Milliarcsecond structures of variable-peaked spectrum sources
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...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
CAMBRIDGE UNIV PRESS
2023
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/pasa.2023.1 http://hdl.handle.net/20.500.11937/96079 |
| _version_ | 1848766091754471424 |
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| author | Ross, Kat Reynolds, C. Seymour, Nick Callingham, J.R. Hurley-Walker, Natasha Bignall, H. |
| author_facet | Ross, Kat Reynolds, C. Seymour, Nick Callingham, J.R. Hurley-Walker, Natasha Bignall, H. |
| author_sort | Ross, Kat |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | 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, MRC 0225-065 and PMN J0322-4820, 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 MRC 0225-065 is resolved into three components, a bright core and two fainter lobes, roughly 430 pc projected separation. A comprehensive analysis of the magnetic field, host galaxy properties, and spectral analysis implies that MRC 0225-065 is a young radio source with recent jet activity over the last-yr. We find PMN J0322-4820 is unresolved on milliarcsecond scales. We conclude PMN J0322-4820 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. |
| first_indexed | 2025-11-14T11:45:38Z |
| format | Journal Article |
| id | curtin-20.500.11937-96079 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:45:38Z |
| publishDate | 2023 |
| publisher | CAMBRIDGE UNIV PRESS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-960792024-11-07T00:54:52Z Milliarcsecond structures of variable-peaked spectrum sources Ross, Kat Reynolds, C. Seymour, Nick Callingham, J.R. Hurley-Walker, Natasha Bignall, H. Science & Technology Physical Sciences Astronomy & Astrophysics quasars: general quasars: individual galaxies: active radio continuum: galaxies galaxies: structure galaxies: jets COMPACT STEEP-SPECTRUM YOUNG RADIO-SOURCES MOLONGLO REFERENCE CATALOG FREE-FREE ABSORPTION JET FEEDBACK VARIABILITY EVOLUTION SKY SCALE CONSTRAINTS astro-ph.GA astro-ph.GA 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, MRC 0225-065 and PMN J0322-4820, 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 MRC 0225-065 is resolved into three components, a bright core and two fainter lobes, roughly 430 pc projected separation. A comprehensive analysis of the magnetic field, host galaxy properties, and spectral analysis implies that MRC 0225-065 is a young radio source with recent jet activity over the last-yr. We find PMN J0322-4820 is unresolved on milliarcsecond scales. We conclude PMN J0322-4820 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. 2023 Journal Article http://hdl.handle.net/20.500.11937/96079 10.1017/pasa.2023.1 English http://dx.doi.org/10.1017/pasa.2023.1 http://purl.org/au-research/grants/arc/FT190100231 https://creativecommons.org/licenses/by/4.0/deed.en CAMBRIDGE UNIV PRESS fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics quasars: general quasars: individual galaxies: active radio continuum: galaxies galaxies: structure galaxies: jets COMPACT STEEP-SPECTRUM YOUNG RADIO-SOURCES MOLONGLO REFERENCE CATALOG FREE-FREE ABSORPTION JET FEEDBACK VARIABILITY EVOLUTION SKY SCALE CONSTRAINTS astro-ph.GA astro-ph.GA Ross, Kat Reynolds, C. Seymour, Nick Callingham, J.R. Hurley-Walker, Natasha Bignall, H. Milliarcsecond structures of variable-peaked spectrum sources |
| title | Milliarcsecond structures of variable-peaked spectrum sources |
| title_full | Milliarcsecond structures of variable-peaked spectrum sources |
| title_fullStr | Milliarcsecond structures of variable-peaked spectrum sources |
| title_full_unstemmed | Milliarcsecond structures of variable-peaked spectrum sources |
| title_short | Milliarcsecond structures of variable-peaked spectrum sources |
| title_sort | milliarcsecond structures of variable-peaked spectrum sources |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics quasars: general quasars: individual galaxies: active radio continuum: galaxies galaxies: structure galaxies: jets COMPACT STEEP-SPECTRUM YOUNG RADIO-SOURCES MOLONGLO REFERENCE CATALOG FREE-FREE ABSORPTION JET FEEDBACK VARIABILITY EVOLUTION SKY SCALE CONSTRAINTS astro-ph.GA astro-ph.GA |
| url | http://dx.doi.org/10.1017/pasa.2023.1 http://dx.doi.org/10.1017/pasa.2023.1 http://hdl.handle.net/20.500.11937/96079 |