Estimation of the flux at 1450MHz of OB stars for FAST and SKA

Abstract

Radio observation is crucial to understanding the wind mechanism of OB stars but very scarce. This work estimates the flux at 1450MHz ($S_{1.4GHz}$) of about 5,000 OB stars identified by the LAMOST spectroscopic survey and confirmed by the Gaia astrometric as well as astrophysical measurements. The calculation is performed under the free-free emission mechanism for wind with the mass loss rate derived from stellar parameters. The estimated $S_{1.4GHz}$ distributes from $10^{-11}$Jy to $10^{-3}$Jy with the peak at about $10^{-8}$Jy. This implies that the complete SKA-II can detect more than half of them, and some tens of objects are detectable by FAST without considering source confusion. An array of FAST would increase the detectable sample by two orders of magnitude.

15 pages. 8 figures

References in corpus (10)

• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The Fundamental Performance of FAST with 19-beam Receiver at L Band
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• Disentangling the spatial substructure of Cygnus OB2 from Gaia DR2
• Recipes for bolometric corrections and Gaia luminosities of B-type stars: Application to an asteroseismic sample
• The Binarity of Early-type Stars from LAMOST Medium-resolution Spectroscopic Survey
• e-MERLIN 21cm constraints on the mass-loss rates of OB stars in Cyg OB2
• Sub-mm free-free emission from the winds of massive stars in the age of ALMA
• Radio stars of the SKA
• Radio observations of evaporating objects in the Cygnus OB2 region