1 / 14

A Search for Quiet Massive X-Ray Binaries

A Search for Quiet Massive X-Ray Binaries. M. Virginia McSwain Yale University Tabetha S. Boyajian Erika Grundstrom Douglas R. Gies Georgia State University. A Quiet Massive X-ray Binary?. 2 typical mechanisms produce X-rays in MXRBs:

wilson
Download Presentation

A Search for Quiet Massive X-Ray Binaries

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A Search for Quiet Massive X-Ray Binaries M. Virginia McSwain Yale University Tabetha S. Boyajian Erika Grundstrom Douglas R. Gies Georgia State University

  2. A Quiet Massive X-ray Binary? • 2 typical mechanisms produce X-rays in MXRBs: • Mass accretion through a Roche lobe overflow stream • Accretion of the stellar wind of the luminous primary (Bondi & Hoyle 1944; Davidson & Ostriker 1973; Kaper 1998) • In the wind accretion model of MXRBs, the observed X-ray luminosity depends on: • the system separation, • the relative wind and companion velocities, • the stellar mass-loss rate, and • the mass of the accretor (Lamers et al. 1976)

  3. Target Selection • Runaway or field OB stars • Suspected single-line spectroscopic binaries (SB1) or known radial velocity variables • Known SB1s with poorly determined orbits • Most targets not known X-ray emitters • Selected 12 targets for radial velocity study Goal: to find SB1s with eccentric orbits, suggestive of past supernova in binary system

  4. HD 1976 P = 26.0 d e = 0.0 (Not an MXRB candidate)

  5. HD 14633 P = 15.41 d e = 0.70 See also Boyajian et al. (2005)

  6. HD 15137 P = 28.99 d e = 0.41 See also Boyajian et al. (2005)

  7. HD 30614 P = 3.19 d e = 0.35 Gas stream between stars

  8. HD 37737 P = 7.85 d e = 0.40

  9. Spectral Models – O Stars • Hot O stars require non-LTE spectral modeling • Used TLUSTY model atmospheres to compute grid of model spectra • He I 4121 and Si IV 4116 lines highly sensitive to Teff,log g, V sin i (Walborn 1971) • These lines were used to determine best fit parameters

  10. HD 14633 – Model Fit Teff = 33000 K log g = 3.95 V sin i = 140 km/s

  11. Spectral Models – B Stars • TLUSTY cannot calculate models below T of 28000 K • But, B stars can be modeled well using LTE Kurucz model atmospheres • Fit H Balmer and He I line profiles with grid of model spectra • Mean value from many lines provides Teff, log g, V sin i

  12. HD 1976 – Model Fit Teff = 15400 K log g = 3.7 V sin i = 160 km/s

  13. HD 14633 – Spectral Energy Distribution

  14. Conclusions & Further Work • Of 12 stars studied, we find 6 MXRB candidates • 3 are weak or moderate X-ray sources: HD 30614, HD 52533, HD 188001 • 3 not known X-ray emitters: HD 14633, HD 15137, HD 37737 • Currently finishing work on spectral models and SED fits to investigate stellar parameters • New X-ray, IR observations will be useful to conclusively identify post-supernova systems with compact companions

More Related