A5059000500- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Molecular Spectroscopy and Structure
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
- Atmospheric Ozone and Climate
- Magnetic confinement fusion research
- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Superconducting Materials and Applications
- Relativity and Gravitational Theory
- Advanced Frequency and Time Standards
- Geophysics and Sensor Technology
Max Planck Institute for Radio Astronomy
2015-2024
Max Planck Institute for Research on Collective Goods
1999-2023
Center for Astrophysics Harvard & Smithsonian
2001-2019
Istituto di Radioastronomia di Bologna
2019
National Time Service Center
2019
Chinese Academy of Sciences
2019
Max Planck Society
2006-2015
Max Planck Innovation
2014
National Radio Astronomy Observatory
2011-2013
Max Planck Institute for Extraterrestrial Physics
2012
We are using the Very Long Baseline Array and Japanese VLBI Exploration of Radio Astronomy project to measure trigonometric parallaxes proper motions masers found in high-mass star-forming regions across Milky Way. Early results from 18 sources locate several spiral arms. The Perseus arm has a pitch angle 16° ± 3°, which favors four rather than two arms for Galaxy. Combining positions, distances, motions, radial velocities yields complete three-dimensional kinematic information. find that on...
Over 100 trigonometric parallaxes and proper motions for masers associated with young, high-mass stars have been measured the Bar Spiral Structure Legacy Survey, a Very Long Baseline Array key science project, European VLBI Network, Japanese Exploration of Radio Astrometry project. These measurements provide strong evidence existence spiral arms in Milky Way, accurately locating many arm segments yielding pitch angles ranging from about 7° to 20°. The widths increase distance Galactic...
We have used the Very Long Baseline Array to measure trigonometric parallax of several member stars Orion Nebula Cluster showing non-thermal radio emission. determined distance cluster be 414 +/- 7 pc. Our determination allows for an improved calibration luminosities and ages young stars. also measured proper motions four which, when accurate radial velocities are measured, will put strong constraints on origin cluster.
We report measurements with the Very Long Baseline Array (VLBA) of position Sgr A* respect to two extragalactic radio sources over a period 8 yr. The apparent proper motion relative J1745-283 is 6.379 ± 0.024 mas yr-1 along angle 20960 018, almost entirely in plane Galaxy. effects orbit Sun around Galactic center can account for this motion, and residual perpendicular Galaxy -0.4 0.9 km s-1. A maximum likelihood analysis expected massive object within observed stellar cluster indicates that...
Whether the Cygnus X complex consists of one physically connected region star formation or multiple independent regions projected close together on sky has been debated for decades. The main reason this puzzling scenario is lack trustworthy distance measurements. We aim to understand structure and dynamics star-forming toward by accurate proper motion To measure trigonometric parallaxes, we observed 6.7 GHz methanol 22 water masers with European VLBI Network Very Long Baseline Array....
We compile and analyze ~200 trigonometric parallaxes proper motions of molecular masers associated with very young high-mass stars. These measurements strongly suggest that the Milky Way is a four-arm spiral. Fitting log-periodic spirals to locations masers, allows us significantly expand our view structure Way. present an updated model for its spiral incorporate it into previously published parallax-based distance-estimation program sources arms. Modeling three-dimensional space yields...
We report phase-referencing VLBA observations of H2O masers near the star-forming region W3(OH) to measure their parallax and absolute proper motions. The measured annual is 0.489 ± 0.017 mas (2.04 0.07 kpc), where error dominated by a systematic atmospheric contribution. This distance consistent with photometric distances from previous determined CH3OH maser astrometry presented in related paper. also find that source driving outflow, "TW-object," moves three-dimensional velocity >7 km s-1...
We report trigonometric parallaxes for the sources NGC 7538 and Cep A, corresponding to distances of 2.65 [+0.12/-0.11] kpc 0.70 [+0.04/-0.04] kpc, respectively. The distance is considerably smaller than its kinematic places it in Perseus spiral arm. A also Local arm or spur. Combining proper motions with observed radial velocities gives location full space motion star forming regions. find significant deviations from circular Galactic orbits these sources: both show large peculiar (> 10...
We have measured the positions of water masers in Sgr B2, a massive star forming region Galactic center, relative to an extragalactic radio source with Very Long Baseline Array. The at 12 epochs over time span one year yield trigonometric parallax B2 and hence distance center Ro=7.9 (+0.8/-0.7) kpc. proper motion A* suggests that is about 0.13 kpc nearer than assuming low-eccentricity orbit.
We present continued radio observations of the tidal disruption event SwiftJ164449.3+573451 extending to \sim216 days after discovery. The data are part a long-term program monitor expansion and energy scale relativistic outflow, trace parsec-scale environment around previously-dormant supermassive black hole (SMBH). new reveal significant change in evolution starting at \sim1 month, with brightening all frequencies that requires an increase by about order magnitude, overall density profile...
ABSTRACT The spiral arms of the Milky Way are being accurately located for first time via trigonometric parallaxes massive star-forming regions with Bar and Spiral Structure Legacy Survey, using Very Long Baseline Array European VLBI Network, Japanese Exploration Radio Astrometry project. Here we describe a computer program that leverages these results to significantly improve accuracy reliability distance estimates other sources known follow structure. Using Bayesian approach, assigned...
Context: The past decade has witnessed a large number of Galactic plane surveys at angular resolutions below 20". However, no comparable high-resolution survey exists long radio wavelengths around 21cm in line and continuum emission. Methods: Employing the Very Large Array (VLA) C-array configuration program, we observe HI line, four OH lines, nineteen Halpha recombination lines as well emission from 1 to 2GHz full polarization over part first quadrant. Results: Covering longitudes 14.5...
Trigonometric parallax measurements of nine water masers associated with the Local arm Milky Way were carried out as part BeSSeL Survey using VLBA. When combined 21 other from literature, data allow us to study distribution and 3-dimensional motions star forming regions in spiral over entire northern sky. Our results suggest that does not have large pitch angle characteristic a short spur. Instead its active formation, overall length (>5 kpc), shallow (~10 degrees) it is more like adjacent...
Emission from the 6.7 GHz methanol maser transition is very strong, relatively stable, has small internal motions, and observed toward numerous massive star-forming regions in Galaxy. Our goal to perform high-precision astrometry using this obtain accurate distances their host regions. Eight strong masers were during five epochs of VLBI observations with European Network between 2006 June, 2008 March. We report trigonometric parallaxes for regions, accuracies as good $\sim22 \mathrmμ$as....
We report measurement of the trigonometric parallax W51 Main/South using Very Long Baseline Array (VLBA). measure a value 0.185 +/- 0.010 mas, corresponding to distance 5.41 (+0.31/-0.28) kpc. is well-known massive star-forming region near tangent point Sagittarius spiral arm Milky Way. Our yields an estimate Galactic center Ro = 8.3 0.46 (statistical) 1.0 (systematic) kpc by simple geometry. Combining and proper motion measurements for W51, we obtained full-space this star forming region....
We report trigonometric parallaxes for three massive star-forming regions, corresponding to distances of 2.34+0.13−0.11 kpc G12.89+0.49 (also known as IRAS 18089−1732), 1.98+0.14−0.12 G15.03−0.68 (in the M17 region), and 8.0+4.0−2.0 G27.36−0.16. Both are located in Carina–Sagittarius spiral arm.
Abstract Astrometric Very Long Baseline Interferometry (VLBI) observations of maser sources in the Milky Way are used to map spiral structure our galaxy and determine fundamental parameters such as rotation velocity (Θ 0 ) curve distance Galactic center ( R ). Here, we present an update on first results, implementing a recent change knowledge about Solar motion. It seems unavoidable that IAU recommended values for Θ need substantial revision. In particular combination 8.5 kpc 220 km s –1 can...
We report the discovery and detailed monitoring of X-ray emission associated with Type IIb SN 2011dh using data from Swift Chandra satellites, placing it among best-studied supernovae (SNe) to date. further present millimeter radio obtained Submillimeter Array, Combined Array for Research in Millimeter-wave Astronomy, Expanded Very Large during first three weeks after explosion. Combining these observations early optical photometry, we show that panchromatic set is well described by...
Abstract We report measurements with the Very Long Baseline Array of proper motion Sgr A* relative to two extragalactic radio sources spanning 18 yr. The apparent is −6.411 ± 0.008 mas yr −1 along Galactic plane and −0.219 0.007 toward North Pole. This can almost entirely be attributed effects Sun’s orbit about center. Removing these yields residuals −0.58 2.23 km s in direction rotation −0.85 0.75 A maximum-likelihood analysis motion, both perpendicular it, expected for a massive object...
We report four trigonometric parallaxes for high-mass star-forming regions within 4 kpc of the Galactic center. These measurements were made with VLBA as part BeSSeL Survey. By associating these sources kinematically large-scale features in CO and HI longitude-velocity diagrams, we begin to outline some major inner Milky Way: Connecting arm, near far 3 arms, Norma arm. The arm first quadrant lies closer center than is offset by long-bar's axis its leading edge, supporting presence an...
We report measurements of parallaxes and proper motions ten high-mass star-forming regions in the Sagittarius spiral arm Milky Way as part BeSSeL Survey with VLBA. Combining these results eight others from literature, we investigated structure kinematics between Galactocentric azimuth around -2 65 deg. found that pitch angle is 7.3 +- 1.5 deg; arm's half-width, defined rms deviation fitted spiral, 0.2 kpc; nearest portion 1.4 kpc Sun. Unlike for adjacent arms, no evidence significant...
We report trigonometric parallaxes and proper motions of water masers for 12 massive star forming regions in the Perseus spiral arm Milky Way as part Bar Spiral Structure Legacy (BeSSel) Survey. Combining our results with 14 parallax measurements literature, we estimate a pitch angle 99 ± 15 section arm. The three-dimensional Galactic peculiar these sources indicate that on average they are moving toward center slower than rotation.
Galactic plane radio surveys play a key role in improving our understanding of wide range astrophysical phenomena. Performing such survey using the latest interferometric telescopes produces large data rates necessitating shift towards fully or quasi-real-time analysis with being stored for only time required to process them. We present here overview and setup 3000 hour Max-Planck-Institut fuer Radioastronomie (MPIfR) MeerKAT Plane (MMGPS). The is unique by operating commensal mode,...