Properties of the 24 Day Modulation in GX 13+1 from Near-Infrared and X-ray Observations

Abstract

A 24 day period for the low-mass X-ray binary GX 13+1 was previously proposed on the basis of 7 years of RXTE ASM observations (Corbet 2003) and it was suggested that this was the orbital period of the system. This would make it the one of the longest known orbital periods for a Galactic low-mass X-ray binary powered by Roche lobe overflow. We present here the results of: (i) K-band photometry obtained with the SMARTS Consortium CTIO 1.3 telescope on 68 nights over a 10 month interval; (ii) Continued monitoring with the RXTE ASM, analyzed using a semi-weighted power spectrum instead of the data filtering technique previously used; and (iii) Swift BAT hard X-ray observations. Modulation near 24 days is seen in both the K-band and additional statistically independent ASM X-ray observations. However, the modulation in the ASM is not strictly periodic. The periodicity is also not detected in the Swift BAT observations, but modulation at the same relative level as seen with the ASM cannot be ruled out. If the 24 day period is the orbital period of system, this implies that the X-ray modulation is caused by structure that is not fixed in location. A possible mechanism for the X-ray modulation is the dipping behavior recently reported from XMM-Newton observations.

Accepted for publication in the Astrophysical Journal

References in corpus (5)

• Swift/BAT and RXTE Observations of the Peculiar X-ray Binary 4U 2206+54 - Disappearance of the 9.6 Day Modulation
• Confirmation of the 62 Day X-Ray Periodicity from M82
• IR Monitoring of the Microquasar GRS 1915+105: Detection of Orbital and Superhump Signatures
• Optical spectroscopy and Doppler tomography of Cygnus X-2
• Periodicities in X-ray Binaries from Swift/BAT Observations

Cited by in corpus (17)

• Optical and Near Infrared Monitoring of the Black-Hole X-ray Binary GX 339-4 During 2002-2010
• XMM-Newton observations of GX 13+1: correlation between photoionised absorption and broad line emission
• Accretion disk and ionized absorber of the 9.7-hour dipping black hole binary MAXI J1305-704
• Chandra X-ray spectroscopy of a clear dip in GX 13+1
• The Disk Wind in the Neutron Star Low-mass X-Ray Binary GX 13+1
• Testing Rate Dependent corrections on timing mode EPIC-pn spectra of the accreting Neutron Star GX 13+1
• Discovery of periodic dips in the light curve of GX 13+1: the X-ray orbital ephemeris of the source
• Relativistic X-Ray Reflection and Photoionised Absorption in the Neutron-Star Low-Mass X-ray Binary GX 13+1
• The thermal-radiative wind in the neutron star low mass X-ray binary GX 13+1
• Discovery of a strong rotation of the X-ray polarization angle in the galactic burster GX 13+1
• New polarimetric study of the galactic X-ray burster GX 13+1
• Monte-Carlo simulations of the detailed iron absorption line profiles from thermal winds in X-ray binaries
• Variable Doppler shifts of the thermal wind absorption lines in low-mass X-ray binaries
• Stratified wind from a super-Eddington X-ray binary is slower than expected
• X-ray Dips and Polarization Angle Swings in GX 13+1
• Infrared interferometry to spatially and spectrally resolve jets in X-ray binaries
• A search for signatures of interactions of X-ray binary outflows with their environments with ALMA