Discovery of a Luminous, Variable, Off-Center Source in the Nucleus of M82 with the [ITAL]Chandra[/ITAL] High-Resolution Camera

Matsumoto, Hironori; Tsuru, Takeshi Go; Koyama, K.; Awaki, Hisamitsu; Canizares, C. R.; Kawai, N.; Matsushita, Satoki; Prestwich, Andrea; Ward, M. J.; Zezas, A.; Kawabe, Ryohei

doi:10.1086/318878

Cited by 217 publications

(204 citation statements)

References 18 publications

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“…The observed X-ray spectrum is consistent with that from the innermost disk radius assuming that the central object has a mass M BH $ 1200=ðcos iÞ 1=2 . While no objects in this mass range have been confirmed, invoking the Eddington limit to X-ray bright sources has led to suggestions of masses in excess of 10-100 M in many instances (see, e.g., Makishima et al 2000) and as high as $700 M in the case of a luminous source in M82 (Kaaret et al 2001;Matsumoto et al 2001). …”

Section: No 1 2002 Luminous Supersoft X-ray Sources In M81mentioning

confidence: 99%

ChandraDiscovery of Luminous Supersoft X‐Ray Sources in M81

Swartz

Ghosh

Suleimanov

et al. 2002

ApJ

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A Chandra ACIS-S imaging observation of the nearby galaxy M81 (NGC 3031) reveals nine luminous soft X-ray sources. The local environments, X-ray spectral properties, and X-ray light curves of the sources are presented and discussed in the context of prevailing physical models for supersoft sources. It is shown that the sample falls within expectations based on population synthesis models taken from the literature, although the high observed luminosities (L obs $ 2 Â 10 36 -3 Â 10 38 ergs s À1 in the 0.2-2.0 keV band) and equivalent blackbody temperatures (T eff $ 40 80 eV) place the brightest detected M81 objects at the high-luminosity end of the class of supersoft sources defined by previous ROSAT and Einstein studies of nearby galaxies. This is interpreted as a natural consequence of the higher sensitivity of Chandra to hotter and more luminous systems. Most of the sources can be explained as canonical supersoft sources: accreting white dwarfs powered by steady surface nuclear burning with X-ray spectra well fitted by hot white dwarf local thermodynamic equilibrium atmosphere models. An exceptionally bright source is scrutinized in greater detail since its estimated bolometric luminosity, L bol $ 1:5 Â 10 39 ergs s À1 , greatly exceeds theoretical estimates for supersoft sources. This source may be beyond the stability limit and undergoing a phase of mass outflow under extreme conditions. Alternatively, a model in which the observed X-ray spectrum arises from an accretion disk around a black hole of mass $1200=ðcos iÞ 1=2 M (viewed at an inclination angle i) cannot be excluded.

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Section: No 1 2002 Luminous Supersoft X-ray Sources In M81mentioning

confidence: 99%

ChandraDiscovery of Luminous Supersoft X‐Ray Sources in M81

Swartz

Ghosh

Suleimanov

et al. 2002

ApJ

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“…Current evidence suggests that ULXs might be a mixed bag of compact objects including stellar-mass black holes (StMBHs: 3-25 M e ) powered by super-Eddington accretion (e.g., King et al 2001;Begelman 2002;Gladstone et al 2009), intermediate-mass black holes (IMBHs: a few × (100-1000) M e ; Kaaret et al 2001Kaaret et al , 2006Matsumoto et al 2001;Miller et al 2004;Farrell et al 2009;Pasham et al 2014;Mezcua et al 2015), and neutron stars (Bachetti et al 2014).…”

Section: Introductionmentioning

confidence: 99%

EVIDENCE FOR HIGH-FREQUENCY QPOs WITH A 3:2 FREQUENCY RATIO FROM A 5000 SOLAR MASS BLACK HOLE

Pasham

Cenko

Zoghbi

et al. 2015

ApJ

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Following the discovery of 3:2 resonance quasi-periodic oscillations (QPOs) in M82X-1, we have constructed power density spectra (PDS) of all 15 (sufficiently long) XMM-Newton observations of the ultraluminous X-ray source NGC 1313 X-1 (L X ≈ 2 × 10 40 erg s −1 ). We detect a strong QPO at a frequency of 0.29 ± 0.01 Hz in data obtained on 2012 December 16. Subsequent searching of all the remaining observations for a 3:2/2:3 frequency pair revealed a feature at 0.46 ± 0.02 Hz on 2003 December 13 (frequency ratio of 1.59 ± 0.09). The global significance of the 0.29 Hz feature considering all frequencies between 0.1 and 4 Hz is >3.5σ. The significance of the 0.46 ± 0.02 Hz QPO is >3.5σ for a search at 2/3 and 3/2 of 0.29 Hz. We also detect lower-frequency QPOs (32.9 ± 2.6 and 79.7 ± 1.2 mHz). All the QPOs are superimposed on a continuum consisting of flat-topped, bandlimited noise, breaking into a power law at a frequency of 16 ± 3 mHz and white noise at 0.1 Hz. NGC 1313 X1ʼs PDS is analogous to stellar-mass black holes' (StMBHs) PDS in the so-called steep power-law state, but with the respective frequencies (both QPOs and break frequencies) scaled down by a factor of ∼1000. Using the inverse mass-to-high-frequency QPO scaling of StMBHs, we estimate NGC 1313 X-1ʼs black hole mass to be 5000 ± 1300 M e , consistent with an inference from the scaling of the break frequency. However, the implied Eddington ratio, L Edd > 0.03 ± 0.01, is significantly lower compared to that of StMBHs in the steep power-law state (L Edd  0.2).

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“…The proportional counter array's field of view (1 • ×1 • ) of M82 includes a number of accreting X-ray sources in addition to M82 X-1 18 . The remarkable stability of the two quasiperiodic oscillations on timescales of a few years (Movies 1 & 2), their 3:2 frequency ratio and their high oscillation luminosities strongly suggest they are not low-frequency quasi-periodic oscillations from a contaminating stellar-mass black hole (see Methods for details).…”

mentioning

confidence: 99%

A 400-solar-mass black hole in the galaxy M82

Pasham

Strohmayer

Mushotzky

2014

Nature

199

197

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The brightest X-ray source in M82 has been thought to be an intermediatemass black hole (10 2−4 solar masses, M ⊙ ) because of its extremely high luminosity and variability characteristics 1−6 , although some models suggest that its mass may be only ∼ 20 M ⊙ 3,7 . The previous mass estimates are based on scaling relations which use low-frequency characteristic timescales which have large intrinsic uncertainties 8,9 . In stellar-mass black holes we know that the high frequency quasi-periodic oscillations that occur in a 3:2 ratio (100-450 Hz) are stable and scale inversely with black hole mass with a reasonably small dispersion 10−15 . The discovery of such stable oscillations thus potentially offers an alternative and less ambiguous mass determination for intermediate-mass black holes, but has hitherto not been realized. Here, we report stable, twin-peak (3:2 frequency ratio) X-ray quasi-periodic oscillations from M82 X-1 at the frequencies of 3.32±0.06Hz and 5.07±0.06 Hz. Assuming that we can scale the stellar-mass relationship, we estimate its black hole mass to be 428±105 M ⊙ . In addition, we can estimate the mass using the relativistic precession model, from which we get a value ofOscillations arising from general relativistic effects should scale inversely with the black hole mass if they arise from orbital motion near the innermost stable circular orbit in the We detected two power spectral peaks at 3.32±0.06 Hz (coherence, Q = centroid frequency (ν)/width(∆ν) > 27) and 5.07±0.06 Hz (Q > 40) consistent with a 3:2 frequency ratio ( Fig. 1a, b). The combined statistical significance of the detection is greater than 4.7σ (see Methods for details).The proportional counter array's field of view (1 • ×1 • ) of M82 includes a number of accreting X-ray sources in addition to M82 X-1 18 . The remarkable stability of the two quasiperiodic oscillations on timescales of a few years (Movies 1 & 2), their 3:2 frequency ratio and their high oscillation luminosities strongly suggest they are not low-frequency quasi-periodic oscillations from a contaminating stellar-mass black hole (see Methods for details). Also a pulsar origin is very unlikely for several reasons. First, a pulsar signal would be much more coherent than that of the observed quasi-periodic oscillations, which clearly have a finite width. Second, based on the observed high quasi-periodic oscillation luminosities it is extremely implausible that they originate from a pulsar (see Methods for details). Finally, it would be highly coincidental to have two pulsars in the same field of view with spins in the 3:2 ratio. Also, based on the average power spectra of the background sky and a sample of accreting super-massive black holes monitored by the proportional counter array in the same epoch as M82, we rule out an instrumental origin for these oscillations 3 & 4). This leaves M82 X-1, persistently the brightest source in the field of view, as the most likely source associated with the 3:2 ratio quasi-periodic oscillation pair.We estimated M82 X-1's black hole ...

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Discovery of a Luminous, Variable, Off-Center Source in the Nucleus of M82 with the [ITAL]Chandra[/ITAL] High-Resolution Camera

Cited by 217 publications

References 18 publications

ChandraDiscovery of Luminous Supersoft X‐Ray Sources in M81

ChandraDiscovery of Luminous Supersoft X‐Ray Sources in M81

EVIDENCE FOR HIGH-FREQUENCY QPOs WITH A 3:2 FREQUENCY RATIO FROM A 5000 SOLAR MASS BLACK HOLE

A 400-solar-mass black hole in the galaxy M82

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