ALMA Band-to-band Phase Referencing: Imaging Capabilities on Long Baselines and High Frequencies

Abstract

High-frequency long-baseline experiments with the Atacama Large Millimeter/submillimeter Array were organized to test the high angular resolution imaging capabilities in the submillimeter wave regime using baselines up to 16 km. Four experiments were conducted, two Band 7 (289 GHz) and two Band 8 (405 GHz) observations. Phase correction using band-to-band (B2B) phase referencing was used with a phase calibrator only 0.7deg away observed in Band 3 (96 GHz) and Band 4 (135 GHz), respectively. In Band 8, we achieved the highest resolution of 14x11 mas. We compared the synthesis images of the target quasar using 20 and 60 s switching cycle times in the phase referencing. In Band 7, the atmosphere had good stability in phase rms (<0.5 rad over 2 minutes), and there was little difference in image coherence between the 20 and 60 s switching cycle times. One Band 8 experiment was conducted under a worse phase rms condition (>1 rad over 2 minutes), which led to a significantly reduced coherence when using the 60 s switching cycle time. One of our four experiments indicates that the residual phase rms error after phase referencing can be reduced to 0.16 rad at 289 GHz in using the 20 s switching cycle time. Such conditions would meet the phase correction requirement of image coherence of >70% in Band 10, assuming a similar phase calibrator separation angle, emphasizing the need for such B2B phase referencing observing at high frequencies.

arXiv comment40 pages, 10 figures, 6 tables

References in corpus (24)

• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• Ringed Substructure and a Gap at 1 AU in the Nearest Protoplanetary Disk
• Submillimeter emission associated with candidate protoplanets
• An Overview of the 2014 ALMA Long Baseline Campaign
• ALMA Long Baseline Observations of the Strongly Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z=3.042
• Tropospheric Phase Calibration in Millimeter Interferometry
• The close circumstellar environment of Betelgeuse - V. Rotation velocity and molecular envelope properties from ALMA
• Radio, optical and X-ray nuclei in nearby 3CRR radio galaxies
• Phase Correction for ALMA with 183 GHz Water Vapour Radiometers
• Discovery of an au-scale excess in millimeter emission from the protoplanetary disk around TW Hya
• Verification of the Effectiveness of VSOP-2 Phase Referencing with a Newly Developed Simulation Tool, ARIS
• ALMA Observations of Anisotropic Dust Mass-loss in the Inner Circumstellar Environment of the Red Supergiant VY Canis Majoris
• ALMA Long Baseline Campaigns: Phase Characteristics of Atmosphere at Long Baselines in the Millimeter and Submillimeter Wavelengths
• ALMA High Angular Resolution Polarization Study; An Extremely Young Class 0 Source, OMC-3/MMS 6
• Atmospheric Phase Correction using CARMA-PACS: High Angular Resolution Observations of the FU-Orionis star PP 13S*
• Verification of the Astrometric Performance of the Korean VLBI Network, using comparative SFPR studies with the VLBA at 14/7 mm
• Astrometrically Registered Simultaneous Observations of the 22 GHz H${}_2$O and the 43GHz SiO masers towards R Leonis Minoris using KVN and Source/Frequency Phase Referencing
• Temporal Evolution of the Size and Temperature of Betelgeuse's Extended Atmosphere
• Phase correction for ALMA - Investigating water vapour radiometer scaling:The long-baseline science verification data case study
• ALMA High-frequency Long Baseline Campaign in 2017: Band-to-band Phase Referencing in Submillimeter Waves
• ALMA Observations of Asteroid 3 Juno at 60 Kilometer Resolution
• Analysis of antenna position measurements and weather station network data during the ALMA Long Baseline Campaign of 2015
• The CARMA Paired Antenna Calibration System: Atmospheric Phase Correction for Millimeter Wave Interferometry and its Application to Mapping the Ultraluminous Galaxy Arp 193
• ALMA Temporal Phase Stability and the Effectiveness of Water Vapor Radiometer

Cited by in corpus (2)

• ALMA High-frequency Long-baseline Campaign in 2017: A Comparison of the Band-to-band and In-band Phase Calibration Techniques and Phase-calibrator Separation Angles
• Uncovering the absorbed atomic Universe with the [OI]63um line