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REVISITING THE MICROLENSING EVENT OGLE 2012-BLG-0026: A SOLAR MASS STAR WITH TWO COLD GIANT PLANETS
Beaulieu, J.-P.,Bennett, D. P.,Batista, V.,Fukui, A.,Marquette, J.-B.,Brillant, S.,Cole, A. A.,Rogers, L. A.,Sumi, T.,Abe, F.,Bhattacharya, A.,Koshimoto, N.,Suzuki, D.,Tristram, P. J.,Han, C.,Gould, A American Astronomical Society 2016 The Astrophysical Journal Vol.824 No.2
<P>Two cold gas giant planets orbiting a G-type main-sequence star in the galactic disk were previously discovered in the high-magnification microlensing event OGLE-2012-BLG-0026. Here, we present revised host star flux measurements and a refined model for the two-planet system using additional light curve data. We performed high angular resolution adaptive optics imaging with the Keck and Subaru telescopes at two epochs while the source star was still amplified. We detected the lens flux, H = 16.39 +/- 0.08. The lens, a disk star, is brighter than predicted from the modeling in the original study. We revisited the light curve modeling using additional photometric data from the B&C telescope in New Zealand and CTIO 1.3 m H-band light curve. We then include the Keck and Subaru adaptive optic observation constraints. The system is composed of a similar to 4-9 Gyr lens star of M-lens = 1.06 +/- 0.05 M circle dot at a distance of D-lens = 4.0 +/- 0.3 kpc, orbited by two giant planets of 0.145 +/- 0.008 M-Jup and 0.86 +/- 0.06 M-Jup, with projected separations of 4.0 +/- 0.5 au and 4.8 +/- 0.7 au, respectively. Because the lens is brighter than the source star by 16 +/- 8% in H, with no other blend within one arcsec, it will be possible to estimate its metallicity using subsequent IR spectroscopy with 8-10 m class telescopes. By adding a constraint on the metallicity it will be possible to refine the age of the system.</P>
J. Beaulieu,E. Millette,E. Trottier,L.-P. Pre´court,C. Dupont,P. Lemieux 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.3
Previously, we reported that a malleable protein matrix (MPM), composed of whey fermented by a proprietary Lactobacillus kefiranofaciens strain, has immunomodulatory and anti-inflammatory properties. MPM consumption leads to a considerable reduction in the cytokine and chemokine production (tumor necrosis factor-α, interleukin-1β, and interleukin-6), thus lowering chronic inflammation or metaflammation. Inhibition of metaflammation should provide positive impact, particularly in the context of dyslipidemia, insulin resistance, and hypertension. In this study, we investigated whether short-term MPM supplementation ameliorates those features of metabolic syndrome (MetS). The ability of MPM to potentially regulate triglyceride level, cholesterol level, blood glucose level, and hypertension was evaluated in different animal models. MPM lowers triglyceride level by 37% (P<.05) in a poloxamer 407 dyslipidemia-induced rat model. It also reduces total cholesterol by 18% (P<.05) and low-density lipoprotein-cholesterol level by 32% (P<.05) and raises high-density lipoprotein-cholesterol level by 17% (P<.01) in Syrian Golden hamsters fed a high fat/high cholesterol diet for 2 weeks. MPM reestablishes the fasting glucose insulin ratio index to normal levels (P=.07) in this latter model and lowers the plasma glucose level area under the curve (−10%, P=.09) in fructose-fed rats after 2 weeks of treatment. In spontaneously hypertensive rats, MPM-treated animals showed a reduction of SBP by at least 13% (P<.05) for 4 weeks. Results from this study suggest that MPM is a functional ingredient with beneficial effects on lipid metabolism, blood glucose control, and hypertension that might contribute to the management of MetS and thus reducing the risk of cardiovascular diseases.
MICROLENSING DISCOVERY OF A POPULATION OF VERY TIGHT, VERY LOW MASS BINARY BROWN DWARFS
Choi, J.-Y.,Han, C.,Udalski, A.,Sumi, T.,Gaudi, B. S.,Gould, A.,Bennett, D. P.,Dominik, M.,Beaulieu, J.-P.,Tsapras, Y.,Bozza, V.,Abe, F.,Bond, I. A.,Botzler, C. S.,Chote, P.,Freeman, M.,Fukui, A.,Furu IOP Publishing 2013 The Astrophysical journal Vol.768 No.2
<P>Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M-circle dot and 0.034 M-circle dot, and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known. The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of similar to 0.02 M-circle dot. Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries.</P>
Choi, J.-Y.,Shin, I.-G.,Park, S.-Y.,Han, C.,Gould, A.,Sumi, T.,Udalski, A.,Beaulieu, J.-P.,Street, R.,Dominik, M.,Allen, W.,Almeida, L. A.,Bos, M.,Christie, G. W.,Depoy, D. L.,Dong, S.,Drummond, J.,Ga IOP Publishing 2012 The Astrophysical journal Vol.751 No.1
<P>We present the analysis of the light curves of nine high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/MOA-2011-BLG-325. For all of the events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius of theta(E) similar to 0.08 mas combined with the short timescale of t(E) similar to 2.7 days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of similar to 0.84M(circle dot) is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we did not find planetary signals for any of the events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio.</P>
MICROLENSING BINARIES DISCOVERED THROUGH HIGH-MAGNIFICATION CHANNEL
Shin, I.-G.,Choi, J.-Y.,Park, S.-Y.,Han, C.,Gould, A.,Sumi, T.,Udalski, A.,Beaulieu, J.-P.,Dominik, M.,Allen, W.,Bos, M.,Christie, G. W.,Depoy, D. L.,Dong, S.,Drummond, J.,Gal-Yam, A.,Gaudi, B. S.,Hun IOP Publishing 2012 The Astrophysical journal Vol.746 No.2
<P>Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3 sigma confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q similar to 0.1, making the companion of the lens a strong brown dwarf candidate.</P>
THE FIRST NEPTUNE ANALOG OR SUPER-EARTH WITH A NEPTUNE-LIKE ORBIT: MOA-2013-BLG-605LB
Sumi, T.,Udalski, A.,Bennett, D. P.,Gould, A.,Poleski, R.,Bond, I. A.,Skowron, J.,Rattenbury, N.,Pogge, R. W.,Bensby, T.,Beaulieu, J. P.,Marquette, J. B.,Batista, V.,Brillant, S.,Abe, F.,Asakura, Y.,B American Astronomical Society 2016 The Astrophysical journal Vol.825 No.2
<P>We present the discovery of the first Neptune analog exoplanet or super-Earth with a Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at 9 similar to 14 times the expected position of the snow line, a(snow), which is similar to Neptune's separation of 11 a(snow) from the Sun. The planet/host-star mass ratio is q = (3.6 +/- 0.7) x 10(-4) and the projected separation normalized by the Einstein radius is s = 2.39 +/- 0.05. There are three degenerate physical solutions and two of these are due to a new type of degeneracy in the microlensing parallax parameters, which we designate 'the wide degeneracy.' The three models have (i) a Neptune-mass planet with a mass of M-p = 21(-7)(+6)M(circle plus) orbiting a low-mass M-dwarf with a mass of M-h = 0.19(-0.06)(+0.05)M(circle dot), (ii) a mini-Neptune with M-p = 7.9(-1.2)(+1.8)M(circle plus) orbiting a brown dwarf host with M-h = 0.068(-0.011)(+0.019)M(circle dot), and (iii) a super-Earth with M-p = 3.2(-0.3)(+0.5)M(circle plus) orbiting a low-mass brown dwarf host with M-h = 0.025(-0.004)(+0.005)M(circle dot), which is slightly favored. The 3D planet-host separations are 4.6(-1.2)(+4.7) au, 2.1(-0.2) (+1.0) au, and 0.94(-0.02)(+0.67) au, which are 8.9(-1.4)(+10.5), 12(-1)(+7), or 14(-1)(+11) times larger than a(snow) for these models, respectively. Keck adaptive optics observations confirm that the lens is faint. This discovery suggests that low-mass planets with Neptune-like orbits are common. Therefore processes similar to the one that formed Neptune in our own solar system or cold super-Earths may be common in other solar systems.</P>
SUB-SATURN PLANET MOA-2008-BLG-310Lb: LIKELY TO BE IN THE GALACTIC BULGE
Janczak, Julia,Fukui, A.,Dong, Subo,Monard, L. A. G.,Kozłowski, Szymon,Gould, A.,Beaulieu, J. P.,Kubas, Daniel,Marquette, J. B.,Sumi, T.,Bond, I. A.,Bennett, D. P.,Abe, F.,Furusawa, K.,Hearnshaw, J. B IOP Publishing 2010 The Astrophysical journal Vol.711 No.2
<P>We report the detection of sub-Saturn-mass planet MOA-2008-BLG-310Lb and argue that it is the strongest candidate yet for a bulge planet. Deviations from the single-lens fit are smoothed out by finite-source effects and therefore are not immediately apparent from the light curve. Nevertheless, we find that a model in which the primary has a planetary companion is favored over the single-lens model by Delta chi(2) similar to 880 for an additional 3 degrees of freedom. Detailed analysis yields a planet/star mass ratio q = (3.3 +/- 0.3) x 10(-4) and an angular separation between the planet and star within 10% of the angular Einstein radius. The small angular Einstein radius, theta(E) = 0.155 theta 0.011 mas, constrains the distance to the lens to be D(L) > 6.0 kpc if it is a star (M(L) > 0.08 M(circle dot)). This is the only microlensing exoplanet host discovered so far that must be in the bulge if it is a star. By analyzing VLT NACO adaptive optics images taken near the baseline of the event, we detect additional blended light that is aligned to within 130 mas of the lensed source. This light is plausibly from the lens, but could also be due to a companion to the lens or source, or possibly an unassociated star. If the blended light is indeed due to the lens, we can estimate the mass of the lens, M(L) = 0.67 +/- 0.14 M(circle dot), planet mass m = 74 +/- 17 M(circle plus), and projected separation between the planet and host, 1.25 +/- 0.10 AU, putting it right on the 'snow line.' If not, then the planet has lower mass, is closer to its host and is colder. To distinguish among these possibilities on reasonable timescales would require obtaining Hubble Space Telescope images almost immediately, before the source-lens relative motion of mu = 5 mas yr(-1) causes them to separate substantially.</P>
Bachelet, E.,Shin, I.-G.,Han, C.,Fouqué,, P.,Gould, A.,Menzies, J. W.,Beaulieu, J.-P.,Bennett, D. P.,Bond, I. A.,Dong, Subo,Heyrovský,, D.,Marquette, J.-B.,Marshall, J.,Skowron, J.,Street, IOP Publishing 2012 The Astrophysical journal Vol.754 No.1
<P>Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA 2010-BLG-477. The measured planet-star mass ratio is q = (2.181 +/- 0.004) x 10(-3) and the projected separation is s = 1.1228 +/- 0.0006 in units of the Einstein radius. The angular Einstein radius is unusually large theta(E) = 1.38 +/- 0.11 mas. Combining this measurement with constraints on the 'microlens parallax' and the lens flux, we can only limit the host mass to the range 0.13 < M/M-circle dot < 1.0. In this particular case, the strong degeneracy between microlensing parallax and planet orbital motion prevents us from measuring more accurate host and planet masses. However, we find that adding Bayesian priors from two effects (Galactic model and Keplerian orbit) each independently favors the upper end of this mass range, yielding star and planet masses of M-* = 0.67(-0.13)(+0.33) M-circle dot and m(p) = 1.5(-0.3)(+0.8) M-JUP at a distance of D = 2.3 +/- 0.6 kpc, and with a semi-major axis of a = 2(-1)(+3) AU. Finally, we show that the lens mass can be determined from future high-resolution near-IR adaptive optics observations independently from two effects, photometric and astrometric.</P>
INTERPRETATION OF A SHORT-TERM ANOMALY IN THE GRAVITATIONAL MICROLENSING EVENT MOA-2012-BLG-486
Hwang, K.-H.,Choi, J.-Y.,Bond, I. A.,Sumi, T.,Han, C.,Gaudi, B. S.,Gould, A.,Bozza, V.,Beaulieu, J.-P.,Tsapras, Y.,Abe, F.,Bennett, D. P.,Botzler, C. S.,Chote, P.,Freeman, M.,Fukui, A.,Fukunaga, D.,Ha IOP Publishing 2013 The Astrophysical journal Vol.778 No.1
<P>A planetary microlensing signal is generally characterized by a short-term perturbation to the standard single lensing light curve. A subset of binary-source events can produce perturbations that mimic planetary signals, thereby introducing an ambiguity between the planetary and binary-source interpretations. In this paper, we present the analysis of the microlensing event MOA-2012-BLG-486, for which the light curve exhibits a short-lived perturbation. Routine modeling not considering data taken in different passbands yields a best-fit planetary model that is slightly preferred over the best-fit binary-source model. However, when allowed for a change in the color during the perturbation, we find that the binary-source model yields a significantly better fit and thus the degeneracy is clearly resolved. This event not only signifies the importance of considering various interpretations of short-term anomalies, but also demonstrates the importance of multi-band data for checking the possibility of false-positive planetary signals.</P>