On Relativistic Disk Spectroscopy in Compact Objects with X-ray CCD Cameras

Abstract

X-ray charge-coupled devices (CCDs) are the workhorse detectors of modern X-ray astronomy. Typically covering the 0.3-10.0 keV energy range, CCDs are able to detect photoelectric absorption edges and K shell lines from most abundant metals. New CCDs also offer resolutions of 30-50 (E/dE), which is sufficient to detect lines in hot plasmas and to resolve many lines shaped by dynamical processes in accretion flows. The spectral capabilities of X-ray CCDs have been particularly important in detecting relativistic emission lines from the inner disks around accreting neutron stars and black holes. One drawback of X-ray CCDs is that spectra can be distorted by photon "pile-up", wherein two or more photons may be registered as a single event during one frame time. We have conducted a large number of simulations using a statistical model of photon pile-up to assess its impacts on relativistic disk line and continuum spectra from stellar-mass black holes and neutron stars. The simulations cover the range of current X-ray CCD spectrometers and operational modes typically used to observe neutron stars and black holes in X-ray binaries. Our results suggest that severe photon pile-up acts to falsely narrow emission lines, leading to falsely large disk radii and falsely low spin values. In contrast, our simulations suggest that disk continua affected by severe pile-up are measured to have falsely low flux values, leading to falsely small radii and falsely high spin values. The results of these simulations and existing data appear to suggest that relativistic disk spectroscopy is generally robust against pile-up when this effect is modest.

Accepted for publication in ApJ

References in corpus (18)

• X-ray Properties of Black-Hole Binaries
• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• Relativistic X-ray Lines from the Inner Accretion Disks Around Black Holes
• A Long, Hard Look at the Low-Hard State in Accreting Black Holes
• Evaluating Spectral Models and the X-ray States of Neutron-Star X-ray Transients
• Relativistic iron emission lines in neutron star low-mass X-ray binaries as probes of neutron star radii
• A systematic look at the Very High and Low/Hard state of GX 339-4: Constraining the black hole spin with a new reflection model
• XMM-Newton study of the complex and variable spectrum of NGC 4051
• A Grid of Relativistic, non-LTE Accretion Disk Models for Spectral Fitting of Black Hole Binaries
• Broad relativistic iron emission line observed in SAX J1808.4-3658
• XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658
• Chandra X-ray spectroscopy of the focused wind in the Cygnus X-1 system. I. The non-dip spectrum in the low/hard state
• Broadband X-ray Spectra of GX 339-4 and the Geometry of Accreting Black Holes in the Hard State
• Initial Measurements of Black Hole Spin in GX 339-4 from Suzaku Spectroscopy
• Evidence of a Broad Relativistic Iron Line from the Neutron Star Low-Mass X-ray Binary Serpens X-1
• A relativistically smeared spectrum in the neutron star X-ray Binary 4U 1705-44: Looking at the inner accretion disc with X-ray spectroscopy
• Disk reflection signatures in the spectrum of the bright Z-source GX 340+0
• Disk Dominated States of 4U 1957+11: Chandra, XMM, and RXTE Observations of Ostensibly the Most Rapidly Spinning Galactic Black Hole

Cited by in corpus (49)

• Measuring Black Hole Spin using X-ray Reflection Spectroscopy
• The Masses and Spins of Neutron Stars and Stellar-Mass Black Holes
• X-ray Reflection Spectroscopy of the Black Hole GX 339-4: Exploring the Hard State with Unprecedented Sensitivity
• Towards precision measurements of accreting black holes using X-ray reflection spectroscopy
• NuSTAR and Swift observations of the very high state in GX 339-4: Weighing the black hole with X-rays
• A Swift survey of accretion onto stellar-mass black holes
• The truncated and evolving inner accretion disc of the black hole GX 339-4
• Constraints on the Neutron Star and Inner Accretion Flow in Serpens X-1 Using NuSTAR
• Accretion disks and coronae in the X-ray flashlight
• A Fast X-ray Disk Wind in the Transient Pulsar IGR J17480-2446 in Terzan 5
• Reflection Spectra of the Black Hole Binary Candidate MAXI J1535-571 in the Hard State Observed by NuSTAR
• The soft component and the iron line as signatures of the disc inner radius in Galactic black hole binaries
• A Hard Look at the Neutron Stars and Accretion Disks in 4U 1636-53, GX 17+2, and 4U 1705-44 with $\text{NuSTAR}$
• The evolution of GX 339-4 in the low-hard state as seen by NuSTAR and Swift
• On the Role of the Accretion Disk in Black Hole Disk-Jet Connections
• The Similarity of Broad Iron Lines in X-ray Binaries and Active Galactic Nuclei
• A Broad Iron Line in LMC X-1
• Testing reflection features in 4U 1705-44 with XMM-Newton, BeppoSAX and RXTE in the hard and soft state
• Suzaku broad-band spectrum of 4U 1705-44: Probing the Reflection component in the hard state
• The broad iron Kalpha line of Cygnus X-1 as seen by XMM-Newton in the EPIC-pn modified timing mode
• Reflection From the Strong Gravity Regime in a z=0.658 Gravitationally Lensed-Quasar
• A dichotomy between the hard state spectral properties of black hole and neutron star X-ray~binaries
• Suzaku Observation of the Black Hole Candidate MAXI J1836-194 in a Hard/Intermediate Spectral State
• NuSTAR and XMM-Newton broad-band spectrum of SAX J1808.4-3658 during its latest outburst in 2015
• Measuring A Truncated Disk in Aquila X-1
• Tracking the Iron K$\alpha$ line and the Ultra Fast Outflow in NGC 2992 at different accretion states
• NuSTAR Observations of the Black Hole GS 1354-645: Evidence of Rapid Black Hole Spin
• Evolution of the accretion disk-corona during bright hard-to-soft state transition: A reflection spectroscopic study with GX 339-4
• Study of the reflection spectrum of the accreting neutron star GX 3+1 using XMM-Newton and INTEGRAL
• SWIFT J1910.2-0546: A possible black hole binary with a retrograde spin or truncated disk
• A relativistic iron emission line from the neutron star low-mass X-ray binary GX 3+1
• X-ray Spectroscopy of MXB 1728-34 with XMM-Newton
• Swift Observations of MAXI J1659-152: A Compact Binary with a Black Hole Accretor
• Black hole spin: theory and observation
• The hard to soft transition of GX 339-4 as seen by Insight-HXMT
• A test of the nature of the Fe K Line in the neutron star low-mass X-ray binary Serpens X-1
• The spin of the black hole GRS 1716-249 determined from the hard intermediate state
• Spectral and Timing Properties of IGR J17091-3624 in the Rising Hard State During its 2016 Outburst
• On the illumination of neutron star accretion discs
• AstroSat view of the newly discovered X-ray transient MAXI~J1803--298 in the Hard-intermediate state
• Black holes: Timing and spectral properties and evolution
• The Accreting Black Hole Swift J1753.5-0127 from Radio to Hard X-Ray
• Chandra Imaging of the Outer Accretion Flow onto the Black Hole at the Center of the Perseus Cluster
• XRB continuum fitting with sensitive high energy X-ray detectors
• A retrograde spin of the black hole in MAXI J1659--152
• Exploring higher order images with Fe K_α-lines from relativistic disks: black hole spin determination and bias
• Broadband observations of the X-ray burster 4U 1705-44 with BeppoSAX
• Relativistic disc line: a tool to constrain neutron star equation of state models
• Extreme X-ray Reflection in the Nucleus of the Seyfert Galaxy NGC 5033