112 research outputs found
Confirmation of Color Dependent Centroid Shift Measured After 1.8 years with HST
We measured precise masses of the host and planet in OGLE-2003-BLG-235
system, when the lens and source were resolving, with 2018 Keck high resolution
images. This measurement is in agreement with the observation taken in 2005
with the Hubble Space Telescope (HST). In 2005 data, the lens and sources were
not resolved and the measurement was made using color-dependent centroid shift
only. Nancy Grace Roman Space Telescope will measure masses using data
typically taken within 3-4 years of the peak of the event which is much shorter
baseline compared to most of the mass measurements to date. Hence, color
dependent centroid shift will be one of the primary method of mass measurements
for Roman. Yet, mass measurements of only two events (OGLE-2003-BLG-235 and
OGLE-2005-BLG-071) are done using the color dependent centroid shift method so
far. The accuracy of the measurements using this method are neither completely
known nor well studied. The agreement of Keck and HST results, shown in this
paper, is very important since this agreement confirms the accuracy of the mass
measurements determined at a small lens-source separation using the color
dependent centroid shift method. This also shows that with >100 high resolution
images, Roman telescope will be able to use color dependent centroid shift at
3-4 years time baseline and produce mass measurements. We find that
OGLE-2003-BLG-235 is a planetary system consists of a 2.34 +- 0.43M_Jup planet
orbiting a 0.56 +- 0.06M_Sun K-dwarf host star at a distance of 5.26 +- 0.71
kpc from the Sun.Comment: Submitted to AJ, under review. arXiv admin note: substantial text
overlap with arXiv:2009.0232
Keck Observations Confirm a Super-Jupiter Planet Orbiting M Dwarf OGLE-2005-BLG-071L
We present adaptive optics imaging from the NIRC2 instrument on the Keck II telescope that resolves the exoplanet host (and lens) star as it separates from the brighter source star. These observations yield the K-band brightness of the lens and planetary host star, as well as the lens-source relative proper motion, ”_(rel,H), in the heliocentric reference frame. The ”_(rel,H) measurement allows for the determination of the microlensing parallax vector, Ï_E, which had only a single component determined by the microlensing light curve. The combined measurements of ”_(rel,H) and K L provide the masses of the host star, M_(host) = 0.426 ± 0.037 Mâ, and planet, m_p = 3.27 ± 0.32M_(Jupiter) with a projected separation of 3.4 ± 0.5 au. This confirms the tentative conclusion of a previous paper that this super-Jupiter mass planet, OGLE-2005-BLG-071Lb, orbits an M dwarf. Such planets are predicted to be rare by the core accretion theory and have been difficult to find with other methods, but there are two such planets with firm mass measurements from microlensing, and an additional 11 planetary microlens events with host mass estimates <0.
0.5Mâ and planet mass estimates >2 Jupiter masses that could be confirmed by high angular follow-up observations. We also point out that OGLE-2005-BLG-071L has separated far enough from its host star that it should be possible to measure the host-star metallicity with spectra from a high angular resolution telescope such as Keck, the Very Large Telescope, the Hubble Space Telescope, or the James Webb Space Telescope
Adaptive Optics Imaging Breaks the Central Caustic Cusp Approach Degeneracy in High Magnification Microlensing Events
We report new results for the gravitational microlensing target
OGLE-2011-BLG-0950 from adaptive optics (AO) images using the Keck observatory.
The original analysis by Choi et al. 2012 reports degenerate solutions between
planetary and stellar binary lens systems. This is due to a degeneracy in high
magnification events where the shape of the light curve peak can be explained
by a source approach to two different cusp geometries with different source
radius crossing times. This particular case is the most important type of
degeneracy for exoplanet demographics, because the distinction between a
planetary mass or stellar binary companion has direct consequences for
microlensing exoplanet statistics. The 8 and 10-year baselines between the
event and the Keck observations allow us to directly measure a relative proper
motion of mas/yr, which confirms the detection of the lens star
system and directly rules out the planetary companion models that predict a
smaller relative proper motion. The combination of the lens
brightness and close stellar binary light curve parameters yield primary and
secondary star masses of and at a distance of kpc, and a primary-secondary projected separation of
AU. Since this degeneracy is likely to be common, the
high resolution imaging method described here will be used to disentangle the
central caustic cusp approach degeneracy for events observed by the
\textit{Roman} exoplanet microlensing survey using the \textit{Roman} images
taken near the beginning or end of the survey.Comment: Revised version, 19 pages, 8 figures. AJ, 164, 21
Acoustics and oceanographic observations collected during the QPE Experiment by Research Vessels OR1, OR2 and OR3 in the East China Sea in the Summer of 2009
This document describes data, sensors, and other useful information pertaining to the ONR sponsored
QPE field program to quantify, predict and exploit uncertainty in observations and prediction of sound
propagation. This experiment was a joint operation between Taiwanese and U.S. researchers to
measure and assess uncertainty of predictions of acoustic transmission loss and ambient noise, and to
observe the physical oceanography and geology that are necessary to improve their predictability. This
work was performed over the continental shelf and slope northeast of Taiwan at two sites: one that was
a relatively flat, homogeneous shelf region and a more complex geological site just shoreward of the
shelfbreak that was influenced by the proximity of the Kuroshio Current. Environmental moorings
and ADCP moorings were deployed and a shipboard SeaSoar vehicle was used to measure
environmental spatial structure. In addition, multiple bottom moored receivers and a horizontal
hydrophone array were deployed to sample transmission loss from a mobile source and ambient noise.
The acoustic sensors, environmental sensors, shipboard resources, and experiment design, and their
data, are presented and described in this technical report.Funding was provided by the Office of Naval Research under Contract No. N00014-08-1-076
Molecular Detection of Invasive Species in Heterogeneous Mixtures Using a Microfluidic Carbon Nanotube Platform
Screening methods to prevent introductions of invasive species are critical for the protection of environmental and economic benefits provided by native species and uninvaded ecosystems. Coastal ecosystems worldwide remain vulnerable to damage from aquatic species introductions, particularly via ballast water discharge from ships. Because current ballast management practices are not completely effective, rapid and sensitive screening methods are needed for on-site testing of ships in transit. Here, we describe a detection technology based on a microfluidic chip containing DNA oligonucleotide functionalized carbon nanotubes. We demonstrate the efficacy of the chip using three ballast-transported species either established (Dreissena bugensis) or of potential threat (Eriocheir sinensis and Limnoperna fortuneii) to the Laurentian Great Lakes. With further refinement for on-board application, the technology could lead to real-time ballast water screening to improve ship-specific management and control decisions
Health-related quality of life in patients with locally recurrent or metastatic breast cancer treated with etirinotecan pegol versus treatment of physicianâs choice: Results from the randomised phase III BEACON trial
Background: Health-related quality of life (HRQoL) enhances understanding of treatment effects that impact clinical decision-making. Although the primary end-point was not achieved, the BEACON (BrEAst Cancer Outcomes with NKTR-102) trial established etirinotecan pegol, a long-acting topoisomerase-1 (TOP1) inhibitor, as a promising therapeutic for patients with advanced/metastatic breast cancer (MBC) achieving clinically meaningful benefits in median overall survival (OS) for patients with stable brain metastases, with liver metastases or â„ 2 sites of metastatic disease compared to treatment of physicianâs choice (TPC). Reported herein are the findings from the preplanned secondary end-point of HRQoL. Patients and methods: HRQoL, assessed by European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Core 30 (QLQ-C30) (version 3.0) supplemented by the breast cancer-specific Quality of Life Questionnaire (QLQ-BR23), was evaluated post randomisation in 733 of 852 patients with either anthracycline-, taxane- and capecitabine-pretreated locally recurrent or MBC randomised to etirinotecan pegol (n = 378; 145 mg/m2 every 3 weeks (q3wk)) or single-agent TPC (n = 355). Patients completed assessments at screening, every 8 weeks (q8wk) during treatment, and end-of-treatment. Changes from baseline were analysed, and the proportions of patients achieving differences (â„5 points) in HRQoL scores were compared. Results: Differences were seen favouring etirinotecan pegol up to 32 weeks for global health status (GHS) and physical functioning scales (P < 0.02); numerical improvement was reported in other functional scales. The findings from HRQoL symptom scales were consistent with adverse event profiles; etirinotecan pegol was associated with worsening gastrointestinal symptoms whereas TPC was associated with worsened dyspnoea and other systemic side-effects. Analysis of GHS and physical functioning at disease progression showed a decline in HRQoL in both treatment arms, with a mean change from baseline of â9.4 and â10.8 points, respectively. Conclusion: There was evidence of benefit associated with etirinotecan pegol compared with current standard of care agents in multiple HRQoL measurements, including global health status and physical functioning, despite worse gastrointestinal symptoms (e.g. diarrhoea). Patients in both arms had a decline in HRQoL at disease progression. Study number: NCT01492101
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