A rule of the Universe, it that the Universe always surprises you.
Una regola dell’Universo, è che l’Universo ti sorprende sempre.
My research involves three broad main topics:
Black Hole Winds, X-ray Quasi Periodic Eruptions, and X-ray missions.
Black Hole Winds
Supermassive black holes have a fundamental role in our Universe.
In fact, they reside at the center of most – if not all –
the fundamental building blocks of our Universe: galaxies.
Surprisingly, lots of matter is pushed out from the vicinity of supermassive black holes, either driven by magnetic forces or by radiation. The impact of black hole winds into the galaxy is likely important: in fact, black holes and galaxies evolution seem to influence each other. Black holes and galaxies are possibly deeply intertwined by means of a mutual exchange of energy, or feedback, and part or most of this energy feedback might be provided by black hole winds.
I investigate cosmic feedback in the form of winds driven by radiation in the proximity of supermassive black holes in distant galaxies.
In my latest article with Daniel Proga, we propose a global scheme for the inner accretion and ejection flow around supermassive black holes.
Radiation-driven accretion disk winds are added to the AGN scheme.
See Giustini & Proga 2019, A&A 630, 94
A free version of the article is available at: https://arxiv.org/abs/1904.07341
Quasi Periodic Eruptions
I am part of the team, lead by CAB’s Giovanni Miniutti, who discovered
X-ray Quasi-periodic Eruptions (QPE) in the nucleus of the galaxy GSN 069.
QPEs are unprecedented cosmic signals: extremely regular and sharp
increases in X-ray brightness, that last about one hour and repeat every about nine hours.
The signal originates close to the central supermassive black hole of the galaxy, but the physical explanation behind this new phenomenon is not known yet. It could involve orbital motions of a second body, or physical instabilities of the very inner accretion flow, perhaps magnetic in nature.
In order to try to understand better what is causing QPEs, new observations of GSN 069 with the largest telescopes around the world and in orbit around the Earth are planned in the next future.
In the meanwhile, the search for QPEs in other galactic nuclei continues.
The second nucleus with X-ray QPEs has been recently identified in the galaxy
RX J1301.9+2747 thanks to new pointed XMM-Newton observations.
X-ray Quasi-periodic Eruptions have been discovered in the nucleus of the galaxy GSN 069
The search for X-ray QPEs
in other galactic nuclei continues.
See Miniutti et al. 2019, Nature 573, 381
A free version of the article is available at:
https://arxiv.org/abs/1909.04693
X-ray missions
I was scientifically born as X-ray observer, and while many things have continuously changed during my scientific career, the constant has been the utilization of X-ray data.
I am an expert user of ESA’s XMM-Newton, whose data I have been analyzing for the past 13 years with undiminished passion and enthusiasm; I visited ESAC for the first time in 2008 to collaborate in the X-ray study of a supermassive black hole variable wind; then I came back during 2012-2014 as Research Fellow in Space Science in the XMM-Newton SOC; now I work at ESAC, in the CAB (CSIC-INTA). Five times during my life the telescope has moved toward the region of the sky I was recommending, delivering data of photons that had traveled millions of light years into my computer.
I have contributed to the development of past and future X-ray missions, and I am member of the Scientific Working Group “Feedback in local AGN and star forming galaxies” of the ESA Large Mission ATHENA.
Here you can find a list of my scientific articles.
Here you can find some of my talks and presentations.
Here you can find my Curriculum Vitae.