170 research outputs found
Poly-L-lactic acid beta-tricalcium phosphate screws: a preliminary in vivo biocompatibility study.
The aim of this study is to assess the biocompatibility of two types of Poly-L-lactic acid (PLLA) screws (with either hydroxiapatite (HA) or β-tricalcium phosphate (β-TCP)) implanted in the left femur of four sheep euthanized at 42, 50, 57 and 84 days after surgery. Titanium screws were also implanted for comparison purposes. No signs of inflammation were seen in the 240 specimens. A rating of "+/-"for macrophages and "-"for neutrophils was assigned to all specimens. All specimens were assigned a rating which ranged from "+/-" to "+++" for fibroblasts and osteoblasts. The presence of macrophages, neutrophils and fibroblasts/osteoblasts was not statistically different for the four implantation periods. PLLA implants with β-TCP have a biocompatibility comparable to PLLA implants with HA
On the discovery of fast molecular gas in the UFO/BAL quasar APM 08279+5255 at z = 3.912
We have performed a high sensitivity observation of the UFO/BAL quasar APM
08279+5255 at z=3.912 with NOEMA at 3.2 mm, aimed at detecting fast moving
molecular gas. We report the detection of blueshifted CO(4-3) with maximum
velocity (v95\%) of km s, with respect to the systemic peak
emission, and a luminosity of K km s
pc (where is the lensing magnification factor). We discuss various
scenarios for the nature of this emission, and conclude that this is the first
detection of fast molecular gas at redshift . We derive a mass flow rate of
molecular gas in the range M/yr, and
momentum boost , therefore consistent with
a momentum conserving flow. For the largest the scaling is also
consistent with a energy conserving flow with an efficiency of 10-20\%.
The present data can hardly discriminate between the two expansion modes. The
mass loading factor of the molecular outflow is .
We also detect a molecular emission line at a frequency of 94.83 GHz,
corresponding to a rest frame frequency of 465.8 GHz, which we tentatively
identified with the cation molecule (5-4), which would be the first
detection of this species at high redshift. We discuss the alternative
possibility that this emission is due to a CO emission line from the, so far
undetected, lens galaxy. Further observations of additional transitions of the
same species with NOEMA can discriminate between the two scenarios
SUPER VI. A giant molecular halo around a z∼2 quasar
We present the discovery of copious molecular gas in the halo of cid_346, a z = 2.2 quasar studied as part of the SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER). New Atacama Compact Array (ACA) CO(3−2) observations detect a much higher flux (by a factor of 14 ± 5) than measured on kiloparsec scales (r ≲ 8 kpc) using previous snapshot Atacama Large Millimeter/submillimeter Array data. Such additional CO(3−2) emission traces a structure that extends out to r ∼ 200 kpc in projected size, as inferred through direct imaging and confirmed by an analysis of the uv visibilities. This is the most extended molecular circumgalactic medium (CGM) reservoir that has ever been mapped. It shows complex kinematics, with an overall broad line profile (FWHM = 1000 km s−1) that is skewed towards redshifted velocities up to at least v ∼ 1000 km s−1. Using the optically thin assumption, we estimate a strict lower limit for the total molecular CGM mass observed by ACA of MmolCGM > 1010 M⊙. There is however room for up to MmolCGM ∼ 1.7 × 1012 M⊙, once optically thick CO emission with αCO = 3.6 M⊙ (K km s−1 pc2)−1 and L′CO(3−2)/L′CO(1−0) = 0.5 are assumed. Since cid_346 hosts quasar-driven ionised outflows and since there is no evidence of merging companions or an overdensity, we suggest that outflows may have played a crucial rule in seeding metal-enriched, dense gas on halo scales. However, the origin of such an extended molecular CGM remains unclear
BAT AGN Spectroscopic Survey XXVII: Scattered X-Ray Radiation in Obscured Active Galactic Nuclei
Accreting supermassive black holes (SMBHs), also known as active galactic
nuclei (AGN), are generally surrounded by large amounts of gas and dust. This
surrounding material reprocesses the primary X-ray emission produced close to
the SMBH and gives rise to several components in the broadband X-ray spectra of
AGN, including a power-law possibly associated with Thomson-scattered
radiation. In this work, we study the properties of this scattered component
for a sample of 386 hard-X-ray-selected, nearby () obscured AGN
from the 70-month Swift/BAT catalog. We investigate how the fraction of
Thomson-scattered radiation correlates with different physical properties of
AGN, such as line-of-sight column density, X-ray luminosity, black hole mass,
and Eddington ratio. We find a significant negative correlation between the
scattering fraction and the column density. Based on a large number of spectral
simulations, we exclude the possibility that this anti-correlation is due to
degeneracies between the parameters. The negative correlation also persists
when considering different ranges of luminosity, black hole mass, and Eddington
ratio. We discuss how this correlation might be either due to the angle
dependence of the Thomson cross-section or to more obscured sources having a
higher covering factor of the torus. We also find a positive correlation
between the scattering fraction and the ratio of [OIII] 5007 to X-ray
luminosity. This result is consistent with previous studies and suggests that
the Thomson-scattered component is associated with the narrow-line region.Comment: Accepted for publication in MNRAS, 18 pages, 9 figures, 2 tables, 1
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SUPER VII. morphology and kinematics of H α emission in AGN host galaxies at cosmic noon using SINFONI
We present spatially resolved H α properties of 21 type 1 AGN host galaxies at z ∼ 2 derived from the SUPER survey. These targets were observed with the adaptive optics capabilities of the SINFONI spectrograph, a near-infrared integral field spectrograph, that provided a median spatial resolution of 0.3 arcsec (∼2 kpc). We model the H α emission line profile in each pixel to investigate whether it traces gas in the narrow line region or if it is associated with star formation. To do this, we first investigate the presence of resolved H α emission after subtracting the AGN PSF. We find extended H α emission in 16 out of the 21 type 1 AGN host galaxies (76 per cent). Based on the BPT diagnostics, optical line flux ratios and line widths (FWHM), we show that the H α emission in five galaxies is ionized by the AGN (30 per cent), in four galaxies by star formation (25 per cent) and for the rest (45 per cent), the ionization source is unconstrained. Two galaxies show extended H α FWHM >600 km s−1, which is interpreted as a part of an AGN-driven outflow. Morphological and kinematic maps of H α emission in targets with sufficient signal-to-noise ratio suggest the presence of rotationally supported discs in six galaxies and possible presence of companions in four galaxies. In two galaxies, we find an anticorrelation between the locations of extended H α emission and [O III]-based ionized outflows, indicating possible negative feedback at play. However, in the majority of galaxies, we do not find evidence of outflows impacting H α-based star formation
SUPER VII. morphology and kinematics of H alpha emission in AGN host galaxies at cosmic noon using SINFONI
We present spatially resolved H α properties of 21 type 1 AGN host galaxies at z ∼ 2 derived from the SUPER survey. These targets were observed with the adaptive optics capabilities of the SINFONI spectrograph, a near-infrared integral field spectrograph, that provided a median spatial resolution of 0.3 arcsec (∼2 kpc). We model the H α emission line profile in each pixel to investigate whether it traces gas in the narrow line region or if it is associated with star formation. To do this, we first investigate the presence of resolved H α emission after subtracting the AGN PSF. We find extended H α emission in 16 out of the 21 type 1 AGN host galaxies (76 per cent). Based on the BPT diagnostics, optical line flux ratios and line widths (FWHM), we show that the H α emission in five galaxies is ionized by the AGN (30 per cent), in four galaxies by star formation (25 per cent) and for the rest (45 per cent), the ionization source is unconstrained. Two galaxies show extended H α FWHM >600 km s−1, which is interpreted as a part of an AGN-driven outflow. Morphological and kinematic maps of H α emission in targets with sufficient signal-to-noise ratio suggest the presence of rotationally supported discs in six galaxies and possible presence of companions in four galaxies. In two galaxies, we find an anticorrelation between the locations of extended H α emission and [O iii]-based ionized outflows, indicating possible negative feedback at play. However, in the majority of galaxies, we do not find evidence of outflows impacting H α-based star formation
SUPER: III. Broad line region properties of AGNs at z ∼2
Aims. The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER) was designed to conduct a blind search for AGN-driven outflows on X-ray-selected AGNs at redshift z∼2 with high (∼2 kpc) spatial resolution, and to correlate them with the properties of their host galaxy and central black hole. The main aims of this paper are: (a) to derive reliable estimates for the masses of the black holes and accretion rates for the Type-1 AGNs in this survey; and (b) to characterise the properties of the AGN-driven winds in the broad line region (BLR). Methods. We analysed rest-frame optical and UV spectra of 21 Type-1 AGNs. We used Hα, Hβ, and MgII line profiles to estimate the masses of the black holes. We used the blueshift of the CIV line profile to trace the presence of winds in the BLR. Results. We find that the Hα and Hβ line widths are strongly correlated, as is the line continuum luminosity at 5100 Å with Hα line luminosity, resulting in a well-defined correlation between black hole masses estimated from Hα and Hβ. Using these lines, we estimate that the black hole masses for our objects are in the range Log (MBH/M·) = 8.4-10.8 and are accreting at λEdd = 0.04-1.3. Furthermore, we confirm the well-known finding that the CIV line width does not correlate with the Balmer lines and the peak of the line profile is blueshifted with respect to the [OIII]-based systemic redshift. These findings support the idea that the CIV line is tracing outflowing gas in the BLR for which we estimated velocities up to ∼4700 km s-1. We confirm the strong dependence of the BLR wind velocity on the UV-to-X-ray continuum slope, the bolometric luminosity, and Eddington ratio. We infer BLR mass outflow rates in the range 0.005-3 M· yr-1, revealing a correlation with the bolometric luminosity consistent with that observed for ionised winds in the narrow line region (NLR), and X-ray winds detected in local AGNs, and kinetic power ∼10-7-10-4 × LBol. The coupling efficiencies predicted by AGN-feedback models are much higher than the values reported for the BLR winds in the SUPER sample; although it should be noted that only a fraction of the energy injected by the AGN into the surrounding medium is expected to become kinetic power in the outflow. Finally, we find an anti-correlation between the equivalent width of the [OIII] line and the CIV velocity shift, and a positive correlation between this latter parameter and [OIII] outflow velocity. These findings, for the first time in an unbiased sample of AGNs at z∼2, support a scenario where BLR winds are connected to galaxy-scale detected outflows, and are therefore capable of affecting the gas in the NLR located at kiloparsec scale distances
The Voyage of Metals in the Universe from Cosmological to Planetary Scales: the need for a Very High-Resolution, High Throughput Soft X-ray Spectrometer
Metals form an essential part of the Universe at all scales. Without metals we would not exist, and the Universe would look completely different. Metals are primarily produced via nuclear processes in stars, and spread out through winds or explosions, which pollute the surrounding space. The wanderings of metals in-and-out of astronomical objects are crucial in determining their own evolution and thus that of the Universe as a whole. Detecting metals and assessing their relative and absolute abundances and energetics can thus be used to trace the evolution of these cosmic components. The scope of this paper is to highlight the most important open astrophysical problems that will be central in the next decades and for which a deep understanding of the Universe’s wandering metals, their physical and kinematical states, and their chemical composition represents the only viable solution. The majority of these studies can only be efficiently performed through High Resolution Spectroscopy in the soft X-ray band
SUPER III. Broad Line Region properties of AGN at z2
The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback
(SUPER) was designed to conduct a blind search for AGN-driven outflows on X-ray
selected AGN at redshift z2 with high (2 kpc) spatial resolution,
and correlate them to the properties of the host galaxy and central black hole.
The main aims of this paper are: a) to derive reliable estimates for the BH
mass and accretion rates for the Type-1 AGN in this survey; b) to characterize
the properties of the AGN driven winds in the BLR. We analyzed rest-frame
optical and UV spectra of 21 Type-1 AGN. We found that the BH masses estimated
from H and H lines are in agreement. We estimate BH masses in
the range Log(M)=8.4-10.8 and Eddington ratios
=0.04-1.3. We confirm that the CIV line width does not
correlate with the Balmer lines and the peak of the line profile is
blue-shifted with respect to the [OIII]-based systemic redshift. These findings
support the idea that the CIV line is tracing outflowing gas in the BLR, with
velocities up to 4700 km/s. We confirm the strong dependence of the BLR
wind velocity with the UV-to-Xray continuum slope, L and
. We inferred BLR mass outflow rates in the range 0.005-3
M/yr, showing a correlation with the bolometric luminosity consistent
with that observed for ionized winds in the NLR and X-ray winds detected in
local AGN, and kinetic power 10 L. Finally,
we found an anti-correlation between the equivalent width of the [OIII] line
with respect to the CIV shift, and a positive correlation with [OIII] outflow
velocity. These findings, for the first time in an unbiased sample of AGN at
z2, support a scenario where BLR winds are connected to galaxy scale
detected outflows, and are capable of affecting the gas in the NLR located at
kpc scale.Comment: Accepted for publication in A&
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