TY - JOUR
T1 - Chandra Observation of Cir X-1 near the Periastron Passage: Evidence for an X-Ray Jet?
AU - Iaria, Rosario
AU - Di Salvo, Tiziana
AU - Burderi, null
PY - 2008
Y1 - 2008
N2 - We present the results of a 25 ks long Chandra observation of the peculiar source Cir X-1 near the periastron passage. We report precise X-ray coordinates of the source, which were compatible with the optical and radio counterpart coordinates. We focus on the study of the detected emission features using the High Energy Transmission Grating Spectrometer on board the Chandra satellite. We detect emission lines associated with Mg XII, Si XIII, Si XIV, S XV, S XVI, Ar XVII, Ar XVIII, Ca XIX, Ca XX, Fe XXV, and Fe XXVI, showing an average redshift of 470 km s-1. The most intense emission features can be fitted with two lines; this is more evident for the 6.6 keV emission feature, which shows a double-peaked structure. We propose that the redshifted and blueshifted lines of Mg XII, Si XIV, S XVI, and Fe XXV can be interpreted as emission from a blue and red beam of an X-ray jet, finding that the angle between the line of sight and the jet direction is 92° and the jet velocity is 0.08c.
AB - We present the results of a 25 ks long Chandra observation of the peculiar source Cir X-1 near the periastron passage. We report precise X-ray coordinates of the source, which were compatible with the optical and radio counterpart coordinates. We focus on the study of the detected emission features using the High Energy Transmission Grating Spectrometer on board the Chandra satellite. We detect emission lines associated with Mg XII, Si XIII, Si XIV, S XV, S XVI, Ar XVII, Ar XVIII, Ca XIX, Ca XX, Fe XXV, and Fe XXVI, showing an average redshift of 470 km s-1. The most intense emission features can be fitted with two lines; this is more evident for the 6.6 keV emission feature, which shows a double-peaked structure. We propose that the redshifted and blueshifted lines of Mg XII, Si XIV, S XVI, and Fe XXV can be interpreted as emission from a blue and red beam of an X-ray jet, finding that the angle between the line of sight and the jet direction is 92° and the jet velocity is 0.08c.
KW - Line: Formation
KW - Line: Identification
KW - Stars: Individual: Constellation Name: Circinus X-1
KW - X-Rays: Binaries
KW - X-Rays: General
KW - Line: Formation
KW - Line: Identification
KW - Stars: Individual: Constellation Name: Circinus X-1
KW - X-Rays: Binaries
KW - X-Rays: General
UR - http://hdl.handle.net/10447/46431
UR - http://adsabs.harvard.edu/abs/2008ApJ...673.1033I
M3 - Article
VL - 673
SP - 1033
EP - 1043
JO - THE ASTROPHYSICAL JOURNAL
JF - THE ASTROPHYSICAL JOURNAL
SN - 0004-637X
ER -