ar X iv : a st ro - p h / 06 02 25 8 v 1 13 F eb 2 00 6 TeV Gamma - Ray Observations of the Perseus and Abell 2029 Galaxy Clusters
نویسنده
چکیده
Galaxy clusters might be sources of TeV gamma rays emitted by high-energy protons and electrons accelerated by large scale structure formation shocks, galactic winds, or active galactic nuclei. Furthermore, gamma rays may be produced in dark matter particle annihilation processes at the cluster cores. We report on observations of the galaxy clusters Perseus and Abell 2029 using the 10 m Whipple Cherenkov telescope during the 2003-2004 and 2004-2005 observing seasons. We apply a two-dimensional analysis technique to scrutinize the clusters for TeV emission. In this paper we first determine flux upper limits on TeV gamma-ray emission from point sources within the clusters. Second, we derive upper limits on the extended cluster emission. We subsequently compare the flux upper limits with EGRET upper limits at 100 MeV and theoretical models. Assuming that the gamma-ray surface brightness profile mimics that of the thermal X-ray emission and that the spectrum of cluster cosmic rays extends all the way from thermal energies to multi-TeV energies with a differential spectral index of -2.1, our results imply that the cosmic ray proton energy density is less than 7.9% of the thermal energy density for the Perseus cluster. Subject headings: galaxies: clusters: general galaxies: individual (NGC 1275) galaxies: clusters: individual (Abell 426, Perseus, Abell 2029) gamma rays: observations
منابع مشابه
ar X iv : a st ro - p h / 98 02 06 9 v 1 5 F eb 1 99 8 1 Beppo - SAX Observations of Galaxy Clusters
The high spatial resolution of the MECS experiment on board Beppo-SAX has encouraged a few scientists, including the author, to perform observations of galaxy clusters. Results from the analysis of the first few observed objects are encouraging. After having reviewed the Beppo-SAX observing program for galaxy clusters and referenced contributions to these proceedings by other authors on the sam...
متن کاملar X iv : a st ro - p h / 98 02 06 3 v 1 5 F eb 1 99 8 The Redshift Distribution of Distant Sources from Gravitational Depletion in Clusters
Gravitational lensing can be used to analyze the redshift distribution of faint galaxies. In particular the magnification bias modifies locally the galaxy number density of lensed sources observed in lensing clusters. This depletion area probes the redshift distribution of galaxies beyond B = 25. In this proceedings I present this new tool to infer the redhsift distribution of faint galaxies.
متن کاملar X iv : a st ro - p h / 99 02 06 2 v 1 4 F eb 1 99 9 SOURCES OF RELATIVISTIC JETS IN THE GALAXY
متن کامل
ar X iv : a st ro - p h / 95 12 02 8 v 1 6 D ec 1 99 5 A search for distant X - ray galaxy clusters
We report on the progress of our search for serendipitous distant X-ray galaxy clusters in the ROSAT PSPC pointed observations archive. The initial aim of our work is to measure the X-ray luminosity function of clusters down to f lim = 4×10 −14 erg cm −2 s −1 and so test the claims of cluster evolution at moderate redshifts. We have R band images and spectroscopy for 45 extended sources detecte...
متن کاملar X iv : a st ro - p h / 05 04 03 6 v 1 1 A pr 2 00 5 Gemini and Chandra observations of Abell 586 , a relaxed strong - lensing cluster
We analyze the mass content of the massive strong-lensing cluster Abell 586 (z = 0.17). We use optical data (imaging and spectroscopy) obtained with the Gemini Multi-Object Spectrograph (GMOS) mounted on the 8-m Gemini-North telescope, together with publicly available X-ray data taken with the Chandra space telescope. Employing different techniques – velocity distribution of galaxies, weak grav...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006