The first scientific experiment using Global e-VLBI observations: a multiwavelength campaign on the gamma-ray Narrow-Line Seyfert 1 PMN J0948+0022

TL;DR

This paper reports the first use of real-time global e-VLBI observations during a multiwavelength campaign on the gamma-ray Narrow-Line Seyfert 1 galaxy PMN J0948+0022, demonstrating rapid data analysis and coordination across continents.

Contribution

It presents the first successful implementation of real-time global e-VLBI observations for a multiwavelength campaign on an active galaxy.

Findings

First real-time global e-VLBI observations conducted.

Prompt data analysis enabled rapid results.

Successful coordination across multiple continents.

Abstract

The detection of gamma-ray emission by Fermi-LAT from the radio loud Narrow Line Seyfert 1 PMN J0948+0022 (Abdo et al. 2009, ApJ 699, 976) triggered a multi-wavelength campaign between March and July 2009. Given its high compactness (Doi et al. 2006, PASJ 58, 829), inverted spectrum, and 0deg declination, the source was an ideal target to observe at 22 GHz with a Global VLBI array extending from Europe to East Asia and Australia. In order to deliver prompt results to be analysed in combination with the other instruments participating in the campaign, the observations were carried out with real time VLBI, for the first time on a Global scale. Indeed, the main results have been published just a few months after the campaign (Abdo et al. 2009, ApJ 707, 727). Here we present additional details about the e-VLBI observations.