Improving Galactic Center Astrometry by Reducing the Effects of Geometric Distortion

Abstract

We present significantly improved proper motion measurements of the Milky Way's central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the W. M. Keck II 10 m telescope's Adaptive Optics camera (NIRC2) in its narrow field mode. For the first time, this distortion model is constructed from on-sky measurements, and is made available to the public. When applied to widely dithered images, it produces residuals in the separations of stars that are a factor of ~3 smaller compared to the outcome using previous models. By applying this new model, along with corrections for differential atmospheric refraction, to widely dithered images of SiO masers at the Galactic center, we improve our ability to tie into the precisely measured radio Sgr A*-rest frame. The resulting infrared reference frame is ~2-3 times more accurate and stable than earlier published efforts. In this reference frame, Sgr A* is localized to within a position of 0.6 mas and a velocity of 0.09 mas/yr, or ~3.4 km/s at 8 kpc (1 sigma). While earlier proper motion studies defined a reference frame by assuming no net motion of the stellar cluster, this approach is fundamentally limited by the cluster's intrinsic dispersion and therefore will not improve with time. We define a reference frame with SiO masers and this reference frame's stability should improve steadily with future measurements of the SiO masers in this region. This is essential for achieving the necessary reference frame stability required to detect the effects of general relativity and extended mass on short-period stars at the Galactic center.

Accepted to ApJ; 54 pages, 21 figures; Keck/NIRC2 narrow camera distortion solution available at http://www.astro.ucla.edu/~ghezgroup/distortion/

References in corpus (10)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Testing the general relativistic ''no-hair'' theorems using the galactic center black hole SgrA*
• Kinematics of the old stellar population at the Galactic Center
• Keck Laser Guide Star Adaptive Optics Monitoring of 2MASS J1534-2952AB: First Dynamical Mass Determination of a Binary T Dwarf
• The proper motion of the Arches cluster with Keck Laser-Guide Star Adaptive Optics
• Periapsis and gravitomagnetic precessions of stellar orbits in Kerr and Kerr-de Sitter black hole spacetimes
• Keck Laser Guide Star Adaptive Optics Monitoring of the M8+L7 Binary LHS 2397aAB: First Dynamical Mass Benchmark at the L/T Transition
• Spectroscopic Binary Mass Determination using Relativity
• Measuring the Mass of a Pre-Main Sequence Binary Star Through the Orbit of TWA 5A

Cited by in corpus (183)

• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager
• Relativistic redshift of the star S0-2 orbiting the Galactic center supermassive black hole
• How to Constrain Your M dwarf II: the mass-luminosity-metallicity relation from 0.075 to 0.70$M_{\odot }$
• Adaptive Optics for Astronomy
• Planet Hunters X. KIC 8462852 - Where's the Flux?
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• Testing General Relativity with stellar orbits around the supermassive black hole in our Galactic center
• The Impact of Stellar Multiplicity on Planetary Systems, I.: The Ruinous Influence of Close Binary Companions
• The Shortest Known Period Star Orbiting our Galaxy's Supermassive Black Hole
• Planets Around Low-Mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems
• They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets
• Individual Dynamical Masses of Ultracool Dwarfs
• Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
• Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center
• Zodiacal Exoplanets in Time (ZEIT) III: A short-period planet orbiting a pre-main-sequence star in the Upper Scorpius OB Association
• Zodiacal Exoplanets In Time (ZEIT) I: A Neptune-sized planet orbiting an M4.5 dwarf in the Hyades Star Cluster
• Friends of Hot Jupiters II: No Correspondence Between Hot-Jupiter Spin-Orbit Misalignment and the Incidence of Directly Imaged Stellar Companions
• The Progenitor of Supernova 2011dh/PTF11eon in Messier 51
• Zodiacal Exoplanets in Time (ZEIT) IV: seven transiting planets in the Praesepe cluster
• Precise Dynamical Masses of Directly Imaged Companions from Relative Astrometry, Radial Velocities, and Hipparcos-Gaia DR2 Accelerations
• Young "Dipper" Stars in Upper Sco and $\rho$ Oph Observed by K2
• Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
• Three Wide Planetary-Mass Companions to FW Tau, ROXs 12, and ROXs 42B
• Re-Evaluating WASP-12b: Strong Emission at 2.315 micron, Deeper Occultations, and an Isothermal Atmosphere
• M-band Imaging of the HR 8799 Planetary System Using an Innovative LOCI-based Background Subtraction Technique
• Characterizing 51 Eri b from 1-5 $\mu$m: a partly-cloudy exoplanet
• The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass
• Direct Imaging and Spectroscopy of a Candidate Companion Below/Near the Deuterium-Burning Limit In The Young Binary Star System, ROXs 42B
• Stellar Populations in the Central 0.5 pc of the Galaxy I: A New Method for Constructing Luminosity Functions and Surface-Density Profiles
• Planets Around Low-Mass Stars (PALMS). III. A Young Dusty L Dwarf Companion at the Deuterium-Burning Limit
• Variability Timescale and Spectral Index of Sgr A* in the Near Infrared: Approximate Bayesian Computation Analysis of the Variability of the Closest Supermassive Black Hole
• Precise analytic treatment of Kerr and Kerr-(anti) de Sitter black holes as gravitational lenses
• Reconnaissance of the HR 8799 Exosolar System II: Astrometry and Orbital Motion
• Characterizing K2 Planet Discoveries: A super-Earth transiting the bright K-dwarf HIP 116454
• Proper motions of the Arches cluster with Keck-LGS Adaptive Optics: the first kinematic mass measurement of the Arches
• The nuclear cluster of the Milky Way: Our primary testbed for the interaction of a dense star cluster with a massive black hole
• Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits
• Keck Observations of the Galactic Center Source G2: Gas Cloud or Star?
• Planets Around Low-Mass Stars (PALMS). I. A Substellar Companion to the Young M Dwarf 1RXS J235133.3+312720
• Wide, Cool and Ultracool Companions to Nearby Stars from Pan-STARRS1
• Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-Consistent Measurements
• VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit
• 3D stellar kinematics at the Galactic center: measuring the nuclear star cluster spatial density profile, black hole mass, and distance
• Orbital Architectures of Planet-Hosting Binaries: I. Forming Five Small Planets in the Truncated Disk of Kepler-444A
• A population of dust-enshrouded objects orbiting the Galactic black hole
• WASP-12b and HAT-P-8b are Members of Triple Star Systems
• Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager
• Robo-AO Kepler Planetary Candidate Survey II: Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars
• Modeling Self-Subtraction in Angular Differential Imaging: Application to the HD 32297 Debris Disk
• Are Inner Disc Misalignments Common? ALMA Reveals an Isotropic Outer Disc Inclination Distribution for Young Dipper Stars
• Planet Hunters. VIII. Characterization of 41 Long-Period Exoplanet Candidates from Kepler Archival Data
• WFIRST Exoplanet Mass Measurement Method Finds a Planetary Mass of $39\pm 8M_{\oplus }$ for OGLE-2012-BLG-0950Lb
• Pinpointing the near-infrared location of Sgr A* by correcting optical distortion in the NACO imager
• Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet
• Robo-AO Kepler Planetary Candidate Survey III: Adaptive Optics Imaging of 1629 Kepler Exoplanet Candidate Host Stars
• New Evidence for a Substellar Luminosity Problem: Dynamical Mass for the Brown Dwarf Binary Gl 417BC
• SCExAO/CHARIS Near-Infrared Direct Imaging, Spectroscopy, and Forward-Modeling of kappa And b: A Likely Young, Low-Gravity Superjovian Companion
• Direct Detection and Orbit Analysis of the Exoplanets HR 8799 bcd from Archival 2005 Keck/NIRC2 Data
• Gemini Planet Imager Observational Calibrations V: Astrometry and Distortion
• Orbital Motion in Pre-Main Sequence Binaries
• A Search for Stellar-Mass Black Holes via Astrometric Microlensing
• Orbit and Dynamical Mass of the Late-T Dwarf Gl 758 B
• Dynamical Masses of Young Stars I: Discordant Model Ages of Upper Scorpius
• The Coldest Brown Dwarf (Or Free Floating Planet)?: The Y Dwarf WISE 1828+2650
• Astrometric performance of the Gemini multi-conjugate adaptive optics system in crowded fields
• Search for a Variation of the Fine Structure around the Supermassive Black Hole in Our Galactic Center
• Characterization of the gaseous companion κ Andromedae b: New Keck and LBTI high-contrast observations
• Dynamical Masses of Young M Dwarfs: Masses and Orbital Parameters of GJ 3305 AB, the Wide Binary Companion to the Imaged Exoplanet Host 51 Eri
• Adaptive Optics imaging of VHS 1256-1257: A Low Mass Companion to a Brown Dwarf Binary System
• Planets Around Low-Mass Stars (PALMS). VI. Discovery of a Remarkably Red Planetary-Mass Companion to the AB Dor Moving Group Candidate 2MASS J22362452+4751425
• Characterization of the atmosphere of the hot Jupiter HAT-P-32Ab and the M-dwarf companion HAT-P-32B
• Keck Observations Confirm a Super-Jupiter Planet Orbiting M-dwarf OGLE-2005-BLG-071L
• A First-Look Atmospheric Modeling Study of the Young Directly-Imaged Planet-Mass Companion, ROXs 42Bb
• Searching for Scatterers: High-Contrast Imaging of Young Stars Hosting Wide-Separation Planetary-Mass Companions
• WISE J072003.20-084651.2B Is A Massive T Dwarf
• Possible Origin of the G2 Cloud from the Tidal Disruption of a Known Giant Star by Sgr A*
• The Mutual Orbit, Mass, and Density of the Large Transneptunian Binary System Varda and Ilmarë
• Orbital Architectures of Planet-Hosting Binaries II. Low Mutual Inclinations Between Planetary and Stellar Orbits
• The Mass-Luminosity Relation in the L/T Transition: Individual Dynamical Masses for the New J-Band Flux Reversal Binary SDSSJ105213.51+442255.7AB
• High-Precision Radio and Infrared Astrometry of LSPM J1314+1320AB - II: Testing Pre--Main-Sequence Models at the Lithium Depletion Boundary with Dynamical Masses
• KELT-4Ab: An inflated Hot Jupiter transiting the bright (V~10) component of a hierarchical triple
• Discovery of a Low-Luminosity, Tight Substellar Binary at the T/Y Transition
• The Hawaii Infrared Parallax Program. III. 2MASS J0249-0557 c: A Wide Planetary-mass Companion to a Low-mass Binary in the beta Pic Moving Group
• Astrometric Accelerations as Dynamical Beacons: Discovery and Characterization of HIP 21152 B, the First T-Dwarf Companion in the Hyades
• The Post-Periapse Evolution of Galactic Center Source G1: The second case of a resolved tidal interaction with a supermassive black hole
• Robo-AO Kepler Survey V: The effect of physically associated stellar companions on planetary systems
• A Search for Companions to Brown Dwarfs in the Taurus and Chamaeleon Star Forming Regions
• Stellar Proper Motions in the Orion Nebula Cluster
• The Effect of Binarity on Circumstellar Disk Evolution
• Characterization of the Inner Knot of the Crab: The Site of the Gamma-ray Flares?
• The orbital motion of the Quintuplet cluster - a common origin for the Arches and Quintuplet clusters?
• MOA-2010-BLG-328Lb: a sub-Neptune orbiting very late M dwarf ?
• Bringing "The Moth" to Light: A Planet-Sculpting Scenario for the HD 61005 Debris Disk
• The Young Substellar Companion ROXs 12 B: Near-Infrared Spectrum, System Architecture, and Spin-Orbit Misalignment
• Compact Radio Sources within 30" of Sgr A*: Proper Motions, Stellar Winds and the Accretion Rate onto Sgr A*
• The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole
• Near-Infrared Spectroscopy of 2M0441+2301 AabBab: A Quadruple System Spanning the Stellar to Planetary Mass Regimes
• Planets Around Low-Mass Stars (PALMS). V. Age-Dating Low-Mass Companions to Members and Interlopers of Young Moving Groups
• The Frequency Of Binary Star Interlopers Amongst Transitional Discs
• The Galactic Center: Improved Relative Astrometry for Velocities, Accelerations, and Orbits near the Supermassive Black Hole
• Discovery of a Visual T-Dwarf Triple System and Binarity at the L/T Transition
• Keck/NIRC2 Imaging of the Warped, Asymmetric Debris Disk around HD 32297
• K2-231 b: A sub-Neptune exoplanet transiting a solar twin in Ruprecht 147
• The Galactic Center as a laboratory for theories of gravity and dark matter
• Circumstellar discs in Galactic centre clusters: Disc-bearing B-type stars in the Quintuplet and Arches clusters
• No difference in orbital parameters of RV-detected giant planets between 0.1 and 5 au in single vs multi-stellar systems
• A Substellar Companion to the Dusty Pleiades Star HD 23514
• Orbit and Stellar Properties of the Young Triple V807 Tau
• MOA-2007-BLG-400 A Super-Jupiter Mass Planet Orbiting a Galactic BulgeK-dwarf Revealed by Keck Adaptive Optics Imaging
• KIC 4150611: a rare multi-eclipsing quintuple with a hybrid pulsator
• An Adaptive Optics Survey of Stellar Variability at the Galactic Center
• The quadruple pre-main sequence system LkCa3: Implications for stellar evolution models
• A formal method for identifying distinct states of variability in time-varying sources: SgrA* as an example
• The Influence of Gas Dynamics on Measuring the Properties of the Black Hole in the Center of the Milky Way with Stellar Orbits and Pulsars
• The McDonald Accelerating Stars Survey (MASS): White Dwarf Companions Accelerating the Sun-like Stars 12 Psc and HD 159062
• MOA-2009-BLG-319Lb: A Sub-Saturn Planet Inside the Predicted Mass Desert
• Chemically-dissected rotation curves of the Galactic Bulge from Main Sequence proper motions
• PRIME: Psf Reconstruction and Identification for Multiple sources characterization Enhancement. Application to Keck NIRC2 imager
• 3.8um Imaging of 400-600K Brown Dwarfs and Orbital Constraints for WISEP J045853.90+643452.6AB
• Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
• A 38 Million Year Old Neptune-Sized Planet in the Kepler Field
• Orbital Motion of Young Binaries in Ophiuchus and Upper Centaurus-Lupus
• Revised Astrometric Calibration of the Gemini Planet Imager
• Deep orbital search for additional planets in the HR 8799 system
• Polarised radio pulsations from a new T dwarf binary
• Dynamical Masses of Young Stars II: Young Taurus Binaries Hubble~4, FF~Tau, and HP~Tau/G3
• The Matryoshka Disk: Keck/NIRC2 Discovery of a Solar System-Scale, Radially Segregated Residual Protoplanetary Disk Around HD 141569A
• Planets Around Low-Mass Stars (PALMS). II. A Low-Mass Companion to the Young M Dwarf GJ 3629 Separated By 0.2"
• Direct-imaging Discovery of a Substellar Companion Orbiting the Accelerating Variable Star, HIP 39017
• Beyond Point Masses. III. Detecting Haumea's Nonspherical Gravitational Field
• Giant Outer Transiting Exoplanet Mass (GOT 'EM) Survey. I. Confirmation of an Eccentric, Cool Jupiter With an Interior Earth-sized Planet Orbiting Kepler-1514
• A Deep Keck/NIRC2 Search for Thermal Emission from Planetary Companions Orbiting Fomalhaut
• ALMA and VLA observations of emission from the environment of Sgr A*
• Discovery of a White Dwarf Companion to HD 159062
• Orbital Motion, Variability, and Masses in the T Tauri Triple System
• The Enigmatic and Ephemeral M Dwarf System KOI 6705: Cheshire Cat or Wild Goose?
• Identification of partially resolved binaries in Pan-STARRS1 data
• The Astrometric Performance Test of 80-cm Telescope at Yaoan Station and Precise CCD Positions of Apophis
• An Extreme-mass Ratio, Short-period Eclipsing Binary Consisting of a B Dwarf Primary and a Pre-main Sequence M Star Companion Discovered by KELT
• Testing the Binary Trigger Hypothesis in FUors
• EPIC 203868608: A low-mass quadruple star system in the Upper Scorpius OB association
• Analytical determination of orbital elements using Fourier analysis. II. Gaia astrometry and its combination with radial velocities
• Multi-Epoch VLBI of L Dwarf Binary 2MASS J0746+2000AB: Precise Mass Measurements and Confirmation of Radio Emission from Both Components
• Methods for multiple telescope beam imaging and guiding in the near infrared
• Masses and Distance of the Young Binary NTTS 045251+3016
• KIC 7177553: a quadruple system of two close binaries
• Probability of Physical Association of 104 Blended Companions to \textit{Kepler} Objects of Interest Using Visible and Near-Infrared Adaptive Optics Photometry
• Unrecognized Astrometric Confusion in the Galactic Centre
• Pushing Point spread function reconstruction to the next level. Application to SPHERE/ZIMPOL
• On the Possibility of Stellar Lenses in the Black Hole Candidate Microlensing Events MACHO-96-BLG-5 and MACHO-98-BLG-6
• Optimal correction of distortion for High Angular Resolution images. Application to GeMS data
• Mid-infrared characterization of the planetary-mass companion ROXs 42B b
• The McDonald Accelerating Stars Survey (MASS): Architecture of the Ancient Five-Planet Host System Kepler-444
• The TRENDS High-contrast Imaging Survey. VIII. Compendium of Benchmark Objects
• The Possible Astrometric Signature of a Planetary-mass Companion to the Nearby Young Star TW Piscis Austrini (Fomalhaut B): Constraints from Astrometry, Radial Velocities, and Direct Imaging
• Dynamical masses for the Pleiades binary system HII-2147
• Unveiling MOA-2007-BLG-192: An M Dwarf Hosting a Likely Super-Earth
• Keck Adaptive Optics Observations of the Protostellar Disk around Radio Source I in the Orion Kleinmann-Low Nebula
• Unveiling the nature of the Gemini multiconjugate adaptive optics system distortions
• Validation of strategies for coupling exoplanet PSFs into single-mode fibres for high-dispersion coronagraphy
• Can a Satellite Galaxy Merger Explain the Active Past of the Galactic Center?
• SImMER: A Pipeline for Reducing and Analyzing Images of Stars
• Boyajian's Star B: The co-moving stellar companion to KIC 8462852
• Circumgalactic Environments around Distant Quasars 3C 9 and 4C 05.84
• New Evidence for a Flux-independent Spectral Index of Sgr A* in the Near-infrared
• Confirmation of Color Dependent Centroid Shift Measured After 1.8 years with HST
• Reconstructing Merger Timelines Using Star Cluster Age Distributions: the Case of MCG+08-11-002
• Radial Velocity Measurements of an Orbiting Star Around Sgr A*
• Adaptive Optics Observations of the Galactic Center Young Stars
• A Candidate High-Velocity Exoplanet System in the Galactic Bulge
• Metadata and Data Management for the Keck Observatory Archive
• AIROPA II: Modeling Instrumental Aberrations for Off-Axis Point Spread Functions in Adaptive Optics
• Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program
• Focal plane $C_n^2(h)$ profiling based on single conjugate adaptive optics compensated images
• V488 Per revisited: no strong mid-infrared emission features and no evidence for stellar/sub-stellar companions
• An Imaging Search for Post-Main-Sequence Planets of Sirius B
• 3D Kinematics of Stellar SiO Masers in the Galactic Center
• Using Gaia DR2 to make a systematic comparison between two geometric distortion solutions
• SCExAO/CHARIS and Gaia Direct Imaging and Astrometric Discovery of a Superjovian Planet 3--4 lambda/D from the Accelerating Star HIP 54515
• HD 165054: an astrometric calibration field for high-contrast imagers in Baade's Window
• Orbital characterization of GJ1108A system, and comparison of dynamical mass with model-derived mass for resolved binaries
• Trigonometric parallaxes of two T dwarfs with Keck and ShaneAO astrometry