Discovery of soft and hard X-ray time lags in low-mass AGNs

Abstract

The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying physical mechanism at work in accreting BH systems spanning a broad range of mass. However, the low-mass end of AGNs has never been explored in detail. In this work, we extend the existing scaling relations to lower-mass AGNs, which serve as anchors between the normal-mass AGNs and BHXRBs. For this purpose, we construct a sample of low-mass AGNs ($M_{\mathrm{BH}}<3\times 10^6{M}_{\odot }$) from the XMM-Newton archive and measure frequency-resolved time delays between the soft (0.3-1 keV) and hard (1-4 keV) X-ray emissions. We report that the soft band lags behind the hard band emission at high frequencies $\sim [1.3-2.6]\times 10^{-3}$ Hz, which is interpreted as a sign of reverberation from the inner accretion disc in response to the direct coronal emission. At low frequencies ($\sim [3-8]\times 10^{-4}$ Hz), the hard band lags behind the soft band variations, which we explain in the context of the inward propagation of luminosity fluctuations through the corona. Assuming a lamppost geometry for the corona, we find that the X-ray source of the sample extends at an average height and radius of $\sim 10r_{\mathrm{g}}$ and $\sim 6r_{\mathrm{g}}$, respectively. Our results confirm that the scaling relations between the BH mass and soft lag amplitude/frequency derived for higher-mass AGNs can safely extrapolate to lower-mass AGNs, and the accretion process is indeed independent of the BH mass.

arXiv comment11 pages, 5 figures, 4 tables, Published in MNRAS

References in corpus (40)

• The slope of the black-hole mass versus velocity dispersion correlation
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• Active Galactic Nuclei as scaled-up Galactic black holes
• RXTE Observation of Cygnus X-1: II. Timing Analysis
• X-ray reverberation around accreting black holes
• Non-linear X-ray variability in X-ray binaries and active galaxies
• Investigating a Fluctuating-accretion Model for the Spectral-timing Properties of Accreting Black Hole Systems
• The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements
• On the X-ray time lags in the black hole candidates
• A New Sample of Low-mass Black Holes in Active Galaxies
• Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
• The flux-dependent amplitude of broadband noise variability in X-ray binaries and active galaxies
• Generating artificial light curves: Revisited and updated
• Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei
• POX 52: A Dwarf Seyfert 1 Galaxy With An Intermediate-Mass Black Hole
• A global look at X-ray time lags in Seyfert Galaxies
• Broad iron L-line and X-ray reverberation in 1H0707-495
• The causal connection between disc and power-law variability in hard state black hole X-ray binaries
• The M-sigma Relation in Local Active Galaxies
• X-ray Microlensing in RXJ1131-1231 and HE1104-1805
• General relativistic modelling of the negative reverberation X-ray time delays in AGN
• Frequency-dependent time lags in the X-ray emission of the Seyfert galaxy NGC 7469
• The origin of the lag spectra observed in AGN: Reverberation and the propagation of X-ray source fluctuations
• Towards modelling X-ray reverberation in AGN: Piecing together the extended corona
• A dynamic black hole corona in an active galaxy through X-ray reverberation mapping
• The XMM-SERVS survey: new XMM-Newton point-source catalog for the XMM-LSS field
• X-ray reverberation in 1H0707-495 revisited
• The Comptonisation of accretion disc X-ray emission: Consequences for X-ray reflection and the geometry of AGN coronae
• The remarkable X-ray variability of IRAS 13224-3809 I: The variability process
• A soft X-ray reverberation lag in the AGN ESO 113-G010
• Revealing the Structure of an Accretion Disk Through Energy Dependent X-ray Microlensing
• Testing the Propagating Fluctuations Model with a Long, Global Accretion Disk Simulation
• Revealing structure and evolution within the corona of the Seyfert galaxy I Zw 1
• Examining the Physical Conditions of a Warm Corona in Active Galactic Nuclei Accretion Discs
• A Physical Model for the X-ray Time Lags of Narrow Line Seyfert Type 1 Active Galactic Nuclei
• A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044
• Low frequency X-ray timing with Gaussian processes and reverberation in the radio-loud AGN 3C 120
• The long term X-ray time-lags of NGC 4051

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• High-density disc reflection spectroscopy of low-mass active galactic nuclei
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• An Analytical Fourier-Transformation Model for the Production of Hard and Soft X-Ray Time Lags in AGNs: Application to 1H 0707-495