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The AGN content of deep radio surveys and radio emission in radio-quiet AGN. Why every astronomer should care about deep radio fields

Published online by Cambridge University Press:  25 July 2014

P. Padovani
Affiliation:
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany email: [email protected]
M. Bonzini
Affiliation:
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany email: [email protected]
N. Miller
Affiliation:
Department of Mathematics and Physical Sciences, Stevenson University, 1525 Greenspring Valley Road, Stevenson, MD 21153-0641, USA
K. I. Kellermann
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA
V. Mainieri
Affiliation:
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany email: [email protected]
P. Rosati
Affiliation:
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany email: [email protected] Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, I-44122, Ferrara, Italy (current address)
P. Tozzi
Affiliation:
INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi, I-50125, Firenze, Italy
S. Vattakunnel
Affiliation:
INAF, Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-34131, Trieste, Italy
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Abstract

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We present our very recent results on the sub-mJy radio source populations at 1.4 GHz based on the Extended Chandra Deep Field South VLA survey, which reaches ~ 30 μJy, with details on their number counts, evolution, and luminosity functions. The sub-mJy radio sky turns out to be a complex mix of star-forming galaxies and radio-quiet AGN evolving at a similar, strong rate and declining radio-loud AGN. While the well-known flattening of the radio number counts below 1 mJy is mostly due to star-forming galaxies, these sources and AGN make up an approximately equal fraction of the sub-mJy sky. Our results shed also light on a fifty-year-old issue, namely radio emission from radio-quiet AGN, and suggest that it is closely related to star formation, at least at z ~ 1.5 − 2. The implications of our findings for future, deeper radio surveys, including those with the Square Kilometre Array, are also discussed. One of the main messages, especially to non-radio astronomers, is that radio surveys are reaching such faint limits that, while previously they were mainly useful for radio quasars and radio galaxies, they are now detecting mostly star-forming galaxies and radio-quiet AGN, i.e., the bulk of the extragalactic sources studied in the infrared, optical, and X-ray bands.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2014 

References

Bonzini, M., Mainieri, V., Padovani, P., et al. 2012, ApJS, 203, 15Google Scholar
Bonzini, M., Padovani, P., Mainieri, V., et al. 2013, MNRAS, 436, 3759Google Scholar
Croton, D. J., Springel, V., White, S. D. M., et al. 2006, MNRAS, 365, 11CrossRefGoogle Scholar
Gehrels, N. 1986, ApJ, 303, 336CrossRefGoogle Scholar
Giacconi, R., Zirm, A., Wang, J., et al. 2002, ApJS, 139, 369CrossRefGoogle Scholar
Gruppioni, C., Pozzi, F., Zamorani, G., et al. 2003, MNRAS, 341, L1Google Scholar
Kellermann, K. I., Fomalont, E. B., Mainieri, V., Padovani, P., Rosati, P., Shaver, P., Tozzi, P., & Miller, N. 2008, ApJS, 179, 71CrossRefGoogle Scholar
Kimball, A. E., Kellermann, K. I., Condon, J. J., Ivezić, Ž., & Perley, R. A. 2011, ApJ (Letters) 739, L29CrossRefGoogle Scholar
Luo, B., Bauer, F. E., Brandt, W. N., et al. 2008, ApJS, 179, 19CrossRefGoogle Scholar
Mainieri, V., Kellermann, K. I., Fomalont, E. B., et al. 2008, ApJS, 179, 95CrossRefGoogle Scholar
Miller, P., Rawlings, S., & Saunders, R. 1993, MNRAS, 263, 425Google Scholar
Miller, N. A., Fomalont, E. B., Kellermann, K. I., et al. 2008, ApJS, 179, 114Google Scholar
Miller, N. A., Bonzini, M., Fomalont, E. B., et al. 2013, ApJS, 205, 13Google Scholar
Morganti, R., Rottgering, H., Snellen, I., et al. 2009, in: Heald, G. & Serra, P. (eds.), Panoramic Radio Astronomy: Wide-field 1-2 GHz research on galaxy evolution, Gröningen, The Netherlands, published online at http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=89, 40Google Scholar
Norris, R. P., Hopkins, A. M., Afonso, J., et al. 2011, PASA, 28, 215Google Scholar
Norris, R. P., Afonso, J., Bacon, D., et al. 2013, PASA, 30, 20Google Scholar
Padovani, P., Mainieri, V., Tozzi, P., Kellermann, K. I., Fomalont, E. B., Miller, N., Rosati, P., & Shaver, P. 2009, ApJ, 694, 235CrossRefGoogle Scholar
Padovani, P. 2011, MNRAS, 411, 1547Google Scholar
Padovani, P., Miller, N., Kellermann, K. I., Mainieri, V., Rosati, P., & Tozzi, P. 2011, ApJ, 740, 20Google Scholar
Sopp, H. M. & Alexander, P. 1991, MNRAS, 251, 14PGoogle Scholar
Tozzi, P., Mainieri, V., Rosati, P., et al. 2009, ApJ, 698, 740CrossRefGoogle Scholar
Ulvestad, J. S., Antonucci, R. R. J., & Barvainis, R. 2005, ApJ, 621, 123CrossRefGoogle Scholar
Vattakunnel, S., Tozzi, P., Matteucci, F., et al., 2012, MNRAS, 420, 2190Google Scholar
Wilson, A. S. & Colbert, E. J. M. 1995, ApJ, 438, 62Google Scholar
Xue, Y. Q., Luo, B., Brandt, W. N., et al. 2011, ApJS, 195, 10Google Scholar