1 v 1 2 N ov 1 99 9 EUV EMISSION IN ABELL 1795 , ABELL 2199 , AND THE COMA CLUSTER

نویسنده

  • Eric J. Korpela
چکیده

We report new EUV data on the cluster of galaxies Abell 1795. These data were taken well away from a detector defect which could have compromised earlier results on this cluster. Our new observations confirm the validity of the original data set. However, we find our results are strongly influenced by the variation of the telescope sensitivity over the field of view and upon the details of the subtraction of the EUV emission from the X-ray plasma. We investigate these effects using our new data and archival data on Abell 1795, Abell 2199 and the Coma cluster. When we use the appropriate correction factors, we find there is no evidence for any excess EUV emission in Abell 1795 or Abell 2199. However, we do find extended EUV emission in the Coma Cluster using our new analysis procedures, confirming that in at least this cluster some as yet unidentified process is operative. Subject headings: galaxy clusters: general

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A reanalysis of EUV emission in clusters of galaxies

We report a new analysis of diffuse EUV emission in clusters of galaxies. We find the cluster emission is strongly influenced by the variation of the telescope sensitivity over the field of view and upon the details of the subtraction of the EUV emission from the X-ray plasma. We investigate these effects on Abell 1795, Abell 2199, and the Coma cluster. When we use the appropriate correction fa...

متن کامل

An Analysis of BeppoSAX LECS Observations of EUV Emission in Clusters of Galaxies

Kaastra et al. (1999) have used the BeppoSAX LECS instrument to search for excess EUV emission in Abell 2199. They claim that the results obtained confirm an independent report of an excess EUV emission in this cluster (Lieu et al. 1999). Using an inflight derived procedure that is better suited to the analysis of extended sources and which avoids uncertainties related to ground-based calibrati...

متن کامل

The extreme ultraviolet excess emission in five clusters of galaxies revisited

Evidence for excess extreme ultraviolet (EUV) emission over a tail of X-ray gas bremsstrahlung emission has been building up recently, but in some cases remains controversial, mostly due to the moderate quality of the EUV data. In order to improve the signal to noise ratio in the EUV, we have performed the wavelet analysis and image reconstructions for five clusters of galaxies observed both at...

متن کامل

Re-observing the EUV emission from Abell 2199: in situ measurement of background distribution by offset pointing

The EUV excess emission from the clusters A2199 and A1795 remains an unexplained astrophysical phenomenon. There has been many unsuccessful attempts to ‘trivialize’ the findings. In this Letter we present direct evidence to prove that the most recent of such attempts, which attributes the detected signals to a background non-uniformity effect, is likewise excluded. We address the issue by a re-...

متن کامل

EUV and X-ray observations of Abell 2199: a three-phase intracluster medium with a massive warm component

Various independent ways of constraining key cosmological parameters yielded a consensus range of values which indicates that at the present epoch the bulk of the universe’s baryons is in the form of a warm (∼ 106 K) gas – a temperature regime which renders them difficult to detect. The discovery of EUV and soft X-ray excess emission from clusters of galaxies was originally interpreted as the f...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999