A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, delta ORIONIS Aa. I. OVERVIEW OF THE X-RAY SPECTRUM

M. F. Corcoran; J. S. Nichols; H. Pablo; T. Shenar; A. M. T. Pollock; W. L. Waldron; A. F. J. Moffat; N. D. Richardson; C. M. P. Russell; K. Hamaguchi; D. P. Huenemoerder; L. Oskinova; W. -R. Hamann; Y. Naze; R. Ignace; N. R. Evans; J. R. Lomax; J. L. Hoffman; K. Gayley; S. P. Owocki; M. Leutenegger; T. R. Gull; K. T. Hole; J. Lauer; R. C. Iping

doi:10.1088/0004-637X/809/2/132

Back

A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, delta ORIONIS Aa. I. OVERVIEW OF THE X-RAY SPECTRUM

Journal article

Peer reviewed

A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, delta ORIONIS Aa. I. OVERVIEW OF THE X-RAY SPECTRUM

M. F. Corcoran, J. S. Nichols, H. Pablo, T. Shenar, A. M. T. Pollock, W. L. Waldron, A. F. J. Moffat, N. D. Richardson, C. M. P. Russell, K. Hamaguchi, …

The Astrophysical journal, Vol.809(2), pp.1-15

08/20/2015

DOI: 10.1088/0004-637X/809/2/132

View Online

Abstract

We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of delta Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, delta Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, delta Ori Aa2, has a much lower X-ray luminosity than the brighter primary (delta Ori Aa1), delta Ori Aa provides a unique system with which to test the spatial distribution of the X-ray emitting gas around delta Ori Aa1 via occultation by the photosphere of, and wind cavity around, the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ks and covering nearly the entire binary orbit. The companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities obtained simultaneously with the X-ray data to better constrain the system parameters, and model the effects of X-rays on the optical and UV spectra. We find that the X-ray emission is dominated by embedded wind shock emission from star Aa1, with little contribution from the tertiary star Ab or the shocked gas produced by the collision of the wind of Aa1 against the surface of Aa2. We find a similar temperature distribution to previous X-ray spectrum analyses. We also show that the line half-widths are about 0.3-0.5 times the terminal velocity of the wind of star Aa1. We find a strong anti-correlation between line widths and the line excitation energy, which suggests that longer-wavelength, lower-temperature lines form farther out in the wind. Our analysis also indicates that the ratio of the intensities of the strong and weak lines of Fe XVII and Ne X are inconsistent with model predictions, which may be an effect of resonance scattering.

Astronomy & Astrophysics

Physical Sciences

Science & Technology

Details

Title: Subtitle: A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, delta ORIONIS Aa. I. OVERVIEW OF THE X-RAY SPECTRUM
Creators: M. F. Corcoran - Universities Space Research Association
J. S. Nichols - Center for Astrophysics Harvard & Smithsonian
H. Pablo - Centre for Research in Astrophysics of Québec
T. Shenar - University of Potsdam
A. M. T. Pollock - European Space Astronomy Centre
W. L. Waldron - Eureka Scientific
A. F. J. Moffat - Centre for Research in Astrophysics of Québec
N. D. Richardson - Centre for Research in Astrophysics of Québec
C. M. P. Russell - NASA GSFC, Greenbelt, MD 20771 USA
K. Hamaguchi - Goddard Space Flight Center
D. P. Huenemoerder - Massachusetts Institute of Technology
L. Oskinova - University of Potsdam
W. -R. Hamann - University of Potsdam
Y. Naze - University of Liège
R. Ignace - East Tennessee State University
N. R. Evans - Center for Astrophysics Harvard & Smithsonian
J. R. Lomax - University of Oklahoma
J. L. Hoffman - University of Denver
K. Gayley - University of Iowa
S. P. Owocki - University of Delaware
M. Leutenegger - Goddard Space Flight Center
T. R. Gull - Goddard Space Flight Center
K. T. Hole - Weber State University
J. Lauer - Center for Astrophysics Harvard & Smithsonian
R. C. Iping - Goddard Space Flight Center
Resource Type: Journal article
Publication Details: The Astrophysical journal, Vol.809(2), pp.1-15
DOI: 10.1088/0004-637X/809/2/132
ISSN: 0004-637X
eISSN: 1538-4357
Publisher: Iop Publishing Ltd
Number of pages: 15
Grant note: NAS8-03060 / Chandra X-ray Center NASA; National Aeronautics & Space Administration (NASA) NNG06EO90A; NNX13AF40G / NASA; National Aeronautics & Space Administration (NASA) NAS8-03060 / National Aeronautics Space Administration; National Aeronautics & Space Administration (NASA) Communaute Francaise de Belgique; Australian Research Council institute of Physics and Astronomy of the University of Potsdam NSERC (Canada); Natural Sciences and Engineering Research Council of Canada (NSERC) AST-0807477 / NSF; National Science Foundation (NSF) Leibniz Institute for Astrophysics Potsdam (AIP) Fonds National de la Recherche Scientifique (Belgium); Fonds de la Recherche Scientifique - FNRS NASA Postdoctoral Program at the Goddard Space Flight Center GO3-14015A; GO3-14015E / National Aeronautics and Space Administration; National Aeronautics & Space Administration (NASA) Leibniz Graduate School for Quantitative Spectroscopy in Astrophysics FRQNT (Quebec) "Action de Recherche Concertee" (CFWB-Academie Wallonie Europe) CRAQ (Centre de Recherche en Astrophysique du Quebec) fellowship PRODEX XMM and Integral contracts
Language: English
Date published: 08/20/2015
Academic Unit: Physics and Astronomy
Record Identifier: 9984428780502771

Metrics

18 Record Views

10 Times Cited - Web of Science

See more details