Deeper Chandra follow-up of Cygnus TeV source perpetuates mystery

被引:32
作者
Butt, YM
Drake, J
Benaglia, P
Combi, JA
Dame, T
Miniati, F
Romero, GE
机构
[1] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[2] Inst Argentino Radioastron, RA-1894 Buenos Aires, DF, Argentina
[3] Natl Univ La Plata, Fac Ciencias Astron & Geofis, RA-1900 La Plata, Argentina
[4] Univ Jaen, Dept Fis, Jaen 23071, Spain
[5] ETH, Dept Phys, CH-8093 Zurich, Switzerland
关键词
acceleration of particles; cosmic rays; gamma rays : observations; ISM : bubbles; open clusters and associations : individual (Cygnus OB2);
D O I
10.1086/502642
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A 50 ks Chandra observation of the unidentified TeV source in Cygnus reported by the HEGRA collaboration reveals no obvious diffuse X-ray counterpart. However, 240 pointlike X-ray sources are detected within or nearby the extended TeV J2032+4130 source region, of which at least 36 are massive stars and two may be radio emitters. That the HEGRA source is a composite, having as a counterpart the multiple pointlike X-ray sources we observe, cannot be ruled out. Indeed, the distribution of pointlike X-ray sources appears nonuniform and concentrated broadly within the extent of the TeV source region. We offer a hypothesis for the origin of the very high energy gamma-ray emission in Cyg OB2 based on the local acceleration of TeV-range cosmic rays and the differential distribution of OB versus less massive stars in this association.
引用
收藏
页码:238 / 244
页数:7
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