Cyclotron lines in highly magnetized neutron stars

Abstract

Cyclotron lines, also called cyclotron resonant scattering features (CRSF) are spectral features, generally appearing in absorption, in the X-ray spectra of objects containing highly magnetized neutron stars, allowing the direct measurement of the magnetic field strength in these objects. Cyclotron features are thought to be due to resonant scattering of photons by electrons in the strong magnetic fields. The main content of this contribution focusses on electron cyclotron lines as found in accreting X-ray binary pulsars (XRBP) with magnetic fields on the order of several 1012 Gauss. Also, possible proton cyclotron lines from single neutron stars with even stronger magnetic fields are briefly discussed.With regard to electron cyclotron lines, we present an updated list of XRBPs that show evidence of such absorption lines. The first such line was discovered in a 1976 balloon observation of the accreting binary pulsar Hercules X-1, it is considered to be the first direct measurement of the magnetic field of a neutron star. As of today (mid 2018), we list 36 XRBPs showing evidence of one ore more electron cyclotron absorption line(s). A few have been measured only once and must be confirmed (several more objects are listed as candidates). In addition to the Tables of objects, we summarize the evidence of variability of the cyclotron line as a function of various parameters (especially pulse phase, luminosity and time), and add a discussion of the different observed phenomena and associated attempts of theoretical modeling. We also discuss our understanding of the underlying physics of accretion onto highly magnetized neutron stars. For proton cyclotron lines, we present tables with seven neutron stars and discuss their nature and the physics in these objects.

arXiv comment32 pages, 15 figures, 8 Tables, accepted by A&A 2018

References in corpus (271)

• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Observations of Accreting Pulsars
• Refined Neutron-Star Mass Determinations for Six Eclipsing X-Ray Pulsar Binaries
• Magnetic Fields of Accreting X-Ray Pulsars with the Rossi X-Ray Timing Explorer
• The Magnificent Seven: Magnetic fields and surface temperature distributions
• Thermal and Bulk Comptonization in Accretion-Powered X-Ray Pulsars
• Discovery of pulsations from NGC 300 ULX1 and its fast period evolution
• Spectral Formation in Accreting X-Ray Pulsars: Bimodal Variation of the Cyclotron Energy with Luminosity
• Spin-Up/Spin-Down of Magnetized Stars with Accretion Disks and Outflows
• Theory of quasi-spherical accretion in X-ray pulsars
• The critical accretion luminosity for magnetized neutron stars
• Discovery of a flux-related change of the cyclotron line energy in Her X-1
• V0332+53 in the outburst of 2004--2005: luminosity dependence of the cyclotron line and pulse profile
• The thermal radiation of the isolated neutron star RX J1856.5-3754 observed with Chandra and XMM-Newton
• The Be/X-ray transient 4U 0115+63/V635 Cas I. A consistent model
• Unstable Disk Accretion to Magnetized Stars: First Global 3D MHD Simulations
• A model for cyclotron resonance scattering features
• Propeller effect in action in the ultraluminous accreting magnetar M82 X-2
• A reflection model for the cyclotron lines in the spectra of X-ray pulsars
• Magnetically Torqued Thin Accretion Disks
• NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1
• Patterns of variability in Be/X-ray pulsars during giant outbursts
• Magnetic field strength of a neutron-star-powered ultraluminous X-ray source
• Proton Cyclotron Features in Thermal Spectra of Ultra-magnetized Neutron Stars
• Torque Enhancement, Spin Equilibrium, and Jet Power from Disk-Induced Opening of Pulsar Magnetic Fields
• Discovery of Cyclotron Resonance Features in the Soft Gamma Repeater SGR 1806-20
• Isolated neutron stars: Magnetic fields, distances, and spectra
• A broad absorption feature in the X-ray spectrum of the isolated neutron star RBS1223 (1RXS J130848.6+212708)
• Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included
• The Proper Motion, Parallax, and Origin of the Isolated Neutron Star RX J185635-3754
• 4U 0115+63 from RXTE and INTEGRAL Data: Pulse Profile and Cyclotron Line Energy
• Study of the accreting pulsar 4U 0115+634 with a bulk and thermal Comptonization model
• A Strong, Broad Absorption Feature in the X-ray Spectrum of the Nearby Neutron Star RX J1605.3+3249
• New Evidence for Proton Cyclotron Resonance in a Magnetar Strength Field from SGR 1806-20
• The quiescent X-ray emission of three transient X-ray pulsars
• On Timing and Spectral Characteristics of the X-ray Pulsar 4U 0115+63: Evolution of the Pulsation Period and the Cyclotron Line Energy
• Spin period change and the magnetic fields of neutron stars in Be X-ray binaries in the Small Magellanic Cloud
• INTEGRAL survey of the Cassiopeia region in hard X rays
• Analytical Hot Spot Shapes and Magnetospheric Radius from 3D Simulations of Magnetospheric Accretion
• The isolated neutron star X-ray pulsars RX J0420.0-5022 and RX J0806.4-4123: new X-ray and optical observations
• Discovery of a Third Harmonic Cyclotron Resonance Scattering Feature in the X-ray Spectrum of 4U 0115+63
• Pulse phase resolved analysis of the HMXB Cen X-3 over two binary orbits
• Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53
• Propeller effect in two brightest transient X-ray pulsars: 4U 0115+63 and V 0332+53
• The variable cyclotron line in GX 301-2
• The Be/X-ray Transient V0332+53: Evidence for a tilt between the orbit and the equatorial plane?
• The Chandra LETGS high resolution X-ray spectrum of the isolated neutron star RX J1856.5-3754
• Confirmation of Two Cyclotron Lines in Vela X-1
• A Further Study of the Luminosity-Dependent Cyclotron Resonance Energies of the Binary X-ray Pulsar 4U0115+63 with RXTE
• No anti-correlation between cyclotron line energy and X-ray flux in 4U 0115+634
• A Decade in the Life of EXO 2030+375: A Multi-wavelength Study of an Accreting X-ray Pulsar
• BeppoSAX observation of 4U1626-67: Discovery of an absorption cyclotron resonance feature
• Pulse-amplitude-resolved spectroscopy of bright accreting pulsars: indication of two accretion regimes
• Outburst of GX 304-1 monitored with INTEGRAL: positive correlation between the cyclotron line energy and flux
• Evidence for precession of the isolated neutron star RX J0720.4-3125
• The distances to the X-ray binaries LSI +61 303 and A0535+262
• A 0535+26 in the August/September 2005 outburst observed by RXTE and INTEGRAL
• INTEGRAL observation of the high-mass X-ray transient V0332+53 during the 2005 outburst decline
• Spectral distribution of Be/X-ray binaries in the Small Magellanic Cloud
• A phase-dependent absorption line in the spectrum of the X-ray pulsar RX J0720.4-3125
• On the orbital parameters of Be/X-ray binaries in the Small Magellanic Cloud
• Constraining the Spin-down of the Nearby Isolated Neutron Star RX J2143.0+0654
• Identifying birth places of young isolated neutron stars
• Constraining the Spin-down of the Nearby Isolated Neutron Star RX J0806.4-4123, and Implications for the Population of Nearby Neutron Stars
• IGR J17544-2619: A new supergiant fast X-ray transient revealed by optical/infrared observations
• Revisiting the Parallax of the Isolated Neutron Star RX J185635-3754 Using HST/ACS Imaging
• Discovery of a Cyclotron Resonant Scattering Feature in the RXTE Spectrum of 4U 0352+309 (X Per)
• Timing the Nearby Isolated Neutron Star RX J1856.5-3754
• On the dependence of the X-ray continuum variations with luminosity in accreting X-ray pulsars
• A Potential Cyclotron Resonant Scattering Feature in the ULX Pulsar NGC 300 ULX1 seen by NuSTAR and XMM-Newton
• Cyclotron Line Features from Near-Critical Fields II: on the Effect of Anisotropic Radiation Fields
• Atmospheres and Spectra of Strongly Magnetized Neutron Stars -- III. Partially Ionized Hydrogen Models
• Positive correlation between the cyclotron line energy and luminosity in sub-critical X-ray pulsars: Doppler effect in the accretion channel
• Detection of pulsations and a spectral feature in the X-ray emission of the isolated neutron star 1RXS J214303.7+065419/RBS 1774
• A Coherent Timing Solution for the Nearby Isolated Neutron Star RX J0720.4-3125
• On the compactness of the isolated neutron star RX J0720.4-3125
• A Coherent Timing Solution for the Nearby Isolated Neutron Star RX J1308.6+2127/RBS 1223
• X-ray spectra from magnetar candidates. II Resonant cross sections for electron-photon scattering in the relativistic regime
• INTEGRAL observations of Her X-1
• Cyclotron Line Variability
• RXTE Discovery of Multiple Cyclotron Lines during the 2004 December Outburst of V0332+53
• Phase dependent view of Cyclotron lines from model accretion mounds on Neutron Stars
• The hard X-ray emission of X Per
• Timing analysis of the isolated neutron star RX J0720.4-3125
• The Magnificent Seven in the dusty prairie -- The role of interstellar absorption on the observed neutron star population
• A new model for the X-ray continuum of the magnetized accreting pulsars
• Long-term variability in the X-ray emission of RX J0720.4-3125
• Near-infrared survey of High Mass X-ray Binary candidates
• Broadband Observations of the Be/X-ray Binary Pulsar RX J0440.9+4431: Discovery of a Cyclotron Absorption Line
• The 0.1-100 keV Spectrum of LMC X-4 in the High State: Evidence for a High Energy Cyclotron Absorption Line
• Long-term change in the cyclotron line energy in Hercules X-1
• 4U 0115+63: phase lags and cyclotron resonant scattering
• 1RXS J214303.7+065419/RBS 1774: A New Isolated Neutron Star Candidate
• Luminosity-dependent changes of the cyclotron line energy and spectral hardness in Cep X-4
• INTEGRAL observations of V0332+53 in outburst
• The origin of RXJ1856.5-3754 and RXJ0720.4-3125 -- updated using new parallax measurements
• Discovery of a Cyclotron Resonance Feature in the X-ray Spectrum of GX 304-1 with RXTE and Suzaku during Outbursts Detected by MAXI in 2010
• Long-term optical/IR variability of the Be/X-ray binary LS V +44 17/RX J0440.9+4431
• The pulsed X-ray light curves of the isolated neutron star RBS1223
• Burial of the polar magnetic field of an accreting neutron star. II. Hydromagnetic stability of axisymmetric equilibria
• Creation of magnetic spots at the neutron star surface
• Evidence for a Neutron Star in the non-pulsating massive X-ray binary 4U2206+54
• GRO J1008-57: an (almost) predictable transient X-ray binary
• High-Resolution X-Ray Spectroscopy of the Bursting Pulsar GRO J1744-28
• IGR J16393-4643: a new heavily-obscured X-ray pulsar
• Cyclotron resonance energies at a low X-ray luminosity: A0535+262 observed with Suzaku
• Strong outburst activity of the X-ray pulsar X Persei during 2001-2011
• Phase resolved spectroscopic study of the isolated neutron star RBS 1223 (1RXS J130848.6+212708)
• Giant outburst of EXO 2030+375: pulse-phase resolved analysis of INTEGRAL data
• Numerical solution of the radiative transfer equation: X-ray spectral formation from cylindrical accretion onto a magnetized neutron star
• INTEGRAL observation of the accreting pulsar GX 1+4
• Broadband spectroscopy using two Suzaku observation of the HMXB GX 301-2
• Multiwavelength monitoring of BD+53 2790, the optical counterpart to 4U~2206+54
• Transient X-ray pulsar V0332+53: pulse phase-resolved spectroscopy and the reflection model
• NuSTAR Detection Of A Cyclotron Line In The Supergiant Fast X-ray Transient IGR J17544-2619
• Swift/BAT and RXTE Observations of the Peculiar X-ray Binary 4U 2206+54 - Disappearance of the 9.6 Day Modulation
• Variable neutron star free precession in Hercules X-1 from evolution of RXTE X-ray pulse profiles with phase of the 35-day cycle
• Discovery and Modeling of a Flattening of the Positive Cyclotron Line/Luminosity Relation in GX 304-1 with RXTE
• Discovery of 5.16s pulsations from the isolated neutron star RBS 1223
• Ballooning Instability in Polar Caps of Accreting Neutron Stars
• X-Ray and Optical Observations of A 0535+26
• Neutron stars - thermal emitters
• Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling
• Cyclotron resonant scattering feature simulations. II. Description of the CRSF simulation process
• Luminosity-dependent spectral and timing properties of the accreting pulsar GX 304-1 measured with INTEGRAL
• A Detailed Study of 2S 0114+650 with the RXTE
• The complex X-ray spectrum of the isolated neutron star RBS1223
• Suzaku view of Be/X-ray binary pulsar GX 304-1 during Type I X-ray outbursts
• Detection of Cyclotron Resonance Scattering Feature in High Mass X-ray Binary Pulsar SMC X-2
• The NuSTAR X-ray Spectrum of Hercules X-1: A Radiation-Dominated Radiative Shock
• RX J0440.9+4431: a persistent Be/X-ray binary in outburst
• Cyclical behaviour and disc truncation in the Be/X-ray binary A0535+26
• NuSTAR Discovery of a cyclotron line in KS 1947+300
• Proper motions of thermally emitting isolated neutron stars measured with Chandra
• Discovery of the Orbit of the Transient X ray Pulsar SAX J2103.5+4545
• Stability of the Cyclotron Resonance Scattering Feature in Her X-1 with RXTE
• MHD instabilities in accretion mounds - II. 3D simulations
• Pulse phase and precession phase resolved spectroscopy of Her X-1: studying a representative Main-On with RXTE
• The first cyclotron harmonic of 4U 1538-52
• NGC 300 ULX1: A test case for accretion torque theory
• BeppoSAX observations of the X-ray pulsar MAXI J1409-619 in low state: discovery of cyclotron resonance features
• Now you see it, now you don't - the circumstellar disk in the GRO J1008--57 system
• A Clumpy Stellar Wind and Luminosity-Dependent Cyclotron Line Revealed by The First Suzaku Observation of the High-Mass X-ray Binary 4U 1538-522
• Long-term optical variability of high-mass X-ray binaries. II. Spectroscopy
• Suzaku observations of the HMXB 1A 1118-61
• Energy-Dependent Harmonic Ratios of the Cyclotron Features of X0331+53 in the 2004-2005 Outburst
• INTEGRAL observations of the variability of OAO 1657-415
• Study of the cyclotron feature in MXB 0656-072
• A Limit on the Number of Isolated Neutron Stars Detected in the ROSAT Bright Source Catalog
• Variable pulse profiles of Her X-1 repeating with the same irregular 35d clock as the turn-ons
• Suzaku Observations of Hercules X-1 : Measurements of the Two Cyclotron Harmonics
• Timing Studies on RXTE Observations of SAX J2103.5+4545
• The pre-outburst flare of the A 0535+26 August/September 2005 outburst
• Narrow phase-dependent features in X-ray Dim Isolated Neutron Stars: a new detection and upper limits
• The Be/X-ray Binary Swift J1626.6-5156 as a Variable Cyclotron Line Source
• BeppoSAX serendipitous discovery of the X-ray pulsar SAX J1802.7-2017
• XMM-Newton observations of the isolated neutron star RX J0806.4-4123
• Discovery of pulsations in the X-ray transient 4U 1901+03
• Modelling the spin pulse profile of the isolated neutron star RX J0720.4--3125 observed with XMM-Newton
• Pulse phase resolved spectroscopy of Vela X-1 with Suzaku
• Superorbital Period in the High Mass X-ray Binary 2S 0114+650
• A look with BeppoSAX at the low-luminosity Galactic X-ray source 4U 2206+54
• A double-peaked outburst of A 0535+26 observed with INTEGRAL, RXTE, and Suzaku
• Cyclotron Line Formation in a Radiation-driven Outflow
• Multiple cyclotron line-forming regions in GX 301-2
• Propeller effect in the transient X-ray pulsar SMC X-2
• Narrow absorption features in the co-added XMM-Newton RGS spectra of isolated Neutron Stars
• Finding a 24-day orbital period for the X-ray binary 1A 1118-616
• GRO J1744-28: an intermediate B-field pulsar in a low mass X-ray binary
• Two ~35 day clocks in Her X-1: evidence for neutron star free precession
• NuSTAR Discovery of a Cyclotron Line in the Be/X-ray Binary RX J0520.5-6932 During Outburst
• The Swift-BAT monitoring reveals a long term decay of the cyclotron line energy in Vela X-1
• Observations of the Transient X-ray Pulsar KS 1947+300 by the INTEGRAL and RXTE Observatories
• Discovery of a Cyclotron Resonance Scattering Feature in the X-ray Spectrum of XTE J1946+274
• Timing and broad band spectroscopy of 1A 1118-61 with Suzaku
• The birthplace and age of the isolated neutron star RX J1856.5-3754
• Further evidence for the presence of a neutron star in 4U 2206+54. INTEGRAL and VLA observations
• An unexpected drop in the magnetic field of the X-ray pulsar V0332+53 after the bright outburst occurred in 2015
• Spectral features in isolated neutron stars induced by inhomogeneous surface temperatures
• A Coherent Timing Solution for the Nearby, Thermally Emitting Isolated Neutron Star RX J0420.0-5022
• Formation of phase lags at the cyclotron energies in the pulse profiles of magnetized, accreting neutron stars
• Changes in the cyclotron line energy on short and long timescales in V 0332+53
• RXTE observations of the 1A 1118-61 in an outburst, and the discovery of a cyclotron line
• 4U 1626-67 as seen by Suzaku before and after the 2008 torque reversal
• NuSTAR discovery of a cyclotron absorption line in the transient X-ray pulsar 2S 1553-542
• Cyclotron Resonance Energies and Orbital Elements of Accretion Pulsar 4U 0115+63 During the Giant Outburst in 2008
• The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE Observations
• Variations in the Cyclotron Resonant Scattering Features during 2011 outburst of 4U 0115+63
• The needle in the haystack - Where to look for more isolated cooling neutron stars
• Accretion regimes in the X-ray pulsar 4U 1901+03
• Measurements of Cyclotron Features and Pulse Periods in the High-Mass X-Ray Binaries 4U 1538-522 and 4U 1907+09 with INTEGRAL
• Confirmation of a High Magnetic Field in GRO J1008-57
• Neutron stars from young nearby associations the origin of RXJ1605.3+3249
• Blank Field Sources in the ROSAT HRI Brera Multiscale Wavelet catalog
• Simultaneous NuSTAR/Chandra observations of the Bursting Pulsar GRO J1744-28 during its third reactivation
• The Swift-BAT hard X-ray sky monitoring unveils the orbital period of the HMXB IGR J16493-4348
• INTEGRAL High Energy Observations of 2S 0114+65
• A Comprehensive Spectral Analysis of the X-Ray Pulsar 4U 1907+09 from Two Observations with the Suzaku X-Ray Observatory
• XMM-Newton reveals a candidate period for the spin of the "Magnificent Seven" neutron star RX J1605.3+3249
• Detection of a cyclotron line in SXP 15.3 during its 2017 outburst
• XMM-Newton RGS spectrum of RX J0720.4-3125: An absorption feature at 0.57 keV
• Discovery of a Transition to Global Spin-up in EXO 2030+375
• Continued decay in the cyclotron line energy in Hercules X-1
• Possible Detection of an Emission Cyclotron Resonance Scattering Feature from the Accretion-powered Pulsar 4U 1626-67
• NuSTAR observations of the supergiant X-ray pulsar IGR J18027-2016: accretion from the stellar wind and possible cyclotron absorption line
• Broad band X-ray spectroscopy of A0535+262 with SUZAKU
• Evidence for a magnetic neutron star in high mass X-ray binary 4U 2206+54 with INTEGRAL/IBIS observations
• On the cyclotron line in Cep X-4
• Cyclotron harmonics in opacities of isolated neutron star atmospheres
• Recovery of the orbital parameters and pulse evolution of V0332+53 during a huge outburst
• Evolution of the X-ray Properties of the Transient Magnetar XTE J1810-197
• NuSTAR discovery of a cyclotron line in the accreting X-ray pulsar IGR J16393-4643
• Timing and Spectroscopy of Accreting X-ray Pulsars: the State of Cyclotron Line Studies
• A possible cyclotron resonance scattering feature near 0.7 keV in X1822-371
• Super-Strong Magnetic Fields of Neutron Stars in Be X-Ray Binaries Estimated with New Torque and Magnetosphere Models
• Discovery of new quasi-periodic oscillations in the X-ray transient source V~0332+53
• Looking at A 0535+26 at low luminosities with NuSTAR
• Pulse phase dependent variations of the cyclotron absorption features of the accreting pulsars A 0535+26, XTE J1946+274 and 4U 1907+09 with Suzaku
• The Orbital Period of Swift J1626.6-5156
• The broad band spectral properties of binary X-ray pulsars
• Spectral and temporal variations of the isolated neutron star RX J0720.4-3125: new XMM-Newton observations
• Application of the Ghosh & Lamb Relation to the Spin-up/down Behavior in the X-ray Binary Pulsar 4U 1626-67
• A0535+26 in the April 2010 outburst: probing the accretion regime at work
• Orbital Period Determinations for Four SMC Be/X-ray Binaries
• Inversion of the decay of the cyclotron line energy in Her X-1
• A broadband self-consistent modelling of the X-ray spectrum of 4U 1626--67
• The continued spectral and temporal evolution of RX J0720.4-3125
• Firm Detection of a Cyclotron Resonance Feature with Suzaku in the X-ray Spectrum of GRO J1008-57 during a Giant Outburst in 2012
• Broadband spectroscopy of the eclipsing high mass X-ray binary 4U 1700-37 with Suzaku
• Suzaku View of the Neutron Star in the Dipping Source 4U 1822$-$37
• The Transient Accereting X-Ray Pulsar XTE J1946+274: Stability of the X-Ray Properties at Low Flux and Updated Orbital Solution
• 4U 1909+07: a well-hidden pearl
• Evidence for an Evolving Cyclotron Line Energy in 4U 1538-522
• Dynamics of the Flows Accreting onto a Magnetized Neutron Star
• Multi-wavelength study of the Be/X-ray binary MXB 0656-072
• Detection of fundamental and first harmonic cyclotron line in X-ray pulsar Cep X-4
• Study of the X-ray pulsar IGR J19294+1816 with NuSTAR: detection of cyclotron line and transition to accretion from the cold disc
• 2S1553-542: a Be/X-ray binary pulsar on the far side of the Galaxy
• Determination of the Magnetic Fields of Magellanic X-Ray Pulsars
• Observations of The High Mass X-ray Binary A0535+26 in Quiescence
• The nature of the X-ray binary IGR J19294+1816 from INTEGRAL, RXTE, and Swift observations
• The donor star of the X-ray pulsar X1908+075
• X-ray Observations and Infrared Identification of the Transient 7.8 s X-ray Binary Pulsar XTE J1829-098
• Studying the accretion geometry of EXO 2030+375 at luminosities close to the propeller regime
• Evidence for a resonant cyclotron line in IGR J16493-4348 from the Swift-BAT hard X-ray survey
• ASCA Identification of SMC X-2 with the 2.37-s Pulsar Discovered by RXTE
• NuSTAR detection of hard X-ray phase lags from the accreting pulsar GS 0834-430
• Orbital parameters of the high-mass X-ray binary 4U 2206+54
• Glancing through the accretion column of EXO 2030+375
• NuSTAR rules out a cyclotron line in the accreting magnetar candidate 4U2206+54
• Staring at 4U 1909+07 with Suzaku
• Spin and Spectral Variations of Peculiar High-Mass X-ray Binary 4U 2206+54
• IGR J19294+1816: a new Be-X ray binary revealed through infrared spectroscopy
• Possible detection of a cyclotron resonance scattering feature in the X-ray pulsar 4U 1909+07
• Activity from the Be/X-ray binary system V0332+53 during its intermediate-luminosity outburst in 2008
• On the spin-down mechanism of the X-ray pulsar 4U 2206+54
• Swift/BAT measurements of the cyclotron line energy decay in the accreting neutron star Her X-1: indication of an evolution of the magnetic field?
• Discovery of a cyclotron absorption line in the transient X-ray pulsar XTE J1829-098
• X-ray and Near Infrared observations of the obscured accreting pulsar IGR J18179-1621
• Broad band X-ray spectrum of KS 1947+300 with BeppoSAX
• Two giant outbursts of V 0332+53 observed with INTEGRAL
• No Confirmed New Isolated Neutron Stars In The SDSS Data Release 4
• Long-term Optical Studies of the Be/X-ray Binary RX J0440.9+4431/LS V+44 17
• INTEGRAL and Swift observations of IGRJ19294+1816 in outburst
• Suzaku observations of the 2013 outburst of KS 1947+300
• A possible phase dependent absorption feature in the transient X-ray pulsar SAX J2103.5+4545
• INTEGRAL and Swift/XRT observations on IGR J18179-1621
• Broad-band spectroscopy of the transient X-ray binary pulsar KS 1947+300 during 2013 giant outburst: Detection of pulsating soft X-ray excess component
• Timing and Spectral Study of IGR J19294+1816 with RXTE: Discovery of Cyclotron Feature
• Variable Absorption Line in XTE J1810-197
• RXTE Studies of Cyclotron Lines in Accreting Pulsars

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• X-ray pulsar XTE J1858+034: discovery of the cyclotron line and the revised optical identification
• Three-dimensional modelling of accretion columns: spatial asymmetry and self-consistent simulations
• AstroSat observations of GRO J2058+42 during the 2019 outburst
• On the cyclotron absorption line and evidence of the spectral transition in SMC X-2 during 2022 giant outburst
• Expectations for Fast Radio Bursts in Neutron Star-Massive Star binaries
• Evolution of timing and spectral characteristics of 4U 1901+03 during its 2019 outburst using the Swift and NuSTAR observatories
• Switches between accretion structures during flares in 4U 1901+03
• Modelling spin-up episodes in accreting millisecond X-ray pulsars
• Catalog of the Galactic population of X-ray pulsars in High-mass X-ray binary systems
• Probing clumpy wind accretion in IGR J18027-2016 with XMM-Newton
• Accreting on the edge: a luminosity-dependent cyclotron line in the Be/X-ray Binary 2S 1553-542 accompanied by accretion regimes transition
• Variations of cyclotron resonant scattering features in Vela X-1 revealed with Insight-HXMT
• Premerger phenomena in neutron-star binary coalescences
• Evidence for neutron star triaxial free precession in Her X-1 from Fermi/GBM pulse period measurements
• The giant outburst of 4U 0115+634 in 2011 with Suzaku and RXTE
• First characterization of Swift J1845.7-0037 with NuSTAR
• Vacuum polarization alters the spectra of accreting X-ray pulsars
• The Symbiotic X-ray binaries Sct X-1, 4U 1700+24 and IGR J17329-2731
• Early neutron star evolution in high-mass X-ray binaries
• Cyclotron line evolution revealed with pulse-to-pulse analysis in the 2020 outburst of 1A 0535+262
• The X-ray pulsar XTE J1858+034 observed with NuSTAR and Fermi/GBM: spectral and timing characterization plus a cyclotron line
• Timing and spectral variability of high mass X-ray pulsar GX 301--2 over orbital phases observed by Insight-HXMT
• X-ray reprocessing in accreting pulsar GX 301-2 observed with Insight-HXMT
• Pulse Frequency Fluctuations of Persistent Accretion Powered Pulsars
• Possible detection of a new cyclotron feature in 4U 1700-37
• X-Ray Views of Galactic Accreting Pulsars in High-Mass X-Ray Binaries
• Meta-analysis of Electron Cyclotron Resonance Absorption Features Detected in High-Mass X-ray Binaries
• A NuSTAR observation of the eclipsing binary system OAO 1657-415: The revival of the cyclotron line
• Comprehensive broadband study of accreting neutron stars with Suzaku: Is there a bi-modality in the X-ray spectrum?
• Discovery of a pulse-phase-transient cyclotron line in the X-ray pulsar Swift J1808.4-1754 and identification of an optical companion
• Luminosity dependence of the multiple cyclotron lines in 4U 0115$+$63
• An in-depth analysis of the variable cyclotron lines in GX 301$-$2
• A peculiar cyclotron line near 16 keV detected in the 2015 outburst of 4U 0115+63?
• Cyclotron line formation in the radiative shock of an accreting magnetized neutron star
• IGR J17503-2636: a candidate supergiant fast X-ray transient
• Detection of X-ray pulsations at the lowest observed luminosity of Be/X-ray binary pulsar EXO 2030+375 with AstroSat
• The unaltered pulsar: GRO J1750-27, a super-critical X-ray neutron star that does not blink an eye
• SRG/ART-XC, Swift, NICER and NuSTAR study of different states of the transient X-ray pulsar MAXI J0903-531
• X-ray flashes from the low-mass X-ray binary IGR J17407-2808
• Investigation of the timing and spectral properties of an Ultra-luminous X-ray pulsar NGC 7793 P13
• Phase dependent evolution within large luminosity range of 1A 0535+262 observed by Insight-HXMT during 2020 giant outburst
• Energy-resolved pulse profile changes in V 0332+53: Indications of wings in the cyclotron absorption line profile
• Disk precession to explain the super-orbital modulation of LMC X-4: results from the Swift monitoring campaign
• Broadband study and the discovery of pulsations from the Be/X-ray binary eRASSU J052914.9-662446 in the Large Magellanic Cloud
• Measuring the magnetic dipole moment and magnetospheric fluctuations of SXP 18.3 with a Kalman filter
• The High Energy X-ray Probe (HEX-P): Studying Extreme Accretion with Ultraluminous X-ray Sources
• Polarised radiative transfer, rotation measure fluctuations and large-scale magnetic fields
• NuSTAR observation of GRO J1744-28 at low mass accretion rate
• An X-ray view of the 2021 outburst of SXP 15.6: constraints on the binary orbit and magnetic field of the Neutron Star
• Observational constraints on the magnetic field of the bright transient Be/X-ray pulsar SXP 4.78
• The ongoing spin-down episode of 4U 1626-67
• Broadband study of the Be X-ray binary RX J0520.5-6932 during its outburst in 2024
• Relativistic quantum-mechanical versus classical magnetic resonant scattering cross sections
• Timing and spectral studies of Cen X-3 in multiple luminosity states using $\text{AstroSat}$
• Study of the X-ray Pulsar XTE J1946+274 with NuSTAR
• Study of the X-ray Pulsar IGR J21343+4738 based on NuSTAR, Swift, and SRG data
• AstroSat observations of eclipsing high mass X-ray binary pulsar OAO 1657-415
• The gravitational Higgs mechanism and resulting smoking gun effects
• Don't torque like that. Measuring compact object magnetic fields with analytic torque models
• Measuring the magnetic dipole moment and magnetospheric fluctuations of accretion-powered pulsars in the Small Magellanic Cloud with an unscented Kalman filter
• LAXPC instrument onboard AstroSat: Five exciting years of new scientific results specially on X-ray Binaries
• NuSTAR discovery of a cyclotron line in GRO J1750-27
• Studying the variations of the cyclotron line in Cen X-3 using Insight-HXMT
• Clumpy wind studies and the non-detection of cyclotron line in OAO 1657-415
• First characterization of a new High Mass X-ray Binary in LMC eRASSU J050810.4$-$660653 with SRG/ART-XC, NuSTAR and Swift
• Exploring the MeV Sky with a Combined Coded Mask and Compton Telescope: The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO)
• Temporal and spectral variations of the X-ray pulsar Cen X-3 observed by NuSTAR
• Cyclotron lines in subcritical X-ray pulsars: Monte Carlo simulations reveal the origin of the observed variability
• Study on the magnetic field of the ultraluminous X-ray pulsar RX J0209.6-7427
• On the Mass and Magnetic Field of the Neutron Star in the Ultraluminous X-Ray Source NGC 300 ULX1
• Spectral and timing analysis of BeXRB eRASSU J050810.4-660653 recently discovered in the Large Magellanic Cloud (LMC)
• Double-hump spectrum, pulse profile dip, and pulsed fraction spectra from the low-accretion regime in the X-ray pulsar MAXI J0655-013
• Drop in the hard pulsed fraction and a candidate cyclotron line in IGR J16320-4751 seen by NuSTAR
• Discovery of a 0.8-mHz quasi-periodic oscillation in the transient X-ray pulsar SXP31.0 and associated timing transitions
• On the nature of the X-ray pulsar XTE J1859+083 and its broadband properties
• Variability study of classical supergiant X-ray binary 4U 1907+09 using NuSTAR
• Detection of a cyclotron line in the Be X-ray pulsar IGR J06074$+$2205
• Spectral evolution of X-ray pulsar 4U 1901+03 during the 2019 outburst based on Insight-HXMT and NuSTAR observations
• On the Spin Period of the Neutron Star in the Ultraluminous X-Ray Source M51 ULX-8
• Statistical features of multiple Compton scattering in a strong magnetic field
• Monte-Carlo simulations on possible collimation effects of outflows to fan-beamed emission of ultraluminous accreting X-ray pulsars
• Constraints on the magnetic field structure in accreting compact objects from aperiodic variability
• Orbital Phase-resolved Analysis of X-ray and Gamma-ray Observations of the High-Mass Gamma-ray Binary 4FGL J1405.1-6119
• Constraints on cyclotron features and accretion regime in the high-mass X-ray binary 4U 1700-37 from NuSTAR
• Exploring the magnetic field of the ultraluminous X-ray pulsar NGC 4631 X-8
• Multiwavelength study of 1eRASS J085039.9-421151 with eROSITA NuSTAR and X-shooter
• Studies of Cepheus X-4 during 2018 outburst observed with AstroSat
• Timing and spectral studies of the Be/X-ray binary EXO 2030+375 using Insight-HXMT observations
• Pulse frequency variations and timing noise of MXB 0656-072 during the 2007-2008 type I outbursts and implications for its magnetic field
• Super-critical accretion of BeXRB SXP 15.3
• A New Monte-Carlo Radiative Transfer Simulation of Cyclotron Resonant Scattering Features
• Probing the emission mechanism and nature of the pulsating compact object in the X-ray binary SAX J1324.4-6200
• Spectral and Timing properties of the recently discovered Be/X-ray pulsar eRASSUJ 052914.9-662446
• Discovery of burst oscillations in the newly discovered millisecond X-ray pulsar SRGA J144459.2$-$604207
• Flux variability of the "10 keV feature" of 4U 0115+63
• Insight-HXMT Spectral and Timing Studies of a Giant Outburst in RX J0440.9+4431
• Time Domain Astronomy with the THESEUS Satellite
• Low-frequency spectra of neutron star + OB supergiant binaries: Does wind density drive persistent and flaring modes of accretion?
• Luminosity dependence of the cyclotron line energy in 1A 0535+262 observed by Insight-HXMT during 2020 giant outburst