Publications (173)
A dusty veil shading Betelgeuse during its Great Dimming
M. Montargès, E. Cannon, E. Lagadec +24
Red supergiants are the most common final evolutionary stage of stars that have initial masses between 8 and 35 times that of the Sun. During this stage, which lasts roughly 100,00…
Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
K. Dodds-Eden, D. Porquet, G. Trap +22
This paper reports measurements of Sgr A* made with NACO in L' -band (3.80 um), Ks-band (2.12 um) and H-band (1.66 um) and with VISIR in N-band (11.88 um) at the ESO VLT, as well a…
Dynamically important magnetic fields near the event horizon of Sgr A*
GRAVITY Collaboration, A. Jiménez-Rosales, J. Dexter +53
We study the time-variable linear polarisation of Sgr A* during a bright NIR flare observed with the GRAVITY instrument on July 28, 2018. Motivated by the time evolution of both th…
GRAVITY: the Calibration Unit
N. Blind, F. Eisenhauer, M. Haug +19
We present in this paper the design and characterisation of a new sub-system of the VLTI 2nd generation instrument GRAVITY: the Calibration Unit. The Calibration Unit provides all…
Polarization analysis of the VLTI and GRAVITY
GRAVITY Collaboration, F. Widmann, X. Haubois N. Schuhler +59
The goal of this work is to characterize the polarization effects of the VLTI and GRAVITY. This is needed to calibrate polarimetric observations with GRAVITY for instrumental effec…
The close circumstellar environment of Betelgeuse. IV. VLTI/PIONIER interferometric monitoring of the photosphere
M. Montargès, P. Kervella, G. Perrin +9
Context. The mass-loss mechanism of cool massive evolved stars is poorly understood. The proximity of Betelgeuse makes it an appealing target to study its atmosphere, map the shape…
First Light for the GRAVITY+ Adaptive Optics: Extreme Adaptive Optics for the Very Large Telescope Interferometer
GRAVITY+ Collaboration, :, F. Allouche +137
GRAVITY+ improves by orders of magnitude the sensitivity, sky-coverage and contrast of the Very Large Telescope Interferometer (VLTI). A central part of this project is the develop…
Single-mode waveguides for GRAVITY II. Single-mode fibers and Fiber Control Unit
G. Perrin, L. Jocou, K. Perraut +22
The 2nd generation VLTI instrument GRAVITY is a two-field infrared interferometer operating in the K band between 1.97 and 2.43 m with either the four 8 m or the four 1.8 m tel…
Modeling the orbital motion of Sgr A*'s near-infrared flares
The GRAVITY Collaboration, M. Bauböck, J. Dexter +53
Infrared observations of Sgr A* probe the region close to the event horizon of the black hole at the Galactic center. These observations can constrain the properties of low-luminos…
The GRAVITY young stellar object survey V. The orbit of the T Tauri binary star WW Cha
GRAVITY Collaboration, F. Eupen, L. Labadie +60
The young T Tauri star WW Cha was recently proposed to be a close binary object with strong infrared and submillimeter excess associated with circum-system emission. This makes WW…
Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale
GRAVITY Collaboration, E. Sturm, J. Dexter +32
The broadening of atomic emission lines by high-velocity motion of gas near accreting supermassive black holes is an observational hallmark of quasars. Observations of broad emissi…
The GRAVITY Young Stellar Object survey -- I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits
K. Perraut, L. Labadie, B. Lazareff +69
The formation and the evolution of protoplanetary disks are important stages in the lifetime of stars. The processes of disk evolution and planet formation are intrinsically linked…
Performance of astrometric detection of a hotspot orbiting on the innermost stable circular orbit of the galactic centre black hole
F. H. Vincent, T. Paumard, G. Perrin +3
The galactic central black hole Sgr A* exhibits outbursts of radiation in the near infrared (so-called IR flares). One model of these events consists in a hotspot orbiting on the i…
Constraining the nature of the Galactic center black hole Sgr A* with present and future observations
F. H. Vincent, E. Gourgoulhon, O. Straub +4
The Galactic center is an ideal laboratory to study strong-field general relativistic phenomena, as the supermassive black hole Sgr A* has the biggest angular Schwarzschild radius…
High-resolution imaging of dust shells using Keck aperture masking and the IOTA Interferometer
J. D. Monnier, R. Millan-Gabet, P. G. Tuthill +10
We present first results of an experiment to combine data from Keck aperture masking and the Infrared-Optical Telescope Array (IOTA) to image the circumstellar environments of evol…
Subtracting the photon noise bias from single-mode optical interferometer visibilities
G. Perrin
I present in this paper a method to subtract the bias due to source photon noise from visibilities measured with a single-mode optical interferometer. Properties of the processed n…
Four-of-a-kind? Comprehensive atmospheric characterisation of the HR 8799 planets with VLTI/GRAVITY
E. Nasedkin, P. Mollière, S. Lacour +95
With four companions at separations from 16 to 71 au, HR 8799 is a unique target for direct imaging, presenting an opportunity for the comparative study of exoplanets with a shared…
The dusty circumstellar environment of Betelgeuse during the Great Dimming as seen by VLTI/MATISSE
E. Cannon, M. Montargès, A. de Koter +23
The 'Great Dimming' of the prototypical red supergiant Betelgeuse, which occurred between December 2019 and April 2020, gives us unprecedented insight into the processes occurring…
The Subaru Coronagraphic Extreme Adaptive Optics system: enabling high-contrast imaging on solar-system scales
N. Jovanovic, F. Martinache, O. Guyon +35
The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is a multipurpose high-contrast imaging platform designed for the discovery and detailed characterization of ex…
Characterization of integrated optics components for the second generation of VLTI instruments
S. Lacour, L. Jocou, T. Moulin +10
Two of the three instruments proposed to ESO for the second generation instrumentation of the VLTI would use integrated optics for beam combination. Several design are studied, inc…
The GRAVITY Young Stellar Object survey -- IX. Spatially resolved kinematics of hot hydrogen gas in the star/disk interaction region of T Tauri stars
GRAVITY Collaboration, J. A. Wojtczak, L. Labadie +58
Aims: We aim to spatially and spectrally resolve the Br-gamma hydrogen emission line with the methods of interferometry in order to examine the kinematics of the hydrogen gas emiss…
MOLsphere and pulsations of the Galactic Center's red supergiant GCIRS 7 from VLTI/GRAVITY
GRAVITY Collaboration, G. RodrÃguez-Coira, T. Paumard +55
GCIRS 7, the brightest star in the Galactic central parsec, formed Myr ago together with dozens of massive stars in a disk orbiting the central black-hole. It has been argu…
A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
R. Abuter, A. Amorim, M. Bauboeck +51
We present a 0.16% precise and 0.27% accurate determination of R0, the distance to the Galactic Center. Our measurement uses the star S2 on its 16-year orbit around the massive bla…
The GRAVITY fringe tracker: correlation between optical path residuals and atmospheric parameters
S. Lacour, R. Dembet, R. Abuter +8
After the first year of observations with the GRAVITY fringe tracker, we compute correlations between the optical path residuals and atmospheric and astronomical parameters. The me…
Distinguishing an ejected blob from alternative flare models at the Galactic centre with GRAVITY
F. H. Vincent, T. Paumard, G. Perrin +5
The black hole at the Galactic centre exhibits regularly flares of radiation, the origin of which is still not understood. In this article, we study the ability of the near-future…
FIRST, a fibered aperture masking instrument. I. First on-sky test results
E. Huby, G. Perrin, F. Marchis +12
In this paper we present the first on-sky results with the fibered aperture masking instrument FIRST. Its principle relies on the combination of spatial filtering and aperture mask…
High contrast at short separation with VLTI/GRAVITY: Bringing Gaia companions to light
N. Pourré, T. O. Winterhalder, J. -B. Le Bouquin +173
Since 2019, GRAVITY has provided direct observations of giant planets and brown dwarfs at separations of down to 95 mas from the host star. Some of these observations have provided…
MACHe3: A new generation detector for non-baryonic dark matter direct detection
D. Santos, F. Mayet, E. Moulin +4
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter (DM) search, using superfluid as a sensitive medium. An experiment on a prototype c…
The close circumstellar environment of Betelgeuse - III. SPHERE/ZIMPOL visible polarimetry of the inner envelope and photosphere
P. Kervella, E. Lagadec, M. Montargès +7
The physical mechanism through which the outgoing material of massive red supergiants is accelerated above the escape velocity is unclear. Thanks to the transparency of its circums…
General relativistic effects on the orbit of the S2 star with GRAVITY
M. Grould, F. H. Vincent, T. Paumard +1
The goal of this paper is to investigate the detection by GRAVITY of different relativistic effects affecting the astrometric and/or spectroscopic observations of S2 such as the tr…
The Pulsation of Chi Cygni Imaged by Optical Interferometry; a Novel Technique to Derive Distance and Mass of Mira Stars
S. Lacour, E. Thiébaut, G. Perrin +13
We present infrared interferometric imaging of the S-type Mira star Chi Cygni. The object was observed at four different epochs in 2005-2006 with the IOTA optical interferometer (H…
FIRST, a fibered aperture masking instrument II. Spectroscopy of the Capella binary system at the diffraction limit
E. Huby, G. Duchêne, F. Marchis +7
FIRST is a prototype instrument built to demonstrate the capabilities of the pupil remapping technique, using single-mode fibers and working at visible wavelengths. We report on ob…
Long-term spectropolarimetric monitoring of the cool supergiant Betelgeuse
I. Bedecarrax, P. Petit, M. Aurière +6
We report on a long-term monitoring of the cool supergiant Betelgeuse, using the NARVAL and ESPaDOnS high-resolution spectropolarimeters, respectively installed at Telescope Bernar…
The GRAVITY metrology system: narrow-angle astrometry via phase-shifting interferometry
M. Lippa, N. Blind, S. Gillessen +26
The VLTI instrument GRAVITY will provide very powerful astrometry by combining the light from four telescopes for two objects simultaneously. It will measure the angular separation…
Kalman-filter control schemes for fringe tracking. Development and application to VLTI/GRAVITY
J. Menu, G. Perrin, E. Choquet +1
The implementation of fringe tracking for optical interferometers is inevitable when optimal exploitation of the instrumental capacities is desired. Fringe tracking allows continuo…
GRAVITY+ Wide: Towards hundreds of z 2 AGN
A. Drescher, M. Fabricius, T. Shimizu +34
As part of the GRAVITY project, the near-infrared beam combiner GRAVITY and the VLTI are currently undergoing a series of significant upgrades to further improve the performa…
The GRAVITY metrology system: modeling a metrology in optical fibers
N. Blind, H. Huber, F. Eisenhauer +20
GRAVITY is the second generation VLT Interferometer (VLTI) instrument for high-precision narrow-angle astrometry and phase-referenced interferometric imaging. The laser metrology s…
Magnetic field and convection in the cool supergiant Betelgeuse
P. Petit, M. Aurière, R. Konstantinova-Antova +4
We present the outcome of a highly-sensitive search for magnetic fields on the cool supergiant Betelgeuse. A time-series of six circularly-polarized spectra was obtained using the…
The GRAVITY young stellar object survey XIV : Investigating the magnetospheric accretion-ejection processes in S CrA N
GRAVITY Collaboration, H. Nowacki, K. Perraut +53
The dust- and gas-rich protoplanetary disks around young stellar systems play a key role in star and planet formation. While considerable progress has recently been made in probing…
Exomoon search with VLTI/GRAVITY around the substellar companion HD 206893 B
Q. Kral, J. Wang, J. Kammerer +130
Direct astrometric detection of exomoons remains unexplored. This study presents the first application of high-precision astrometry to search for exomoons around substellar compani…
GCIRS 7, a pulsating M1 supergiant at the Galactic centre. Physical properties and age
T. Paumard, O. Pfuhl, F. Martins +10
The stellar population in the central parsec of the Galaxy is dominated by an old (several Gyr) population, but young, massive stars dominate the luminosity function. We have studi…
The dust disk and companion of the nearby AGB star L2 Puppis - SPHERE/ZIMPOL polarimetric imaging at visible wavelengths
P. Kervella, M. Montargès, E. Lagadec +6
The bright southern star L2 Pup is a particularly prominent asymptotic giant branch (AGB) star, as its distance of 64 pc makes it the nearest of its type. We report new adaptive op…
The GRAVITY young stellar object survey III. The dusty disk of RY Lup
GRAVITY Collaboration, Y. -I. Bouarour, K. Perraut +55
We use PIONIER data from the ESO archive and GRAVITY data that were obtained in June 2017 with the four 8m telescopes. We use a parametric disk model and the 3D radiative transfer…
First VLTI/GRAVITY Observations of HIP 65426 b: Evidence for a Low or Moderate Orbital Eccentricity
S. Blunt, W. O. Balmer, J. J. Wang +95
Giant exoplanets have been directly imaged over orders of magnitude of orbital separations, prompting theoretical and observational investigations of their formation pathways. In t…
Resolving asymmetries along the pulsation cycle of the Mira star X Hya
X. Haubois, M. Wittkowski, G. Perrin +6
The mass-loss process in Mira stars probably occurs in an asymmetric way where dust can form in inhomogeneous circumstellar molecular clumps. Following asymmetries along the pulsat…
Constraints on the Orbit of the Young Substellar Companion GQ Lup B from High-Resolution Spectroscopy and VLTI/GRAVITY Astrometry
Vidya Venkatesan, S. Blunt, J. J. Wang +99
Understanding the orbits of giant planets is critical for testing planet formation models, particularly at wide separations greater than 10 au where traditional core accretion beco…
The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution
R. Garcia Lopez, K. Perraut, A. Caratti o Garatti +70
To investigate the inner regions of protoplanetary disks, we performed near-infrared interferometric observations of the classical TTauri binary system S CrA. We present the first…
Reaching micro-arcsecond astrometry with long baseline optical interferometry; application to the GRAVITY instrument
S. Lacour, F. Eisenhauer, S. Gillessen +10
A basic principle of long baseline interferometry is that an optical path difference (OPD) directly translates into an astrometric measurement. In the simplest case, the OPD is equ…
GRAVITY: getting to the event horizon of Sgr A*
F. Eisenhauer, G. Perrin, W. Brandner +45
We present the second-generation VLTI instrument GRAVITY, which currently is in the preliminary design phase. GRAVITY is specifically designed to observe highly relativistic motion…
The angular diameter and distance of the Cepheid Zeta Geminorum
P. Kervella, V. Coude du Foresto, G. Perrin +3
Cepheids are the primary distance indicators for extragalactic astronomy and therefore are of very high astrophysical interest. Unfortunately, they are rare stars, situated very fa…
A dynamical measure of the black hole mass in a quasar 11 billion years ago
R. Abuter, F. Allouche, A. Amorim +124
Tight relationships exist in the local universe between the central stellar properties of galaxies and the mass of their supermassive black hole. These suggest galaxies and black h…
Combining Gaia and GRAVITY: Characterising five new Directly Detected Substellar Companions
T. O. Winterhalder, S. Lacour, A. Mérand +96
Precise mass constraints are vital for the characterisation of brown dwarfs and exoplanets. Here we present how the combination of data obtained by Gaia and GRAVITY can help enlarg…
Using the motion of S2 to constrain scalar clouds around SgrA*
GRAVITY Collaboration, A. Foschi, R. Abuter +67
The motion of S2, one of the stars closest to the Galactic Centre, has been measured accurately and used to study the compact object at the centre of the Milky Way. It is commonly…
A project of a new detector for direct Dark Matter search: MACHe3
D. Santos, F. Mayet, Yu. M. Bunkov +5
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter (DM) search. A cell of superfluid He3 has been developed and the idea of using a la…
Imaging the spotty surface of Betelgeuse in the H band
X. Haubois, G. Perrin, S. Lacour +9
This paper reports on H-band interferometric observations of Betelgeuse made at the three-telescope interferometer IOTA. We image Betelgeuse and its asymmetries to understand the s…
Flares and variability from Sagittarius A*: five nights of simultaneous multi-wavelength observations
X. Haubois, K. Dodds-Eden, A. Weiss +8
Aims. We report on simultaneous observations and modeling of mid-infrared (MIR), near-infrared (NIR), and submillimeter (submm) emission of the source Sgr A* associated with the su…
First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
S. Lacour, M. Nowak, J. Wang +85
To date, infrared interferometry at best achieved contrast ratios of a few times on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast obs…
GRAVITY faint: reducing noise sources in GRAVITY with a fast metrology attenuation system
F. Widmann, S. Gillessen, T. Ott +28
With the upgrade from GRAVITY to GRAVITY the instrument will evolve into an all-sky interferometer that can observe faint targets, such as high redshift AGN. Observing the fain…
An image of the dust sublimation region in the nucleus of NGC 1068
GRAVITY Collaboration, O. Pfuhl, R. Davies +40
We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with the GRAVITY instrument on the European Southern Observatory Very Large Telescope Inter…
Evolution of the magnetic field of Betelgeuse from 2009 - 2017
P. Mathias, M. Aurière, A. López Ariste +14
Betelgeuse is an M-type supergiant that presents a circularly polarized (Stokes V) signal in its line profiles, interpreted in terms of a surface magnetic field. The weak circular…
First Detection of Polarization of the Submillimetre Diffuse Galactic Dust Emission by Archeops
A. Benoit, P. Ade, A. Amblard +65
We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon--bor…
An Extremely Top-Heavy IMF in the Galactic Center Stellar Disks
H. Bartko, F. Martins, S. Trippe +19
We present new observations of the nuclear star cluster in the central parsec of the Galaxy with the adaptive optics assisted, integral field spectrograph SINFONI on the ESO/VLT. O…
CubeSats as pathfinders for planetary detection: the FIRST-S satellite
S. Lacour, V. Lapeyrère, L. Gauchet +6
The idea behind FIRST (Fibered Imager foR a Single Telescope) is to use single-mode fibers to combine multiple apertures in a pupil plane as such as to synthesize a bigger aperture…
Evidence for localized onset of episodic mass loss in Mira
G. Perrin, S. T. Ridgway, S. Lacour +9
We report Multi-telescope interferometric measurements taken with the Interferometric Optical Telescope Array (IOTA) to provide imagery of the LPV Mira in the H-band. This waveleng…
Asymmetries on red giant branch surfaces from CHARA/MIRC optical interferometry
A. Chiavassa, R. Norris, M. Montargès +14
Context. Red giant branch (RGB) stars are very bright objects in galaxies and are often used as standard candles. Interferometry is the ideal tool to characterize the dynamics and…
The Fringe Detection Laser Metrology for the GRAVITY Interferometer at the VLTI
H. Bartko, S. Gillessen, S. Rabien +19
Interferometric measurements of optical path length differences of stars over large baselines can deliver extremely accurate astrometric data. The interferometer GRAVITY will simul…
The Cosmic Microwave Background Anisotropy Power Spectrum measured by Archeops
A. Benoit, P. Ade, A. Amblard +65
We present a determination by the Archeops experiment of the angular power spectrum of the cosmic microwave background anisotropy in 16 bins over the multipole range l=15-350. Arch…
Improved GRAVITY astrometric accuracy from modeling of optical aberrations
GRAVITY Collaboration, R. Abuter, A. Amorim +60
The GRAVITY instrument on the ESO VLTI pioneers the field of high-precision near-infrared interferometry by providing astrometry at the as level. Measurements at such…
Accretion-ejection morphology of the microquasar SS433 resolved at sub-au scale
GRAVITY Collaboration, P. -O. Petrucci, I. Waisberg +67
We present the first optical observation at sub-milliarcsecond (mas) scale of the microquasar SS 433 obtained with the GRAVITY instrument on the VLT interferometer. The 3.5 hour ex…
Discovery of a star sensitive to the spin of Sgr A*
K. Abd El Dayem, R. Abuter, N. Aimar +85
The paper reports the discovery of a faint main‑sequence star (S301) on an 8.7‑year, highly eccentric orbit around the Milky Way’s central black hole, whose high velocity makes its…
Multi-wavelength torus-jet model for Sgr~A*
F. H. Vincent, M. A. Abramowicz, A. A. Zdziarski +4
Context. The properties of the accretion flow surrounding the supermassive central black hole of the Galaxy, Sgr A*, will be scrutinized by the new-generation instrument GRAVITY an…
Sub-milliarcsecond Optical Interferometry of the HMXB BP Cru with VLTI/GRAVITY
GRAVITY Collaboration, I. Waisberg, J. Dexter +68
We observe the HMXB BP Cru using interferometry in the near-infrared K band with VLTI/GRAVITY. Continuum visibilities are at most partially resolved, consistent with the predicted…
First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
GRAVITY Collaboration, R. Abuter, M. Accardo +130
GRAVITY is a new instrument to coherently combine the light of the European Southern Observatory Very Large Telescope Interferometer to form a telescope with an equivalent 130 m di…
Resolving the complex structure of the dust torus in the active nucleus of the Circinus galaxy
K. R. W. Tristram, K. Meisenheimer, W. Jaffe +13
To test the dust torus model for active galactic nuclei directly, we study the extent and morphology of the nuclear dust distribution in the Circinus galaxy using high resolution i…
Gravity versus astrophysics in black hole images and photon rings: Equatorial emissions and spherically symmetric space-times
I. Urso, F. H. Vincent, M. Wielgus +2
The EHT collaboration released in 2019 the first horizon-scale images of a black hole accretion flow, opening a novel route for plasma physics comprehension and gravitational tests…
Are dust shell models well-suited to explain interferometric data of late-type stars in the near-infrared?
P. Schuller, P. Salomé, G. Perrin +7
Recently available near-infrared interferometric data on late-type stars show a strong increase of diameter for asymptotic giant branch (AGB) stars between the K (2.0 - 2.4 μm) an…
The Flux Distribution of Sgr A*
The GRAVITY Collaboration, R. Abuter, A. Amorim +54
The Galactic Center black hole Sagittarius A* is a variable NIR source that exhibits bright flux excursions called flares. The low-flux density turnover of the flux distribution is…
Using the motion of S2 to constrain vector clouds around SgrA*
GRAVITY Collaboration, A. Foschi, R. Abuter +53
The dark compact object at the centre of the Milky Way is well established to be a supermassive black hole with mass , but the nature…
The GRAVITY Young Stellar Object survey. VII. The inner dusty disks of T Tauri stars
The GRAVITY Collaboration, K. Perraut, L. Labadie +55
These protoplanetary disks in T Tauri stars play a central role in star and planet formation. We spatially resolve at sub-au scales the innermost regions of a sample of T Tauri's d…
A new analysis of the nucleus of NGC 1068 with MIDI observations
A. Poncelet, G. Perrin, H. Sol
We present a new analysis of the very first mid-infrared N-band long-baseline interferometric observations of an extragalactic source: the nucleus of the Seyfert 2 galaxy NGC 1068,…
Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
GRAVITY Collaboration, R. Abuter, A. Amorim +53
The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we…
The GRAVITY Young Stellar Object Survey. VI. Mapping the variable inner disk of HD 163296 at sub-au scales
J. Sanchez-Bermudez, A. Caratti o Garatti, R. Garcia Lopez +53
Protoplanetary disks drive some of the formation process (e.g., accretion, gas dissipation, formation of structures, etc.) of stars and planets. Understanding such physical process…
The central parsec of NGC 3783: a rotating broad emission line region, asymmetric hot dust structure, and compact coronal line region
GRAVITY Collaboration, A. Amorim, M. Bauböck +47
Using VLTI/GRAVITY and SINFONI data, we investigate the sub-pc gas and dust structure around the nearby type 1 AGN hosted by NGC 3783. The K-band coverage of GRAVITY uniquely allow…
A geometric distance to the supermassive black Hole of NGC 3783
GRAVITY Collaboration, A. Amorim, M. Bauböck +45
The angular size of the broad line region (BLR) of the nearby active galactic nucleus (AGN) NGC 3783 has been spatially resolved by recent observations with VLTI/GRAVITY. A reverbe…
Laboratory characterization of FIRSTv2 photonic chip for the study of substellar companions
K. Barjot, E. Huby, S. Vievard +14
FIRST (Fibered Imager foR a Single Telescope instrument) is a post-AO instrument that enables high contrast imaging and spectroscopy at spatial scales below the diffraction limit.…
Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
GRAVITY Collaboration, M. Nowak, S. Lacour +65
Our objective is to estimate the C/O ratio in the atmosphere of beta Pictoris b and obtain an estimate of the dynamical mass of the planet, as well as to refine its orbital paramet…
Constraining particle acceleration in Sgr A* with simultaneous GRAVITY, Spitzer, NuSTAR and Chandra observations
R. Abuter, A. Amorim, M. Bauböck +81
We report the time-resolved spectral analysis of a bright near-infrared and moderate X-ray flare of Sgr A*. We obtained light curves in the -, -, and -bands in the mid- an…
Astrometric detection of a Neptune-mass candidate planet in the nearest M-dwarf binary system GJ65 with VLTI/GRAVITY
GRAVITY Collaboration, R. Abuter, A. Amorim +65
The detection of low-mass planets orbiting the nearest stars is a central stake of exoplanetary science, as they can be directly characterized much more easily than their distant c…
VLTI/GRAVITY Provides Evidence the Young, Substellar Companion HD 136164 Ab formed like a "Failed Star"
William O. Balmer, L. Pueyo, S. Lacour +93
Young, low-mass Brown Dwarfs orbiting early-type stars, with low mass ratios (), appear intrinsically rare and present a formation dilemma: could a handful of these…
Mid-IR observations of NGC 1068 with VLT/VISIR
A. Poncelet, C. Doucet, G. Perrin +2
We present a speckle analysis of the active galactic nucleus (AGN) inside the archetype Seyfert type 2 galaxy NGC 1068. This study is based on 12.8 microns images obtained with the…
The inner dust shell of Betelgeuse detected by polarimetric aperture-masking interferometry
X. Haubois, B. Norris, P. G. Tuthill +9
Theory surrounding the origin of the dust-laden winds from evolved stars remains mired in controversy. Characterizing the formation loci and the dust distribution within approximat…
Exploring the presence of a fifth force at the Galactic Center
The GRAVITY Collaboration, K. Abd El Dayem, R. Abuter +60
Aims: The presence of a Yukawa-like correction to Newtonian gravity is investigated at the Galactic Center, leading to a new upper limit for the intensity of such a correction. Met…
GRAVITY K-band spectroscopy of HD 206893 B: brown dwarf or exoplanet
J. Kammerer, S. Lacour, T. Stolker +94
We aim to reveal the nature of the reddest known substellar companion HD 206893 B by studying its near-infrared colors and spectral morphology and by investigating its orbital moti…
The interferometric baselines and GRAVITY astrometric error budget
S. Lacour, F. Eisenhauer, S. Gillessen +9
GRAVITY is a new generation beam combination instrument for the VLTI. Its goal is to achieve microarsecond astrometric accuracy between objects separated by a few arcsec. This $10^…
Cosmological constraints from Archeops
A. Benoit, P. Ade, A. Amblard +65
We analyze the cosmological constraints that Archeops places on adiabatic cold dark matter models with passive power-law initial fluctuations. Because its angular power spectrum ha…
High dynamic range imaging with a single-mode pupil remapping system : a self-calibration algorithm for redundant interferometric arrays
S. Lacour, E. Thiébaut, G. Perrin
The correction of the influence of phase corrugation in the pupil plane is a fundamental issue in achieving high dynamic range imaging. In this paper, we investigate an instrumenta…
The GRAVITY young stellar object survey: XI. Imaging the hot gas emission around the Herbig Ae star HD 58647
Y. -I. Bouarour, R. Garcia Lopez, J. Sanchez-Bermudez +45
We aim to investigate the origin of the HI Br emission in young stars by using GRAVITY to image the innermost region of circumstellar disks, where important physical processes…
The ExoGRAVITY project: using single mode interferometry to characterize exoplanets
S. Lacour, J. J. Wang, M. Nowak +89
Combining adaptive optics and interferometric observations results in a considerable contrast gain compared to single-telescope, extreme AO systems. Taking advantage of this, the E…
Geometric modeling of M87* as a Kerr black hole or a non-Kerr compact object
F. H. Vincent, M. Wielgus, M. A. Abramowicz +4
Context. The Event Horizon Telescope (EHT) collaboration recently obtained first images of the surroundings of the supermassive compact object M87* at the center of the galaxy M87.…
Future mmVLBI Research with ALMA: A European vision
R. P. J. Tilanus, T. P. Krichbaum, J. A. Zensus +165
Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated…