The Spectrum of SS 433 in the H and K Bands

Abstract

SS~433 is an X-ray binary and the source of sub-relativistic, precessing, baryonic jets. We present high-resolution spectrograms of SS 433 in the infrared H and K bands. The spectrum is dominated by hydrogen and helium emission lines. The precession phase of the emission lines from the jet continues to be described by a constant period, P_jet= 162.375 d. The limit on any secularly changing period is $|\dot{P}|\lesssim 10^{-5}$. The He I 2.0587 micron line has complex and variable P Cygni absorption features produced by an inhomogeneous wind with a maximum outflow velocity near 900 km/s. The He II emission lines in the spectrum also arise in this wind. The higher members of the hydrogen Brackett lines show a double-peaked profile with symmetric wings extending more than +/-1500 km/s from the line center. The lines display radial velocity variations in phase with the radial velocity variation expected of the compact star, and they show a distortion during disk eclipse that we interpret as a rotational distortion. We fit the line profiles with a model in which the emission comes from the surface of a symmetric, Keplerian accretion disk around the compact object. The outer edge of the disk has velocities that vary from 110 to 190 km/s. These comparatively low velocities place an important constraint on the mass of the compact star: Its mass must be less than 2.2 M_solar and is probably less than 1.6 M_solar.

ApJ, accepted

References in corpus (5)

• Spectroscopic Observations of the Mass Donor Star in SS 433
• High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
• Structure and Magnetic Fields in the Precessing Jet System SS 433 I. Multi-Frequency Imaging from 1998
• Structure and Magnetic Fields in the Precessing Jet System SS433 III. Evolution of the Intrinsic Brightness of the Jets from a Deep Multi-Epoch VLA Campaign
• Superbroad Component in Emission Lines of SS 433

Cited by in corpus (6)

• On masses of the components in SS433
• SS433: a massive X-ray binary at advanced evolutionary stage
• Mass ratio in SS433 revisited
• Super-Keplerian Equatorial Outflows in SS 433. Centrifugal Ejection of the Circumbinary Disk
• CI Camelopardalis: The first sgB[e]-High Mass X-ray Binary Twenty Years on, a Supernova Imposter in our own Galaxy?
• An optical spectroscopic and polarimetric study of the microquasar binary system SS 433