Elena Pierpaoli
California Institute of Technology, Astronomy, Faculty Member
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... Matts Roos & SM Harun-or-Rashid Department of Physics, Division of High Energy Physics, ... (3) In a previous publication (Roos & Harun-or-Rashid 1998) we tried to determine the preferred region in the (Ωm, ΩΛ)-plane... more
... Matts Roos & SM Harun-or-Rashid Department of Physics, Division of High Energy Physics, ... (3) In a previous publication (Roos & Harun-or-Rashid 1998) we tried to determine the preferred region in the (Ωm, ΩΛ)-plane by combining three independent observational con-...
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We present a new cluster catalog extracted from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045 ≤ z... more
We present a new cluster catalog extracted from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045 ≤ z < 0.78 in 9600 sq. deg. of the sky. We provide ...
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We present an alternative estimate of the unresolved point source contribution to the WMAP temperature power spectrum based on current knowledge of sources from radio sur-veys in the 1.4−90 GHz range. We implement a stochastic... more
We present an alternative estimate of the unresolved point source contribution to the WMAP temperature power spectrum based on current knowledge of sources from radio sur-veys in the 1.4−90 GHz range. We implement a stochastic extrapolation of radio point sources in ...
The best current constraints on the sum of neutrino masses comes from cosmology. Here, we detail the prospects for future mass constraints from cosmological 21 cm observations of the epoch of reionization. We show that future instruments... more
The best current constraints on the sum of neutrino masses comes from cosmology. Here, we detail the prospects for future mass constraints from cosmological 21 cm observations of the epoch of reionization. We show that future instruments such as SKA and FFTT should ...
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We investigate the implications of recent cosmic microwave background radiation (CMB) and large scale structure (LSS) results the neutrino background and mass. We use the recent WMAP data, together with previous CBI data and 2dF matter... more
We investigate the implications of recent cosmic microwave background radiation (CMB) and large scale structure (LSS) results the neutrino background and mass. We use the recent WMAP data, together with previous CBI data and 2dF matter power spectrum, to ...
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Issues a) and b) are in fact closely related together and to the point sources detection. While randomlydistributed point sources don't interfere with cluster reconstruction (and viceversa,Pires et al, 05), correlated sources... more
Issues a) and b) are in fact closely related together and to the point sources detection. While randomlydistributed point sources don't interfere with cluster reconstruction (and viceversa,Pires et al, 05), correlated sources are an issue. Radio point sources are in ...
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ABSTRACT We present a new cluster catalog extracted from SDSS-DR6 using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045<z<0.78. We compare the AMF catalog with... more
ABSTRACT We present a new cluster catalog extracted from SDSS-DR6 using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045<z<0.78. We compare the AMF catalog with the maxBCG, GMBCG and Wen et al ones. A comparison with the maxBCG catalog shows that clusters match at about the 40% level for all redshifts. The AMF catalog matches all maxBCG clusters with 100<Ngal and the maxBCG one about 90% of AMF clusters with 100<Lambda200. For the catalog produced by Wen, Han, and Liu from SDSS DR6 data, we find matches for about 25% of their clusters. We find 539 matches with X-ray clusters, 119 with temperature measurements. We present scaling relations between optical and X-ray properties and cluster center comparison. Finally, we study the properties of the Brightest Cluster Galaxies (BCGs). We find that the BCG luminosity distribution is close to a Gaussian, whose mean has a redshift evolution broadly consistent with pure aging of the galaxies. Richer clusters tend to have brighter BCGs, however less dominant than in poorer systems. 4-9% of our BCGs are at least 0.3 mag bluer in the g-r colour than the red-sequence at their given redshift. Such a fraction decreases to 1-6% for clusters above a richness of 50, where 3% of the BCGs are 0.5 mag below the red-sequence. In terms of redshift evolution, the overall blue fraction seems to increase with redshift from 5% at 0.1<z<0.2 to 10% at 0.2<z<0.3. We also cross-matched our catalog with UV data from Galex. We show a correlation between offset from the optical red-sequence and the amount of UV-excess. We cross-matched our catalog with the ACCEPT cluster sample, and find that blue BCGs tend to be in clusters with low entropy and short cooling times. Research supported by NASA and NSF.
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STRUCTURE FORMATION AND LIGHT GRAVITINOS WARM DARK MATTER ELENA PIERPAOLI Department of Physics, Theoretical Physics, I Keble Road, Oxford OX1 3NP. England Light gravitinos (m & 0.1-1 KeV) are predicted to be the lightest... more
STRUCTURE FORMATION AND LIGHT GRAVITINOS WARM DARK MATTER ELENA PIERPAOLI Department of Physics, Theoretical Physics, I Keble Road, Oxford OX1 3NP. England Light gravitinos (m & 0.1-1 KeV) are predicted to be the lightest supersimmetric particles in the gauge-...