The Angular Broadening of the Galactic Center Pulsar SGR J1745-29: A New Constraint on the Scattering Medium

Abstract

The pulsed radio emission from the Galactic Center (GC) magnetar SGR J1745-29 probes the turbulent, magnetized plasma of the GC hyperstrong scattering screen through both angular and temporal broadening. We present the first measurements of the angular size of SGR J1745-29, obtained with the Very Long Baseline Array and the phased Very Large Array at 8.7 and 15.4 GHz. The source sizes are consistent with the scatter--broadened size of Sagittarius A* at each frequency, demonstrating that SGR J1745-29 is also located behind the same hyperstrong scattering medium. Combining the angular broadening with temporal scattering obtained from pulsar observations provides a complete picture of the scattering properties. If the scattering occurs in a thin screen, then it must be at a distance Δ>~ 5 kpc. A best-fit solution for the distance of a thin screen is Δ=5.9 +/-0.3 kpc, consistent with being located in the Scutum spiral arm. This is a substantial revision of the previously held model in which the scattering screen is located very close to the GC. As also discussed in Spitler et al., these results suggest that GC searches can detect millisecond pulsars gravitationally bound to Sgr A* with observations at >~ 10 GHz and ordinary pulsars at even lower frequencies.

ApJL submitted

References in corpus (10)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• PSRCHIVE and PSRFITS An Open Approach to Radio Pulsar Data Storage and Analysis
• A strong magnetic field around the supermassive black hole at the centre of the Galaxy
• DiFX: A software correlator for very long baseline interferometry using multi-processor computing environments
• NuSTAR discovery of a 3.76-second transient magnetar near Sagittarius A*
• Swift Discovery of a New Soft Gamma Repeater, SGR J1745-29, near Sagittarius A*
• Radio properties of the magnetar near Sagittarius A* from observations with the Australia Telescope Compact Array
• Pulse Broadening Measurements from the Galactic Center Pulsar J1745--2900
• Discovery of two pulsars towards the Galactic Centre
• Density of warm ionized gas near the Galactic Center: Low radio frequency observations

Cited by in corpus (72)

• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration
• BlackHoleCam: fundamental physics of the Galactic center
• A Quantitative Test of the No-Hair Theorem with Sgr A* using stars, pulsars, and the Event Horizon Telescope
• Non-Cosmological FRBs from Young Supernova Remnant Pulsars
• Detecting Dark Matter with Imploding Pulsars in the Galactic Center
• The Scattering and Intrinsic Structure of Sagittarius A* at Radio Wavelengths
• Local Circumnuclear Magnetar Solution to Extragalactic Fast Radio Bursts
• Modeling Seven Years of Event Horizon Telescope Observations with Radiatively Inefficient Accretion Flow Models
• Pulse Broadening Measurements from the Galactic Center Pulsar J1745--2900
• Imaging an Event Horizon: Mitigation of Scattering Toward Sagittarius A*
• Dark Matter-induced Collapse of Neutron Stars: A Possible Link Between Fast Radio Bursts and the Missing Pulsar Problem
• The Peculiar Pulsar Population of the Central Parsec
• The Event Horizon Telescope: exploring strong gravity and accretion physics
• Black Hole Disks in Galactic Nuclei
• The Proper Motion of the Galactic Center Pulsar Relative to Sagittarius A*
• Realfast: Real-Time, Commensal Fast Transient Surveys with the Very Large Array
• Simultaneous multifrequency radio observations of the Galactic Centre magnetar SGR J1745-2900
• Milky Way scattering properties and intrinsic sizes of active galactic nuclei cores probed by very long baseline interferometry surveys of compact extragalactic radio sources
• Large magnetic field variations towards the Galactic Centre magnetar, PSR J1745-2900
• The Breakthrough Listen Search For Intelligent Life Near the Galactic Center I
• The Intrinsic Two-Dimensional Size of Sagittarius A*
• The Galactic centre pulsar population
• On Detecting Millisecond Pulsars at the Galactic Center
• Discovery of Substructure in the Scatter-Broadened Image of Sgr A*
• The Thousand-Pulsar-Array programme on MeerKAT III: Giant pulse characteristics of PSR J0540$-$6919
• Detection of the magnetar SGR J1745-2900 up to 291 GHz with evidence of polarized millimetre emission
• The Galactic center chimneys: The base of the multiphase outflow of the Milky Way
• Pulse Morphology of the Galactic Center Magnetar PSR J1745-2900
• Stochastic Optics: A Scattering Mitigation Framework for Radio Interferometric Imaging
• Single-pulse radio observations of the Galactic Center magnetar PSR J1745-2900
• Locating the intense interstellar scattering towards the inner Galaxy
• Simultaneous Multi-band Radio & X-ray Observations of the Galactic Center Magnetar SGR 1745$-$2900
• Probing the Interstellar Dust towards the Galactic Centre: Dust Scattering Halo around AX J1745.6-2901
• The Intrinsic Shape of Sagittarius A* at 3.5-mm Wavelength
• A magnetar parallax
• Asymmetric structure in Sgr A* at 3mm from closure phase measurements with VLBA, GBT and LMT
• Testing General Relativity with the Black Hole Shadow Size and Asymmetry of Sagittarius A*: Limitations from Interstellar Scattering
• The intrinsic structure of Sagittarius A* at 1.3 cm and 7 mm
• Radio Scattering Horizons for Galactic and Extragalactic Transients
• An 86-GHz search for Pulsars in the Galactic Center with the Atacama Large Millimeter/submillimeter Array
• MeqSilhouette : A mm-VLBI observation and signal corruption simulator
• Where are the magnetar binary companions? Candidates from a comparison with binary population synthesis predictions
• A population of compact radio variables and transients in the radio bright zone at the Galactic center observed with the Jansky Very Large Array
• Searching for pulsars in the Galactic Centre at 3 and 2 mm
• Neutron Star Physics in the Square Kilometer Array Era : An Indian Perspective
• Radio Detection of PSR J1813-1749 in HESS J1813-178: The Most Scattered Pulsar Known
• Multi-epoch searches for relativistic binary pulsars and fast transients in the Galactic Centre
• How Spatially Resolved Polarimetry Informs Black Hole Accretion Flow Models
• Axion Constraints from Quiescent Soft Gamma-ray Emission from Magnetars
• Micro-arcsecond structure of Sagittarius A* revealed by high-sensitivity 86 GHz VLBI observations
• Detection of a dense group of hyper-compact radio sources in the central parsec of the Galaxy
• A single HII region model of the strong interstellar scattering towards Sgr A*
• Two Extreme Steep-Spectrum, Polarized Radio Sources Towards the Galactic Bulge
• Single-pulse observations of the Galactic Center magnetar PSR J1745$-$2900 at 3.1 GHz
• Confronting the jet model of Sgr A* with the Faraday rotation measure observations
• $4-8\mathrm{GHz}$ Spectro-temporal Emission from the Galactic Center Magnetar $\mathrm{PSR}J1745-2900$
• VLA Observations of Single Pulses from the Galactic Center Magnetar
• NE2025: An Updated Electron Density Model for the Galactic Interstellar Medium
• Searching for Magnetar Binaries Disrupted by Core-Collapse Supernovae
• Exploring the Interstellar Medium Using an Asymmetric X-ray Dust Scattering Halo
• Probing Accretion Turbulence in the Galactic Center with EHT Polarimetry
• Deep learning inference with the Event Horizon Telescope I. Calibration improvements and a comprehensive synthetic data library
• The KaVA and KVN Pulsar Project
• Rotation Measure synthesis study and polarized properties of PSR J1745-2900 at 7 mm
• Improved Treatment of Bosonic Dark Matter Dynamics in Neutron Stars: Consequences and Constraints
• Pulsar Timing Constraints on Cumulative and Individual Mass of Stars in the Galactic Center
• Detecting gravitational waves from the galactic center with Pulsar Timing
• The Core-shift of Sagittarius A* as a Discriminant between Disk and Jet Emission Models with millimeter-VLBI
• VLBA Observations of Strong Anisotripic Radio Scattering towards the Orion Nebula
• Correlation of Burst Behaviour with Magnetar Age
• Multiobjective optimization for scattering mitigation and scattering screen reconstruction in VLBI observations of the Galactic Center