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http://hdl.handle.net/2289/6697Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | Callingham, J.R. | - |
| dc.contributor.author | Ekers, R.D. | - |
| dc.contributor.author | Gaensler, B.M. | - |
| dc.contributor.author | Dwarakanath, K.S. | - |
| dc.contributor.author | +20 Co-authors | - |
| dc.date.accessioned | 2017-08-14T11:53:09Z | - |
| dc.date.available | 2017-08-14T11:53:09Z | - |
| dc.date.issued | 2017-02-20 | - |
| dc.identifier.citation | The Astrophysical Journal, 2017, Vol.836, p174 | en_US |
| dc.identifier.issn | 0004-637X | - |
| dc.identifier.issn | 1538-4357-(Online) | - |
| dc.identifier.uri | http://hdl.handle.net/2289/6697 | - |
| dc.description | Open Access | en_US |
| dc.description.abstract | We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is the widest fractional bandwidth all-sky survey to date, ideal for identifying peaked-spectrum sources at low radio frequencies. Our peaked-spectrum sources are the low-frequency analogs of gigahertz-peaked spectrum (GPS) and compact-steep spectrum (CSS) sources, which have been hypothesized to be the precursors to massive radio galaxies. Our sample more than doubles the number of known peaked-spectrum candidates, and 95% of our sample have a newly characterized spectral peak. We highlight that some GPS sources peaking above 5 GHz have had multiple epochs of nuclear activity, and we demonstrate the possibility of identifying high-redshift (z > 2) galaxies via steep optically thin spectral indices and low observed peak frequencies. The distribution of the optically thick spectral indices of our sample is consistent with past GPS/CSS samples but with a large dispersion, suggesting that the spectral peak is a product of an inhomogeneous environment that is individualistic. We find no dependence of observed peak frequency with redshift, consistent with the peaked-spectrum sample comprising both local CSS sources and high-redshift GPS sources. The 5 GHz luminosity distribution lacks the brightest GPS and CSS sources of previous samples, implying that a convolution of source evolution and redshift influences the type of peaked-spectrum sources identified below 1 GHz. Finally, we discuss sources with optically thick spectral indices that exceed the synchrotron self-absorption limit. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | IOP Sciences for The American Astronomical Society | en_US |
| dc.relation.uri | http://adsabs.harvard.edu/abs/2017ApJ...836..174C | en_US |
| dc.relation.uri | https://arxiv.org/abs/1701.02771 | en_US |
| dc.relation.uri | http://dx.doi.org/10.3847/1538-4357/836/2/174 | en_US |
| dc.rights | 2017, The American Astronomical Society. | en_US |
| dc.title | Extragalactic peaked-spectrum radio sources at low frequencies | en_US |
| dc.type | Article | en_US |
| Appears in Collections: | Research Papers (A&A) | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 2017_AstrophyJournal_836_174.pdf | Open Access | 3.14 MB | Adobe PDF | View/Open |
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