Large-Amplitude X-Ray Outbursts from Galactic Nuclei: A Systematic Survey using ROSAT Archival Data

By J. Donley, W. N. Brandt, M. Eracleous, T. Boller. 2002

177 citations recorded by the source corpus.

In recent years, luminous X-ray outbursts with variability amplitudes as high as ≈400 have been serendipitously detected from a small number of active and inactive galaxies. These outbursts may result from the tidal disruptions of stars by supermassive black holes, as well as accretion disk instabilities. In order to place the first reliable constraints on the rate of such outbursts in the universe and to test the stellar tidal disruption hypothesis, we have performed a systematic and complete survey for them by cross-correlating ROSAT All-Sky Survey (RASS) and pointed Position Sensitive Proportional Counter data. We have detected five galaxies that were in outburst during the RASS, three of which show no signs of nuclear activity; these objects had been reported on individually in previous studies. After making reasonable corrections for the complicated selection effects, we conclude that the rate of large-amplitude X-ray outbursts from inactive galaxies in the local universe is ≈9.1 × 10-6 galaxy-1 yr-1. This rate is consistent with the predicted rate of stellar tidal disruption events in such galaxies. When only the two active galaxies are considered, we find a rate for active galaxies of ≈8.5 × 10-4 galaxy-1 yr-1. In order to place tighter constraints on these rates, additional outbursts must be detected.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/4c828f99aaf97c8c9ed6a40a51897c9562dc3cdd

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In Astronomy and Astrophysics

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In Nuclear and High Energy Physics

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Citations in the corpus

• OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES (2010, background): “A number of candidate TDEs have been identified in X-ray surveys (Bade et al. 1996; Komossa & Bade 1999; Donley et al. 2002; Esquej et al. 2008; Cappelluti et al. 2009; Maksym et al. 2010) —for a review see Komossa (2002)— and in the UV GALEX Deep Imaging Survey (Gezari et al. 2006, 2008, 2009b).”
• Consequences of Strong Compression in Tidal Disruption Events (2012, background): “On the observational side, uncertainties stem from both the low sample size and unclear sources of systematic error; nonetheless, observational estimates of the TDE rate per galaxy generally find ṄTDE ∼ 10−4–10−5 yr−1 (Donley et al. 2002; Gezari et al. 2008).”
• A bright year for tidal disruptions (2015, background): “…2011; Cenko et al. 2012b, Pasham et al. 2015), soft X-ray (e.g., Bade et al. 1996, Grupe et al. 1999, Komossa & Bade 1999, Komossa & Greiner 1999, Donley et al. 2002, Esquej et al. 2008, Maksym et al. 2010, Saxton et al. 2012), ultraviolet (e.g., Stern et al. 2004, Gezari et al. 2006, 2008,…”
• Ultraviolet Detection of the Tidal Disruption of a Star by a Supermassive Black Hole (2006, methodology): “…band and detected luminous ( ergs s ), soft [ K] X-42 44 1 510 –10 T p (6–12)# 10bb ray flares from several galaxies with no previous evidence for AGN activity, and with a flare rate of≈ yr per 5 11 # 10 galaxy (Donley et al. 2002) that is consistent with the theoretical stellar disruption rate.”
• ASASSN-15oi: a rapidly evolving, luminous tidal disruption event at 216 Mpc (2016, background): “…2011; Cenko et al. 2012b; Pasham et al. 2015), soft X-ray (e.g., Bade, Komossa & Dahlem 1996; Grupe, Thomas & Leighly 1999; Komossa & Greiner 1999; Donley et al. 2002; Maksym, Ulmer & Eracleous 2010; Saxton et al. 2012), ultraviolet (e.g., Stern et al. 2004; Gezari et al. 2006, 2008, 2009), and…”
• Rates of stellar tidal disruption as probes of the supermassive black hole mass function (2014, background): “The non-thermal X-ray transient Swift J1644+57 was interpreted as a jetted TDE viewed along the jet axis (Bloom et al. 2011; Levan et al. 2011; Burrows et al. 2011; Zauderer et al. 2011), with bright radio emission produced by the shock interaction between the jet and the dense circumnuclear medium ”
• Swift J1112.2−8238: a candidate relativistic tidal disruption flare (2015, result): “The resulting rate is found to be ∼3 × 10−10 per galaxy per year, in stark contrast to the ∼10−5 inferred from thermal TDF detections (e.g. Donley et al. 2002; van Velzen & Farrar 2014).”
• Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes (2015, background): “…& Bade 1999; Gezari et al. 2012; Arcavi et al. 2014; Holoien et al. 2014; Vinkó et al. 2015), with inferred event rates of 10−5 per year per galaxy (Donley et al. 2002; van Velzen & Farrar 2014), although the observed light curves and spectra (Gezari et al. 2012) do not always match the simplest…”
• GIANT AGN FLARES AND COSMIC RAY BURSTS (2008, background): “Donley et al. (2002), comparing the ROSAT All Sky Survey and pointed observations, report evidence for soft x-ray flares of AGN whose estimated rate suggests T4 ≈ 0.1 bγ, where bγ is the photon beaming fraction.”
• Fueling Low-Level AGN Activity through Stochastic Accretion of Cold Gas (2006, background): “…the rates of short-duration X-ray flares (which have traditionally been associated with stellar disruptions, e.g.Hills 1975; Meszaros & Silk 1977) have found rates∼ 2 − 3 orders of magnitude below those needed to account for the low-luminosity AGN luminosity function (e.g., Donley et al. 2002).”
• A CONTINUUM OF H- TO He-RICH TIDAL DISRUPTION CANDIDATES WITH A PREFERENCE FOR E+A GALAXIES (2014, methodology): “The expected rate of TDEs lies in the range of 10−5 to 10−4 events per galaxy per year (e.g. Donley et al. 2002; Wang & Merritt 2004; Kesden 2012; but see also 4 using a Newtonian calculation for a non-spinning black hole (see e.g. Kesden 2012 for a relativistic derivation yielding higher limits…”
• Radio transients from stellar tidal disruption by massive black holes (2011, background): “…tidal disruptions are rare, and potentially difficult to detect in the bright and dust-extincted central regions of galaxies, surveys atX-ray (e.g. Donley et al. 2002; Esquej et al. 2008), optical (van Velzen et al. 2010) and far UV wavelengths (Gezari et al. 2006, 2008, 2009) have now detected∼…”
• Finite, Intense Accretion Bursts from Tidal Disruption of Stars on Bound Orbits (2012, background): “It has been inferred from observations that the event rate of tidal disruption is ∼ 10−5yr−1 per galaxy (Donley et al. 2002).”
• The Mass Function of Active Black Holes in the Local Universe (2007, background): “Finally, future time-domain surveys may place limits on the frequency of flares from the tidal disruption of stars captured by BHs in dwarf galaxies (e.g., Rees 1988; Donley et al. 2002; Gezari et al. 2006; Milosavljević et al. 2006).”
• Optical Flares from the Tidal Disruption of Stars by Massive Black Holes (2009, methodology): “We adopt γ = 10−5 yr−1 as found by Donley et al. (2002) using the ROSAT All-Sky Survey, which is also in line with conservative theoretical estimates.”
• Now You See It, Now You Don't: The Disappearing Central Engine of the Quasar J1011+5442 (2015, background): “…this would be a strong indication that the previous “on-state” was not caused by a TDE since the rate of such events is expected to be ∼ 10−5–10−4 galaxy−1 yr−1 (both on theoretical and observational grounds, e.g., Merritt & Poon 2004; Donley et al. 2002; Gezari et al. 2008; Maksym et al. 2010).”