FP6Reintegration grant2005–2007

MSEPOA · Multi-wavelength searches of the elusive population of obscured AGN

FP6 — Marie Curie Actions (Human Resources and Mobility)

Duration
2005-07-01 → 2007-06-30
EU contribution
€80,000
Participants
1
Scheme
IRG

Lines connect the coordinator with its partners.

Results in brief

Final Activity Report Summary - MSEPOA (Multi-wavelength searches of the elusive population of obscured AGN)

The main objective of our project is the systematic study of the properties of Active Galactic Nuclei (AGN) and their environments, on the basis of multi-wavelength observations and in particular to isolate those AGN whose properties indicate that their central engine is heavily obscured by dust. Combining the expertise and unique datasets to which the involved scientists have access to, is one of the main assets of our research project. A comprehensive catalogue of all identified sources in the northern and southern fields of the GOODS survey (of which the fellow is member) was established (Vizier), while at the same time a catalogue of obscured AGN from the XMM survey (to which the host team has access) was established (http://aiantas.astro.noa.gr/~dathanas/sheep1cat.html). Both catalogues contain full multi-wavelength information for all sources. Constructing the full Spectral Energy Distributions (SEDs) we detected several obscured AGN that in the optical wavelengths remained heavily obscured by large amounts of dust, dominated mostly by star light. We examined the host structural properties and AGN environments, but did not find a strong correlation between galaxy merging and AGN activity, besides a trend with AGN luminosity. Another line of research concerned the study of a particular type of active galaxies, the BAL QSOs, which are quasars sustaining large scale outflows that obscure the quasar continuum and broad emission lines. We approached this topic from both the perspective of a spectroscopic survey of a statistically significant sample, as well as the detailed modeling of the spectra of selected objects. Our results indicative that radiatively accelerated winds is the most probable mechanism and allowed us to constrain the physical parameters (outflow velocities and geometries) within a range of possible best fit values. It is thus clear that the realisation of the project has helped to promote the professional reintegration of the fellow in her home country, as well as, has helped expanding her fields of expertise and research activities and those of the host group. Beyond her research activities, the fellow has also been very active in carrying out educational and dissemination activities targeting the general public, in order to demonstrate the impact of the research and science results for the society at large.

Data: CORDIS, © European Union

Project objective

We propose to use X-ray data from two pioneering in their kind and complementary multi-wavelength surveys, in order to perform a systematic study of obscured AGN. These leverage substantial investments of space- and ground-based telescope time, yielding a unique dataset to study the obscured Universe. The elusive population of obscured AGN most likely dominates the population of accreting super massive black holes, however, it remains mostly undetected.The impact of multi-wavelength observations for the study of AGN is crucial and the only way to obtain accurate demographics of obscured AGN at high red shift. If our findings will show substantial and widespread obscuration, this will have important implications for the cosmic accretion history of black holes. The pro posed collaboration will promote the professional reintegration of the proposed researcher and will help expanding the activities of the X-ray group of the Institute of Astronomy and Astrophysics of the National Observatory of Athens, by blending the fields of expertise of the researchers involved and by combining the unique datasets to which each party has access.

Original text from CORDIS.

Participants

  • NATIONAL OBSERVATORY OF ATHENS · ATHENSCoordinatorGreece

Links

Data: CORDIS, © European Union