10 research outputs found
A Multi-Wavelength Analysis of Dust and Gas in the SR 24S Transition Disk
We present new Atacama Large Millimeter/sub-millimeter Array (ALMA) 1.3 mm
continuum observations of the SR 24S transition disk with an angular resolution
(12 au radius). We perform a multi-wavelength investigation by
combining new data with previous ALMA data at 0.45 mm. The visibilities and
images of the continuum emission at the two wavelengths are well characterized
by a ring-like emission. Visibility modeling finds that the ring-like emission
is narrower at longer wavelengths, in good agreement with models of dust
trapping in pressure bumps, although there are complex residuals that suggest
potentially asymmetric structures. The 0.45 mm emission has a shallower profile
inside the central cavity than the 1.3 mm emission. In addition, we find that
the CO and CO (J=2-1) emission peaks at the center of the
continuum cavity. We do not detect either continuum or gas emission from the
northern companion to this system (SR 24N), which is itself a binary system.
The upper limit for the dust disk mass of SR 24N is , which gives a disk mass ratio in dust between the two
components of . The current ALMA observations may imply that either
planets have already formed in the SR 24N disk or that dust growth to mm-sizes
is inhibited there and that only warm gas, as seen by ro-vibrational CO
emission inside the truncation radii of the binary, is present.Comment: Accepted for publication in Ap
TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet
The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c on an 8.4-day orbit that is accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of our ongoing RV follow-up program. We performed a photodynamical modeling of the HARPS and PFS RVs, along with transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up Observing Program (TFOP). We determined the planet masses and radii of TOI-1130 b and TOI-1130 c to be Mb = 19.28 \ub1 0.97Mâ and Rb = 3.56 \ub1 0.13 Râ, and Mc = 325.59 \ub1 5.59Mâ and Rc = 13.32-1.41+1.55 Râ, respectively. We have spectroscopically confirmed the existence of TOI-1130 b, which had previously only been validated. We find that the two planets have orbits with small eccentricities in a 2:1 resonant configuration. This is the first known system with a hot Jupiter and an inner lower mass planet locked in a mean-motion resonance. TOI-1130 belongs to the small, yet growing population of hot Jupiters with an inner low-mass planet that poses a challenge to the pathway scenario for hot Jupiter formation. We also detected a linear RV trend that is possibly due to the presence of an outer massive companion
TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet
The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas
giant planet, TOI-1130 c, on an 8.4-day orbit, accompanied by an inner
Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We
collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS
and PFS spectrographs as part of our ongoing RV follow-up program. We perform a
photodynamical modeling of the HARPS and PFS RVs, and transit photometry from
the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up
Observing Program. We determine the planet masses and radii of TOI-1130 b and
TOI-1130 c to be Mb = 19.28 0.97 M and Rb = 3.56 0.13
R, and Mc = 325.59 5.59 M and Rc = 13.32+1.55-1.41
R, respectively. We spectroscopically confirm TOI-1130 b that was
previously only validated. We find that the two planets orbit with small
eccentricities in a 2:1 resonant configuration. This is the first known system
with a hot Jupiter and an inner lower mass planet locked in a mean-motion
resonance. TOI-1130 belongs to the small yet increasing population of hot
Jupiters with an inner low-mass planet that challenges the pathway for hot
Jupiter formation. We also detect a linear RV trend possibly due to the
presence of an outer massive companion.Comment: 19 pages, Accepted to A&
TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet
The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c on an 8.4-day orbit that is accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of our ongoing RV follow-up program. We performed a photodynamical modeling of the HARPS and PFS RVs, along with transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up Observing Program (TFOP). We determined the planet masses and radii of TOI-1130 b and TOI-1130 c to be Mb = 19.28 ± 0.97Mâ and Rb = 3.56 ± 0.13 Râ, and Mc = 325.59 ± 5.59Mâ and Rc = 13.32-1.41+1.55 Râ, respectively. We have spectroscopically confirmed the existence of TOI-1130 b, which had previously only been validated. We find that the two planets have orbits with small eccentricities in a 2:1 resonant configuration. This is the first known system with a hot Jupiter and an inner lower mass planet locked in a mean-motion resonance. TOI-1130 belongs to the small, yet growing population of hot Jupiters with an inner low-mass planet that poses a challenge to the pathway scenario for hot Jupiter formation. We also detected a linear RV trend that is possibly due to the presence of an outer massive companion
Effect of levamisole in steroid-dependent nephrotic syndrome
Introduction. Childhood idiopathic nephrotic syndrome is characterized by frequent relapsing courses or steroid dependency. Levamisole is a popular drug for treatment of these patients. The purpose of this study was to evaluate levamisole in children with steroid-dependent nephrotic syndrome. Materials and Methods. We retrospectively studied 304 children with a diagnosis of steroid-dependent nephrotic syndrome or frequently relapsing nephrotic syndrome. The mean age at the time of diagnosis was 4.84 years. Following induction of complete remission with steroid therapy based on the International Study of Kidney Disease in Children's protocol and when they were taking alternative days of steroid, 2.5 mg/kg of levamisole was administered. Results. The steroid dose was significantly decreased (mean reduction of 0.39 ñ 0.46 g to 0.33 ñ 0.38 g) after treatment with levamisole (P <.001). The number of relapses also significantly decreased (mean reduction of 0.92 ñ 0.98 episodes to 1.07 ñ 1.20 relapses per year; P <.001). The 14.5-month administration of levamizole had a sensitivity of 67.5 and a specificity of 71.9 to reach a dose reduction of more than 50 in steroid therapy. The duration of levamizole treatment was associated with more than 50 reduction in the number of relapses (P <.001). A 14.5-month treatment with levamizole had a sensitivity of 62.3 and a specificity of 63.6 to reach a relapse reduction of more than 50. Conclusions. Levamisole appears to be effective in prolonging the duration of remission and decreasing the steroid dose in children with steroid-dependent nephrotic syndrome