J. Wambsganß
A5039031101- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Relativity and Gravitational Theory
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Impact of Light on Environment and Health
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Statistical and numerical algorithms
- Space Science and Extraterrestrial Life
- Physics and Engineering Research Articles
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
Heidelberg University
2013-2024
International Space Science Institute
2018-2024
Heidelberg University
2009-2019
Centre National de la Recherche Scientifique
2009-2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2005-2019
Max Planck Institute for Astronomy
2018-2019
Netherlands Institute for Radio Astronomy
2019
Centro de Astrobiología
2019
Scottish Universities Physics Alliance
2019
University of Edinburgh
2019
Abstract We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). used Hubble Space Telescope (HST) to carry out precise astrometry source star long-duration ( t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in direction Galactic bulge. HST imaging, conducted at eight epochs over interval 6 yr, reveals a clear relativistic astrometric deflection...
Continued photometric monitoring of the gravitational lens system 0957+561A, B in g and r bands with Apache Point Observatory (APO) 3.5 m telescope during 1996 shows a sharp g-band event trailing (B) image light curve at precise time predicted an earlier paper. The prediction was based on observation 1995 leading (A) differential delay 415 days. This success confirms so-called short delay, absence any such feature near 540 days rejects "long delay" for this system, thus resolving...
Contrary to naive expectation, diluting the stellar component of lensing galaxy in a highly magnified system with smoothly distributed "dark" matter increases rather than decreases microlensing fluctuations caused by remaining stars. For bright pair images straddling critical curve, saddle point (of arrival time surface) is much more strongly affected associated minimum. With mass ratio smooth 4 : 1, macromagnification μ = 9.5 will spend half its magnitude fainter predicted. The anomalous...
We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with planet–star mass ratio q = [9.5 ± 2.1] × 10−5 via gravitational microlensing. The planetary deviation was detected in real-time thanks to high cadence Microlensing Observations Astrophysics survey, light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns stellar distance at Ml 0.64+0.21−0.26 M☉ Dl 5.9+0.9−1.4 kpc, respectively, so separation are Mp 20+7−8 M⊕ 3.3+1.4−0.8 AU,...
We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, second planet discovered by microlensing and first in a high-magnification event. These include photometric astrometric measurements from Hubble Space Telescope, as well constraints higher order effects extracted ground-based light curve, such microlens parallax, planetary orbital motion finite-source effects. Our primary analysis leads conclusion that host Jovian OGLE-2005-BLG-071Lb is an M dwarf foreground...
We present the first microlensing candidate for a free-floating exoplanet–exomoon system, MOA-2011-BLG-262, with primary lens mass of Mhost ∼ 4 Jupiter masses hosting sub-Earth moon. The argument an exomoon hinges on system being relatively close to Sun. data constrain product MLπrel where ML is and πrel lens–source relative parallax. If nearby (large πrel), then small (a few masses) companion sub-Earth-mass exomoon. best-fit solution has large proper motion, μrel = 19.6 ± 1.6 mas yr−1,...
Aims. We report the discovery of a planet with high planet-to-star mass ratio in microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over 12-day interval, one longest for any planetary event. The host is an M dwarf, range 0.07 M⊙ < Mhost 0.49 at 90% confidence. planet-star q = 0.0132 ± 0.003 has been measured extremely well, so best-estimated mass, mp 2.6 Jupiter masses median 0.19 M⊙.
We present the first example of binary microlensing for which parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible a confluence two relatively unusual circumstances. First, lens bright enough (I=15.6) to permit measurements. Second, we measure not only usual 7 binary-lens parameters, but also 'microlens parallax' (which yields mass) and components instantaneous orbital velocity. Thus measure, effectively, 6 'Kepler+1' parameters...
We present the analysis of first circumbinary planet microlensing event, OGLE-2007-BLG-349. This event has a strong planetary signal that is best fit with mass ratio $q \approx 3.4\times10^{-4}$, but there an additional due to lens mass, either another or star. find acceptable light curve fits two classes models: 2-planet models (with single host star) and models. The also reveals significant parallax effect, which constrains system be $M_L 0.7 M_\odot$. Hubble Space Telescope images resolve...
We report the detection of a Cold Neptune m_planet=21+/-2MEarth orbiting 0.38MSol M dwarf lying 2.5-3.3 kpc toward Galactic center as part campaign combining ground-based and Spitzer observations to measure distribution planets. This is first time that complex real-time protocols described by Yee et al. (2015), which aim maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey follow-up teams successfully combined their efforts within...
view Abstract Citations (196) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interpretation of the Microlensing Event in QSO 2237+0305 Wambsganss, J. ; Paczynski, B. Schneider, P. We present a model microlensing for image A gravitationally lensed which Irwin et al. reported 1989 an increase apparent luminosity by about 0.5 mag on time scale few months. Our model, with Salpeter mass function over range 0.1-1.0 M_sun_ and transverse velocity...
The current searches for microlensing events towards the galactic bulge can be used to detect planets around lensing stars. Their effect is a short-term modulation on smooth lightcurve produced by main star. Current and planned experiments should sensitive enough discover ranging from Jupiter mass down Earth mass. For successful detection of planets, it necessary accurately frequently monitor event photometrically, once has been "triggered". We present large variety two-dimensional...
We examine the effect that shape of source brightness profile has on magnitude fluctuations images in quasar lens systems due to microlensing. do this by convolving a variety accretion disk models (including Gaussian disks, uniform "cones," and Shakura-Sunyaev thermal model) with two magnification maps plane, one convergence kappa = 0.4 shear gamma (positive parity), other 0.6 (negative parity). By looking at histograms convolutions using chi-squared tests determine number observations would...
The numerical kernel approach to difference imaging has been implemented and applied gravitational microlensing events observed by the PLANET collaboration. effect of an error in source-star coordinates is explored a new algorithm presented for determining precise microlens blended events, essential accurate photometry images. It shown how photometric reference flux need not be measured directly from image but can obtained measurements images combined with knowledge statistical...
view Abstract Citations (129) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Expected Color Variations of the Gravitationally Microlensed QSO 2237+0305 Wambsganss, J. ; Paczynski, B. The continuum source a quasar may have different sizes in wavelengths. When such crosses caustic due to gravitational microlensing observed color will change. We show typical light curves and corresponding for our model 2237+0305A, image that has been reported...
We present the continuation of our long-term spectroscopic monitoring gravitationally lensed quasar QSO 2237+0305. investigate chromatic variations observed in UV/optical continuum both images A and B, compare them with numerical simulations to infer energy profile accretion disk. Our procedure combines microlensing ray-shooting technique Bayesian analysis, derives probability distributions for source sizes as a function wavelength. find that effective caustic crossing timescale is 4.0 ± 1.0...
Abstract Within less than 15 years, the count of known planets orbiting stars other Sun has risen from none to more 400 with detections arising four successfully applied techniques: Doppler‐wobbles, planetary transits, gravitational microlensing, and direct imaging. While hunt for twin Earths is on, a statistically well‐defined sample population in all their variety required probing models planet formation orbital evolution so that origin harbour life, like including ours, can be understood....
When an image of a strongly lensed quasar is microlensed, the different components its spectrum are expected to be differentially magnified owing sizes corresponding emitting region. Chromatic changes observed in continuum while emission lines should deformed as function size, geometry and kinematics regions from which they originate. Microlensing has been reported only handful systems so far. In this paper we search for microlensing deformations optical spectra pairs images 17 quasars with...
We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was ∼1 AU west of in projection. combine these with a kinematic model Galaxy to derive distance estimates each lens, error bars are small compared Sun's galactocentric distance. The ensemble therefore yields well-defined cumulative distribution lens distances. In principle, it is possible compare this against set...
Weak gravitational lensing by large-scale structure affects the determination of cosmological deceleration parameter q0. We find that induced dispersions on truly standard candles are 0.04 and 0.02 mag at redshift z = 1 0.5, respectively, in a COBE-normalized cold dark matter universe with Ω0 0.40, Λ0 0.6, H 65 km s-1 Mpc-1, σ8 0.79. It is shown one would observe q0 -0.395−0.095+0.125 -0.398−0.077+0.048 (the error bars 2 σ limits) zero intrinsic dispersion compared to truth -0.400. A COBE...