X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

Abstract

We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantly on timescales of hours. The lowest X-ray flux in the 2-10 keV band seen by XMM-Newton was only 0.7% of the maximum seen by RXTE just before the X-ray minimum. The slope of the X-ray continuum above 5 keV did not vary in any observation, which suggests that the electron temperature of the hottest plasma associated with the stellar source did not vary significantly at any phase. Through the minimum, the absorption to the stellar source increased by a factor of 5-10 to NH ~3-4E23 cm-2. The thermal Fe XXV emission line showed significant excesses on both the red and blue sides of the line outside the minimum and exhibited an extreme red excess during the minimum. The Fe fluorescence line at 6.4 keV increased in equivalent width from 100 eV outside the minimum to 200 eV during the minimum. From these observed features, we discuss two possible causes of the X-ray minimum; the eclipse of the X-ray plasma and an intrinsic fading of the X-ray emissivity. The drop in the colliding wind X-ray emission also revealed the presence of an additional X-ray component which exhibited no variation on timescales of weeks to years. This component may be produced by the collision of high speed outflows at v \~1000-2000 km s-1 from Eta Carinae with ambient gas within a few thousand AU from the star.

arXiv comment35 pages, 14 figures, accepted for publication in ApJ

References in corpus (25)

• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• An Overview of the Performance and Scientific Results from the Chandra X-Ray Observatory (CXO)
• In Hot Pursuit of the Hidden Companion of Eta Carinae: An X-ray Determination of the Wind Parameters
• High resolution X-Ray spectroscopy of Zeta Puppis with the XMM-Newton Reflection Grating Spectrometer
• Latitude-dependent effects in the stellar wind of Eta Carinae
• Detection of Doppler Shifted X-ray Line Profiles from the Wind of Zeta Puppis (O4f)
• Direct measurement of the size and shape of the present-day stellar wind of Eta Carinae
• The Binarity of Eta Carinae Revealed from Photoionization Modeling of the Spectral Variability of the Weigelt Blobs B and D
• Imaging Performance of the XMM-Newton X-ray telescopes
• On the He II Emission In Eta Carinae and the Origin of Its Spectroscopic Events
• A Change in the Physical State of $\eta$ Carinae?
• Detection of He II 4686 in eta Carinae
• Early Chandra X-ray Observations of Eta Carinae
• The CHANDRA HETGS X-ray Grating Spectrum of Eta Car
• Variability of eta Carinae III
• Eta Carinae's Brightness Variations Since 1998: HST Observations of the Central Star
• A spectroscopic event of eta Car viewed from different directions: The data and first results
• Accretion by the Secondary in Eta Carinae During the Spectroscopic Event: I. Flow Parameters
• Chandra Observations of Associates of $\eta$ Car: I. Luminosities
• Waiting in the Wings: Reflected X-ray Emission from the Homunculus Nebula
• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event: II. X-Ray Emission Cycle
• Suzaku Observation of Diffuse X-ray Emission from the Carina Nebula
• X-ray spectroscopy of Eta Carinae with XMM-Newton
• The high energy X-ray tail of Eta Car revealed by BeppoSAX
• A spectral and spatial analysis of eta Carinae's diffuse X-ray emission using CHANDRA

Cited by in corpus (62)

• An Introduction to the Chandra Carina Complex Project
• The periodicity of the eta Carinae events
• 3D modelling of the colliding winds in Eta Carinae - evidence for radiative inhibition
• Spiralling out of control: 3D hydrodynamical modelling of the colliding winds in $\eta$Carinae
• 3D models of radiatively driven colliding winds in massive O+O star binaries - III. Thermal X-ray emission
• Fermi Large Area Telescope Observation of a Gamma-ray Source at the Position of Eta Carinae
• Constraining the Absolute Orientation of Eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission
• Constraints on decreases in Eta Carinae's mass loss from 3D hydrodynamic simulations of its binary colliding winds
• Nonthermal X-rays from low-energy cosmic rays: Application to the 6.4 keV line emission from the Arches cluster region
• A multispectral view of the periodic events in eta Carinae
• Modeling the RXTE light curve of $\eta$ Carinae from a 3-D SPH simulation of its binary wind collision
• 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
• Non-thermal X-rays from Colliding Wind Shock Acceleration in the Massive Binary Eta Carinae
• The first X-ray survey of Galactic Luminous Blue Variables
• XMM-Newton X-ray study of early type stars in the Carina OB1 association
• He II $\lambda$4686 emission from the massive binary system in $\eta$ Car: constraints to the orbital elements and the nature of the periodic minima
• Chandra X-ray Grating Spectrometry of Eta Carinae near X-ray Minimum: I. Variability of the Sulfur and Silicon Emission Lines
• He II 4686 in eta Carinae: collapse of the wind-wind collision region during periastron passage
• Gamma-ray follow-up studies on Eta Carinae
• Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage
• X-ray Emission from Eta Carinae near Periastron in 2009 I: A Two State Solution
• Colliding Stellar Winds Structure and X-ray Emission
• Understanding the X-ray Flaring from Eta Car
• Hard X-ray identification of Eta Carinae and steadiness close to periastron
• Near-infrared integral field spectroscopy of the Homunculus nebula around Eta Carinae using Gemini/CIRPASS
• 3D radiative transfer simulations of Eta Carinae's inner colliding winds - I. Ionization structure of helium at apastron
• A Lighthouse Effect in Eta Carinae
• Using X-Ray Observations to Explore the Binary Interaction in Eta Carinae
• Particle acceleration and non-thermal emission in colliding-wind binary systems
• Superluminous supernovae: No threat from Eta Carinae
• The Orientation of the Eta Carinae Binary System
• Super-hard X-Ray Emission from eta Carinae Observed with Suzaku
• 3D Printing Meets Computational Astrophysics: Deciphering the Structure of Eta Carinae's Inner Colliding Winds
• Modelling the Central Constant Emission X-ray component of eta Carinae
• X-ray diagnostics of massive star winds
• Explaining the Early Exit of Eta Carinae from its 2009 X-Ray Minimum with the Accretion Model
• The NuSTAR Hard X-ray Survey of the Norma Arm Region
• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. V. the Infrared Decline
• Competitive X-ray and Optical Cooling in the Collisionless Shocks of WR 140
• Orbital Parameters for the $250M_{\odot }$ Eta Carinae Binary System
• Eta Carinae's Thermal X-ray Tail Measured with XMM-Newton and NuSTAR
• Suzaku X-Ray Spectroscopy of a Peculiar Hot Star in the Galactic Center Region
• 3D Radiative Transfer in $\eta$ Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds
• Accretion at the periastron passage of Eta Carinae
• Gamma-ray and X-ray constraints on non-thermal processes in $\eta$ Carinae
• Suzaku Monitoring of Hard X-ray Emission from Eta Carinae over a Single Binary Orbital Cycle
• Colliding-wind binary systems: Diffusive shock acceleration and non-thermal emission
• A high-velocity transient outflow in Eta Carinae
• Simulating the Response of the Secondary Star of Eta Carinae to Mass Accretion at Periastron Passage
• A lepto-hadronic model of gamma rays from the Eta Carinae and prospects for neutrino telescopes
• Puzzling X-rays from the new colliding wind binary WR65
• X-Atlas: An Online Archive of Chandra's Stellar High Energy Transmission Gratings Observations
• The X-ray properties of Eta Carinae during its 2020 X-ray minimum
• NICER X-ray Observations of Eta Carinae During its Most Recent Periastron Passage
• The environment of the wind-wind collision region of $\eta$ Carinae
• The Interaction of the Eta Carinae Primary Wind with a Century Old Slow Equatorial Ejecta
• Explaining the transient fast blue absorption lines in the massive binary system Eta Carinae
• A Case Study in Astronomical 3-D Printing: The Mysterious Eta Carinae
• Numerical simulations of wind-equatorial gas interaction in eta Carinae
• Precession and Nutation in the eta Carinae binary system: Evidences from the X-ray light curve
• Eta Carinae: an evolving view of the central binary, its interacting winds and its foreground ejecta