The Merger in Abell 576: A Line-of-Sight Bullet Cluster?
| dc.contributor.author | Dupke, Renato A. | |
| dc.contributor.author | Mirabal, Nestor | |
| dc.contributor.author | Bregman, Joel N. | |
| dc.contributor.author | Evrard, August E. | |
| dc.date.accessioned | 2020-09-08T15:30:16Z | |
| dc.date.available | 2020-09-08T15:30:16Z | |
| dc.date.issued | 2007-05-22 | |
| dc.description.abstract | Using a combination of Chandra and XMM-Newton observations, we confirmed the presence of a significant velocity gradient along the northeast-southwest direction in the intracluster gas of the cluster Abell 576. The results are consistent with a previous ASCA SIS analysis of this cluster. The error-weighted average over the ACIS-S3 and EPIC MOS1 and MOS2 spectrometers for the maximum velocity difference is >3.3 × 10³ km s⁻¹ at the 90% confidence level, similar to the velocity limits estimated indirectly for the Bullet Cluster (1E 0657-56). The probability that the velocity gradient is generated by standard random gain fluctuations with Chandra and XMM-Newton is <0.1%. The regions of maximum velocity gradient are in CCD zones that have the lowest temporal gain variations. It is unlikely that the velocity gradient is due to Hubble distance differences between projected clusters (probability lesssim0.01%). We mapped the distribution of elemental abundance ratios across the cluster and detected a strong chemical discontinuity using the abundance ratio of silicon to iron, equivalent to a variation from 100% SN Ia iron mass fraction in the west-northwest regions to 32% in the eastern region. The "center" of the cluster is located at the chemical discontinuity boundary, which is inconsistent with the radially symmetric chemical gradient found in some regular clusters, but consistent with a cluster merging scenario. We predict that the velocity gradient as measured will produce a variation of the cosmic microwave background (CMB) temperature toward the east of the core of the cluster that will be detectable by current and near-future bolometers. The measured velocity gradient opens up the possibility that this cluster is passing through a near line-of-sight merger stage where the cores have recently crossed. | en_US |
| dc.description.sponsorship | The authors would like to thank Jimmy Irwin, Ed LloydDavies, Maxim Markevitch, Chris Mullis, Kenneth Rines and Ming Sun for useful discussions and suggestions. We also thank the anonymous referee for useful suggestions. We acknowledge support from NASA Grants NAG 5-3247, NNG05GQ11 & GO5-6139X. This research made use of the HEASARC ASCA database and NED. | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.1086/520708 | en_US |
| dc.format.extent | 30 pages | en_US |
| dc.genre | journal articles preprints | en_US |
| dc.identifier | doi:10.13016/m2mgy6-dqcm | |
| dc.identifier.citation | Renato A. Dupke, Nestor Mirabal, Joel N. Bregman and August E. Evrard, The Merger in Abell 576: A Line-of-Sight Bullet Cluster?, ApJ 668 781 (2007), DOI: https://doi.org/10.1086/520708 | en_US |
| dc.identifier.uri | https://doi.org/10.1086/520708 | |
| dc.identifier.uri | http://hdl.handle.net/11603/19599 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | IOP | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology (JCET) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology (CSST)/Center for Research and Exploration in Space Sciences and Technology II (CREST II) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | © 2007. The American Astronomical Society. All rights reserved | |
| dc.title | The Merger in Abell 576: A Line-of-Sight Bullet Cluster? | en_US |
| dc.type | Text | en_US |