EoR Foregrounds: the Faint Extragalactic Radio Sky

A wealth of new data from upgraded and new radio interferometers are rapidly improving and transforming our understanding of the faint extra-galactic radio sky. Indeed the mounting statistics at sub-mJy and uJy flux levels is finally allowing us to get stringent observational constraints on the faint radio population and on the modeling of its the various components. In this paper I will provide a brief overview of the latest results in areas that are potentially important for an accurate treatment of extra-galactic foregrounds in experiments designed to probe the Epoch of Reionization.Comment: 8 pages, 2 figures. Invited review at IAU Symposium No. 333 "Peering towards Cosmic Dawn". This submission includes updated figures wrt the version published in the proceedings volume (where an error in the plotting routine produced wrong labels for the y- and x-axis

The AGN Fueling/Feedback Cycle: A Multiphase Study of a Sample of Local Radio Galaxies

A key mode of AGN feedback is energy input from radio-emitting jets; this is common in massive early-type galaxies (ETG) and drives interactions with the multiphase intergalactic medium (IGM) surrounding them. The mechanisms by which jetted AGN are fuelled and the way in which this forms part of a feedback loop are not yet understood. A systematic study of the various gas phases (ionised and molecular) and of the stellar and dust components in a the cores of a representative sample of massive, radio-loud ETGs (in which jets are currently active) is needed to provide a crucial comparison to existing studies of radio-quiet ETGs (e.g. ATLAS^3D; Cappellari et al. 2011). In particular, it will enable a better understanding of the feeding of AGNs, and will isolate the role played by jet-induced feedback (likely the dominant feedback mode in local, massive ETGs) in the overall formation and evolution of ETGs. In this talk I will present the first results of an ongoing multiphase study of a volume-limited sample (z<0.03) of radio galaxies. For all sources, we have already gathered VLT/VIMOS IFS observations (Warren et al. in prep.) and 12CO(2-1) APEX observations (Prandoni et al. 2010; Laing et al. in prep.). ALMA follow-up for observations were obtained in Cycle 3. (Ruffa et al. in prep.)

An ngVLA Wide Area AGN Survey

The next generation Very Large Array (ngVLA) will have unprecedented sensitivities and mapping speeds at $1-8$ GHz. We discuss how the active galactic nuclei (AGN) community can benefit from a wide-area, medium depth ngVLA survey. We propose a 10 deg$^2$ survey in the Stripe 82 field using the 8 GHz band with an rms depth of $1\,\mu$Jy beam$^{-1}$. We will detect $\sim$130,000 galaxies, including radio-quiet AGN out to $z\sim7$. We can measure the luminosity and space density evolution of radio-quiet and radio-loud AGN. We can also measure AGN evolution through clustering of both populations using cross-correlation functions. A wide area ngVLA survey will benefit from existing multiwavelength AGN populations, particularly in the Stripe 82 field, as well as new information from next-generation optical and infrared survey instruments such as LSST and WFIRST.Comment: ngVLA Science Use Case to appear in the ngVLA Science Book (http://ngvla.nrao.edu/page/scibook

Exploring AGN Activity over Cosmic Time with the SKA

In this Chapter we present the motivation for undertaking both a wide and deep survey with the SKA in the context of studying AGN activity across cosmic time. With an rms down to 1 $\mu$Jy/beam at 1 GHz over 1,000 - 5,000 deg$^2$ in 1 year (wide tier band 1/2) and an rms down to 200 nJy/beam over 10 - 30 deg$^2$ in 2000 hours (deep tier band 1/2), these surveys will directly detect faint radio-loud and radio-quiet AGN (down to a 1 GHz radio luminosity of about $2\times10^{23}$ W/Hz at $z=6$). For the first time, this will enable us to conduct detailed studies of the cosmic evolution of radio AGN activity to the cosmic dawn ($z\gtrsim6$), covering all environmental densities.Comment: 17 pages, 7 figures, to appear as part of 'Continuum Science' in Proceedings 'Advancing Astrophysics with the SKA (AASKA14)

Radio Observations of the Hubble Deep Field South Region II: The 1.4 GHz Catalogue and Source Counts

This paper is part of a series describing the results from the Australia Telescope Hubble Deep Field South (ATHDFS) survey obtained with the Australia Telescope Compact Array (ATCA). This survey consists of observations at 1.4, 2.5, 5.2 and 8.7 GHz, all centred on the Hubble Deep Field South. Here we present the first results from the extended observing campaign at 1.4 GHz. A total of 466 sources have been catalogued to a local sensitivity of 5 sigma (11 microJy rms). A source extraction technique is developed which: 1) successfully excludes spurious sources from the final source catalogues, and 2) accounts for the non-uniform noise in our image. A source catalogue is presented and the general properties of the 1.4 GHz image are discussed. We also present source counts derived from our ATHDFS 1.4 GHz catalogue. Particular attention is made to ensure the counts are corrected for survey incompleteness and systematic effects. Our counts are consistent with other surveys (e.g. ATESP, VIRMOS, and Phoenix Deep Field), and we find, in common with these surveys, that the HDFN counts are systematically lower.Comment: Accepted by AJ. 51 pages, 21 figures, 2 table

New constraints on the 1.4 GHz source number counts and luminosity functions in the Lockman Hole field

We present a study of the 1173 sources brighter than $S_{1.4\,\rm GHz}= 120\,\mu$Jy detected over an area of $\simeq 1.4\,\hbox{deg}^{2}$ in the Lockman Hole field. Exploiting the multi-band information available in this field for $\sim$79% of the sample, sources have been classified into radio loud (RL) active galactic nuclei (AGNs), star forming galaxies (SFGs) and radio quiet (RQ) AGNs, using a variety of diagnostics available in the literature. Exploiting the observed tight anti-correlations between IRAC band 1 or band 2 and the source redshift we could assign a redshift to 177 sources missing a spectroscopic measurement or a reliable photometric estimate. A Monte Carlo approach was used to take into account the spread around the mean relation. The derived differential number counts and luminosity functions at several redshifts of each population show a good consistency with models and with earlier estimates made using data from different surveys and applying different approaches. Our results confirm that below $\sim300\,\mu$Jy SFGs$+$RQ AGNs overtake RL AGNs that dominate at brighter flux densities. We also confirm earlier indications of a similar evolution of RQ AGNs and SFGs. Finally, we discuss the angular correlation function of our sources and highlight its sensitivity to the criteria used for the classification.Comment: 14 pages, 10 figures, 4 tables, MNRAS in pres

The new 64m Sardinia Radio Telescope and VLBI facilities in Italy

The Sardinia Radio Telescope (SRT) is a new major radio astronomical facility available in Italy for single dish and interferometric observations. It represents a flexible instrument for Radio Astronomy, Geodynamical studies and Space Science, either in single dish or VLBI mode. The SRT combines a 64m steerable collecting area, one of the largest all over the World with state-of-the-art technology (including an active surface) to enable high efficiency observations up to the 3-mm band.This new radio telescope together with the two 32m antennas in Noto and Medicina can be used for VLBI observations on a national basis (VLBIT). Data can be correlated in a short time (in real time soon) thanks to fiber-optics connection among the radio telescopes and the software correlator installed at the Radio Astronomy Institute in Bologna (IRA/INAF). In the poster I will present capabilities of the SRT telescope as well as the VLBIT project and I will shortly discuss the scientific prospects of the VLBIT. <P /

Kinematics Modelling of Molecular Gas in NGC 3100

SlidesA kinematics modelling of molecular gas in the centre of NGC 3100, a FRI radio galaxy hosted by a S0 galaxy at redshift z = 0.0088. The inner region of NGC 3100 has been observed with ALMA at Band 6 during Cycle 3. The CO(2-1) 230-GHz line (rest-frequency) was clearly detected. The analysis of the line through the integrated intensity map (moment 0) and the integrated velocity map (moment 1) revealed a ring-like rotating structure. A tilted-ring model was built through the software 3D-Barolo to better understand the complex kinematics of the gas. The modelling allowed us to explore purely rotational velocity fields as well as fields including non-circular motions