CYCLOTRON MASER EMISSION FROM POWER-LAW ELECTRONS WITH STRONG PITCH-ANGLE ANISOTROPY

Journal Article · Tue May 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/822/2/58· OSTI ID:22663058

Zhao, G. Q.; Feng, H. Q.; Liu, Q. ^[1]; Wu, D. J.; Chen, L. ^[2]; Tang, J. F. ^[3]

---

1. Institute of Space Physics, Luoyang Normal University, Luoyang 471022 (China)
2. Purple Mountain Observatory, CAS, Nanjing 210008 (China)
3. Xinjiang Astronomical Observatory, CAS, Urumqi 830011 (China)

Energetic electrons with power-law spectra are commonly observed in astrophysics. This paper investigates electron cyclotron maser emission (ECME) from the power-law electrons, in which strong pitch-angle anisotropy is emphasized. The electron distribution function proposed in this paper can describe various types of pitch-angle anisotropy. Results show that the emission properties of ECME, including radiation growth, propagation, and frequency properties, depend considerably on the types of electron pitch-angle anisotropy, and different wave modes show different dependences on the pitch angle of electrons. In particular, the maximum growth rate of the X2 mode rapidly decreases with respect to the electron pitch-angle cosine μ {sub 0} at which the electron distribution peaks, while the growth rates for other modes (X1, O1, O2) initially increase before decreasing as μ {sub 0} increases. Moreover, the O mode, as well as the X mode, can be the fastest growth mode, in terms of not only the plasma parameter but also the type of electron pitch-angle distribution. This result presents a significant extension of the recent researches on ECME driven by the lower energy cutoff of power-law electrons, in which the X mode is generally the fastest growth mode.

• OSTI ID: 22663058
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 822; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
ASTROPHYSICS
COSMIC RADIATION
CYCLOTRON RADIATION
DISTRIBUTION
DISTRIBUTION FUNCTIONS
EMISSION
INCLINATION
MASERS
PLASMA
SPECTRA
SUN
TAIL ELECTRONS