High Mass XRay Binaries for Small Telescopes

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High Mass X-Ray Binaries for Small Telescopes

• Gordon E. Sarty (University of Saskatchewan),
• Richard Huziak (Saskatoon Centre RASC),
• Laszlo Kiss, Helen Johnston (University of
  Sydney),
• Michael Ashley, Andre Phillips (University of New
  South Wales)
• Bogumil Pilecki (ASAS), Paul Roche (Las Cumbres
  Observatory Global Telescope Network), Kinwah Wu
  (University College London)

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A Team Effort
UNSW APT
All Sky Automated Survey (ASAS public database)
The AAVSO (represented here by Rick Huziak
public database)
Faulkes Telescopes (LCOGT.net) (2 2m 28 1m 40
or 50 0.4m to 0.6m - public database)
Me (Laszlo, Kinwah, Helen) at Siding Spring
Observatories
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What are HMXBs?
The Traditional Types

• Supergiant X-Ray Binaries

• Be X-Ray Binaries

• Proposed New Types
• g Cas Be-like but with White Dwarf instead of
  NS/BH
• Slow-wind fed Be-like but with diskless O-V star
• IR-cocooned, INTEGRAL sources

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Photometric Search for Periods
Neutron star spin and mass transfer
Population of orbital periods

• Only 40 of 73 galactic HMXBs with optical
  counterparts have known orbital periods (48
  listed in our JAAVSO paper some are Magellanic
  Cloud sources) so 1st we are looking for
  orbital periods
• Some HMXBs have very slow neutron star spins that
  may be visible photometrically so 2nd we are
  looking for spin periods
• 15 sources observed so far

Plots from Raguzova Popov, AAT 24, 151 (2005)
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Why we care

• HMXB population will evolve to NSNS or NSBH
  binaries via a second supernova
• The compact binaries will emit gravitational
  waves
• Compact binaries will merge to produce
  short-duration g-ray bursts which will produce
  intense gravitational waves
• The mathematics of gravitational wave detection
  by instruments like LIGO and LISA require a
  priori knowledge of the population of objects to
  be observed

• Theoretical calculations of HMXB population
  distributions have been done but they need
  observational confirmation

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What you need

• Any size telescope HMXBs are bright, typically
  10th magnitude, some are 7th and 8th magnitude
  which makes them tough for CCDs (PEP enthusiasts
  take note!)

• Filters BVRI but V and I are most useful because
  V-I color will tell us about the circumstellar
  material
• Research optimal (as opposed pretty picture
  optimal) CCDs or PEPs

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Beyond orbital periods Winds and Disks
Okazaki Negueruela, AA 377, 161 (2001)

• Bondi accretion

• Interactions of Be star decretion disk and
  neutron star accretion disk

S. Bergenius, Masters thesis, Stockholm
University
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Beyond orbital periods Circumstellar material

• Luminous gas/plasma clumps are present around and
  between the stars
• The figure, right, shows an X-ray model but
  similar things can happen in the optical when the
  OB-V star has a magnetic field

• Hot plasma can get trapped on magnetic field
  lines in a balance between centrifugal and
  gravitational forces eclipse-like light curves
  (observed in single Be stars before)

Sako et al., arXivastro-ph/0309503
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Some Highlights

• RXJ1744.7-2713 HD 161103 (LPH095) Possible
  g-Cas type, 8th mag (Sagittarius)
• LS 5039 V479 Sct RXJ1826.2-1450 (LPH100)
  g-ray binary/microquasar, p3.9d (AAVSO 1820-14)
• 1H1936541 (LPH115) very variable (light curves
  in next slides) (AAVSO 193053, Cygnus)
• RXJ2030.54751 SAO 49725 (LPH123) Possible
  g-Cas type (AAVSO 202747, Cygnus)
• 1H2202501 V2175 Cyg (LPH127) Need
  observations! (AAVSO 215749, near Cyg-Lac
  border)
• 1H222360 (LPH128) p9.56d (AAVSO 220454, near
  Cyg-Cep-Lac border)

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Preliminary look Orbital period?
Thanks to those who responded to AAVSO Alert
Notice 348!
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Eclipse - like
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Spin?
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Watch for more observing calls
(Scenes from DAO)
Thank You!