M74 X-1 (CXOU J013651.1+154547): An Extremely Variable Ultraluminous X-Ray Source

Abstract

Ultraluminous X-ray sources (ULXs) have been described variously as the most luminous normal X-ray binaries, as hypernovae, and as "intermediate-mass" black holes with masses of hundreds to thousands of solar masses. We present results on M74 X-1 (CXOU J013651.1+154547), a ULX in the nearby spiral galaxy M74 (NGC 628), from observations by Chandra and XMM-Newton. M74 X-1is a persistent source which exhibits extreme variability and changes in spectral state on timescales of several thousand seconds. Its variability timescales and behavior resemble some Galactic microquasars. This suggests that the emission mechanism may be related to relativistically beamed jets, and that M74 X-1 could be an extragalactic "microblazar" -- a microquasar whose jet axis is aligned with our line of sight. We also note that its spectrum is consistent with the presence of a low-temperature disk blackbody component, which, assuming it is due to radiation from an accretion disk, could indicate that M74 X-1 contains an intermediate-mass black hole.

10 pages, 13 figures; accepted by the Astrophysical Journal

References in corpus (29)

• Ultraluminous X-Ray Sources in External Galaxies
• The Nature of Accreting Black Holes in Nearby Galaxy Nuclei
• The Nature of Ultra-Luminous Compact X-Ray Sources in Nearby Spiral Galaxies
• First Results from the X-ray and Optical Survey of the Chandra Deep Field South
• Super-Eddington Fluxes from Thin Accretion Disks?
• On the formation and evolution of black-hole binaries
• X-ray Spectroscopic Evidence for Intermediate Mass Black Holes: Cool Accretion Disks in Two Ultra--Luminous X-ray Sources
• A ROSAT HRI survey of bright nearby galaxies
• Population X: Are the super-Eddington X-ray sources beamed jets in microblazars or intermediate mass black holes?
• A Catalog of Candidate Intermediate-luminosity X-ray Objects
• Radio Emission from an Ultraluminous X-Ray Source
• Magnetic reconnection: flares and coronal heating in Active Galactic Nuclei
• Evidence for a Disk-Jet Interaction in the Microquasar GRS 1915+105
• ROSAT monitoring of persistent giant and rapid variability in the narrow-line Seyfert 1 galaxy IRAS 13224-3809
• External Compton emission from relativistic jets in Galactic black hole candidates and ultraluminous X-ray sources
• The X-ray Luminosity Function of "The Antennae" Galaxies (NGC4038/39) and the Nature of Ultra-Luminous X-ray Sources
• Variable-Frequency QPOs from the Galactic Microquasar GRS 1915+105
• The Lack of Very Ultraluminous X-ray Sources in Early-type Galaxies
• The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1
• The runaway black hole GRO J1655-40
• ROSAT HRI Monitoring of Extreme X-ray Variability in the Narrow-Line Quasar PHL 1092
• Chandra observations of five ultraluminous X-ray sources in nearby galaxies
• The Time-Variable Ultra-Luminous X-ray Sources of "The Antennae"
• Chandra Observation of Luminous and Ultraluminous X-ray Binaries in M101
• The optical counterpart of the ultra-luminous x-ray source NGC 5204 X-1
• Chandra reveals a black-hole X-ray binary within the ultraluminous supernova remnant MF 16
• The rapid X-ray variability of V4641 Sagittarii (SAX J1819.3-2525 = XTE J1819-254)
• X-Ray Flares and Oscillations from the Black Hole Candidate X-Ray Transient XTE J1650-500 at Low Luminosity
• A 10-day ASCA Observation of the Narrow-line Seyfert~1 galaxy IRAS 13224-3809

Cited by in corpus (24)

• X-ray observations of ultraluminous X-ray sources
• Planetary Nebulae in Face-On Spiral Galaxies. I. Planetary Nebula Photometry and Distances
• A 62 Day X-Ray Periodicity and an X-Ray Flare from the Ultraluminous X-Ray Source in M82
• The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environment
• Spectroscopy of Optical Counterparts of Ultraluminous X-ray Sources
• X-ray emission from the extended disks of spiral galaxies
• Chandra monitoring observations of the ultraluminous X-ray source NGC 5204 X-1
• Suzaku Observations of M82 X-1 : Detection of a Curved Hard X-ray Spectrum
• Radio and X-ray Properties of Relativistic Beaming Models for Ultra-Luminous X-ray Sources
• Ultraluminous X-ray Sources Powered by Radiatively Efficient Two-Phased Super-Eddington Accretion onto Stellar Mass Black holes
• Broad band polarimetric investigation of Type IIP supernova 2013ej
• The dependence of the estimated luminosities of ULX on spectral models
• Discovery of a Highly Variable Dipping Ultraluminous X-ray source in M94
• A Search For Supernova Remnants in The Nearby Spiral Galaxy M74 (NGC 628)
• X-ray and Optical Eclipses in ULXs as Possible Indicators of Black Hole Mass
• The spectral and temporal properties of an Ultra-Luminous X-ray source in NGC 6946
• Quasi periodic whispers from a transient ULX in M\,101: signatures of a fast-spinning neutron star?
• Investigation of the Connection Between X-ray Binaries and Compact Star Clusters in NGC 628
• Astrophysics in 2005
• Detection of X-ray elongated emission from a ultraluminous X-ray source in the interacting pair of galaxies NGC 5953/5954
• New Transient ULX Candidate in NGC 4254: Evidence of Circumbinary Disk?
• The kilo-second variability of X-ray sources in nearby galaxies
• Exploring the nature of an ultraluminous X-ray source in NGC 628
• A Study of Spectral Variability between flaring and non-flaring state in M74 X-1