An Ultraluminous X-ray Source Powered by An Accreting Neutron Star

Abstract

Ultraluminous X-ray sources (ULX) are off-nuclear point sources in nearby galaxies whose X-ray luminosity exceeds the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their luminosity ranges from $10^{40}$ erg s${}^{-1}<L_X$(0.5 - 10 keV) $<10^{40}$ erg s${}^{-1}$. Since higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end ($L_X$ > $10^{40}$ erg s${}^{-1}$), which require black hole masses MBH >50 solar masses and/or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries. Here we report broadband X-ray observations of the nuclear region of the galaxy M82, which contains two bright ULXs. The observations reveal pulsations of average period 1.37 s with a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to $L_X$(3 - 30 keV) = $4.9\times 10^{39}$ erg s${}^{-1}$. The pulsating source is spatially coincident with a variable ULX which can reach $L_X$ (0.3 - 10 keV) = $1.8\times 10^{40}$ erg s${}^{-1}$. This association implies a luminosity ~100 times the Eddington limit for a 1.4 solar mass object, or more than ten times brighter than any known accreting pulsar. This finding implies that neutron stars may not be rare in the ULX population, and it challenges physical models for the accretion of matter onto magnetized compact objects.

arXiv comment24 pages, 5 figures, 4 tables, published on Nature

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• A new sample of transient ultraluminous X-ray sources serendipitously discovered by Swift/XRT
• Long-term Spectral Variability of the Ultra-luminous X-ray source Holmberg IX X--1
• ULX behaviour: the ultraluminous state, winds & interesting anomalies
• The two Ultraluminous X-ray sources in the galaxy NGC 925
• Understanding the coexistence of spin-up and spin-down behaviors in long period X-ray pulsars
• First Detection of Mid-Infrared Variability from an Ultraluminous X-Ray Source Holmberg II X-1
• The origin of the bimodal luminosity distribution of ultraluminous X-ray pulsars
• Quasi periodic whispers from a transient ULX in M\,101: signatures of a fast-spinning neutron star?
• Radiative MHD Simulations of Photon Bubbles in Radiation-Supported Magnetized Atmospheres of Neutron Stars with Isotropic Thomson Scattering
• The Transient Ultra-luminous X-ray Source, ULX-4, in M51
• A multi-wavelength view of distinct accretion regimes in the pulsating ultraluminous X-ray source NGC 1313 X-2
• Optical Counterparts of ULXs and Their Host Environments in NGC 4490/4485
• An 8.56 keV absorption line in the hyperluminous X-ray source in NGC 4045: ultra-fast outflow or cyclotron line?
• Accreting Black Holes
• The MAVERIC survey: A catalogue of radio sources in southern globular clusters from the Australia Telescope Compact Array
• Limits on thickness and efficiency of Polish doughnuts in application to the ULX sources
• Isolated pulsar population synthesis with simulation-based inference
• Neutron Star QPOs from Oscillating, Precessing Hot, Thick Flow
• Possible Periodic Dips in the Pulsating Ultraluminous X-ray Source M51 ULX-7
• Discovery of pulsation dropout and turn-on during the high state of the accreting X-ray pulsar LMC X-4
• Discovery of a second outbursting hyperluminous X-ray source
• Study on the magnetic field strength of NGC 300 ULX1
• A Study of the 20 Day Superorbital Modulation in the High-Mass X-ray Binary IGR J16493-4348
• Getting More Out of Black Hole Superradiance: a Statistically Rigorous Approach to Ultralight Boson Constraints from Black Hole Spin Measurements
• GRMHD simulations of accreting neutron stars I: nonrotating dipoles
• On the magnetic field of the ultraluminous X-ray pulsar M82 X-2
• NGC 7793 P9: An Ultraluminous X-Ray Source Evolved from a Canonical Black Hole X-Ray Binary
• A new pulsating neutron star in the Ultraluminous X-ray source NGC 4559 X7?
• On the Nature of the X-ray Emission from the Ultraluminous X-ray Source, M33 X-8: New Constraints from NuSTAR and XMM-Newton
• Not an Oxymoron: Some X-ray Binary Pulsars with Enormous Spinup Rates Reveal Weak Magnetic Fields
• X-ray spectral and optical properties of a ULX in NGC 4258 (M106)
• Anti-glitches in accreting pulsars from superfluid vortex avalanches
• Unveiling the disc structure in ultraluminous X-ray source NGC 55 ULX-1
• Comparing the Super-Eddington accretion of SMC X-3 and RX J0209.6-7427 with Swift J0243.6+6124
• Optical Counterpart to the Ultraluminous X-Ray Source in the UGC6456 Galaxy
• Discovery and analysis of a ULX nebula in NGC 3521
• Populations of Neutron Star Ultraluminous X-ray Sources: Mind your b's and B's
• Spitzer IRAC observations of IR excess in Holmberg IX X-1: A circumbinary disk or a variable jet?
• Investigating the nature of the ultraluminous X-ray sources in the galaxy NGC 925
• Propeller states in locally super-critical ULXs
• Bright X-ray pulsars as sources of MeV neutrinos in the sky
• On the Magnetic Fields of Ultraluminous X-ray Pulsars
• Spectral state transitions in Circinus ULX5
• Central X-ray point-sources found to be abundant in low-mass, late-type galaxies predicted to contain an intermediate-mass black hole
• X-ray emission evolution of the Galactic ultra-luminous X-ray pulsar Swift J0243.6+6124 during the 2017-2018 outburst observed by the MAXI GSC
• AT2018lqh: Black Hole Born from a Rotating Star?
• Detection of 125.5-day Optical Periodic Modulation of the Neutron Star M51 ULX-8
• Searching for Super-Eddington Quasars using a Photon Trapping Accretion Disc Model
• Slow Decline and Rise of the Broad [OIII] Emission Line in Globular Cluster Black Hole Candidate RZ2109
• Stellar Properties of the Host Galaxy of an Ultraluminous X-ray Source in NGC 5252
• Optical Counterparts of ULXs in NGC 1672
• Exploring the nature of ultra-luminous X-ray sources across stellar population ages using detailed binary evolution calculations
• Fundamental physics with neutron stars
• Identification of a Helium Donor Star in NGC 247 ULX-1
• Broadband X-ray Spectral Study of Ultra-luminous X-ray Source M81 X--6
• Sustained super-Eddington accretion around neutron stars & black holes
• The long stare at Hercules X-1 -- I. Emission lines from the outer disk, the magnetosphere boundary and the accretion curtain
• A New Possible Accretion Scenario for Ultra-Luminous X-ray Sources
• Atmospheric oscillations provide simultaneous measurement of neutron star mass and radius
• Recurrent X-ray flares of the black hole candidate in the globular cluster RZ 2109 in NGC 4472
• Mass and spin measurements for the neutron star 4U1608-52 through the relativistic precession model
• Swift-XRT 6-year monitoring of the ultraluminous X-ray source M33-X8
• Does the 62-day X-ray periodicity come from ULX M82 X-1?
• Lens Flare: Magnified X-Ray Binaries as Passive Beacons in SETI
• VLT MUSE observations of the bubble nebula around NGC 1313 X-2 and evidence for additional photoionization
• Role of magnetically dominated disc-outflow symbiosis on bright hard-state black hole sources: ultra-luminous X-ray sources to quasars
• Repeating Ultraluminous X-ray Bursts and Repeating Fast Radio Bursts: A Possible Association?
• A Sparkler in the Fireworks Galaxy: Discovery of an Ultraluminous X-ray Transient with a Strong Oxygen Line in NGC 6946
• Winds in ultraluminous X-ray sources: new challenges
• X-Ray Views of Galactic Accreting Pulsars in High-Mass X-Ray Binaries
• On the nature of the ultraluminous X-ray source Holmberg II X-1
• Measuring the black hole mass in Ultraluminous X-ray Sources with the X-ray Scaling Method
• A multi-observatory database of X-ray pulsars in the Magellanic Clouds
• Constraining the mass of accreting black holes in ultraluminous X-ray sources with ultrafast outflows
• A broadband X-ray imaging spectroscopy in the 2030s: the FORCE mission
• High Energy Gamma Rays from Nebulae Associated with Extragalactic Microquasars and Ultra-Luminous X-ray Sources
• The impact of precession on the observed population of ULXs
• What Determines Unique Spectra of Super-Eddington Accretors?: Origin of Optically Thick and Low Temperature Coronae in Super-Eddington Accretion Flows
• High-Mass X-Ray Binaries with Be Donors as Ultraluminous X-Ray Sources
• X-ray Binaries in External Galaxies
• High Excitation Emission Line Nebula associated with an Ultra Luminous X-ray Source at $z=$ 0.027 in the \textit{AKARI} North Ecliptic Pole Deep Field
• NuSTAR observations of the ultraluminous X-ray source M33 X-8: a black hole in a very high state?
• ULX collimation by outflows in moderately magnetized neutron stars
• Discovery of Red-shifted He-like Iron Absorption Line from Luminous Accreting Neutron Star SMC X-1
• A Luminous X-ray Flare From The Nucleus of The Dormant Bulgeless Spiral Galaxy NGC 247
• X-ray properties of two transient ULX candidates in galaxy NGC 7090
• Spectral Evolution of Ultraluminous X-ray Pulsar NGC 300 ULX-1
• On the Physical Nature of the Source of Ultraluminous X-ray Pulsations
• Discovery of two eclipsing X-ray binaries in M51
• Simultaneous NICER and NuSTAR observations of the Ultraluminous source NGC 4190 ULX-1
• Radial modes of levitating atmospheres around Eddington-luminosity neutron stars
• GR-RMHD Simulations of Super-Eddington Accretion Flows onto a Neutron Star with Dipole and Quadrupole Magnetic Fields
• Testing Gravity with Black Hole X-Ray Data
• X-ray emissions from magnetic polar regions of neutron stars
• Neutrino beaming in ultraluminous X-ray pulsars as a result of gravitational lensing by neutron stars
• The ultraluminous X-ray source M81 X-6: a weakly magnetised neutron star with a precessing accretion disc?
• Supersoft, luminous X-ray sources in galactic nuclei
• Globular Cluster Ultraluminous X-ray Sources in the Furthest Early-Type Galaxies
• The Orbit of NGC 5907 ULX-1
• Hard X-ray flares and spectral variability in NGC 4395 ULX1
• Optical Counterparts of an Ultraluminous X-Ray Source X-1 in NGC 2500
• A transient ultraluminous X-ray source in NGC 55
• An extreme Ultraluminous X-ray source X-1 in NGC 5055
• The High Energy X-ray Probe (HEX-P): Studying Extreme Accretion with Ultraluminous X-ray Sources
• The ULX Source X-3 in NGC 4258: A Search for Its X-ray and Optical Properties
• The largest bright ULX population in a galaxy: X-ray variability and Luminosity Function in the Cartwheel ring Galaxy
• Thick-disc model to explain the spectral state transition in NGC 247
• Constraint on the accretion of NGC 6946 X-1 using broadband X-ray data
• X-ray irradiation of the stellar wind in HMXBs with B supergiants: Implications for ULXs
• Investigation of the timing and spectral properties of an Ultra-luminous X-ray pulsar NGC 7793 P13
• Modelling multiwavelength emission of Ultra-luminous X-ray Sources accreting above the Eddington limit
• Monitoring Observations of SMC X-1's Excursions (MOOSE) I: Program Description and Initial High-State Spectral Results
• The Great Pretenders Among the ULX Class
• Ultraluminous X-ray sources with He star companions
• Mean opacities of a strongly magnetized high temperature plasma
• An Intermediate-Mass Black Hole Candidate in M51?
• Observational constraints on the magnetic field of the bright transient Be/X-ray pulsar SXP 4.78
• Ultraluminous X-ray Sources in Seven Edge-On Spiral Galaxies
• Exploring GRBs and supernovae connection: does a superluminous hypernova population exist?
• Blue Supergiant X-ray Binaries in the Nearby Dwarf Galaxy IC 10
• Monitoring observations of SMC X-1's excursions (MOOSE)-II: A new excursion accompanies spin-up acceleration
• The Advanced X-ray Imaging Satellite
• Ultra Luminous X-ray sources - new distance indicators?
• Radial oscillations of a radiation-supported levitating shell in Eddington luminosity neutron stars
• Evidence for Fe K${}_{\alpha }$ line and soft X-ray lag in NGC 7456 ULX-1
• Digging a little deeper: characterising three new extreme ULX candidates
• X-ray reverberation models of the disc wind in ultraluminous X-ray source NGC 5408 X-1
• Populations of ultraluminous X-ray sources in galaxies: origin and evolution
• Intermediate Mass Black Holes: A brief review
• Don't torque like that. Measuring compact object magnetic fields with analytic torque models
• Radiative Shocks around Super-Eddington Accreting Black Holes
• Optical Counterparts of ULXs in Two Dwarf Galaxies: NGC 4861 and NGC 4449
• New Transient ULX Candidate in NGC 4254: Evidence of Circumbinary Disk?
• Identification of a New Ultraluminous X-ray Source in NGC 1316
• Are there magnetars in high-mass X-ray binaries?
• Multi-wavelength spectroscopic analysis of the ULX Holmberg II X-1 and its nebula suggests the presence of a heavy black hole accreting from a B-type donor
• X-raying the Birth of Binary Neutron Stars and Neutron Star-Black Hole Binaries
• Exploring the Spectral Variability of the Ultra-luminous X-ray source M81 X-6 with Suzaku and XMM-Newton
• Bubble in the Whale: Identifying the Optical Counterparts and Extended Nebula for the Ultraluminous X-ray Sources in NGC 4631
• Observational limits on the X-ray emission from the bubble nebula surrounding Ho IX X-1
• Characteristics and evolution of Be-type high mass X-ray binaries as potential Ultraluminous X-ray Sources
• Formation of millisecond pulsar-helium star binaries
• A Long-term Study of Ultraluminous X-ray Sources in NGC 891
• The variability behavior of NGC 925 ULX-3
• The hunt for new pulsating ultraluminous X-ray sources: a clustering approach
• Nature of donors in ultra-luminous X-ray binaries powered by neutron stars
• Long-Term X-Ray/UV Variability in ULXs
• A Striking Confluence Between Theory and Observations of High-Mass X-ray Binary Pulsars
• Spectral analysis of ultraluminous X-ray pulsars with models of X-ray pulsars
• NGC 300 ULX1: A new ULX pulsar in NGC 300
• Clumpy jets from black hole-massive star binaries as engines of Fast Radio Bursts
• Astrophysical black holes
• Clumpy wind studies and the non-detection of cyclotron line in OAO 1657-415
• Broadband X-ray spectral analysis of the ULX NGC 1313\,X-1 using JeTCAF: Origin of the ULX bubble
• Luminous Fast Blue Optical Transients as "Failed" Gravitational-wave Sources: Helium Core$-$Black Hole Mergers Following Delayed Dynamical Instability
• Simultaneous X-ray/UV observations of ultraluminous X-ray source Holmberg II X-1 with Indian space mission AstroSat
• Optical and X-ray Follow-Up to a Globular Cluster Ultraluminous X-ray Source in NGC 4472
• Searching for the highest energy of pulsation and critical luminosity of Swift J0243.6+6124 observed by Insight-HXMT
• NGC 2403 XMM4: evidence for a super-Eddington neutron star with a possible transient pulsation
• Ultraluminous X-ray sources in Globular Clusters
• PSR J1227$-$6208 and its massive white dwarf companion: pulsar emission analysis, timing update and mass measurements
• Peculiar outbursts of an ultra luminous source likely signs of an aperiodic disc-wind
• Detectability of Population III stellar remnants as X-ray binaries from tidal captures in the local Universe
• Phase-Dependent Spectral Shape Changes in the Ultraluminous X-Ray Pulsar NGC 5907 ULX1
• Pulsating ultraluminous X-ray sources: modeling the thermal emission and polarization properties
• X-ray Pulsars
• Variability in high-mass X-ray binaries
• The X-ray Point Source Population Hosted by Globular Clusters in the Elliptical Galaxy NGC 4261
• Super-Eddington accretion in high-redshift quasar hosts: Black-hole driven outflows, galaxy quenching, and the nature of little red dots
• Study on the magnetic field of the ultraluminous X-ray pulsar RX J0209.6-7427
• Magnetic precession as a model for QPOs in PULXs: flat-top noise ULXs are different
• The population of hyperluminous X-ray sources as seen by XMM-Newton
• Energy flow and radiation efficiency in radiative GRMHD simulations of neutron star ultraluminous X-ray sources
• The nature of the X-ray pulsar in M31: an intermediate mass X-ray binary?
• XMM-Newton multi-year campaign on NGC 55 ULX-1: Resolving the wind and its variability with RGS
• On the Mass and Magnetic Field of the Neutron Star in the Ultraluminous X-Ray Source NGC 300 ULX1
• X-ray binaries with neutron stars at different accretion stages
• Comprehensive X-ray and Multiwavelength Study of ULXs in NGC 1566
• Identification of three new ultraluminous X-ray sources in NGC 4631 and NGC 1097: Evidence for stellar-mass black holes
• On the Spin Period of the Neutron Star in the Ultraluminous X-Ray Source M51 ULX-8
• Spectral study of X-ray sources in some galaxies recently observed by Chandra
• A Study of Spectral Variability between flaring and non-flaring state in M74 X-1
• Radiative GRMHD simulations of accretion disks
• Optical Counterparts of Two Candidate Ultraluminous X-ray Sources in NGC 4536
• Spectral variability in NGC 1042 ULX1
• Synchrotron cutoff in Ultraluminous X-ray sources
• A possible origin of the Galactic Center magnetar SGR 1745-2900
• The First Glimpse of ULXs Through the Near-Infrared Images Captured by the James Webb Space Telescope
• New outburst from the luminous supersoft source SSS1 in NGC 300 with periodic modulation
• Estimating the black hole mass of NGC1313 X-1 based on the spectral and timing properties
• Constraints on the collimated X-ray emission of SS 433 from the reflection on molecular clouds
• Monte-Carlo simulations on possible collimation effects of outflows to fan-beamed emission of ultraluminous accreting X-ray pulsars
• Exploring the nature of an ultraluminous X-ray source in NGC 628
• Searching for X-ray sources in nearby late-type galaxies with low star formation rates
• The Bright X-Ray Source in NGC 3413
• A comparative study of occurrence rates and nature of Ultraluminous X-ray sources in spiral and elliptical galaxies
• Ultraluminous X-ray sources in the group-centric elliptical galaxy NGC 5813
• Probing extreme black-hole outflows on short timescales via high spectral-resolution X-ray imagers
• Automatic detection of tidal disruption events and other long duration transients in XMM-Newton data
• First Search for an X-ray -- Optical Reverberation Signal in an Ultraluminous X-ray Source
• Possible optical counterparts of ULXs in NGC 1672
• Recurrent Instability in LMXB Accretion Disks: How Strange is GRS 1915+105?
• Radio Nebulæ from Hyper-Accreting X-ray Binaries as Common Envelope Precursors and Persistent Counterparts of Fast Radio Bursts
• A Synthetic Population of Ultra-Luminous X-ray Sources: Optical-X-ray Correlation
• A novel sub-grid model for super-Eddington accretion of spinning black holes in galaxy-scale simulations
• The maximum dipole moments of neutron stars implied by the Barrow-Gibbons conjecture
• Monitoring of the eclipsing Wolf-Rayet ULX in the Circinus galaxy
• An expanded ultraluminous X-ray source catalogue
• Ultraluminous X-ray sources in the first eROSITA survey I. Candidate catalogs
• Time Domain Astronomy with the THESEUS Satellite
• Unveiling the biconical geometry of the outflow in the ultraluminous X-ray source NGC 5204 X-1
• Probing spectral variability in NGC 4490 ULX-8 over 24 years of XMM-Newton, Chandra and Swift-XRT observations
• A Multi-Mission Catalogue of Ultraluminous X-ray Source Candidates
• Ultra-luminous X-ray sources as neutron stars propelling and accreting at super-critical rates in high-mass X-ray binaries
• Spectral and Temporal Properties of Ultra-luminous X-ray Source NGC 55 ULX1
• Exploring the magnetic field of the ultraluminous X-ray pulsar NGC 4631 X-8
• Pulsar scintillation studies with LOFAR III. Annual variations in PSR~J0814$+$7429