DOI

https://doi.org/10.48717/305z-g909

Project

RSG20

Title

e-EVN: EY048, EP137A, RSG20

Abstract

Following a more detailed investigation of the phase calibrators in the vicinity of our target, a short-lived powerful IMBH jet, we would like to kindly request a short eVLBI observation (2 hours, L-band) to verify the suitability of several candidate calibrators. Based on the analysis of the RFC VLBI catalogue and source structure information, the calibrator J2324+1213 (0.78° separation) is considered a reliable primary phase calibrator, thanks to its likely steep spectrum and flux density at 18 cm. In addition, we propose to probe the following calibrators (5 calibrators in total, including J2324+1213): 1. Two nearby in-beam calibrator candidates (identified from VizieR data), which are promising flat-spectrum sources: * J232132.62+120938.0 (3.5 arcmin separation, ~1.3 mJy) * J232146.32+121844.0 (6.2 arcmin separation, ~4.1 mJy) 2.  and two further apart but stronger calibrators (also identified from VizieR data):   * J232234.01+124120.6: flux(1.77GHz) =88.966 mJy, spectral index=-0.9989, angular separation = 0.527824 deg,  23 22 34.0122024  +12 41 20.694408,  350.64171751  +12.68908178, flux (3 GHz) =   49.259 mJy * J232339.61+115511.1: flux(1.77GHz) 88.856 mJy, spectral index = -0.782, angular separation = 0.588455 deg,  23 23 39.6171648  +11 55 11.157708 ,  350.91507152  +11.91976603, flux (3 GHz) =   55.945 mJy   This short observation will allow us to assess the compactness and suitability of these sources, particularly to identify a stable in-beam calibrator. We believe that this short exploratory eVLBI run will significantly improve the calibration strategy and the scientific return of the approved project.