EDP Sciences
Free access
Volume 423, Number 1, August III 2004
Page(s) 65 - 73
Section Cosmology (including clusters of galaxies)
DOI http://dx.doi.org/10.1051/0004-6361:20034006

A&A 423, 65-73 (2004)
DOI: 10.1051/0004-6361:20034006

The analysis of Abell 1835 using a deprojection technique

S. M. Jia1, 2, Y. Chen1, F. J. Lu1, L. Chen1, 2 and F. Xiang1

1  Particle Astrophysics Center, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, PR China
    e-mail: jiasm@mail.ihep.ac.cn
2  Department of Astronomy, Beijing Normal University, Beijing 100875, PR China

(Received 26 June 2003 / Accepted 1 April 2004 )

We present the results from a detailed deprojection analysis of Abell 1835 as observed by XMM-Newton. If we fit the spectra with an isothermal plasma model, the deprojected temperature profile is flat in the outer region around 7.6 keV and decreases to ~5.6 keV in the center, which may be connected with the gas cooling. In the central part, a two-component thermal plasma model can fit the spectrum significantly better. Moreover, the cool component ( $T \sim 1.8$ keV) has a much lower metal abundance than the hot component ( $T \sim 8$ keV), which may be due to the longer cooling time for the cool gas with lower abundance. In addition, it was found that without a main isothermal component, the standard cooling flow model cannot fit the spectrum satisfactorily. From the isothermal model fitting results we also derived the electron density  $n_{\rm e}$, and fitted its radial distribution with a double- $\beta$ model. The  $n_{\rm e}$ profile inferred with the double- $\beta$ model and the deprojected X-ray gas temperature profile were then combined to derive the total mass and the total projected mass of the cluster. The projected mass is lower than that derived from the weak lensing method. However, assuming that the cluster extends to a larger radius ~ 15' as found by Clowe & Schneider (2002), the two results are consistent within the error bars. Furthermore, we calculated the projected mass within the radius of ~153 kpc implied by the presence of a gravitational lensing arc, which is about half of the mass determined from the optical lensing.

Key words: galaxies: clusters: individual: Abell 1835 -- X-rays: galaxies

SIMBAD Objects

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