Black hole masses from power density spectra: determinations and consequences

Nikołajuk, M.; Piasecki, M.; Kuraszkiewicz, Joanna

doi:10.1046/j.1365-8711.2001.04522.x

Cited by 78 publications

(90 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar anti-correlation between the rate at which variability power is injected into the light curve and black hole mass has also been found for AGN optical variations (KBS09). Czerny et al (2001) find an anti-correlation between M BH and the frequency at which the PSD reaches a reference value, which is consistent with an anti-correlation between M BH and the amplitude of the high-frequency PSD. However, our result differs from most previous work in that we do not compute the variance over some range of timescales, directly from the observed light curve, but rather we fit a parameter ς , which is the rate at which variability power is injected into the light curve.…”

Section: Comparison With Black Hole Masssupporting

confidence: 85%

A Stochastic Model for the Luminosity Fluctuations of Accreting Black Holes

Kelly

Sobolewska

Siemiginowska

2011

ApJ

152

209

View full text Add to dashboard Cite

In this work, we have developed a new stochastic model for the fluctuations in light curves of accreting black holes. The model is based on a linear combination of stochastic processes and is also the solution to the linear diffusion equation perturbed by a spatially correlated noise field. This allows flexible modeling of the power spectral density (PSD), and we derive the likelihood function for the process, enabling one to estimate the parameters of the process, including break frequencies in the PSD. Our statistical technique is computationally efficient, unbiased by aliasing and red noise leak, and fully accounts for irregular sampling and measurement errors. We show that our stochastic model provides a good approximation to the X-ray light curves of galactic black holes, and the optical and X-ray light curves of active galactic nuclei (AGNs). We use the estimated timescales of our stochastic model to recover the correlation between characteristic timescale of the high-frequency X-ray fluctuations and black hole mass for AGNs, including two new "detections" of the timescale for Fairall 9 and NGC 5548. We find a tight anti-correlation between the black hole mass and the amplitude of the driving noise field, which is proportional to the amplitude of the high-frequency X-ray PSD, and we estimate that this parameter gives black hole mass estimates to within ∼0.2 dex precision, potentially the most accurate method for AGNs yet. We also find evidence that ≈13% of AGN optical PSDs fall off flatter than 1/f 2 and, similar to previous work, find that the optical fluctuations are more suppressed on short timescales compared to the X-rays, but are larger on long timescales, suggesting that the optical fluctuations are not solely due to reprocessing of X-rays.

show abstract

Section: Comparison With Black Hole Masssupporting

confidence: 85%

A Stochastic Model for the Luminosity Fluctuations of Accreting Black Holes

Kelly

Sobolewska

Siemiginowska

2011

ApJ

152

209

View full text Add to dashboard Cite

show abstract

“…One may reconcile the absence of power in the high frequency regime to the scattering of the X-ray photons in the wind from the companion WolfRayet star, reducing the amplitude of the fast X-ray variability (Berger & van der Klis 1994). If we reconcile the absence of power above 0.1 Hz to the reprocessing of the X-ray emission in the circumstellar environment, then this feature does provide an interesting sidelight to the paradigm which states that the variability time-scale scales linearly with the mass of the compact object (Hayashida et al 1998;Czerny et al 2001), and introduce an additional factor, viz. reprocessing in the dense circumstellar material, where it exists, into the picture.…”

Section: Power Density Spectrummentioning

confidence: 99%

“…The distinct feature of the power density spectra of the source is the shifting of the spectra towards low frequency regime (vis-a-vis the "normal" frequency regime of other Galactic X-ray binaries), corresponding to very massive black hole systems (Hayashida et al 1998;Czerny et al 2001). Sunyaev & Revnivtsev (2000) have compiled the power density spectra (multiplied by frequency) of the most common Galactic X-ray binaries, both neutron stars and black hole candidates (in their low/hard states).…”

Section: Power Density Spectrummentioning

confidence: 99%

Binary corrected X-ray light curve of Cygnus X-3: Implications for the timing properties of the compact binary system

Choudhury

Rao

Vadawale

et al. 2004

A&A

View full text Add to dashboard Cite

Abstract. We study the binary corrected X-ray light curve of Cygnus X-3 using the RXTE-ASM (All Sky Monitor) data and RXTE-PCA data. We find that the X-ray template derived from the EXOSAT observations adequately explains the binary variations. Using the recently determined quadratic binary ephemeris we correct the RXTE-PCA lightcurve and obtain the power spectrum which shows distinct features of shifting towards the low frequency regime vis-a-vis the Galactic X-ray binaries. The power spectrum doesn't vary from the hard to the soft state. We also obtain the binary corrected RXTE-ASM monitoring lightcurve and examine the previously obtained correlation between soft X-ray (2−12 keV from RXTE ASM), hard X-ray (20−100 keV from CGRO−BATSE) and radio (2.2 GHz from GBI) after the binary correction. We find that the correlation time scale is less than a day.

show abstract

“…The difference in time-scales could be explained by the difference in the mass of the compact object in the center of these objects. The results from these first studies made it clear that the observed AGN X-ray variations are most probably determined by BH mass (M BH ) rather than luminosity (Hayashida et al 1998;Czerny et al 2001;Uttley et al 2002), and even suggested that X-ray variability might be used as a tool to estimate M BH in these objects. McHardy et al (2006) were the first to demonstrate clearly that AGN are scaled-up versions of BHB.…”

Section: Introductionmentioning

confidence: 99%

CAIXA: a catalogue of AGN in theXMM-Newtonarchive

Ponti

Papadakis

Bianchi

et al. 2012

A&A

249

353

View full text Add to dashboard Cite

Context. We report on the results of the first XMM-Newton systematic "excess variance" study of all the radio quiet, X-ray un-obscured AGN. The entire sample consist of 161 sources observed by XMM-Newton for more than 10 ks in pointed observations, which is the largest sample used so far to study AGN X-ray variability on time scales less than a day. Aims. Recently it has been suggested that the same engine might be at work in the core of every black hole (BH) accreting object. In this hypothesis, the same variability should be observed in all AGN, once rescaled by the M BH (M BH ) and accretion rate (ṁ). Methods. We systematically compute the excess variance for all AGN, on different time-scales (10, 20, 40 and 80 ks) and in different energy bands (0.3-0.7, 0.7-2 and 2-10 keV). Results. We observe a highly significant and tight (∼0.7 dex) correlation between σ 2 rms and M BH . The subsample of reverberation mapped AGN shows an even smaller scatter (only a factor of 2-3) comparable to the one induced by the M BH uncertainties. This implies that X-ray variability can be used as an accurate tool to measure M BH and this method is more accurate than the ones based on single epoch optical spectra. This allows us to measure M BH for 65 AGN and estimate lower limits for the remaining 96 AGN. On the other hand, the σ 2 rms vs. accretion rate dependence is weaker than expected based on the PSD break frequency scaling. This strongly suggests that both the PSD high frequency break and the normalisation depend on accretion rate in such a way that they almost completely counterbalance each other (PSD amp ∝ṁ −0.8 ). A highly significant correlation between σ 2 rms and 2-10 keV spectral index is observed. The highly significant correlations between σ 2 rms and both the L Bol and the FWHM Hβ are consistent with being just by-products of the σ 2 rms vs. M BH relation. The soft and medium σ 2 rms is very well correlated with the hard σ 2 rms , with no deviations from a linear one to one correlation. This suggests that the additional soft components (i.e. soft excess, warm absorber) add a minor contribution to the total variability. Once the variability is rescaled for M BH andṁ, no significant difference between narrow-line and broad-line Seyfert 1 is observed. Conclusions. The results are in agreement with a picture where, to first approximation, all local AGN have the same variability properties once rescaled for M BH andṁ.

show abstract

Black hole masses from power density spectra: determinations and consequences

Cited by 78 publications

References 87 publications

A Stochastic Model for the Luminosity Fluctuations of Accreting Black Holes

A Stochastic Model for the Luminosity Fluctuations of Accreting Black Holes

Binary corrected X-ray light curve of Cygnus X-3: Implications for the timing properties of the compact binary system

CAIXA: a catalogue of AGN in theXMM-Newtonarchive

Contact Info

Product

Resources

About