132 research outputs found
Possibilities to Improve the Therapy of the Patients with Ureteral Concretions
The aim of the given study was to improve the results of treatment of patients with concretions of the upper third of the ureter.Materials and methods. The clinical trial was carried out as a non-interventional open, controlled, in two groups of patients with baseline control. The inclusion criteria concerned the patients with concretions of the upper third of the ureter 0.7-0.9 mm in size, which had one session of an extracorporeal shock-wave lithotripsy (ESWL), and after the procedure the size of the concretions fragments was up to3 mm. The study involved 60 patients, all patients in the main group (n = 30) were treated using phytotherapy, within 1 month starting with basic therapy under hospital conditions and continuing with preventative treatment in an outpatient setting. The control group (n = 30) received baseline therapy (up to 10 days) at the stationary stage. Results and discussion. In patients of the main group, fragments of concretions came out significantly faster, namely: in the main group, the fragments came out in 21 patients (70.0 %), while in the control group in 15 patients (50.0 %) (p1- p2, p <0.05) to the 7th day, and in the main group, the fragments came out in one patient more than 14 days, and in the control group – in 5 patients, p <0.05. The "stone path" in the bottom third of the ureter was in 1 patient (3.3 %) of the main group and in 3 patients (10.0 %) in the control group (p1-p2, p <0.05). The "stone path" departure time in patients of the main group was 2 days, and in patients of the control group it was 4.1 days from the time of its formation (p1-p2, p <0.05). Bacteriuria was observed in the main group on the 10th day 6.6 % less relative to the control group.Conclusion. At comparing the obtained results in patients of both groups in 1 month it was noted that high efficacy of the treatment was registered in 6 (20 %) patients of the main group and in 3 patients (10 %) of the control group (p <0.05), moderate efficiency was registered in 23 (76.7 %) patients of the main group and in 22 (73.3 %) patients of the control group respectively, low efficacy was registered in 1 (3.33 %) patient in the main group and 5 (16.7 %) patients of the control group (p <0,05), which points to the effectiveness of Urolesan capsules use in complex therapy of patients with concretions of the one third of ureter
Orbital parameters, chemical composition, and magnetic field of the Ap binary HD 98088
HD 98088 is a synchronised, double-lined spectroscopic binary system with a
magnetic Ap primary component and an Am secondary component. We study this rare
system using high-resolution MuSiCoS spectropolarimetric data, to gain insight
into the effect of binarity on the origin of stellar magnetism and the
formation of chemical peculiarities in A-type stars. Using a new collection of
29 high-resolution Stokes VQU spectra we re-derive the orbital and stellar
physical parameters and conduct the first disentangling of spectroscopic
observations of the system to conduct spectral analysis of the individual
stellar components. From this analysis we determine the projected rotational
velocities of the stars and conduct a detailed chemical abundance analysis of
each component using both the SYNTH3 and ZEEMAN spectrum synthesis codes. The
surface abundances of the primary component are typical of a cool Ap star,
while those of the secondary component are typical of an Am star. We present
the first magnetic analysis of both components using modern data. Using
Least-Squares Deconvolution, we extract the longitudinal magnetic field
strength of the primary component, which is observed to vary between +1170 and
-920 G with a period consistent with the orbital period. There is no field
detected in the secondary component. The magnetic field in the primary is
predominantly dipolar, with the positive pole oriented approximately towards
the secondary.Comment: Accepted for publication by MNRAS, 17 pages, 12 figure
Abundance and stratification analysis of the CP star HD 103498
Slow rotation and absence of strong mixing processes in atmospheres of
chemically peculiar stars develop ideal conditions for the appearance of
abundance anomalies through the mechanism of microscopic particle diffusion.
This makes these objects look spectroscopically and photometrically different
from their "normal" analogs. As a result, it is often difficult to accurately
determine atmospheric parameters of these stars and special methods are needed
for the consistent analysis of their atmospheres. The main aim of the present
paper is to analyse atmospheric abundance and stratification of chemical
elements in the atmosphere of the chemically peculiar star HD 103498. We find
that two model atmospheres computed with individual and stratified abundances
provide reasonable fit to observed spectroscopic and photometric indicators:
Teff=9300 K, logg=3.5 and Teff=9500K, logg=3.6. It is shown that Mg has a large
abundance gradient in the star's atmosphere with accumulation of Mg ions in the
uppermost atmospheric layers, whereas Si demonstrates opposite behaviour with
accumulation in deep layers. In addition, a detailed non-LTE analysis showed
that none of Mg transitions under consideration is a subject of noticeable
non-LTE effects. Comparing observed photometry transformed to physical units we
estimated the radius of HD 103498 to be between R=(4.56 +/- 0.77)Rsun for
Teff=9300K, logg=3.5 and R=(4.39 +/- 0.75)Rsun for Teff=9500K, logg=3.6 models
respectively. We note that the lack of suitable observations in absolute units
prevents us to uniquely determine the Teff of the star at the current stage of
analysis.Comment: 9 pages, 7 figures and 3 tables, accepted for publication in MNRA
Non-local thermodynamic equilibrium effects determine the upper atmospheric temperature structure of the ultra-hot Jupiter KELT-9b
Several results indicate that the atmospheric temperature of the ultra-hot
Jupiter KELT-9b in the main line formation region is a few thousand degrees
higher than predicted by self-consistent models. We test whether non-local
thermodynamic equilibrium (NLTE) effects are responsible for the presumably
higher temperature. We employ the Cloudy NLTE radiative transfer code to
self-consistently compute the upper atmospheric temperature-pressure (TP)
profile of KELT-9b, assuming solar metallicity. The Cloudy NLTE TP profile is
2000 K hotter than that obtained with previous models assuming local
thermodynamic equilibrium (LTE). In particular, in the 1-10 bar range
the temperature increases from 4000 K to 8500 K, remaining
roughly constant at lower pressures. We find that the high temperature in the
upper atmosphere of KELT-9b is driven principally by NLTE effects modifying the
Fe and Mg level populations, which strongly influence the atmospheric thermal
balance. We employ Cloudy to compute LTE and NLTE synthetic transmission
spectra on the basis of the TP profiles computed in LTE and NLTE, respectively,
finding that the NLTE model generally produces stronger absorption lines than
the LTE model (up to 30%), which is largest in the ultraviolet. We compare the
NLTE synthetic transmission spectrum with the observed H and H
line profiles obtaining an excellent match, thus supporting our results. The
NLTE synthetic transmission spectrum can be used to guide future observations
aiming at detecting features in the planet's transmission spectrum. Metals,
such as Mg and Fe, and NLTE effects shape the upper atmospheric temperature
structure of KELT-9b and thus affect the mass-loss rates derived from it.
Finally, our results call for checking whether this is the case also of cooler
planets.Comment: Accepted for publication on A&A. The abstract has been shortened to
fit the available spac
Spectral analysis of Kepler SPB and Beta Cep candidate stars
We determine the fundamental parameters of SPB and Beta Cep candidate stars
observed by the Kepler satellite mission and estimate the expected types of
non-radial pulsators by comparing newly obtained high-resolution spectra with
synthetic spectra computed on a grid of stellar parameters assuming LTE and
check for NLTE effects for the hottest stars. For comparison, we determine Teff
independently from fitting the spectral energy distribution of the stars
obtained from the available photometry. We determine Teff, log(g),
micro-turbulent velocity, vsin(i), metallicity, and elemental abundance for 14
of the 16 candidate stars, two of the stars are spectroscopic binaries. No
significant influence of NLTE effects on the results could be found. For hot
stars, we find systematic deviations of the determined effective temperatures
from those given in the Kepler Input Catalogue. The deviations are confirmed by
the results obtained from ground-based photometry. Five stars show reduced
metallicity, two stars are He-strong, one is He-weak, and one is Si-strong. Two
of the stars could be Beta Cep/SPB hybrid pulsators, four SPB pulsators, and
five more stars are located close to the borders of the SPB instability region.Comment: 10 pages, 10 figures, 10 table
The CARMENES search for exoplanets around M dwarfs: Radial-velocity variations of active stars in visual-channel spectra
Previous simulations predicted the activity-induced radial-velocity (RV)
variations of M dwarfs to range from cm/s to km/s, depending on
various stellar and activity parameters. We investigate the observed relations
between RVs, stellar activity, and stellar parameters of M dwarfs by analyzing
CARMENES high-resolution visual-channel spectra (m), which were
taken within the CARMENES RV planet survey during its first months of
operation. During this time, of the CARMENES-sample stars were observed
at least five times. From each spectrum we derived a relative RV and a measure
of chromospheric H emission. In addition, we estimated the chromatic
index (CRX) of each spectrum, which is a measure of the RV wavelength
dependence. Despite having a median number of only measurements per star,
we show that the RV variations of the stars with RV scatter of m/s and a
projected rotation velocity km/s are caused mainly by activity.
We name these stars `active RV-loud stars' and find their occurrence to
increase with spectral type: from for early-type M dwarfs
(MV) through for mid-type M dwarfs (MV) to
for late-type M dwarfs (MV). Their RV-scatter amplitude is
found to be correlated mainly with . For about half of the stars, we
also find a linear RVCRX anticorrelation, which indicates that their
activity-induced RV scatter is lower at longer wavelengths. For most of them we
can exclude a linear correlation between RV and H emission. Our results
are in agreement with simulated activity-induced RV variations in M dwarfs. The
RV variations of most active RV-loud M dwarfs are likely to be caused by dark
spots on their surfaces, which move in and out of view as the stars rotate.Comment: A&A accepte
Magnetic field, chemical composition and line profile variability of the peculiar eclipsing binary star AR Aur
AR Aur is the only eclipsing binary known to contain a HgMn star, making it
an ideal case for a detailed study of the HgMn phenomenon. HgMn stars are a
poorly understood class of chemically peculiar stars, which have traditionally
been thought not to possess significant magnetic fields. However, the recent
discovery of line profile variability in some HgMn stars, apparently
attributable to surface abundance patches, has brought this belief into
question. In this paper we investigate the chemical abundances, line profile
variability, and magnetic field of the primary and secondary of the AR Aur
system, using a series of high resolution spectropolarimetric observations. We
find the primary is indeed a HgMn star, and present the most precise abundances
yet determined for this star. We find the secondary is a weak Am star, and is
possibly still on the pre-main sequence. Line profile variability was observed
in a range of lines in the primary, and is attributed to inhomogeneous surface
distributions of some elements. No magnetic field was detected in any
observation of either stars, with an upper limit on the longitudinal magnetic
field in both stars of 100 G. Modeling of the phase-resolve longitudinal field
measurements leads to a 3 sigma upper limit on any dipole surface magnetic
field of about 400 G.Comment: Accepted for publication in MNRAS, 11 pages, 9 figure
A detailed analysis of the Gl 486 planetary system
Context. The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with a warm transiting rocky planet of about 1.3 R-circle plus and 3.0 M-circle plus. It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets. Aims. To prepare for future studies, we aim to thoroughly characterise the planetary system with new accurate and precise data collected with state-of-the-art photometers from space and spectrometers and interferometers from the ground. Methods. We collected light curves of seven new transits observed with the CHEOPS space mission and new radial velocities obtained with MAROON-X at the 8.1 m Gemini North telescope and CARMENES at the 3.5 m Calar Alto telescope, together with previously published spectroscopic and photometric data from the two spectrographs and TESS. We also performed near-infrared interferometric observations with the CHARA Array and new photometric monitoring with a suite of smaller telescopes (AstroLAB, LCOGT, OSN, TJO). This extraordinary and rich data set was the input for our comprehensive analysis. Results. From interferometry, we measure a limb-darkened disc angular size of the star Gl 486 at theta(LDD) = 0.390 +/- 0.018 mas. Together with a corrected Gaia EDR3 parallax, we obtain a stellar radius R-* = 0.339 +/- 0.015 R-circle plus. We also measure a stellar rotation period at P-rot = 49.9 +/- 5.5 days, an upper limit to its XUV (5-920 A) flux informed by new Hubble/STIS data, and, for the first time, a variety of element abundances (Fe, Mg, Si, V, Sr, Zr, Rb) and C/O ratio. Moreover, we imposed restrictive constraints on the presence of additional components, either stellar or sub-stellar, in the system. With the input stellar parameters and the radial-velocity and transit data, we determine the radius and mass of the planet Gl 486 b at R-p = 1.343(-0.062)(+0.063) R-circle plus and M-p = 3.00(-0.12)(+0.13) M-circle plus, with relative uncertainties of the planet radius and mass of 4.7% and 4.2%, respectively. From the planet parameters and the stellar element abundances, we infer the most probable models of planet internal structure and composition, which are consistent with a relatively small metallic core with respect to the Earth, a deep silicate mantle, and a thin volatile upper layer. With all these ingredients, we outline prospects for Gl 486 b atmospheric studies, especially with forthcoming James Webb Space Telescope (Webb) observations.The David & Lucile Packard FoundationHeising-Simons FoundationGemini ObservatoryUniversity of ChicagoMax Planck SocietyConsejo Superior de Investigaciones Cientificas (CSIC)Spanish GovernmentEuropean Commission FICTS-2011-02
ICTS-2017-07-CAHA-4
CAHA16-CE-3978German Research Foundation (DFG) FOR2544National Science Foundation (NSF) AST-1636624
AST-2034336
2108465
DGE 1746045European Research Council (ERC) 639889National Aeronautics & Space Administration (NASA) XRP NNX16AD43GNational Science Foundation (NSF) AST 1909165Wise Observatory, Tel-Aviv University, Israel TAU2021A-015Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the ERDF PID2019-109522GB-C5[1:4]
PID2019-107061GBC64
PID2019-110689RB-100
PGC2018-095317-B-C21
PGC2018-102108-BI00Centre of Excellence "Severo Ochoa" CEX2019-000920-SCentre of Excellence "Maria de Maeztu" CEX2019-000920-SInstituto de Astrofisica de Andalucia SEV-2017-0709Centro de Astrobiologia MDM2017-0737German Research Foundation (DFG)European Commission FOR2544 (KU 3625/2-1)Germany's Excellence Strategy to the Excellence Cluster ORIGINS EXC-2094 -390783311European Research Council (ERC)European Commission 639889Bulgarian National Science Fund through VIHREN-2021 KP-06-DB/5Schweizerischer Nationalfonds zur Forderung der wissenschaftlichen Forschung/Fonds national suisse de la recherche scientifique PZ00P2_174028United Kingdom Science Technology and Facilities Council 630008203Princeton UniversityUniversidad La Laguna through the Margarita Salas Fellowship from the Spanish Ministerio de UniversidadesEU Next Generation funds UNI/551/2021Generalitat de Catalunya (CERCA programme
A data-driven approach to constraining the atmospheric temperature structure of KELT-9b
Context. Observationally constraining the atmospheric temperature-pressure
(TP) profile of exoplanets is an important step forward for improving planetary
atmosphere models, further enabling one to place the detection of spectral
features and the measurement of atomic and molecular abundances through
transmission and emission spectroscopy on solid ground. Aims. The aim is to
constrain the TP profile of the ultra-hot Jupiter KELT-9b by fitting synthetic
spectra to the observed H and H lines and identify why
self-consistent planetary TP models are unable to fit the observations.
Methods. We construct 126 one-dimensional TP profiles varying the lower and
upper atmospheric temperatures, as well as the location and gradient of the
temperature rise. For each TP profile, we compute transmission spectra of the
H and H lines employing the Cloudy radiative transfer code,
which self-consistently accounts for non-local thermodynamic equilibrium (NLTE)
effects. Results. The TP profiles leading to best fit the observations are
characterised by an upper atmospheric temperature of 10000-11000 K and by an
inverted temperature profile at pressures higher than 10 bar. We find
that the assumption of local thermodynamic equilibrium (LTE) leads to
overestimate the level population of excited hydrogen by several orders of
magnitude, and hence to significantly overestimate the strength of the Balmer
lines. The chemical composition of the best fitting models indicate that the
high upper atmospheric temperature is most likely driven by metal
photoionisation and that FeII and FeIII have comparable abundances at pressures
lower than 10 bar, possibly making the latter detectable. Conclusions.
Modelling the atmospheres of ultra-hot Jupiters requires one to account for
metal photoionisation. [abridged]Comment: Accepted for publication by A&
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