Scientific areas of interest
Galaxy formation and evolution. Multi-wavelength observations of galaxies in the local and high-redshift Universe. Feedback mechanisms from star formation and accreting super massive black holes. Multi-phase and multi-scale galactic outflows. The circumgalactic and intergalactic medium. Galaxy interactions and mergers. (Sub)-millimetre telescopes and observational techniques. Dual and binary active galactic nuclei. The thermal and kinetic Sunyaev-Zel'dovich (SZ) effect.
Towards an Atacama Large Aperture Submillimeter Telescope
Astrophysical observations at (sub-)mm wavelengths (λ from ~300 μm to ~3mm) allow us to study the cold and dense material in the Universe, hence probing the formation of stars and planets, and the interstellar and circumgalactic medium of galaxies across all cosmic times. The current generation of 10-m class single dish telescopes delivered the first surveys of the sky at (sub-)mm wavelengths, allowing us to go far beyond the previously optical/IR- biased view of the Universe. Follow-up observations with interferometers then revealed, in exquisite detail, the morphology and kinematics of such (sub-)mm sources, enabling tests and revisions of theoretical models for the formation and evolution of planets, stars, and galaxies. However, it is now clear that without a step change in the capabilities of single-dish facilities in the 2030s, interferometers (like the ALMA observatory) will soon become source-starved. The current generation of 10-m class single dish telescopes, with their limited field of view, spatial resolution, and sensitivity, can only reveal the ‘tip of the iceberg’ of the (sub-)mm source population, both for Galactic and extragalactic studies. These limitations cannot be compensated for by interferometers, which are all intrinsically affected by a low mapping speed and by the loss of diffuse extended signals.
The Atacama Large Aperture Submillimeter telescope (AtLAST) is a concept for a 50m -diameter single dish observatory to be built in the Chilean desert. With its extremely large field of view (the goal is ~ 2 degrees diameter), spatial resolution (up to ~1.5” at 350 μm), and sensitivity to both point sources and large-scale structures, AtLAST will be transformational for all fields of Astronomy in the 2030s. I am the Coordinator of a collaborative Horizon2020 project which by the end of 2024 will deliver a comprehensive design study for AtLAST. To know more about the design study, and read relevant articles and publications, visit the AtLAST project webpage.
Recent AtLAST-related publications (only those with a significant contribution from myself):
Cicone et al. "SUPER. VI. A giant molecular halo around a z~2 quasar", A&A Letters, in press (2021). ADS link to the article
Klaassen, Mroczkowski, Cicone et al. "The Atacama Large Aperture Submillimeter Telescope (AtLAST)". Proceedings of the SPIE, Vol. 11445, 20 pp. (2020). ADS link.
Cicone et al. "The hidden circumgalactic medium". Astro2020 Science White paper, BAAS, Vol 51., Issue 3, id 51 (2019). ADS link.
Properties of cold gas and dust in local (Ultra) Luminous Infrared Galaxies
One of my main areas of research is the study of local (U)LIRGs. In these sources, the enhanced star formation and AGN activity generate the most massive, extended and energetic multi-phase outflows known. In addition to outflows, the dislocation of gas due to the gravitational interaction and tidal forces make these galaxies very interesting targets for studying extended circumgalactic medium reservoirs.
Cicone et al. "Enhanced UV radiation and dense clumps in the molecular outflow of Mrk 231", A&A, Volume 633, id.A163, 13 pp., January 2020. ADS link to the article
Sirressi, Cicone et al. "Testing the blast-wave AGN feedback scenario in MCG-03-58-007", MNRAS., Volume 489, Issue 2, p.1927-1938, October 2019. ADS link to the article
Cicone et al. : "ALMA [CI]3P1-3P0 observations of NGC 6240: a puzzling molecular outflow, and the role of outflows in the global αCO factor of (U)LIRGs", The Astrophysical Journal, Volume 863, Issue 2, id.143, 18pp, Aug 2018. ADS link to the article
ALMA CO(2-1) image and spectra showing the extended and massive molecular outflow in NGC6240 (Cicone et al. 2018, ApJ)
The baryon cycle in high-redshift active galactic nuclei
The SINFONI survey for unveiling the physics and effect of radiative feedback (SUPER, PI: Mainieri) is an ESO large program at the very large telescope (VLT). As part of SUPER, we have obtained high-resolution, spatially-resolved spectroscopic observations of multiple optical emission lines (Hb, [OIII], Ha) for a statistically-significant sample of ~40 active galactic nuclei at z~2. The main goal of SUPER is to probe the baryon cycle and the effects of AGN feedback at the peak epoch of AGN activity and cosmic assembly, in a sample probing four orders of magnitude in AGN luminosity. Most of the SUPER sample has been observed also at sub-millimetre and millimeter wavelengths with ALMA and APEX. For an updated list of publications, check the SUPER website.
The APEX low-redshift legacy survey for molecular gas (ALLSMOG, PI: Wagg) is a large ESO observing program aimed at constraining the molecular gas content of ~100 nearby star forming galaxies through the carbon monoxide (CO) emission line. ALLSMOG is the first large systematic extragalactic survey of CO ever conducted with the Atacama pathfinder experiment (APEX) telescope. APEX is located on the Chajnantor plateau at 5000 meters above sea level, in the Chilean Andes. The final data release comprises APEX CO(2-1) emission line observations of 88 low-mass (108.5<M∗ [M⊙] < 1010) star-forming galaxies, and IRAM 30m observations of the CO(1-0) and CO(2-1) emission lines in additional nine galaxies with M∗< 109M⊙. ALLSMOG allows us to probe the molecular gas content of more typical and lower stellar mass galaxies than have been studied by previous extragalactic CO surveys. The reduced data products are public and can be retrieved through the ESO Phase 3 archive query. For additional info check the ALLSMOG website.
Scaling relations between the molecular gas content - as traced by Carbon Monoxide emission - and galaxy properties, for a statistically significant sample of local star-forming galaxies from the ALLSMOG and COLDGASS surveys (Cicone et al. 2017, A&A).
From dual to binary super massive black holes
With collaborators from the INAF-Observatory of Brera we are conducting pilot studies and observations aimed at designing a sample of binary and dual AGN candidates, in preparation for future follow up studies with MAORY+MICADO (PI: Severgnini). MAORY is the Adaptive Optic (AO) module that will be installed at the E-ELT at the first light of the telescope. The MAORY science cases white book is available at this link.
Severgnini, Braito, Cicone et al. "A possible sub-kiloparsec dual AGN buried behind the galaxy curtain". A&A, Vol. 646, id. A153 (2021). ADS link to the article.
Serafinelli, Severgnini et al. "Unveiling sub-pc supermassive black hole binary candidates in Active Galactic Nuclei". The Astrophysical Journal, Vol. 902, Issue 1, id. 10. ADS link to the article.
Severgnini, Cicone et al. "Swift data hint at a binary Super Massive Black Hole candidate at sub-parsec separation", MNRAS, Volume 479, Issue 3, p. 3804-3813, Sep 2018. ADS link to the article
Identification of high-redshift radio-loud AGNs
As members of the Large Synoptic Survey Telescope (LSST) consortium, the Observatory of Brera is developing the skills to exploit the LSST database to perform a statistical study of the quasar population in the first billion years of the Universe. By exploiting the currently available multi-wavelength databases, our group has already successfully identified a large sample of previously unknown radio-loud AGNs at z>5. We are now in the process of obtaining follow-up observations to confirm the redshifts and constrain the physical properties of these sources.
Belladitta et al. "The first blazar observed at z > 6", A&A, Volume 635, id.L7. March 2020. ADS link to the article
Belladitta et al. "An extremely X-ray weak blazar at z = 5", A&A, Volume 629, id.A68. September 2019. ADS link to the article
Caccianiga et al. "The space density of z > 4 blazars", MNRAS, Volume 484, Issue 1, p.204. March 2019. ADS link to the article