I am an astronomer at INAF/Osservatorio Astrofisico di Arcetri where I research formation of planets. Since September 2015 I am the principal investigator and leader of the young research group RESERVOIRS financed by Ministero dell'Istruzione, Università e Ricerca (MIUR) program "Scientific Independence of young Researchers (SIR)". Find out more here


(left) Artist's impression of an infant star surrounded by a protoplanetary disk in which planets are forming c(redit: Calcada/ESO). (right) The Atacama Large Millimeter Array in the Chilean Andes (credit: Clem & Adri Bacri-Normier/ESO)

I investigate the physical structure and chemical composition of protoplanetary disks where comets, planets and moons are forming at this right moment. Most of my recent work is based on observations with the Atacama Large Millimeter Array (ALMA).

Recent highlights

New gas mass constraints for protoplanetary disk

A major unknown in planet formation studies is the mass of protoplanetary disks. The line emission of molecular deuterated hydrogen (HD) can provide robust and reliable disk gas mass measurements. We re-examined a set of spectra of 15 Herbig Ae/Be disks taken with the Herschel Space Observatory. In general all disks have masses below the gravitational instability threshold. A new strong constraint is found for HD 163296 (0.067 Solar mass) implying that the gas-phase CO depletion is at most a factor of a few.
Kama, Trampan, Fedele, et al. 2020, A&A, 634, 88

Long lived dust rings

Protoplanetary disks observed with ALMA often show a charateristic multi-rings profiles intervaled by gaps of low dust density. What is the fate of these rings? Will they be destroyed by the interaction with the protoplanets? We investigated the case of HD 169142 simulating the presence of 2 giant protoplanets with the smoothed-particles-hydrodynamics code PHANTOM (Price et al. 2018). The two planets create a trap for the dust that is long-lived. Such a trap, could be the formation region of new low-mass planets
Toci, Lodato, Fedele, et al. 2020, ApJ, 888, 4

CQ Taurus, a new planetary system in the making?
Observations with the Atacama Large Millimetre Array (ALMA) of the young pre-main-sequence star CQ Tau (1.67 Solar mass) in the Taurus-Auriga star forming region reveals a large cavity in the surrounding protoplanetary disk. Such a cavity is likely produced by one or more giant proto-planets sweeping away the gas and forming a dust trap (seen as a ring in the figure on the right) extending from nearly 40 to 60 astronomical unit from the star. Is such a ring a precursor of a Kuiper belt analogue?
Ubeira-Gabellini et al. MNRAS, 2019, 486, 463

Organic acid in the TW Hya protoplanetary disk
The formic acid contains a carboxylic group (-COOH), which stands as the basis for synthesis of more complex carboxylic and amino acids used by life on Earth. More specifically, this species is involved in a chemical route leading to glycine, the simplest amino acid, the basis of many proteins. Using the Atacama Large Millimeter Array we detected, for the first time, formic acid in the planet forming disk around TW Hya.
Favre, Fedele, Semenov et al. 2018, ApJL, 862, L2

Signature of a proto-planet in the AS 209 protoplanetary disk
Using ALMA observations of CO and its rare isotopologues coupled with both thermochemical we find a clear evidence of a perturbation of the gas surface density in the protoplanetary disk of AS 209. These findings are in very good agreement with hydrodynamical simulations of planet-disk interactions. The observed perturbation requires is caused by a giant planet of nearly 0.2-0.3 Jupiter masses.
Favre, Fedele, Maud et al. 2019, ApJ, 871, 107

ALMA continuum observations of the protoplanetary disk AS 209
ALMA reveals two dust gaps in the protoplanetary disk around AS 209 in the Ophiucus star forming regions. The two dust gaps are a clear evidence of the interaction between the disk with young (unseen) planets
Fedele, Tazzari, Booth et al. A&A 2018, 610, 24

Probing disk physics and chemistry with Sulphur-bearing molecules
We carried out a deep search for Sulphur-bearing species in the protoplanetary disk of DM Tau with ALMA. Of the various species observed, only CS was detected. The ratio of CS to SO (undetected) hints at a non-solar Carbon/Oxygen abundance ratio with Carbon being more abundant than Oxygen in gas phase
Semenov, Favre, Fedele et al. 2018, A&A, 617, 28

ALMA reveals dust and gas gaps in the protoplanetary systems HD 169142
ALMA observations of cold gas and dust revealed the presence of gaps and rings in HD 169142. The most plausible explanation is that these pronounced gaps in the gas distribution were carved out by giant protoplanets
Fedele et al. A&A 2017, 600, 72


  • 14 Main author
  • 57 Co-author
  • 2240 Citations
  • 29 h-index

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