Millimeter-wave emission during the 2003 low excitation phase of eta Carinae

Abstract

In this paper we present observations of eta Carinae in the 1.3 mm and 7 mm radio continuum, during the 2003.5 low excitation phase. The expected minimum in the light curves was confirmed at both wavelengths and was probably due to a decrease in the number of UV photons available to ionize the gas surrounding the binary system. At 7 mm a very well defined peak was superimposed on the declining flux density. It presented maximum amplitude in 29 June 2003 and lasted for about 10 days. We show that its origin can be free-free emission from the gas at the shock formed by wind-wind collision, which is also responsible for the observed X-ray emission. Even though the shock strength is strongly enhanced as the two stars in the binary system approach each other, during periastron passage the X-ray emission is strongly absorbed and the 7 mm observations represent the only direct evidence of this event.

References in corpus (6)

• In Hot Pursuit of the Hidden Companion of Eta Carinae: An X-ray Determination of the Wind Parameters
• Eta Carinae: Binarity Confirmed
• Radio emission models of Colliding-Wind Binary Systems
• Early Chandra X-ray Observations of Eta Carinae
• The CHANDRA HETGS X-ray Grating Spectrum of Eta Car
• Wind-Wind Collision in the eta Carinae Binary System: a Shell-Like Event Near Periastron

Cited by in corpus (30)

• The periodicity of the eta Carinae events
• Spiralling out of control: 3D hydrodynamical modelling of the colliding winds in $\eta$Carinae
• A multispectral view of the periodic events in eta Carinae
• On the influence of the companion star in Eta Carinae: 2D radiative transfer modeling of the ultraviolet and optical spectra
• Possible Implications of Mass Accretion in Eta Carinae
• 3D models of radiatively driven colliding winds in massive O+O star binaries - II. Thermal radio to sub-mm emission
• Accretion by the Secondary in Eta Carinae During the Spectroscopic Event: I. Flow Parameters
• Chandra X-ray Grating Spectrometry of Eta Carinae near X-ray Minimum: I. Variability of the Sulfur and Silicon Emission Lines
• Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage
• Submillimetre Variability of Eta Carinae: cool dust within the outer ejecta
• MHD numerical simulations of colliding winds in massive binary systems - I. Thermal vs non-thermal radio emission
• Hard X-ray identification of Eta Carinae and steadiness close to periastron
• Long-Term Optical Monitoring of Eta Carinae. Multiband light curves for a complete orbital period
• Using X-Ray Observations to Explore the Binary Interaction in Eta Carinae
• $\eta$ Carinae Baby Homunculus Uncovered by ALMA
• The Source of the Helium Visible Lines in Eta Carinae
• The Eta Carinae optical 2009.0 event, a new "eclipse-like" phenomenon
• The Orientation of the Eta Carinae Binary System
• Modelling the Radio Light Curve of Eta Carinae
• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. V. the Infrared Decline
• Wind-wind collision in the eta Carinae binary system - III. The HeII 4686 line profile
• Wind-wind collision in the Carinae binary system II: Constrains to the binary orbital parameters from radio emission near periastron passage
• Orbital Parameters for the $250M_{\odot }$ Eta Carinae Binary System
• Submillimetre Emission from Eta Carinae
• Constraining the orbital orientation of Eta Carinae from H Paschen lines
• Prediction for the He I 10830A Absorption Wing in the Coming Event of Eta Carinae
• The X-ray properties of Eta Carinae during its 2020 X-ray minimum
• $\eta$ Carinae: high angular resolution continuum, H30$\alpha$ and He30$\alpha$ ALMA images
• The orientation of Eta Carinae and the powering mechanism of intermediate luminosity optical transients (ILOTs)
• Telluric absorption lines in the ALMA spectra of $\eta$ Car