Blazar Mrk 501 shows rhythmic oscillations in its $\gamma$-ray emission

Abstract

Quasi-periodic oscillations (QPO) originating from innermost regions of blazars can provide unique perspective of some of the burning issues in blazar studies including disk-jet connection, launch of relativistic jets from the central engine, and other extreme conditions near the fast rotating supermassive black holes. However, a number of hurdles associated with searching QPOs in blazars e.g., red-noise dominance, modest significance of the detection and periodic modulation lasting for only a couple of cycles, make it difficult to estimate the true significance of the detection. In this work, we report a $\sim$ 330-day QPO in the Fermi/LAT observations of the blazar Mrk 501 spanning nearly a decade. To establish consistency of the result, we adopted multiple approaches to the time series analysis and employed four widely known methods. Among these, Lomb-Scargle periodogram and weighted wavelet z-transform represent frequency domain based methods whereas epoch folding and z-transformed discrete auto-correlation function are time-domain based analysis. Power spectrum response method was followed to properly account for the red-noise, largely inherent in blazar light curves. Both local and global significance of the signal were found to be above 99\% over possible spurious detection. In the context where not many $\gamma$-ray QPOs have been reported to last more than 5 cycles, this might be one of the few instances where we witness a sub-year timescale $\gamma$-ray QPO persisting nearly 7 cycles. A number of possible scenarios linked with binary supermassive black hole, relativistic jets, and accretion disks can be invoked to explain the transient QPO.

arXiv comment9 pages and 6 figures, MNRAS accepted

References in corpus (44)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• Fermi Large Area Telescope First Source Catalog
• Understanding the Lomb-Scargle Periodogram
• On characterising the variability properties of X-ray light curves from active galaxies
• Multi-messenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A
• Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert
• Lense-Thirring Precession and QPOs in Low Mass X-Ray Binaries
• General physical properties of bright Fermi blazars
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• A massive binary black-hole system in OJ287 and a test of general relativity
• Formation of Precessing Jets by Tilted Black-hole Discs in 3D General Relativistic MHD Simulations
• False periodicities in quasar time-domain surveys
• Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113
• Oscillations of vertically integrated relativistic tori -- I. Axisymmetric modes in a Schwarzschild spacetime
• Dissecting the region around IceCube-170922A: the blazar TXS 0506+056 as the first cosmic neutrino source
• Correlated Multi-Waveband Variability in the Blazar 3C~279 from 1996 to 2007
• Quasi-periodicities at year-like timescales in Blazars
• Quasi-periodic accretion and gravitational waves from oscillating "toroidal neutron stars" around a Schwarzschild black hole
• A model for periodic blazars
• The Blazar PG 1553+113 as a Binary System of Supermassive Black Holes
• Detection of Possible Quasi-periodic Oscillations in the Long-term Optical Light Curve of the BL Lac Object OJ 287
• Kinematics of and emission from helically orbiting blobs in a relativistic magnetized jet
• Discovery of a ~5 day characteristic timescale in the Kepler power spectrum of Zw 229-15
• Revisiting Quasi-Periodic modulation in $\gamma$-ray Blazar PKS 2155-304 with Fermi Pass 8 data
• Gamma-ray quasi-periodicities of blazars. A cautious approach
• First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign
• Quasi-periodicities of PKS 2155-304
• Gamma-ray and Optical Oscillations of 0716+714, MRK 421, and BL Lac
• Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
• X-ray and radio variability in the low luminosity Active Galactic Nucleus NGC 7213
• Multifrequency Photo-polarimetric WEBT Observation Campaign on the Blazar S5 0716+714: Source Microvariability and Search for Characteristic Timescales
• A search for cyclical sources of gamma-ray emission on the period range from days to years in the Fermi-LAT sky
• Jet precession driven by a supermassive black hole binary system in the BL Lac object PG 1553+113
• Gamma-ray and optical oscillations in the blazar PKS 0537-441
• Radio and $\gamma$-ray variability in the BL Lac PKS 0219 -164: Detection of quasi-periodic oscillations in the radio light curve
• Harmonic QPOs and Thick Accretion Disk Oscillations in BL Lac Object AO 0235+164
• Hard X-ray properties of NuSTAR blazars
• A $\gamma$-ray Quasi-Periodic modulation in the Blazar PKS 0301$-$243?
• Possible ~ 1 hour quasi-periodic oscillation in narrow-line Seyfert 1 galaxy MCG--06--30--15
• Possible Quasi-Periodic modulation in the z = 1.1 $\gamma$-ray blazar PKS 0426-380
• Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26
• Multiwavelength periodicity study of Markarian 501

Cited by in corpus (29)

• Systematic search for gamma-ray periodicity in active galactic nuclei detected by the Fermi Large Area Telescope
• A comprehensive power spectral density analysis of astronomical time series I: the Fermi-LAT gamma-ray light curves of selected blazars
• Multiwaveband Quasi--periodic Oscillation in the Blazar 3C 454.3
• Quasi-periodic oscillations in the $\gamma$-ray light curves of bright active galactic nuclei
• Transient Quasi-Periodic Oscillations at $\gamma$-rays in the TeV Blazar PKS 1510-089
• Looking at Blazar Light Curve Periodicities with Gaussian Processes
• Detection of a quasi-periodic oscillation in gamma-ray light curve of the high redshift blazar B2 1520+31
• Multi-waveband quasi-periodic oscillations in the light curves of blazar CTA 102 during its 2016-2017 optical outburst
• A Possible $\gamma$-ray Quasi-periodic Oscillation of $\sim$ 314 days in the Blazar OJ 287
• A Quasi-periodic Oscillation in the gamma-ray Emission from the Non-blazar Active Galactic Nucleus PKS 0521-36
• Multi-messenger characterization of Mrk 501 during historically low X-ray and $\gamma$-ray activity
• Long term γ -ray variability of blazars
• A Possible 3-Year Quasi-Periodic Oscillation in γ-Ray Emission from the FSRQ S5 1044+71
• X-ray Intraday Variability of the TeV Blazar PKS 2155-304 with Suzaku During 2005-2014
• Detection of a quasi-periodic oscillation in the optical light curve of the remarkable blazar AO 0235+164
• The gamma-ray and Optical Variability Analysis of the BL Lac Object 3FGL J0449.4-4350
• X-ray timing and spectral variability properties of blazars S5 0716+714, OJ 287, Mrk 501, and RBS 2070
• Detection of Quasi-Periodic Oscillations in the Blazar S4 0954+658 with TESS
• Study of correlation between optical flux and polarization variations in BL Lac objects
• Quasi-periodic oscillation detected in $\gamma$-rays in blazar PKS 0346-27
• The detection of possible transient Quasi-Periodic Oscillations in the $\gamma$-ray light curve of PKS 0244-470 and 4C+38.41
• Exploring Short-Term Optical Variability of Blazars Using $\text{TESS}$
• Probing the Delay Time of Supermassive Black Hole Binary Mergers With Gravitational Waves
• Revisiting radio variability of the blazar 3C 454.3
• Gamma-ray Blazar variability: New statistical methods of time-flux distributions
• A relativistic orbit model for temporal properties of AGN
• A Supermassive Binary Black Hole Candidate in Mrk 501
• Not so Swift: 20 years of multiwavelength observations of Mrk 421 and Mrk 501
• Variability Study and Searching for QPOs with day-like periods in the blazar S5 0716+714 with TESS