相关论文: Extreme Ultraviolet Emission from Abell 4059
Since all of the five clusters of galaxies observed by the Extreme Ultraviolet Explorer deep survey telescope are found to possess a diffuse EUV emitting component which is unrelated to the virial gas at X-ray temperatures, the question…
We present studies of the Extreme Ultraviolet (EUV) emission in the Fornax cluster of galaxies; a relatively nearby well-studied cluster with X-ray emitting cluster gas and a very large radio source. We examine both the large-scale (~size…
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…
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…
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…
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…
Observations with the Extreme Ultraviolet Explorer satellite are purported to show extreme ultraviolet (EUV) and soft X-ray excesses in several clusters of galaxies (Bonamente, Lieu & Mittaz 2001). If interpreted as thermal emission, this…
We present results of a re-analysis of archival EUVE data of the central region of the Virgo cluster. We employ the new analysis method developed by Bowyer, Bergh\"ofer & Korpela (1999) and find diffuse emission reaching out to a distance…
Observations with the Extreme Ultraviolet Explorer (EUVE) have shown the Coma Cluster to be a source of EUV emission in excess of that produced by X-ray gas in the cluster. We have re-examined the EUVE data on this cluster in an attempt to…
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 ($\sim$ 10$^6$ K) gas - a…
Several authors (S. Bowyer, T. Berghoeffer, and E. Korpela, hereinafter abbreviated as BBK) recently announced that the luminous extended EUV radiation from the clusters Abell 1795 and Abell 2199, which represents the large scale presence…
Observations with the Extreme UltraViolet Explorer (EUVE) satellite have shown that the inner region of the Virgo cluster (centered in M87 galaxy) has a strong Extreme UltraViolet (EUV) emission (up to $13^{\prime}$) in excess to the…
Various independent ways of constraining the Hubble constant and the baryonic content of the universe finally converged at a consensus range of values which indicates that at the present epoch the bulk of the universe's baryons is in the…
With tantalizing evidence of the recent e-Rosita mission, re-discovering very soft X-rays and EUV radiation from a cluster of galaxies or its environment, the question of the origin of cluster EUV excess is revisited in this work. It will…
We present a comprehensive search for non-thermal high-energy $\gamma$-ray emission from the nearby merging galaxy cluster Abell~119 ($z=0.044$) using archival observations spanning over seven decades in photon energy. Our analysis combines…
An extremely soft X-ray excess throughout galaxy clusters has been claimed as a new feature of these sytems, with important physical implications. We have reexamined this feature in the five clusters for which it has been discussed, using…
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).…
Galaxy clusters are among the most massive gravitationally bound systems in the Universe and are considered major reservoirs of high-energy cosmic rays, yet no conclusive $\gamma$-ray detection from them has been achieved. This…
Clusters of galaxies are strong emitters of EUV and soft X-rays substantially in excess of the contribution from the hot intra-cluster medium at X-ray temperatures. After the initial discovery of EUV excess emission in the Virgo cluster,…
Using data from the ROSAT Wide Field Camera all-sky survey, we have established upper limits to the extreme ultraviolet (EUV) flux from a sample of 30 bright, nearby, non-active spiral galaxies. These galaxies were chosen to be those most…