-ray spectral variability of PG 1126-041. The absorption from the X-ray partially covering gas and from the blueshifted CIV troughs appear to vary in a coordinated way. Conclusions. The line of sight toward PG 1126-041 offers a privileged view through a highly dynamic nuclear wind originating on inner accretion disk scales, making the source a very promising candidate for future detailed studies of the physics of accretion disk winds around SMBHs
Coordinated X-ray and UV absorption within the accretion disk wind of the active galactic nucleus PG 1126-041
Accretion disk winds launched close to supermassive black holes (SMBHs) are a
viable mechanism to provide feedback between the SMBH and the host galaxy. We
aim to characterize the X-ray properties of the inner accretion disk wind of
the nearby active galactic nucleus (AGN) PG 1126-041, and to study its
connection with the ultraviolet (UV)-absorbing wind. We perform spectroscopic
analysis of eight XMM-Newton observations of PG 1126-041 taken between 2004 and
2015, using both phenomenological models and the most advanced accretion disk
wind models available. For half of the dataset, we can compare the X-ray
analysis results with the results of quasi-simultaneous, high-resolution
spectroscopic UV observations taken with the Cosmic Origins Spectrograph (COS)
on board the Hubble Space Telescope. The X-ray spectra of PG 1126-041 are
complex and absorbed by ionized material which is highly variable on multiple
time scales, sometimes as short as 11 days. Accretion disk wind models can
account for most of the X-ray spectral complexity of PG 1126-041, with the
addition of massive clumps, represented by a partially covering absorber.
Variations in column density ( cm) of the
partially covering absorber drive the observed X-ray spectral variability of PG
1126-041. The absorption from the X-ray partially covering gas and from the
blueshifted C IV troughs appear to vary in a coordinated way. The line of sight
toward PG 1126-041 offers a privileged view through a highly dynamic nuclear
wind originating on inner accretion disk scales, making the source a very
promising candidate for future detailed studies of the physics of accretion
disk winds around SMBHs.Comment: 24 pages, 13 figures, accepted for publication in Astronomy &
Astrophysic
Similar levels of efficacy of two different maintenance doses of adalimumab on clinical severity and quality of life of patients with hidradenitis suppurativa
Adalimumab is the only biologic agent approved for the treatment of moderate-to-severe hidradenitis suppurativa (HS) patients (i.e., with Hurley II or III), which is recommended in two different maintenance doses (i.e., 40 mg weekly or 80 mg every two weeks). We conducted a prospective multicentric study to measure outcomes related to the severity of disease and quality of life (QoL) of patients affected by moderate-to-severe HS, treated with adalimumab at a maintenance dosing of 40 mg or 80 mg. Assessments were performed at baseline (T0) and after 32 weeks of treatment (T32). We enrolled 85 moderate-to-severe HS Italian patients, 43 men (50.6%) and 42 women, aged between 16 and 62 years (median 31 years, interquartile range 24.4-43.8). Statistically significant improvements were observed for clinical status (with a mean reduction of 7.1 points for the International Hidradenitis Suppurativa Severity Score System (IHS4)), pain levels (3.1 mean decrease in VAS), and QoL (3.4 mean improvement in DLQI score). Patients with no comorbidities, and those with higher levels of perceived pain showed significantly greater improvement in QoL than their counterpart from T0 to T32. As for the proportion of patients who at follow-up reached the minimal clinical important difference (MCID) in QoL, significantly higher proportions of success were observed for age (patients in the 29-39 category), pain (patients with higher reported pain), and Hurley stage III. While both treatment regimen groups (i.e., 40 vs. 80 mg) improved significantly, no statistical differences were observed when comparing the two treatment dosages
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