Description du projet
Caractériser les poussées de croissance dans les trous noirs supermassifs
Les trous noirs sont «noirs» car ils constituent des zones de l’espace où une énorme quantité de matière est comprimée dans de très petites régions, générant une attraction gravitationnelle tellement importante que même la lumière ne peut s’en échapper. Et les trous noirs supermassifs (TNSM) sont encore plus massifs. Les astronomes pensent que des TNSM pourraient se trouver au centre de presque toutes les grandes galaxies, et qu’ils se sont probablement formés en même temps que les galaxies qui les abritent. La manière dont les TNSM accumulent toute cette masse reste un mystère. Les données suggèrent que de courtes périodes de croissance intense peuvent être entrecoupées de longues périodes de calme. Le projet ExSMBHs, financé par l’UE, mène une étude d’observation complète afin de mieux caractériser les modes d’accrétion extrêmes des TNSM et de faire la lumière sur leur évolution conjointe avec les galaxies qui les abritent.
Objectif
How do supermassive black holes (SMBHs) turn their accretion “on” and “off”? How fast can they grow? How is this related to their circumnuclear environments? What are the consequences for the emergence of the first SMBHs and their co-evolution with galaxies? The key to answering these and other questions is found in understanding SMBH accretion, in all possible modes and cosmic epochs. Recent progress in both theory and observations strongly support “extreme” modes of SMBH accretion, namely abrupt changes seen on timescales of weeks and the possibility of (also long-lived) super-Eddington accretion. Both of these sorts of extreme accretion are not yet well understood. Here I propose to change this, by leading a multi-faceted observational program that will reveal, survey, and characterize extreme modes of SMBH accretion. Some of the efforts I will lead include: (1) Responsive, multi-wavelength, and spectroscopic follow-up observations of hyper-variable and flaring accreting SMBHs, to provide new insights as to what starts or stops SMBH accretion, and a new way to study super-Eddington accretion; (2) Proprietary multi-epoch SDSS-V spectroscopy will allow me to determine how common these dramatic events are, and to look for trends with BH and host galaxy properties; (3) A complete, detailed survey of highly accreting SMBHs in the local universe; and (4) An exploratory survey of super-Eddington, advection-dominated SMBHs at significant redshifts. These and other new insights will be combined with newly established, highly complete distributions of the black hole masses and accretion rates at both low and high redshifts, to understand the role of extreme accretion modes in the general SMBH population and to help guide future surveys. This research has to be done now, as we try to complete our understanding of (cosmic) SMBH accretion and (co-)evolution; before we are flooded with millions transients; and before the next generation facilities and surveys are finalized.
Champ scientifique
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
69978 Tel Aviv
Israël