EHT Status Update, December 15 2017

Over the past two months, the EHT team has been working hard on processing a preliminary data set that does not yet include any data from the South Pole station. Using this data set, the team has refined the data processing pipelines that will be used to calibrate the data, and also tested many of the analysis tools that will be used to make images and search for signatures of strong gravity effects at the event horizons of supermassive black holes.

The wait for data from the South Pole is because the station closes for the winter, with no flights in or out from February to October. The EHT data captured by the South Pole Telescope has been in "cold storage" since April, waiting for the cargo flights to resume. In early November, the EHT data disks were sent from the South Pole Station to a journey by air, sea, and land going through McMurdo Station on the coast of Antartica, through Christchurch in New Zealand, and Port Hueneme in California.

On Wednesday, December 13, the long-awaited shipment of hard disk drives from the South Pole finally arrived at the MIT Haystack Observatory. Half of the data will soon be on its way to the Max Planck Institute for Astronomy in Bonn, Germany, where it should arrive next week. After the disks have warmed up, they will be loaded into playback drives and processed with data from the other 7 EHT stations to complete the Earth-sized virtual telescope that links dishes from the South Pole, to Hawaii, Mexico, Chile, Arizona, and Spain. It should take about 3 weeks to complete the comparison of recordings, and after that the final analysis of the 2017 EHT data can begin!

Below are some photos of the data shipment from South Pole being delivered.

Shep Doeleman,
EHT Director

EHT data disks packaged at the South Pole Station
South Pole Telescope winterover Andrew Nadolski sealing the crate containing the EHT data disks following the April 2017 campaign at the South Pole Station. Credit: Daniel Michalik
FedEx truck delivering crates with EHT data from SPT
The disks arrive to the MIT Haystack Observatory, as usual, via FedEx - there is no faster way to ship the Petabytes of EHT data than by loading hard disks onto planes, ships, trains and automobiles. Credit: MIT Haystack Observatory
EHT data from the SPT unloaded from a FedEx truck
Crates containing EHT disk drives are unloaded - it may be low-tech, but it is an integral part of forging an Earth-sized telescope. Credit: MIT Haystack Observatory
EHT data disks in the crate delivered from the South Pole
Inside the crates are individual boxes with modules that each hold 8 hard disks with a total capacity of 64 Terabytes. Credit: MIT Haystack Observatory
EHT disks from the SPT at MIT Haystack Observatory
The modules are warming up and on their way to the disk "library", where they will be catalogued and readied for processing together with data from the other 7 EHT stations. The last data from the EHT observations in April 2017 have finally arrived! Credit: MIT Haystack Observatory
VLBI data storage at the MPIfR, Bonn, Germany
VLBI data storage room full of data disks collected from other EHT stations at the Max Planck Institute for Radioastronomy in Bonn. The South Pole data will be added to this data library next week, enabling the analysis of the full EHT dataset from 2017 to begin! Credit: Heino Falcke