Imaging detections
So far we have been working on X-ray archival data (mainly imaging ROSAT pointings) and optical data (both from wide field cameras and catalogs). Our approach consist to find the soft X-ray structures in correspondance of an overdensity of galaxies
in a relatively narrow range of redshift.
Main results
- Contraints on the temperature evolution of the WHIM (from observations) with redshift (Zappacosta et al. 2005, A&A accepted; astro-ph/0501402)
- Detection of an high redshift (z~0.78) optical superstructure with no signs of WHIM X-ray emission (Zappacosta et al. 2005, A&A accepted; astro-ph/0501402)
- Detection of WHIM signature in the Sculptor supercluter at z~0.1 (Zappacosta et al. 2004, MNRAS accepted; astro-ph/0402575)
- Detection of WHIM at z~0.45 (Zappacosta et al. 2002, A&A, 394, 7)
- Measure and confirmation (z=0.40) of redshift of the WHIM detected in Zappacosta et al. 2002 through a spectroscopic survey of the galaxies belonging to the super-structure (Mannucci et al. A&A 2007, 468, 807)
Detections in QSO spectra
Detection (3 σ level) of the OVII absorption line at z=0.03 in the continuum grating spectrum of a background blazar (H2356-309). This line is produced by the WHIM permeating the Sculptor Wall which is a superstructure traced by the galaxy distribution which crosses the sighline to the blazar at z=0.03 which is exactly the redshift of the detected line. This result has been possible by observing the blazar both with XMM and Chandra satellites.
Main results
- Oral contribution at the 4th UC Irvine Center for Cosmology Workshop:
Galaxy Formation and Evolution as Revealed by Cosmic Gas, April 17-19, 2008, Irvine, California, USA
- Oral contribution at the The Warm & Hot Universe workshop, May 7-9, 2008
Columbia University
New York City, USA
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Detection of a WHIM filament at z~0.45 (soft X-ray ROSAT PSPC map)
Correlation between soft X-ray flux and galaxy distribution as a function of the gas temperature in the Sculptor supercluster. For the coolest temperature the correlation is significant. This indicates the presence of < 5×106K plasma related to the superstructure.
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