The GAPS programme at TNG Rainer, M.; Borsa, F.; Pino, L. ...
Astronomy and astrophysics (Berlin),
05/2021, Letnik:
649
Journal Article
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Context.
Transiting ultra-hot Jupiters are ideal candidates for studying the exoplanet atmospheres and their dynamics, particularly by means of high-resolution spectra with high signal-to-noise ...ratios. One such object is KELT-20b. It orbits the fast-rotating A2-type star KELT-20. Many atomic species have been found in its atmosphere, with blueshifted signals that indicate a day- to night-side wind.
Aims.
We observe the atmospheric Rossiter-McLaughlin effect in the ultra-hot Jupiter KELT-20b and study any variation of the atmospheric signal during the transit. For this purpose, we analysed five nights of HARPS-N spectra covering five transits of KELT-20b.
Methods.
We computed the mean line profiles of the spectra with a least-squares deconvolution using a stellar mask obtained from the Vienna Atomic Line Database (
T
eff
= 10 000 K, log
g
= 4.3), and then we extracted the stellar radial velocities by fitting them with a rotational broadening profile in order to obtain the radial velocity time-series. We used the mean line profile residuals tomography to analyse the planetary atmospheric signal and its variations. We also used the cross-correlation method to study a previously reported double-peak feature in the
FeI
planetary signal.
Results.
We observed both the classical and the atmospheric Rossiter-McLaughlin effect in the radial velocity time-series. The latter gave us an estimate of the radius of the planetary atmosphere that correlates with the stellar mask used in our work (
R
p+atmo
∕
R
p
= 1.13 ± 0.02). We isolated the planetary atmospheric trace in the tomography, and we found radial velocity variations of the planetary atmospheric signal during transit with an overall blueshift of ≈10 km s
−1
, along with small variations in the signal depth, and less significant, in the full width at half maximum (FWHM). We also find a possible variation in the structure and position of the
FeI
signal in different transits.
Conclusions.
We confirm the previously detected blueshift of the atmospheric signal during the transit. The FWHM variations of the atmospheric signal, if confirmed, may be caused by more turbulent condition at the beginning of the transit, by a variable contribution of the elements present in the stellar mask to the overall planetary atmospheric signal, or by iron condensation. The
FeI
signal show indications of variability from one transit to the next.
Context.
Stellar activity is currently challenging the detection of young planets via the radial velocity (RV) technique.
Aims.
We attempt to definitively discriminate the nature of the RV variations ...for the young active K5 star BD+20 1790, for which visible (VIS) RV measurements show divergent results on the existence of a substellar companion.
Methods.
We compare VIS data with high precision RVs in the near-infrared (NIR) range by using the GIANO–B and IGRINS spectrographs. In addition, we present for the first time simultaneous VIS-NIR observations obtained with GIARPS (GIANO–B and HARPS–N) at Telescopio Nazionale Galileo (TNG). Orbital RVs are achromatic, so the RV amplitude does not change at different wavelengths, while stellar activity induces wavelength-dependent RV variations, which are significantly reduced in the NIR range with respect to the VIS.
Results.
The NIR radial velocity measurements from GIANO–B and IGRINS show an average amplitude of about one quarter with respect to previously published VIS data, as expected when the RV jitter is due to stellar activity. Coeval multi-band photometry surprisingly shows larger amplitudes in the NIR range, explainable with a mixture of cool and hot spots in the same active region.
Conclusions.
In this work, the claimed massive planet around BD+20 1790 is ruled out by our data. We exploited the crucial role of multi-wavelength spectroscopy when observing young active stars: thanks to facilities like GIARPS that provide simultaneous observations, this method can reach its maximum potential.
Background:
Purified cannabidiol (CBD) was administered to highly refractory patients with Dravet (DS) or Lennox–Gastaut (LGS) syndromes in an ongoing expanded access program (EAP). Herein, we report ...interim results on CBD safety and seizure outcomes in patients treated for a 12-month period.
Material and Methods:
Thirty centers were enrolled from December 2018 to December 2019 within the open-label prospective EAP up to a maximum of 25 mg/kg per day. Adverse effects and liver function tests were assessed after 2 weeks; 1, 3, and 6 months of treatment; and periodically thereafter. Seizure endpoints were the percentage of patients with ≥50 and 100% reduction in seizures compared to baseline.
Results:
A total of 93 patients were enrolled and included in the safety analysis. Eighty-two patients 27 (32.9%) DS, 55 (67.1%) LGS with at least 3 months of treatment have been included in the effectiveness analysis; median previously failed antiseizure medications was eight. Pediatric and adult patients were uniformly represented in the cohort. At 3-month follow-up, compared to the 28-day baseline period, the percentage of patients with at least a 50% reduction in seizure frequency was 40.2% (plus 1.2% seizure-free). Retention rate was similar according to diagnosis, while we found an increased number of patients remaining under treatment in the adult group. CBD was mostly coadministered with valproic acid (62.2%) and clobazam (41.5%). In the safety dataset, 29 (31.2%) dropped out: reasons were lack of efficacy 16 (17.2%) and adverse events (AEs) 12 (12.9%), and one met withdrawal criteria (1.1%). Most reported AEs were somnolence (22.6%) and diarrhea (11.9%), followed by transaminase elevation and loss of appetite.
Conclusions:
CBD is associated with improved seizure control also in a considerable proportion of highly refractory patients with DS and LGS independently from clobazam use. Overall, CBD safety and effectiveness are not dose-related in this cohort.
Aims. Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low or medium resolution ...cannot disentangle the true sky continuum from instrumental effects (e.g. diffuse light in the wings of strong lines). We aim to obtain, for the first time, a high-resolution infrared spectrum that is deep enough to set significant constraints on the continuum emission between the lines in the H-band. Methods. During the second commissioning run of the GIANO high-resolution infrared spectrograph at La Palma Observatory, we pointed the instrument directly at the sky and obtained a deep spectrum that extends from 0.97 to 2.4 μm. Results. The spectrum shows about 1500 emission lines, a factor of two more than in previous works. Of these, 80% are identified as OH transitions; half of these are from highly excited molecules (hot-OH component) that are not included in the OH airglow emission models normally used for astronomical applications. The other lines are attributable to O2 or unidentified. Several of the faint lines are in spectral regions that were previously believed to be free of line emission. The continuum in the H-band is marginally detected at a level of about 300 photons/m2/s/arcsec2/μm, equivalent to 20.1 AB-mag/arcsec2. The observed spectrum and the list of observed sky lines are published at the CDS. Conclusions. Our measurements indicate that the sky continuum in the H-band could be even darker than previously believed. However, the myriad of airglow emission lines severely limits the spectral ranges where very low background can be effectively achieved with low- or medium-resolution spectrographs. We identify a few spectral bands that could still remain quite dark at the resolving power foreseen for VLT-MOONS (R ≃ 6600).
Purpose: To measure anti‐cardiolipin (aCL), anti‐β2 glycoprotein I (anti‐β2GPI), and anti‐prothrombin (aPT) antibodies in young patients with epilepsy, and to correlate their presence with ...demographic data, clinical diagnoses, laboratory and neuroradiologic findings, and antiepileptic drugs (AEDs).
Methods: Sera from one hundred forty‐two consecutive patients with epilepsy with a median age of 10 years were tested for aCL and anti‐β2GPI autoantibodies by solid‐phase assays. aPT antibodies also were assayed in sera from 90 patients. Positive results were confirmed after a minimum of 6 weeks. Antinuclear antibodies (ANAs) and antibodies against extractable nuclear antigens (ENAs) also were tested.
Results: An overall positivity of 41 (28.8%) of 142 sera was found. Fifteen patients were positive for aCL, 25 for anti‐β2GPI, and 18 for aPT antibodies. Several patients (12%) displayed more than one specificity in their serum. Only one of these patients had a concurrent positivity for ANAs and ENAs. A predominance of younger patients was found in the antibody‐positive group. All types of epilepsy were represented in the positive group. No relation between antibody positivity and AEDs was found. Diffuse ischemic lesions at computed tomography (CT)/magnetic resonance imaging (MRI) scans were present in higher percentages in patients who were antibody positive. No positive patient had a history of previous thrombosis or other features related to systemic lupus erythematosus (SLE), and no patient was born of a mother with SLE.
Conclusions: Our study suggests a relation between epilepsy and aPL in young patients. A pathogenetic role for these autoantibodies cannot be excluded, and their determination might prove useful even from a therapeutic point of view.
The GAPS programme at TNG Benatti, S.; Damasso, M.; Desidera, S. ...
Astronomy and astrophysics (Berlin),
07/2020, Letnik:
639
Journal Article
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Context.
Observations of exoplanetary systems demonstrate that a wide variety of planetary architectures are possible. Determining the rate of occurrence of Solar System analogues – with inner ...terrestrial planets and outer gas giants – remains an open question.
Aims.
Within the framework of the Global Architecture of Planetary Systems (GAPS) project, we collected more than 300 spectra with HARPS-N at the Telescopio Nazionale
Galileo
for the bright G9V star HD 164922. This target is known to host one gas giant planet in a wide orbit (
P
b
~1200 days, semi-major axis ~ 2 au) and a Neptune-mass planet with a period of
P
c
~76 days. We aimed to investigate the presence of additional low-mass companions in the inner region of the system.
Methods.
We compared the radial velocities (RV) and the activity indices derived from the HARPS-N time series to measure the rotation period of the star and used a Gaussian process regression to describe the behaviour of the stellar activity. We then combined a model of planetary and stellar activity signals in an RV time series composed of almost 700 high-precision RVs, both from HARPS-N and literature data. We performed a dynamical analysis to evaluate the stability of the system and the allowed regions for additional potential companions. We performed experiments on the injection and recovery of additional planetary signals to gauge the sensitivity thresholds in minimum mass and orbital separation imposed by our data.
Results.
Thanks to the high sensitivity of the HARPS-N dataset, we detected an additional inner super-Earth with an RV semi-amplitude of 1.3 ± 0.2 m s
−1
and a minimum mass of
m
d
sin
i
= 4 ± 1
M
⊕
. It orbits HD 164922 with a period of 12.458 ± 0.003 days. We disentangled the planetary signal from activity and measured a stellar rotation period of ~ 42 days. The dynamical analysis shows the long-term stability of the orbits of the three-planet system and allows us to identify the permitted regions for additional planets in the semi-major axis ranges 0.18–0.21 au and 0.6–1.4 au. The latter partially includes the habitable zone of the system. We did not detect any planet in these regions, down to minimum detectable masses of 5 and 18
M
⊕
, respectively. A larger region of allowed planets is expected beyond the orbit of planet b, where our sampling rules out bodies with minimum mass >50
M
⊕
. The planetary orbital parameters and the location of the snow line suggest that this system has been shaped by a gas disk migration process that halted after its dissipation.
This work addresses the challenge of deriving a simple but effective multi-physic model useful for the design and simulation of hyperthermia devices for ensuring a high-quality treatment. An existing ...compact patch antenna working at 434 MHz is re-designed using the proposed methodology. The proposed general approach is used to investigate the specific case of the hyperthermia treatment of abdominal rhabdomyosarcoma. Instead of using patient-specific geometries with discrete vascular tree models, a surface phantom with a continuum 3D blood perfusion model of tumors is used. The geometrical parameters of the antennas are selected to provide a robust design against the variation of the phantom parameters. The effectiveness of the antenna is evaluated simulating the treatment with a recent non-linear multi-physic model, considering the different description of tumor vasculature. A more robust and effective design is obtained, with respect to its previous version. Indeed, the antenna bandwidth is increased with about 7%. The treatment performed using the old version of the antenna lead to unsuccessful results (40 °C after 60 min), whilst the novel robust design could successfully treat the target region. The new version of the patch can withstand a temperature of 42.5 °C for 60 min of treatment. To further enhance the effectiveness of the treatment, the use of a time-modulated power is studied. The proposed model could be extended to different body regions and used to develop an application-oriented design of antennas for hyperthermia treatment.
Wolf-Hirschhorn syndrome (WHS) is a rare genetic disorder, which is caused by partial deletion of the short arm of one chromosome 4. Brain magnetic resonance (MR) imaging findings are lacking. We ...report on brain findings in 10 children with WHS. We evaluated the MR imaging films of 10 subjects affected by WHS, which had been confirmed by genetic study. The age range at MR imaging was between 1 month and 9 years. In 9/10 cases enlargement of the third lateral ventricles was present. In 9/10 cases a global reduction of cerebral hemispheres white matter was present. In 10/10 cases diffuse thinning of the corpus callosum was visible; it was severe in 7/10 cases. In 5/10 cases small foci of T (2) hyper intense signal were visible within the subcortical white matter. In three of the six cases studied within the first year of life frontal periventricular cysts were present. In three of the four cases studied after the first year of life a squared shape of the frontal horns of the lateral ventricles was visible. The MR imaging findings reported in WHS cannot be considered pathognomonic of the syndrome, however, they may suggest WHS.
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