scholarly journals Galaxy And Mass Assembly (GAMA): the 325 MHz radio luminosity function of AGN and star-forming galaxies

2016 ◽  
Vol 457 (1) ◽  
pp. 730-744 ◽  
Author(s):  
Matthew Prescott ◽  
T. Mauch ◽  
M. J. Jarvis ◽  
K. McAlpine ◽  
D. J. B. Smith ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Radio Luminosity ◽  
Star Forming ◽  
Mass Assembly ◽  
Radio Luminosity Function

scholarly journals The optically selected 1.4-GHz quasar luminosity function below 1 mJy

2020 ◽  
Vol 492 (4) ◽  
pp. 5297-5312 ◽  
Author(s):  
Eliab Malefahlo ◽  
Mario G Santos ◽  
Matt J Jarvis ◽  
Sarah V White ◽  
Jonathan T L Zwart
Keyword(s):  
Luminosity Function ◽  
Significant Contribution ◽  
Detection Threshold ◽  
Simulated Data ◽  
Sloan Digital Sky Survey ◽  
Radio Luminosity ◽  
Host Galaxies ◽  
Star Forming ◽  
Sky Survey ◽  
Radio Luminosity Function

ABSTRACT We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test the technique using simulated data, confirming that we can reconstruct the RLF over three orders of magnitude below the typical 5σ detection threshold. We apply our method to 1.4-GHz flux densities from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey, extracted at the positions of optical quasars from the Sloan Digital Sky Survey over seven redshift bins up to z = 2.15, and measure the RLF down to two orders of magnitude below the FIRST detection threshold. In the lowest redshift bin (0.2 < z < 0.45), we find that our measured RLF agrees well with deeper data from the literature. The RLF for the radio-loud quasars flattens below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 25.5$ and becomes steeper again below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 24.8$, where radio-quiet quasars start to emerge. The radio luminosity where radio-quiet quasars emerge coincides with the luminosity where star-forming galaxies are expected to start dominating the radio source counts. This implies that there could be a significant contribution from star formation in the host galaxies, but additional data are required to investigate this further. The higher redshift bins show a similar behaviour to the lowest z bin, implying that the same physical process may be responsible.

scholarly journals The GLEAM 200-MHz local radio luminosity function for AGN and star-forming galaxies

2021 ◽  
Vol 38 ◽  
Author(s):  
T. M. O. Franzen ◽  
N. Seymour ◽  
E. M. Sadler ◽  
T. Mauch ◽  
S. V. White ◽  
...  
Keyword(s):  
Spectral Index ◽  
Luminosity Function ◽  
Radio Continuum ◽  
Radio Luminosity ◽  
Low Frequencies ◽  
Star Forming ◽  
Wide Range ◽  
Murchison Widefield Array ◽  
Radio Luminosity Function ◽  
Local Radio

Abstract The GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) is a radio continuum survey at 76–227 MHz of the entire southern sky (Declination $<\!{+}30^{\circ}$ ) with an angular resolution of ${\approx}2$ arcmin. In this paper, we combine GLEAM data with optical spectroscopy from the 6dF Galaxy Survey to construct a sample of 1 590 local (median $z \approx 0.064$ ) radio sources with $S_{200\,\mathrm{MHz}} > 55$ mJy across an area of ${\approx}16\,700\,\mathrm{deg}^{2}$ . From the optical spectra, we identify the dominant physical process responsible for the radio emission from each galaxy: 73% are fuelled by an active galactic nucleus (AGN) and 27% by star formation. We present the local radio luminosity function for AGN and star-forming (SF) galaxies at 200 MHz and characterise the typical radio spectra of these two populations between 76 MHz and ${\sim}1$ GHz. For the AGN, the median spectral index between 200 MHz and ${\sim}1$ GHz, $\alpha_{\mathrm{high}}$ , is $-0.600 \pm 0.010$ (where $S \propto \nu^{\alpha}$ ) and the median spectral index within the GLEAM band, $\alpha_{\mathrm{low}}$ , is $-0.704 \pm 0.011$ . For the SF galaxies, the median value of $\alpha_{\mathrm{high}}$ is $-0.650 \pm 0.010$ and the median value of $\alpha_{\mathrm{low}}$ is $-0.596 \pm 0.015$ . Among the AGN population, flat-spectrum sources are more common at lower radio luminosity, suggesting the existence of a significant population of weak radio AGN that remain core-dominated even at low frequencies. However, around 4% of local radio AGN have ultra-steep radio spectra at low frequencies ( $\alpha_{\mathrm{low}} < -1.2$ ). These ultra-steep-spectrum sources span a wide range in radio luminosity, and further work is needed to clarify their nature.

scholarly journals Does the evolution of the radio luminosity function of star-forming galaxies match that of the star formation rate function?

2017 ◽  
Vol 469 (2) ◽  
pp. 1912-1923 ◽  
Author(s):  
Matteo Bonato ◽  
Mattia Negrello ◽  
Claudia Mancuso ◽  
Gianfranco De Zotti ◽  
Paolo Ciliegi ◽  
...  
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Rate Function ◽  
Radio Luminosity ◽  
Star Forming ◽  
Radio Luminosity Function

scholarly journals Determining the Core Radio Luminosity Function of Radio AGNs via Copula

2018 ◽  
Vol 239 (2) ◽  
pp. 33 ◽  
Author(s):  
Zunli Yuan ◽  
Jiancheng Wang ◽  
D. M. Worrall ◽  
Bin-Bin Zhang ◽  
Jirong Mao
Keyword(s):  
Luminosity Function ◽  
Radio Luminosity ◽  
The Core ◽  
Radio Luminosity Function

scholarly journals The 1.4-GHz cosmic star formation history at z < 1.3

2019 ◽  
Vol 36 ◽  
Author(s):  
James E. Upjohn ◽  
Michael J. I. Brown ◽  
Andrew M. Hopkins ◽  
Nicolas J. Bonne
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Radio Continuum ◽  
Star Formation History ◽  
Star Forming ◽  
Formation History ◽  
Radio Measurements ◽  
Radio Luminosity Function

AbstractWe measure the cosmic star formation history out to z = 1.3 using a sample of 918 radio-selected star-forming galaxies within the 2-deg2 COSMOS field. To increase our sample size, we combine 1.4-GHz flux densities from the VLA-COSMOS catalogue with flux densities measured from the VLA-COSMOS radio continuum image at the positions of I &lt; 26.5 galaxies, enabling us to detect 1.4-GHz sources as faint as 40 μJy. We find that radio measurements of the cosmic star formation history are highly dependent on sample completeness and models used to extrapolate the faint end of the radio luminosity function. For our preferred model of the luminosity function, we find the star formation rate density increases from 0.017 M⊙ yr−1 Mpc−3 at z ∼ 0.225 to 0.092 M⊙ yr−1 Mpc−3 at z ∼ 1.1, which agrees to within 40% of recent UV, IR and 3-GHz measurements of the cosmic star formation history.

scholarly journals Erratum: Supernova Remnants in the Local Group – I. A model for the radio luminosity function and visibility times of supernova remnants

2019 ◽  
Vol 487 (4) ◽  
pp. 5813-5813 ◽  
Author(s):  
Sumit K Sarbadhicary ◽  
Carles Badenes ◽  
Laura Chomiuk ◽  
Damiano Caprioli ◽  
Daniel Huizenga
Keyword(s):  
Supernova Remnants ◽  
Luminosity Function ◽  
Local Group ◽  
Radio Luminosity ◽  
Group I ◽  
Radio Luminosity Function
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