Milliarcsecond Structures of Variable Peaked-Spectrum Sources

Abstract

Spectral variability offers a new technique to identify small scale structures from scintillation, as well as determining the absorption mechanism for peaked-spectrum (PS) radio sources. In this paper, we present very long baseline interferometry (VLBI) imaging using the Long Baseline Array (LBA) of two PS sources, MRC0225-065 and PMNJ0322-4820, identified as spectrally variable from observations with the Murchison Widefield Array (MWA). We compare expected milliarcsecond structures based on the detected spectral variability with direct LBA imaging. We find MRC0225-065 is resolved into three components, a bright core and two fainter lobes, roughly 430pc projected separation. A comprehensive analysis of the magnetic field, host galaxy properties, and spectral analysis implies that MRC0225-065 is a young radio source with recent jet activity over the last 10^2-10^3years. We find PMNJ0322-4820 is unresolved on milliarcsecond scales. We conclude PMNJ0322-4820 is a blazar with flaring activity detected in 2014 with the MWA. We use spectral variability to predict morphology and find these predictions consistent with the structures revealed by our LBA images.

Accepted for publication in PASA. 11 pages, 4 figures

References in corpus (15)

• The NumPy array: a structure for efficient numerical computation
• Roma-BZCAT: A multifrequency catalogue of Blazars
• The 5th edition of the Roma-BZCAT. A short presentation
• The Dynamic Evolution of Young Extragalactic Radio Sources
• Extragalactic Peaked-Spectrum Radio Sources at Low Frequencies
• Relativistic jet feedback II: Relationship to gigahertz peak spectrum and compact steep spectrum radio galaxies
• RAiSE III: 3C radio AGN energetics and composition
• VLBA images of High Frequency Peakers
• Are young radio sources in equipartition?
• Interplanetary Scintillation studies with the Murchison Wide-field Array II: Properties of sub-arcsecond compact sources at low radio frequencies
• The properties of powerful radio sources at 90 GHz
• Spectral Variability of Radio Sources at Low Frequencies
• Infrared colour properties of nearby radio-luminous galaxies
• Variability and parsec-scale radio structure of candidate compact symmetric objects
• Wide-Band Spectral Variability of Peaked Spectrum Sources

Cited by in corpus (3)

• Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band
• Towards an astronomical use of new-generation geodetic observations. I. From the correlator to full-polarization images
• A Multi-Mechanism Hybrid Model of Peaked-Spectrum Radio Sources