On the metal abundance in the core of M 87

Citation
S. Molendi et F. Gastaldello, On the metal abundance in the core of M 87, ASTRON ASTR, 375(1), 2001, pp. L14-L17
Citations number
13
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS
ISSN journal
14320746 → ACNP
Volume
375
Issue
1
Year of publication
2001
Pages
L14 - L17
Database
ISI
SICI code
1432-0746(200108)375:1<L14:OTMAIT>2.0.ZU;2-Z
Abstract
We revisit the XMM-Newton observation of M 87 to make a new and more detail ed measurement of the metal abundance profile. After having verified that s pectral 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 tempe rature gradient observed in M 87, and a power-law component to account for the emission of the nucleus and knot A, give a substantially at abundance p rofile. The drastic abundance decrement found by fitting a single temperatu re 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 d ata.