Descrizione del progetto
Definire gli scatti di crescita nei buchi neri supermassicci
I buchi neri sono «neri» perché sono aree nello spazio in cui un’enorme quantità di materia viene compressa in regioni molto piccole, producendo un’attrazione gravitazionale così enorme che nemmeno la luce può sfuggirgli. Ancora più massicci sono i buchi neri supermassicci. Gli astronomi sostengono che i buchi neri supermassicci potrebbero essere al centro di quasi tutte le grandi galassie e probabilmente si sono formati insieme alle galassie in cui si trovano. Il modo in cui i buchi neri supermassicci accumulano tutta questa massa è ancora un mistero. I dati suggeriscono che brevi periodi di potente attività di crescita possono essere intervallati da lunghi periodi di quiete. Il progetto ExSMBHs, finanziato dall’UE, sta conducendo uno studio osservazionale completo per caratterizzare meglio le modalità di accrescimento estremo nei buchi neri supermassicci e chiarire la loro coevoluzione con le galassie che costituiscono la loro casa.
Obiettivo
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.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-STG - Starting GrantIstituzione ospitante
69978 Tel Aviv
Israele