TENTATIVE EVIDENCE FOR RELATIVISTIC ELECTRONS GENERATED BY THE JET OF THE YOUNG SUN-LIKE STAR DG Tau

被引:41
作者
Ainsworth, Rachael E. [1 ,2 ]
Scaife, Anna M. M. [3 ]
Ray, Tom P. [1 ,2 ]
Taylor, Andrew M. [1 ]
Green, David A. [4 ]
Buckle, Jane V. [4 ,5 ]
机构
[1] Dublin Inst Adv Studies, Dublin 2, Ireland
[2] Univ Dublin Trinity Coll, Sch Phys, Dublin 2, Ireland
[3] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England
[4] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England
[5] Kavli Inst Cosmol, Cambridge CB3 0HA, England
基金
欧洲研究理事会; 爱尔兰科学基金会;
关键词
radiation mechanisms: non-thermal; stars: individual (DG Tau); stars: low-mass; stars: mass-loss; RADIO-CONTINUUM OBSERVATIONS; MAGNETIC-FIELDS; SCALE; OUTFLOWS; CLOUDS;
D O I
10.1088/2041-8205/792/1/L18
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from active galactic nuclei. We present data at 325 and 610 MHz taken with the Giant Metrewave Radio Telescope of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass young stellar object at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpret this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength B-min approximate to 0.11 mG and particle energy E-min approximate to 4 x 10(40) erg, which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.
引用
收藏
页数:5
相关论文
共 35 条
[11]   VLA OBSERVATIONS OF MASS-LOSS FROM T-TAURI STARS [J].
COHEN, M ;
BIEGING, JH ;
SCHWARTZ, PR .
ASTROPHYSICAL JOURNAL, 1982, 253 (02) :707-715
[12]   RADIO VARIABILITY AND STRUCTURE OF T-TAURI STARS [J].
COHEN, M ;
BIEGING, JH .
ASTRONOMICAL JOURNAL, 1986, 92 (06) :1396-1402
[13]   The NRAO VLA Sky Survey [J].
Condon, JJ ;
Cotton, WD ;
Greisen, EW ;
Yin, QF ;
Perley, RA ;
Taylor, GB ;
Broderick, JJ .
ASTRONOMICAL JOURNAL, 1998, 115 (05) :1693-1716
[14]   COSMOLOGICAL EVOLUTION OF RADIO-SOURCES [J].
CONDON, JJ .
ASTROPHYSICAL JOURNAL, 1984, 287 (02) :461-474
[15]   Magnetic fields in molecular clouds: Observations confront theory [J].
Crutcher, RM .
ASTROPHYSICAL JOURNAL, 1999, 520 (02) :706-713
[16]   TIME-DEPENDENT DIFFUSIVE ACCELERATION OF TEST PARTICLES AT SHOCKS [J].
DRURY, LO .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1991, 251 (02) :340-350
[17]   Imaging and kinematic studies of young stellar object jets in Taurus [J].
Eisloffel, J ;
Mundt, R .
ASTRONOMICAL JOURNAL, 1998, 115 (04) :1554-1575
[18]   Which jet launching mechanism(s) in T Tauri stars? [J].
Ferreira, J. ;
Dougados, C. ;
Cabrit, S. .
ASTRONOMY & ASTROPHYSICS, 2006, 453 (03) :785-796
[19]   Deep 610-MHz Giant Metrewave Radio Telescope observations of the Spitzer extragalactic First Look Survey field -: I.: Observations, data analysis and source catalogue [J].
Garn, Timothy ;
Green, David A. ;
Hales, Sally E. G. ;
Riley, Julia M. ;
Alexander, Paul .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2007, 376 (03) :1251-1260
[20]  
Green DA, 2007, B ASTRON SOC INDIA, V35, P77