Published in:

Astrophysical Journal 624,2 (2005) 638-655;


The Whipple Observatory 10 m γ-ray telescope has been used to survey the error boxes of EGRET unidentified sources in an attempt to find counterparts at energies of 350 GeV and above. Twenty-one unidentified sources detected by EGRET (more than 10% of the total number) have been included in this survey. In no case is a statistically significant signal found in the EGRET error box, which implies that, at least for this sample, the γ-ray spectra of these sources steepen between 100 MeV and 350 GeV. For each EGRET source location, we list candidate associations and derive upper limits on the integral γ-ray flux above 350 GeV.


galaxies : jets;; gamma rays : observations;; surveys;; gamma-ray sources;; source 3eg j2227+6122;; x-ray;; galactic plane;; ls i+61-degrees-303;; supernova-remnants;; galaxy clusters;; sax j0635+0533;; tev energies;; error box

Date of this Version

January 2005



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.