2. STATUS OF TEV GAMMA-RAY ASTRONOMY c. 2003

An updated catalog of sources is shown in Table 1 and is plotted in Figure 1. The criterion for inclusion in this catalog is that the detection should be significant and be published in the refereed literature. Four sources have been added since the last catalog (6). Of more significance perhaps is that three new classes of object are represented (starburst galaxies, radio galaxies, OB Associations). It is noteworthy that many of the sources listed are not in the EGRET Catalog (7), an indication that the TeV sky opens a new window on the universe. The allotted grade gives some measure of the credibility that should be assigned to the reported detections; "A" sources have been independently verified at the 5 level. On this scale the EGRET sources would be classified as "B" (except for 3C273 which would be classified as "A" since it was also detected by COS B (8); (9)). In this new catalog the status of several of the TeV sources (marked with an asterisk) has been upgraded (and only one has been downgraded). This suggests that the field has achieved a degree of maturity and that systematic effects in most experiments (but perhaps not all) are understood and accounted for. We propose therefore that an acceptable standard for the publication of a claim for the detection of a new source by a mature experiment should be the 4 level of significance.

Figure 1. The 18 claimed sources of TeV gamma rays c. 2003; confirmed sources are drawn in red.