Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-07-12
Astronomy and Astrophysics
Astrophysics
16 pages, 10 figures. Accepted in MNRAS
Scientific paper
10.1111/j.1365-2966.2005.09405.x
We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg^2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy/beam. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of galaxies in this supercluster and for a possible extended SZ decrement due to diffuse warm/hot gas in the intercluster medium. We measure negative flux values in the positions of the ten richest clusters in the region. Collectively, this implies a 3.0-sigma detection of the SZ effect. In the clusters A2061 and A2065 we find decrements of approximately 2-sigma. Our main result is the detection of two strong and resolved negative features at -70+-12 mJy/beam (-157+-27 microK) and -103+-10 mJy/beam (-230+-23 microK), respectively, located in a region with no known clusters, near the centre of the supercluster. We discuss their possible origins in terms of primordial CMB anisotropies and/or SZ signals related to either unknown clusters or to a diffuse extended warm/hot gas distribution. Our analyses have revealed that a primordial CMB fluctuation is a plausible explanation for the weaker feature (probability of 37.82%). For the stronger one, neither primordial CMB (probability of 0.33%) nor SZ can account alone for its size and total intensity. The most reasonable explanation, then, is a combination of both primordial CMB and SZ signal. Finally, we explore what characteristics would be required for a filamentary structure consisting of warm/hot diffuse gas in order to produce a significant contribution to such a spot taking into account the constraints set by X-ray data.
Cleary Kieran
Davies Rod D.
Davis Richard J.
Dickinson Clive
Falcon Nelson
No associations
LandOfFree
A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-371544