Probing the nature of compact ultra-steep spectrum radio sources with the e-EVN and e-MERLIN

Abstract

We present first results from electronic Multi-Element Remotely Linked Interferometer Network (e-MERLIN) and electronic European VLBI Network (e-EVN) observations of a small sample of ultra-steep spectrum radio sources, defined as those sources with a spectral index alpha < -1.4 between 74 MHz and 325 MHz, which are unresolved on arcsecond scales. Such sources are currently poorly understood and a number of theories as to their origin have been proposed in the literature. The new observations described here have resulted in the first detection of two of these sources at milliarcsecond scales and show that a significant fraction of ultra-steep spectrum sources may have compact structures which can only be studied at the high resolution available with very long baseline interferometry (VLBI).

arXiv commentFive pages, two tables, one figure. Accepted to MNRAS Letters

References in corpus (13)

• A MaxBCG Catalog of 13,823 Galaxy Clusters from the Sloan Digital Sky Survey
• The VLA Low-frequency Sky Survey
• The Cosmic Lens All-Sky Survey: I. Source selection and observations
• The Massive Hosts of Radio Galaxies Across Cosmic Time
• A Sample of 669 Ultra Steep Spectrum Radio Sources to Find High Redshift Radio Galaxies
• Protoclusters associated with z > 2 radio galaxies. I. Characteristics of high redshift protoclusters
• Deep ATLAS radio observations of the CDFS-SWIRE field
• Dust and star formation in distant radio galaxies
• A search for steep spectrum radio relics and halos with the GMRT
• A search for AGN in the most extreme UV-selected starbursts using the European VLBI Network
• VLBI detection of an Infrared-Faint Radio Source
• The first VLBI image of an Infrared-Faint Radio Source
• High-redshift obscured quasars: radio emission at sub-kiloparsec scales

Cited by in corpus (7)

• The Very Large Array Low-frequency Sky Survey Redux (VLSSr)
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
• Deep GMRT 610 MHz Observations of the ELAIS N1 Field : Catalogue and Source Counts
• A compact core-jet structure in the changing-look Seyfert NGC 2617
• The e-MERLIN Data Reduction Pipeline
• High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars
• LLAGN and jet-scaling probed with the EVN