Nonthermal Radio Emission from the X-Ray--Bright K5 IV Star 1E 1751+7046
Abstract
VLA observations are analyzed of the K5 IV star 1E 1751 + 7046, which is known to be an X-ray source on the basis of Einstein observations and which shows some similarity to stars of the FK Comae type. Radio continuum emission has been detected at 3.6, 6, and 20 cm, and the spectral energy distribution is nearly flat. There is no evidence for circular polarization, and upper limits are given. The 6-cm flux is roughly one order of magnitude less than reported in a previous VLA observation, indicating that this star may flare at radio wavelengths. The inferred radio variability and the nearly flat spectral energy distribution suggest that the emission is of nonthermal origin. A variety of possible emission mechanisms is examined, and it is concluded that the emission is best explained in terms of a gyrosynchrotron/synchrotron model with the electrons following a power-law energy distribution. A brief comparison of the radio properties of 1E 1751 + 7046 with FK Comae-like stars and RS CVn systems is given.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1991
- DOI:
- 10.1086/169691
- Bibcode:
- 1991ApJ...368..272S
- Keywords:
-
- K Stars;
- Radio Emission;
- Stellar Radiation;
- X Ray Stars;
- Brightness Temperature;
- Interstellar Masers;
- Nonthermal Radiation;
- Spectral Energy Distribution;
- Synchrotron Radiation;
- Very Large Array (Vla);
- Astrophysics;
- RADIATION MECHANISMS;
- STARS: FLARE;
- STARS: INDIVIDUAL ALPHANUMERIC: 1E 1751;
- 7046;
- STARS: LATE-TYPE;
- STARS: RADIO RADIATION;
- STARS: X-RAYS