Colloquium Abstract - Hunt - 2024Oct04

October 4, 2024

11:00am Mountain

Lucas Hunt (NRAO)

 

Comparing Sources from the International Celestial Reference Frame at S, X, K and Q-band

 

Abstract

We present multi-frequency images of 453 compact extragalactic radio sources — most of them from the ICRF-3 — with sub-milliarcsecond (sub-mas) resolution, based on Very Long Baseline Array (VLBA) imaging observations taken between April and June 2021. We compare images and astrometry from S (2.3 GHz), X (8.4 GHz), K (24 GHz) and Q-band (43 GHz) in order to study the astrophysical differences and determine the optimal frequency band for Celestial Reference Frame observations. In order to do this we conducted multi-epoch, quasi-simultaneous S/X, K and Q-band astrometric-imaging observations. We characterize each source by the following properties: peak brightness, core and total flux density, the ratio of peak and core to total flux (compactness measure), radial source extent, structure index, source size, and jet direction. We will show how source structure compares amongst all four bands and we will assess the potential advantages of higher radio frequencies for Celestial Reference Frame work.


Local Host: Justin Linford

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