KEPLER OBSERVATIONS OF RAPID OPTICAL VARIABILITY IN ACTIVE GALACTIC NUCLEI

By R. Mushotzky, R. Edelson, Wayne H. Baumgartner, P. Gandhi. 2011

162 citations recorded by the source corpus.

Over three quarters in 2010–2011, Kepler monitored optical emission from four active galactic nuclei (AGNs) with ∼30 minute sampling, >90% duty cycle, and ≲0.1% repeatability. These data determined the AGN optical fluctuation power spectral density (PSD) functions over a wide range in temporal frequency. Fits to these PSDs yielded power-law slopes of −2.6 to −3.3, much steeper than typically seen in the X-rays. We find evidence that individual AGNs exhibit intrinsically different PSD slopes. The steep PSD fits are a challenge to recent AGN variability models but seem consistent with first-order magnetorotational instability theoretical calculations of accretion disk fluctuations.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/cff922a3fe831276bf4ab4afafb3c03e65dd2a91

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Citations in the corpus

A DESCRIPTION OF QUASAR VARIABILITY MEASURED USING REPEATED SDSS AND POSS IMAGING (2011, background): “Note that recent optical data from the Kepler mission (Mushotzky et al. 2011), which have a sampling of 1 data point roughly every 30 minutes and 0.1% errors, suggest an additional break to a steeper slope (∼ 1/f3), but this dependence is seen on time scales shorter than can be resolved in SDSS…”
IS QUASAR OPTICAL VARIABILITY A DAMPED RANDOM WALK? (2012, methodology): “The OGLE data are clearly not competitive with the Kepler study by Mushotzky et al. (2011) in this regime.”
PLANETARY CANDIDATES OBSERVED BY KEPLER. VI. PLANET SAMPLE FROM Q1–Q16 (47 MONTHS) (2015, unknown): “E P] 6 F eb nuclei (Mushotzky et al. 2011).”
A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission (2014, background): “Kepler’s scientific contributions extend beyond exoplanets to fields ranging from asteroseismology (Chaplin et al. 2011) to active galactic nuclei variability (Mushotzky et al. 2011).”
THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES (2015, methodology): “For the input light curves, we assumed a fluctuation power spectrum of the formP(ν) ∝ ν−2.7, similar to the properties of nearby AGNs monitored by theKepler mission (Mushotzky et al. 2011), and we carried out simulations with light curves of varying duration and various values ofFvar.”
A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates (2016, background): “Some recent studies have also suggested that the DRW model may be a simplistic description of quasar variability (Mushotzky et al. 2011; Zu et al. 2013; Graham et al. 2014; Simm et al. 2016; ?).”
Active galactic nuclei: what’s in a name? (2017, background): “These studies have been revealing properties significantly different from those characterizing X-ray variability (e.g. Mushotzky et al. 2011; Simm et al. 2016), including steeper PSD highfrequency slopes (ranging between ∼− 3 and −4) and the detection of the PSD break at systematically longer…”
A systematic search for close supermassive black hole binaries in the Catalina Real-time Transient Survey (2015, methodology): “…used as popular statistical descriptors of quasar optical variability, e.g., Kelly et al. (2009); MacLeod et al. (2012), there is a growing body of evidence that a more sophisticated approach is required (Mushotzky et al. 2011; Zu et al. 2013; Graham et al. 2014; Kasliwal, Vogeley & Richards 2015).”
False periodicities in quasar time-domain surveys (2016, methodology): “This choice of model is motivated by the analysis of the high-quality Kepler light curves of nearby AGN which showed much steeper power spectra than the standard DRW model allows (Mushotzky et al. 2011; Edelson et al. 2013, 2014), with power-law indices α 3.”