* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Cosmology News -> Abell 2029
Post Info TOPIC: Abell 2029
Blobrana


L

Posts: 131433
Date:
RE: Abell 2029
Permalink  
 

Title: Deep Chandra Observations of the Extended Gas Sloshing Spiral in A2029
Authors: Rachel Paterno-Mahler, Elizabeth L. Blanton, Scott W. Randall, Tracy E. Clarke

Recent X-ray observations of galaxy clusters have shown that there is substructure present in the intracluster medium (ICM), even in clusters that are seemingly relaxed. This substructure is sometimes a result of sloshing of the ICM, which occurs in cool core clusters that have been disturbed by an off-axis merger with a sub-cluster or group. We present deep Chandra observations of the cool core cluster Abell 2029, which has a sloshing spiral extending radially outward from the center of the cluster to approximately 400 kpc at its fullest extent---the largest continuous spiral observed to date. We find a surface brightness excess, a temperature decrement, a density enhancement, an elemental abundance enhancement, and a smooth pressure profile in the area of the spiral. The sloshing gas seems to be interacting with the southern lobe of the central radio galaxy, causing it to bend and giving the radio source a wide-angle tail (WAT) morphology. This shows that WATs can be produced in clusters that are relatively relaxed on large scales. We explore the interaction between heating and cooling in the central region of the cluster. Energy injection from the active galactic nucleus (AGN) is likely insufficient to offset the cooling, and sloshing may be an important additional mechanism in preventing large amounts of gas from cooling to very low temperatures.

Read more (1711kb, PDF)



__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Title: X-ray observations of the galaxy cluster Abell 2029 to the virial radius
Authors: S. A. Walker, A. C. Fabian, J. S. Sanders, M. R. George, Y. Tawara

We present Suzaku observations of the galaxy cluster Abell 2029, which exploit Suzaku's low particle background to probe the ICM to radii beyond those possible with previous observations (reaching out to the virial radius), and with better azimuthal coverage. We find significant anisotropies in the temperature and entropy profiles, with a region of lower temperature and entropy occurring to the south east, possibly the result of accretion activity in this direction. Away from this cold feature, the thermodynamic properties are consistent with an entropy profile which rises, but less steeply than the predictions of purely gravitational hierarchical structure formation. Excess emission in the northern direction can be explained due to the overlap of the emission from the outskirts of Abell 2029 and nearby Abell 2033 (which is at slightly higher redshift). These observations suggest that the assumptions of spherical symmetry and hydrostatic equilibrium break down in the outskirts of galaxy clusters, which poses challenges for modelling cluster masses at large radii and presents opportunities for studying the formation and accretion history of clusters.

Read more (1219kb, PDF)



__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Cosmology News -> Abell 2029


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard