LISM structure - Fragmented superbubble shell?

被引:62
作者
Frisch, PC
机构
[1] Univ. Chicago, Dept. Astronomy Astrophysics, Chicago, IL 60637
关键词
local interstellar medium; superbubbles; local bubble models;
D O I
10.1007/BF00170807
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Small scale structure in local interstellar matter (LISM) is considered. Overall morphology of the local cloud complex is inferred from Ca II absorption lines and observations of H I in white dwarf stars. Clouds with column densities ranging from 2-100 x 10(17) cm(-2) are found within 20 pc of the Sun. Cold (50 K) dense (similar to 10(5) cm(-3)) small (5-10 au) clouds could be embedded and currently undetected in the upwind gas. The Sun appears to be embedded in a filament of gas with thickness less than or equal to 0.7 pc, and cross-wise column density less than or equal to 2 x 10(17) cm(-2). The local magnetic field direction is parallel to the filament, suggesting that the physical process causing the filamentation is MHD related. Enhanced abundances of refractory elements and LISM kinematics indicate outflowing gas from the Scorpius-Centaurus Association. The local flow vector and lambda Sco data are consistent with a 4,000,000 year old superbubble shell at similar to-22 km s(-1), which is a shock front passing through preshock gas at similar to-12 km s(-1), and yielding cooled postshock gas at similar to-26 km s(-1)in the upwind direction. A preshock magnetic field strength of 1.6 mu G, and postshock field strength of 5.2 mu G embedded in the superbubble shell, are consistent with the data.
引用
收藏
页码:213 / 222
页数:10
相关论文
共 26 条
[1]  
BERTIN P, 1993, ASTRON ASTROPHYS, V278, P549
[2]  
BERTIN P, 1995, ASTRON ASTROPHYS, V302, P889
[3]   ULTRA-HIGH-RESOLUTION OBSERVATIONS OF CA+ IONS IN THE LOCAL INTERSTELLAR-MEDIUM [J].
CRAWFORD, IA ;
DUNKIN, SK .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1995, 273 (01) :219-224
[4]   ROSAT EUV OBSERVATIONS OF DA WHITE-DWARFS AND LATE-TYPE STARS AND THE STRUCTURE OF THE LOCAL INTERSTELLAR-MEDIUM [J].
DIAMOND, CJ ;
JEWELL, SJ ;
PONMAN, TJ .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1995, 274 (02) :589-601
[5]  
DRAINE BT, 1991, ASTROPH SP SCI, V233, P111
[6]   PROBING THE INTERSTELLAR-MEDIUM WITH PULSARS ON AU SCALES [J].
FRAIL, DA ;
WEISBERG, JM ;
CORDES, JM ;
MATHERS, C .
ASTROPHYSICAL JOURNAL, 1994, 436 (01) :144-151
[7]  
Frisch P., 1986, GALAXY SOLAR SYSTEM, P83
[8]   MORPHOLOGY AND IONIZATION OF THE INTERSTELLAR CLOUD SURROUNDING THE SOLAR-SYSTEM [J].
FRISCH, PC .
SCIENCE, 1994, 265 (5177) :1423-1427
[9]   CHARACTERISTICS OF NEARBY INTERSTELLAR MATTER [J].
FRISCH, PC .
SPACE SCIENCE REVIEWS, 1995, 72 (3-4) :499-592
[10]   THE LOCAL INTERSTELLAR-MEDIUM .7. THE LOCAL INTERSTELLAR WIND AND INTERSTELLAR MATERIAL IN FRONT OF THE NEARBY STAR ALPHA-OPHIUCHI [J].
FRISCH, PC ;
YORK, DG ;
FOWLER, JR .
ASTROPHYSICAL JOURNAL, 1987, 320 (02) :842-&