Comparison of Hectospec Virial Masses with SZE Measurements

Details Comparison of Hectospec Virial Masses with SZE Measurements Comparison of Hectospec Virial Masses with SZE Measurements

2009-12-30

arxiv.org/abs/1001.0006v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

6 pages, 2 figures, accepted to ApJ Letters, minor revisions, shortened title

Scientific paper

We present the first comparison of virial masses of galaxy clusters with their Sunyaev-Zel'dovich Effect (SZE) signals. We study 15 clusters from the Hectospec Cluster Survey (HeCS) with MMT/Hectospec spectroscopy and published SZE signals. We measure virial masses of these clusters from an average of 90 member redshifts inside the radius $r_{100}$. The virial masses of the clusters are strongly correlated with their SZE signals (at the 99% confidence level using a Spearman rank-sum test). This correlation suggests that $Y_{SZ}$ can be used as a measure of virial mass. Simulations predict a powerlaw scaling of $Y_{SZ}\propto M_{200}^\alpha$ with $\alpha\approx$1.6. Observationally, we find $\alpha$=1.11$\pm$0.16, significantly shallower (given the formal uncertainty) than the theoretical prediction. However, the selection function of our sample is unknown and a bias against less massive clusters cannot be excluded (such a selection bias could artificially flatten the slope). Moreover, our sample indicates that the relation between velocity dispersion (or virial mass estimate) and SZE signal has significant intrinsic scatter, comparable to the range of our current sample. More detailed studies of scaling relations are therefore needed to derive a robust determination of the relation between cluster mass and SZE.

Affiliated with

Also associated with

No associations

Rating

Comparison of Hectospec Virial Masses with SZE Measurements 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 Comparison of Hectospec Virial Masses with SZE Measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comparison of Hectospec Virial Masses with SZE Measurements will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-103635