Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era
Abstract
:1. Introduction
2. Source Sample and Observations
3. Results
3.1. Spectral Shapes
3.2. Spectral Indices
4. Discussion
4.1. Variability of the Radio Spectra
4.2. Dusty Sources
5. Conclusions
- (1)
- The high-frequency spectra are flat, ranging between −0.2 and −0.7, indicating an original electron acceleration spectrum index as hard as 1.5.
- (2)
- The break frequencies are strikingly high (tens of gigahertz), and are variable from source to source and between epochs.
- (3)
- The TEMZ model could explain the variability of the radio spectra by characterizing both evolving shocks and achromatic variability, both seen in the sources in the Planck sample.
- (4)
- Intrinsic cold dust may be present in some (low-redshift) AGN that show an upturn in their high-frequency Planck spectra. In high-redshift sources, this is probably due to contamination by Galactic cirrus.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Observatory | Observing Frequencies (GHz) |
---|---|
Metsähovi Radio Observatory | 37 |
Owens Valley Radio Observatory | 15 |
U. Michigan Radio Astronomy Observatory | 4.8, 8.0, 14.5 |
RATAN-600 | 1.1, 2.3, 4.8, 7.7, 11.2, 21.7 |
Survey 1 | Survey 2 | Survey 3 | Survey 4 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Class | αLF | αHF | νbr | αLF | αHF | νbr | αLF | αHF | νbr | αLF | αHF | νbr |
BLO | 0.005 | −0.454 | 81.5 | 0.096 | −0.369 | 61.3 | 0.082 | −0.409 | 57.2 | −0.090 | −0.371 | 37.2 |
HPQ | 0.008 | −0.560 | 61.2 | 0.030 | −0.647 | 65.2 | 0.000 | −0.481 | 61.2 | 0.027 | −0.535 | 55.0 |
LPQ | 0.081 | −0.784 | 54.1 | 0.120 | −0.695 | 48.8 | 0.074 | −0.640 | 42.0 | −0.080 | −0.679 | 43.2 |
QSO | 0.205 | −0.495 | 55.5 | 0.017 | −0.530 | 72.6 | 0.230 | −0.410 | 44.7 | 0.150 | −0.541 | 43.5 |
Source Name | z |
---|---|
0238-084 | 0.005 |
0430+052 | 0.033 |
0415+379 | 0.049 |
0446+112 | 1.207 |
1954+513 | 1.223 |
0333+321 | 1.258 |
2037+511 | 1.686 |
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Lähteenmäki, A.; The Planck Collaboration. Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era. Galaxies 2016, 4, 49. https://doi.org/10.3390/galaxies4040049
Lähteenmäki A, The Planck Collaboration. Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era. Galaxies. 2016; 4(4):49. https://doi.org/10.3390/galaxies4040049
Chicago/Turabian StyleLähteenmäki, Anne, and The Planck Collaboration. 2016. "Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era" Galaxies 4, no. 4: 49. https://doi.org/10.3390/galaxies4040049