The Transformational Power of Frequency Phase Transfer Methods for ngEHT

Abstract

(Sub) mm VLBI observations are strongly hindered by limited sensitivity, with the fast tropospheric fluctuations being the dominant culprit. We predict great benefits from applying next-generation frequency phase transfer calibration techniques for the next generation Event Horizon Telescope, using simultaneous multi-frequency observations. We present comparative simulation studies to characterise its performance, the optimum configurations, and highlight the benefits of including observations at 85\,GHz along with the 230 and 340\,GHz bands. The results show a transformational impact on the ngEHT array capabilities, with orders of magnitude improved sensitivity, observations routinely possible over the whole year, and ability to carry out micro-arcsecond astrometry measurements at the highest frequencies, amongst others. This will enable the addressing of a host of innovative open scientific questions in astrophysics. We present a solution for highly scatter-broadened sources such as SgrA*, a prime ngEHT target. We conclude that adding the 85\,GHz band provides a pathway to an optimum and robust performance for ngEHT in sub-millimeter VLBI, and strongly recommmend its inclusion in the simultaneous multi-frequency receiver design.

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Cited by in corpus (10)

• Key Science Goals for the Next-Generation Event Horizon Telescope
• The Black Hole Explorer: Motivation and Vision
• Reference Array and Design Consideration for the next-generation Event Horizon Telescope
• First Very Long Baseline Interferometry Detections at 870μm
• Demonstrating Photon Ring Existence with Single-Baseline Polarimetry
• Enabling Transformational ngEHT Science via the Inclusion of 86 GHz Capabilities
• Orbital configurations of spaceborne interferometers for studying photon rings of supermassive black holes
• Receivers for the Black Hole Explorer (BHEX) Mission
• Shared-optical-path VLBI frequency phase transfer from 86 to 258 GHz on an 8600 km baseline: Demonstrated with the APEX and IRAM 30 m telescopes
• Beyond Sgr A* and M87*: Sub-Microarcsecond Black Hole Shadow Detection via Lunar-based Extremely Long Baseline Interferometry