DETECTION OF GAMMA-RAY EMISSION FROM THE QUASAR PKS 0208-512

被引：41

作者：

BERTSCH, DL

DINGUS, BL

FICHTEL, CE

HARTMAN, RC

HUNTER, SD

KANBACH, G

KNIFFEN, DA

LIN, YC

MATTOX, JR

MAYERHASSELWANDER, HA

MICHELSON, PF

VONMONTIGNY, C

NOLAN, PL

PINKAU, K

SCHNEID, E

SREEKUMAR, P

THOMPSON, DJ

机构：

[1] MAX PLANCK INST EXTRATERR PHYS,W-8046 GARCHING,GERMANY

[2] HAMPDEN SYDNEY COLL,HAMPDEN SYDNEY,VA 23943

[3] STANFORD UNIV,HANSEN EXPTL PHYS LAB,STANFORD,CA 94305

[4] COMP SCI CORP,ASTRON PROGRAM,COMPTON OBSERV SCI SUPPORT CTR,LOS ANGELES,CA 90045

[5] GRUMMAN AEROSP CORP,BETHPAGE,NY 11714

来源：

ASTROPHYSICAL JOURNAL | 1993年 / 405卷 / 01期

关键词：

GALAXIES; ACTIVE; GAMMA-RAYS; OBSERVATIONS; QUASARS; INDIVIDUAL; (PKS; 0208; 512);

D O I：

10.1086/186756

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

High-energy gamma-ray emission has been detected from the quasar PKS 0208 - 512 in the energy range above 30 MeV by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory. This region of sky was observed in five different viewing periods, and evidence of time variability in the gamma-ray emission by more than a factor of 3 was found. At the maximum intensity between 1991 September 19 and October 3, the flux density above 100 MeV was (9.1 +/- 0.4) x 10(-7)gamma cm-2 s-1. The photon spectrum during this period may be expressed as a power law with an exponent of -1.69 +/- 0.05 between 30 MeV and 4 GeV. This is the hardest quasar spectrum observed by EGRET up to the present time.

引用

页码：L21 / L24

页数：4

共 30 条

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