Observing Supermassive Black Holes across cosmic time: from phenomenology to physics

In the last decade, a combination of high sensitivity, high spatial resolution observations and of coordinated multi-wavelength surveys has revolutionized our view of extra-galactic black hole (BH) astrophysics. We now know that supermassive black holes reside in the nuclei of almost every galaxy, grow over cosmological times by accreting matter, interact and merge with each other, and in the process liberate enormous amounts of energy that influence dramatically the evolution of the surrounding gas and stars, providing a powerful self-regulatory mechanism for galaxy formation. The different energetic phenomena associated to growing black holes and Active Galactic Nuclei (AGN), their cosmological evolution and the observational techniques used to unveil them, are the subject of this chapter. In particular, I will focus my attention on the connection between the theory of high-energy astrophysical processes giving rise to the observed emission in AGN, the observable imprints they leave at different wavelengths, and the methods used to uncover them in a statistically robust way. I will show how such a combined effort of theorists and observers have led us to unveil most of the SMBH growth over a large fraction of the age of the Universe, but that nagging uncertainties remain, preventing us from fully understating the exact role of black holes in the complex process of galaxy and large-scale structure formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and Treves A. (Eds), 2015, Springer International Publishing AG, Cha

Star Formation and Dynamics in the Galactic Centre

The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the vicinity of a supermassive black hole (SMBH). Despite the hostile environment, several tens of early-type stars populate the central parsec of our Galaxy. A fraction of them lie in a thin ring with mild eccentricity and inner radius ~0.04 pc, while the S-stars, i.e. the ~30 stars closest to the SMBH (<0.04 pc), have randomly oriented and highly eccentric orbits. The formation of such early-type stars has been a puzzle for a long time: molecular clouds should be tidally disrupted by the SMBH before they can fragment into stars. We review the main scenarios proposed to explain the formation and the dynamical evolution of the early-type stars in the GC. In particular, we discuss the most popular in situ scenarios (accretion disc fragmentation and molecular cloud disruption) and migration scenarios (star cluster inspiral and Hills mechanism). We focus on the most pressing challenges that must be faced to shed light on the process of star formation in the vicinity of a SMBH.Comment: 68 pages, 35 figures; invited review chapter, to be published in expanded form in Haardt, F., Gorini, V., Moschella, U. and Treves, A., 'Astrophysical Black Holes'. Lecture Notes in Physics. Springer 201

Opening up dialogues and airways: using vignettes in research to enrich asthma understandings in sport and exercise

This article explores the lived experience of asthma in a specific population of sport and exercise participants, drawing on an approach currently under-utilised in studies of asthma: vignettes. These were used as an elicitation technique in research with19 frequent exercisers and sports participants with asthma, eight of whom responded to vignettes. We describe and evaluate this approach as deployed in relation to a phenomenological study of the lived experience of asthma, and consider how employing vignette-based research can encourage people with asthma to reflect critically on their experiences and ways of being-in-the-world. This was found to be a powerful way of challenging taken-for-granted assumptions, and stimulating consideration of behaviour change. The findings we report here cohere around two principal themes that emerged as salient: 1) somatic empathy; and 2) the power of sharing stories and opening up dialogues. Understanding the complexity of asthma experiences can, we argue, be of great practical value both to those with asthma and also to healthcare and exercise professionals in tailoring more effective treatments

Establishment of a non-permanent GPS network to monitor deformations in Zafarraya Fault and Sierra Tejada Antiform (Spain)

The NW-SE to NNW-SSE convergence between the African and Eurasian plates in the western Mediterranean has developed the recent relief of the Betic-Rif Cordilleras. The central part of the Internal Zones of the Betic Cordilleras is deformed by large open folds and faults, mainly with normal character. The Zafarraya fault, located to the N of the Sierra Tejeda antiform, was active during the 1884 Andalusia earthquake of 6.7 estimated magnitude. In the framework of an interdisciplinary research project, a non-permanent GPS-network has been established at Zafarraya Fault and Sierra Tejeda antiform to monitor deformations related to these active tectonic structures