Daniela Coia

Internal Research Fellow


Research interests: Clusters of galaxies


After obtaining my basic degree on ISO observations of IRAS 60
micron  sources, I moved to University College Dublin where I
joined a group  called the ARCS consortium. The consortium was a
collaboration of many  institutes, such as ESAC(ex VilSpa),
University College Dublin,  CEA-Saclay, INAF/Osservatorio di
Trieste and OMP/Toulouse, founded by  Leo Metcalfe to propose and
analyze deep observations of gravitationally  lensing galaxy
clusters with the Infrared Space Observatory at 7 and 15  micron,
as part of the ISO Central Programme. These observations yielded 
important results for infrared galaxy counts, thanks to the
lensing  properties of the selected clusters. The counts obtained
by the  consortium were up to three times deeper than those
performed in general  field surveys. The survey has shown a strong
evolution for infrared  galaxies since z ~ 1.


Moreover, we used these same observations to study the properties
of the  clusters themselves. The results, including the data
reduction used, are  contained in my PhD thesis and in a number of
papers published over a  few years.

We integrated these results with optical (HST) and X-Rays 
(Chandra/XMM-Newton) archival observations to have a more complete 
picture of the infrared sources detected.

The main conclusion is that in most cases the star formation
deduced  from optical lines greatly underestimates the real star
formation,  probably because of dust obscuration in actively star
forming regions.


The ARCS consortium still survives today and includes among others
Leo Metcalfe, Bruno Altieri, Celia Sanchez, Ricardo Perez. We are
now extending the work described above to new clusters and
wavelengths  taking advantage of the sensitivity of the instruments
aboard the Spitzer Space Telescope, IRAC (3.6 - 8 micron) and MIPS
(24 micron). In  the future, we plan to exploit the excellent
capabilities of next ESA's infrared mission, the Herschel Space
Observatory.