EDP Sciences
Free access
Volume 375, Number 1, August III 2001
Page(s) L14 - L17
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20010871

A&A 375, L14-L17 (2001)
DOI: 10.1051/0004-6361:20010871

On the metal abundance in the core of M 87

S. Molendi1 and F. Gastaldello1, 2

1  Istituto di Fisica Cosmica, CNR, via Bassini 15, 20133 Milano, Italy
2  Università di Milano Bicocca, Dip. di Fisica, P.za della Scienza 3 20133 Milano, Italy

(Received 11 May 2001 / Accepted 19 June 2001)

We revisit the XMM-Newton observation of M 87 to make a new and more detailed measurement of the metal abundance profile. After having verified that spectral fits with single temperature models show a dramatic abundance drop within 1 arcmin of the cluster core, we show that more appropriate models, which include a multi-temperature component to account for the strong temperature gradient observed in M 87, and a power-law component to account for the emission of the nucleus and knot A, give a substantially flat abundance profile. The drastic abundance decrement found by fitting a single temperature component to the data is an artifact known as "Fe-bias" (Buote 2000a,b) following from the application of an oversimplified spectral model to the data.

Key words: X-rays: galaxies -- galaxies: clusters -- galaxies: individual: M 87

Offprint request: S. Molendi, silvano@ifctr.mi.cnr.it

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