250 research outputs found
Multiwavelength campaign on Mrk 509 XV. A global modeling of the broad emission lines in the Optical, UV and X-ray bands
We model the broad emission lines present in the optical, UV and X-ray
spectra of Mrk 509, a bright type 1 Seyfert galaxy. The broad lines were
simultaneously observed during a large multiwavelength campaign, using the
XMM-Newton-OM for the optical lines, HST-COS for the UV lines and
XMM-Newton-RGS and Epic for the X-ray lines respectively. We also used FUSE
archival data for the broad lines observed in the far-ultra-violet. The goal is
to find a physical connection among the lines measured at different wavelengths
and determine the size and the distance from the central source of the emitting
gas components. We used the "Locally optimally emission Cloud" (LOC) model
which interprets the emissivity of the broad line region (BLR) as regulated by
powerlaw distributions of both gas density and distances from the central
source. We find that one LOC component cannot model all the lines
simultaneously. In particular, we find that the X-ray and UV lines likely may
originate in the more internal part of the AGN, at radii in the range
~5x10^{14}-3x10^{17} cm, while the optical lines and part of the UV lines may
likely be originating further out, at radii ~3x10^{17}-3x^{18} cm. These two
gas components are parametrized by a radial distribution of the luminosities
with a slope gamma of ~1.15 and ~1.10, respectively, both of them covering at
least 60% of the source. This simple parameterization points to a structured
broad line region, with the higher ionized emission coming from closer in,
while the emission of the low-ionization lines is more concentrated in the
outskirts of the broad line region.Comment: 10 pages, 5 figures, accepted for publication in Astronomy and
Astrophysic
Multiwavelength campaign on Mrk 509 XII. Broad band spectral analysis
(Abridged) The simultaneous UV to X-rays/gamma rays data obtained during the
multi-wavelength XMM/INTEGRAL campaign on the Seyfert 1 Mrk 509 are used in
this paper and tested against physically motivated broad band models. Each
observation has been fitted with a realistic thermal comptonisation model for
the continuum emission. Prompted by the correlation between the UV and soft
X-ray flux, we use a thermal comptonisation component for the soft X-ray
excess. The UV to X-rays/gamma-rays emission of Mrk 509 can be well fitted by
these components. The presence of a relatively hard high-energy spectrum points
to the existence of a hot (kT~100 keV), optically-thin (tau~0.5) corona
producing the primary continuum. On the contrary, the soft X-ray component
requires a warm (kT~1 keV), optically-thick (tau~15) plasma. Estimates of the
amplification ratio for this warm plasma support a configuration close to the
"theoretical" configuration of a slab corona above a passive disk. An
interesting consequence is the weak luminosity-dependence of its emission, a
possible explanation of the roughly constant spectral shape of the soft X-ray
excess seen in AGNs. The temperature (~ 3 eV) and flux of the soft-photon field
entering and cooling the warm plasma suggests that it covers the accretion disk
down to a transition radius of 10-20 . This plasma could be the
warm upper layer of the accretion disk. On the contrary the hot corona has a
more photon-starved geometry. The high temperature ( 100 eV) of the
soft-photon field entering and cooling it favors a localization of the hot
corona in the inner flow. This soft-photon field could be part of the
comptonised emission produced by the warm plasma. In this framework, the change
in the geometry (i.e. ) could explain most of the observed flux and
spectral variability.Comment: 19 pages, 14 figures. Accepted for publication in A&
Anatomy of the AGN in NGC 5548: V. A clear view of the X-ray narrow emission lines
Context. Our consortium performed an extensive multi-wavelength campaign of
the nearby Seyfert 1 galaxy NGC 5548 in 2013-14. The source appeared unusually
heavily absorbed in the soft X-rays, and signatures of outflowing absorption
were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and
radiative recombination continuum (RRC) features were found to dominate the
soft X-ray spectrum due to the low continuum flux.
Aims. Here we focus on characterising these narrow emission features using
data obtained from the XMM-Newton RGS (770 ks stacked spectrum).
Methods. We use SPEX for our initial analysis of these features.
Self-consistent photoionisation models from Cloudy are then compared with the
data to characterise the physical conditions of the emitting region.
Results. Outflow velocity discrepancies within the O VII triplet lines can be
explained if the X-ray narrow-line region (NLR) in NGC 5548 is absorbed by at
least one of the six warm absorber components found by previous analyses. The
RRCs allow us to directly calculate a temperature of the emitting gas of a few
eV ( K), favouring photoionised conditions. We fit the data with a
Cloudy model of log erg cm s, log cm and log v km s for the emitting
gas; this is the first time the X-ray NLR gas in this source has been modelled
so comprehensively. This allows us to estimate the distance from the central
source to the illuminated face of the emitting clouds as pc,
consistent with previous work.Comment: Accepted by A&A, 15 pages, 6 figure
PP016âExposure to antipsychotics with pro-arrhythmic risk: Combining adverse drug reactions with drug utilization data
e22 Volume 35 Number 8S Department of Clinical Pharmacology, and Department of Dentistry, Oral and Maxillofacial Surgery; Department of Clinical Pharmacology; and Department of Dentistry, Oral and Maxillofacial Surgery, Jichi Medical University, Shimotsukeshi, Japan Introduction: Docetaxel, cisplatin plus 5-FU (DCF) regimen is a useful chemotherapy against malignant diseases such as advanced head and neck cancer. However, DCF regimen is sometimes withdrawn by severe myelosuppression and nonhematologic toxic effects, including mucositis. Previous animal and clinical studies showed that the degrees of docetaxel-, cisplatin-, and 5-FUâinduced toxicities depend on their dosing time. We have reported that the frequency of docetaxel-induced intestinal mucositis was greater after dosing at an active phase than at an inactive phase in mice. The aim of the present study was to determine the influence of dosing schedule of DCF regimen on chemotherapy-induced toxicities in clinical practice. Patients (or Materials) and Methods: Patients with oral squamous cell carcinoma treated with DCF regimen were randomly allocated to the following 2 groups: chemotherapy started from morning (10:30) in the first group and evening (18:30) in the second group. Hematologic and nonhematologic adverse effects were assessed for 14 days after the start of chemotherapy. Results: The most frequently observed mild to severe adverse effects were neutropenia, diarrhea, stomatitis, and nausea. The frequency of grade 3 to 4 neutropenia was 62.5% (5 of 8) in the morning group and 28.6% (2 of 7) in the evening group. Grade 3 to 4 event of stomatitis and grade 3 event of nausea were more detected in the morning group. Conclusion: These findings suggest that chronotherapy of DCF regimen might diminish severe adverse effects in patients with oral squamous cell carcinoma. Disclosure of Interest: None declared
Multiwavelength campaign on Mrk 509. XIII. Testing ionized-reflection models on Mrk 509
Active Galactic Nuclei (AGN) are the most luminous persistent objects in the
universe. An excess of X-ray emission below about 2 keV, called soft-excess, is
very common in Type 1 AGN spectra. The origin of this feature remains debated.
Originally modeled with a blackbody, there are now several possibilities to
model the soft-excess, including warm Comptonization and blurred ionized
reflection. In this paper, we test ionized-reflection models on Mrk 509, a
bright Seyfert 1 galaxy for which we have a unique data set, in order to
determine whether it can be responsible for the strong soft-excess. We use ten
simultaneous XMM-Newton and INTEGRAL observations performed every four days. We
present here the results of the spectral analysis, the evolution of the
parameters and the variability properties of the X-ray emission. The
application of blurred ionized-reflection models leads to a very strong
reflection and an extreme geometry, but fails to reproduce the broad-band
spectrum of Mrk 509. Two different scenarios for blurred ionized reflection are
discussed: stable geometry and lamp-post configuration. In both cases we find
that the model parameters do not follow the expected relations, indicating that
the model is fine-tuned to fit the data without physical justification. A
large, slow variation of the soft-excess without counterpart in the hard X-rays
could be explained by a change in ionization of the reflector. However, such a
change does not naturally follow from the assumed geometrical configuration.
Warm Comptonization remains the most probable origin of the soft-excess in this
object. Nevertheless, it is possible that both ionized reflection and warm
Comptonization mechanisms can explain the soft-excess in all objects, one
dominating the other one, depending on the physical conditions of the disk and
the corona.Comment: 12 pages, A&A accepte
High-energy monitoring of NGC 4593 with XMM-Newton and NuSTAR. X-ray spectral analysis
We present results from a joint XMMâNewton/NuSTAR monitoring of the Seyfert 1 NGC 4593, consisting of 5 Ă 20 ks simultaneous observations spaced by 2 d, performed in 2015 January. The source is variable, both in flux and spectral shape, on time-scales down to a few ks and with a clear softer-when-brighter behaviour. In agreement with past observations, we find the presence of a warm absorber well described by a two-phase ionized outflow. The source exhibits a cold, narrow and constant Fe Kα line at 6.4 keV, and a broad component is also detected. The broad-band (0.3â79 keV) spectrum is well described by a primary power law with Î â 1.6â1.8 and an exponential cut-off varying from 90^(+40_+(â20) to >700 keV, two distinct reflection components, and a variable soft excess correlated with the primary power law. This campaign shows that probing the variability of Seyfert 1 galaxies on different time-scales is of prime importance to investigate the high-energy emission of active galactic nuclei
Multiwavelength campaign on Mrk 509 XIV. Chandra HETGS spectra
We present in this paper the results of a 270 ks Chandra HETGS observation in
the context of a large multiwavelength campaign on the Seyfert galaxy Mrk 509.
The HETGS spectrum allows us to study the high ionisation warm absorber and the
Fe-K complex in Mrk 509. We search for variability in the spectral properties
of the source with respect to previous observations in this campaign, as well
as for evidence of ultra-fast outflow signatures. The Chandra HETGS X-ray
spectrum of Mrk 509 was analysed using the SPEX fitting package. We confirm the
basic structure of the warm absorber found in the 600 ks XMM-Newton RGS
observation observed three years earlier, consisting of five distinct
ionisation components in a multikinematic regime. We find little or no
variability in the physical properties of the different warm absorber phases
with respect to previous observations in this campaign, except for component D2
which has a higher column density at the expense of component C2 at the same
outflow velocity (-240 km/s). Contrary to prior reports we find no -700 km/s
outflow component. The O VIII absorption line profiles show an average covering
factor of 0.81 +/- 0.08 for outflow velocities faster than -100 km/s, similar
to those measured in the UV. This supports the idea of a patchy wind. The
relative metal abundances in the outflow are close to proto-solar. The narrow
component of the Fe Kalpha emission line shows no changes with respect to
previous observations which confirms its origin in distant matter. The narrow
line has a red wing that can be interpreted to be a weak relativistic emission
line. We find no significant evidence of ultra-fast outflows in our new
spectrum down to the sensitivity limit of our data.Comment: 12 pages, 9 figures, accepted for publication in Astronomy &
Astrophysic
Anatomy of the AGN in NGC 5548: I. A global model for the broadband spectral energy distribution
An extensive multi-satellite campaign on NGC 5548 has revealed this
archetypal Seyfert-1 galaxy to be in an exceptional state of persistent heavy
absorption. Our observations taken in 2013-2014 with XMM-Newton, Swift, NuSTAR,
INTEGRAL, Chandra, HST and two ground-based observatories have together enabled
us to establish that this unexpected phenomenon is caused by an outflowing
stream of weakly ionised gas (called the obscurer), extending from the vicinity
of the accretion disk to the broad-line region. In this work we present the
details of our campaign and the data obtained by all the observatories. We
determine the spectral energy distribution of NGC 5548 from near-infrared to
hard X-rays by establishing the contribution of various emission and absorption
processes taking place along our line of sight towards the central engine. We
thus uncover the intrinsic emission and produce a broadband continuum model for
both obscured (average summer 2013 data) and unobscured ( 2011) epochs of
NGC 5548. Our results suggest that the intrinsic NIR/optical/UV continuum is a
single Comptonised component with its higher energy tail creating the 'soft
X-ray excess'. This component is compatible with emission from a warm,
optically-thick corona as part of the inner accretion disk. We then investigate
the effects of the continuum on the ionisation balance and thermal stability of
photoionised gas for unobscured and obscured epochs.Comment: Accepted for publication in A&A, 19 pages, 13 figure
Accretion, ejection and reprocessing in supermassive black holes
This is a White Paper in support of the mission concept of the Large
Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We
discuss the potential of LOFT for the study of active galactic nuclei. For a
summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large
Observatory for X-ray Timin
A fast and long-lived outflow from the supermassive black hole in NGC 5548
Supermassive black holes in the nuclei of active galaxies expel large amounts
of matter through powerful winds of ionized gas. The archetypal active galaxy
NGC 5548 has been studied for decades, and high-resolution X-ray and UV
observations have previously shown a persistent ionized outflow. An observing
campaign in 2013 with six space observatories shows the nucleus to be obscured
by a long-lasting, clumpy stream of ionized gas never seen before. It blocks
90% of the soft X-ray emission and causes simultaneous deep, broad UV
absorption troughs. The outflow velocities of this gas are up to five times
faster than those in the persistent outflow, and at a distance of only a few
light days from the nucleus, it may likely originate from the accretion disk.Comment: 25 pages, 8 figures. This is the author's version of the work. It is
posted here by permission of the AAAS for personal use, not for
redistribution. The definitive version was published in Science,
electronically available at Science Express (June 19, 2014). For a brief
video explaining the key results of this paper, please visit
http://www.issibern.ch/teams/ngc5548/?page_id=2
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