No Time for Dead Time: Timing analysis of bright black hole binaries with NuSTAR

Abstract

Timing of high-count rate sources with the NuSTAR Small Explorer Mission requires specialized analysis techniques. NuSTAR was primarily designed for spectroscopic observations of sources with relatively low count-rates rather than for timing analysis of bright objects. The instrumental dead time per event is relatively long (~2.5 msec), and varies by a few percent event-to-event. The most obvious effect is a distortion of the white noise level in the power density spectrum (PDS) that cannot be modeled easily with the standard techniques due to the variable nature of the dead time. In this paper, we show that it is possible to exploit the presence of two completely independent focal planes and use the cross power density spectrum to obtain a good proxy of the white noise-subtracted PDS. Thereafter, one can use a Monte Carlo approach to estimate the remaining effects of dead time, namely a frequency-dependent modulation of the variance and a frequency-independent drop of the sensitivity to variability. In this way, most of the standard timing analysis can be performed, albeit with a sacrifice in signal to noise relative to what would be achieved using more standard techniques. We apply this technique to NuSTAR observations of the black hole binaries GX 339-4, Cyg X-1 and GRS 1915+105.

13 pages, 8 figures, submitted to ApJ

References in corpus (6)

• X-ray reverberation around accreting black holes
• NuSTAR and XMM-Newton Observations of NGC 1365: Extreme Absorption Variability and a Constant Inner Accretion Disk
• Timing and Flux Evolution of the Galactic Center Magnetar SGR J1745-2900
• Evolution of the 0.01 - 25 Hz power spectral components in Cygnus X-1
• Observations of MCG-5-23-16 with Suzaku, XMM-Newton and NuSTAR: Disk tomography and Compton hump reverberation
• Production of Millisecond Dips in Sco X-1 Count Rates by Dead Time Effects

Cited by in corpus (45)

• Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13
• A quasi-periodic modulation of the iron line centroid energy in the black hole binary H 1743-322
• AstroSat/LAXPC reveals the high energy variability of GRS 1915+105 in the chi class
• AstroSat view of MAXI J1535-571: broadband spectro-temporal features
• Phase-resolved spectroscopy of a quasi-periodic oscillation in the black hole X-ray binary GRS 1915+105 with NICER and NuSTAR
• Prolonged sub-luminous state of the new transitional pulsar candidate CXOU J110926.4-650224
• Disk-Wind Connection During the Heartbeats of GRS 1915+105
• Thermal Emission and Radioactive Lines, but No Pulsar, in the Broadband X-Ray Spectrum of Supernova 1987A
• NuSTAR observations of the Transient Galactic Black Hole Binary Candidate Swift J1858.6-0814: A New Sibling of V404 Cyg and V4641 Sgr?
• Looking at A 0535+26 at low luminosities with NuSTAR
• Exploring the radial disc ionization profile of the black hole X-ray binary GRS 1915+105
• Spectral and Timing Properties of IGR J17091-3624 in the Rising Hard State During its 2016 Outburst
• NuSTAR and XMM-Newton observations of the 2015 outburst decay of GX 339-4
• Detection of Very Low-Frequency Quasi-Periodic Oscillations in the 2015 Outburst of V404 Cygni
• AstroSat view of the newly discovered X-ray transient MAXI~J1803--298 in the Hard-intermediate state
• An underlying clock in the extreme flip-flop state transitions of the black hole transient Swift J1658.2-4242
• An XMM-Newton and NuSTAR study of IGR J18214-1318: a non-pulsating high-mass X-ray binary with a neutron star
• Multi-wavelength observations of IGR J17544-2619 from quiescence to outburst
• Broadband X-ray Spectral and Timing Analyses of the Black Hole Binary Candidate Swift J1658.2-4242: Rapid Flux Variation and the Turn-on of a Transient QPO
• Accurate X-ray Timing in the Presence of Systematic Biases With Simulation-Based Inference
• NuSTAR and Chandra observations of new X-ray transients in the central parsec of the Galaxy
• Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934
• Re-awakening of GRS 1716--249 after 23 years, observed by {\it Swift}/XRT and {\it NuSTAR}
• NICER/NuSTAR Characterization of 4U 1957+11: A Near Maximally Spinning Black Hole Potentially in the Mass Gap
• The stochastic X-ray variability of the accreting millisecond pulsar MAXI J0911-655
• A broadband spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8-1613
• MAXI and NuSTAR observations of the faint X-ray transient MAXI J1848-015 in the GLIMPSE-C01 Cluster
• Reflection and timing study of the transient black hole X-ray binary MAXI J1803-298 with NuSTAR
• Chandra, NuSTAR, and Optical Observations of the Cataclysmic Variables IGR J17528-2022 and IGR J20063+3641
• Swift J1728.9-3613 is a black hole X-ray binary: spectral and timing study using NICER
• Probing the Properties of the Pulsar Wind in the Gamma-Ray Binary HESS J0632+057 with NuSTAR and VERITAS Observations
• Proof of principle X-ray reflection mass measurement of the black hole in H1743-322
• Multi-Wavelength Observation Campaign of the TeV Gamma-Ray Binary HESS J0632+057 with NuSTAR, VERITAS, MDM, and Swift
• A Hidden Pulse: Uncovering a New Timing Signal in Cygnus X-1 with AstroSat
• X-ray polarimetry-timing
• NuSTAR and Swift observations of Swift J1357.2-0933 during an early phase of its 2017 outburst
• Likely detection of magnetic field related LFQPO in the soft X-ray re-brightening of GRS~1915+105
• Fourier Domain
• Searching for quasi-periodicities in short transients: the curious case of GRB 230307A
• Spectral and Timing Analysis of NuSTAR and Swift/XRT Observations of the X-Ray Transient MAXI J0637-430
• Flux variability of the "10 keV feature" of 4U 0115+63
• NuSTAR and AstroSat observations of thermonuclear X-ray bursts with short-recurrence times in 4U 1636$-$536
• The Effects of Instrumental Deadtime on NICER Timing Products
• Broad-band spectral study of LMXB black hole candidate 4U 1957+11 with NuSTAR
• Photospheric Radius Expansion and a double-peaked type-I X-ray burst from GRS 1741.9-2853