H{alpha} EMISSION VARIABILITY IN THE {gamma}-RAY BINARY LS I +61 303

Journal Article · Sat Nov 20 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/724/1/379· OSTI ID:21471187

McSwain, M Virginia ^[1]; Grundstrom, Erika D ^[2]; Gies, Douglas R ^[3]

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1. Department of Physics, Lehigh University, 16 Memorial Drive E, Bethlehem, PA 18015 (United States)
2. Physics and Astronomy Department, Vanderbilt University, 6301 Stevens Center, Nashville, TN 37235 (United States)
3. Department of Physics and Astronomy, Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30303-4106 (United States)

LS I +61 303 is an exceptionally rare example of a high-mass X-ray binary that also exhibits MeV-TeV emission, making it one of only a handful of '{gamma}-ray binaries'. Here we present H{alpha} spectra that show strong variability during the 26.5 day orbital period and over decadal timescales. We detect evidence of a spiral density wave in the Be circumstellar disk over part of the orbit. The H{alpha} line profile also exhibits a dramatic emission burst shortly before apastron, observed as a redshifted shoulder in the line profile, as the compact source moves almost directly away from the observer. We investigate several possible origins for this red shoulder, including an accretion disk, mass-transfer stream, and a compact pulsar wind nebula that forms via a shock between the Be star's wind and the relativistic pulsar wind.

• OSTI ID: 21471187
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 724; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY RANGE
GAMMA RADIATION
IONIZING RADIATIONS
MASS
MASS TRANSFER
MEV RANGE
NEBULAE
ORBITS
PULSARS
RADIATIONS
STARS
STELLAR ACTIVITY
STELLAR FLARES
STELLAR WINDS
TEV RANGE