Letter to the Editor

Bregman, David B.

doi:10.1177/1941738113475595

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…The nuclear location of PTF10iya, together with the observed spectrum (reminiscent of the ‘big blue bump’; Sanders et al 1989; Bregman 1990), naturally leads us to consider accretion on to a SMBH as a possible origin (Shields 1978; Malkan & Sargent 1982). Here we determine if gas accretion (either in the form of a normal AGN or a LINER) is consistent with the observed properties of PTF10iya.…”

Section: Discussionmentioning

confidence: 99%

PTF10iya: a short-lived, luminous flare from the nuclear region of a star-forming galaxy

Cenko¹,

Bloom²,

Kulkarni³

et al. 2012

Monthly Notices of the Royal Astronomical Society

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We present the discovery and characterization of PTF10iya, a short‐lived (Δt≈ 10 d, with an optical decay rate of ∼0.3 mag d−1), luminous ( mag) transient source found by the Palomar Transient Factory. The ultraviolet/optical spectral energy distribution is reasonably well fitted by a blackbody with T≈ (1–2) × 104 K and peak bolometric luminosity LBB≈ (1–5) × 1044 erg s−1 (depending on the details of the extinction correction). A comparable amount of energy is radiated in the X‐ray band that appears to result from a distinct physical process. The location of PTF10iya is consistent with the nucleus of a star‐forming galaxy (z= 0.224 05 ± 0.000 06) to within 350 mas (99.7 per cent confidence radius), or a projected distance of less than 1.2 kpc. At first glance, these properties appear reminiscent of the characteristic ‘big blue bump’ seen in the near‐ultraviolet spectra of many active galactic nuclei (AGNs). However, emission‐line diagnostics of the host galaxy, along with a historical light curve extending back to 2007, show no evidence for AGN‐like activity. We therefore consider whether the tidal disruption of a star by an otherwise quiescent supermassive black hole may account for our observations. Though with limited temporal information, PTF10iya appears broadly consistent with the predictions for the early ‘super‐Eddington’ phase of a solar‐type star being disrupted by a ∼107 M⊙ black hole. Regardless of the precise physical origin of the accreting material, the large luminosity and short duration suggest that otherwise quiescent galaxies can transition extremely rapidly to radiate near the Eddington limit; many such outbursts may have been missed by previous surveys lacking sufficient cadence.

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Section: Discussionmentioning

confidence: 99%

PTF10iya: a short-lived, luminous flare from the nuclear region of a star-forming galaxy

Cenko¹,

Bloom²,

Kulkarni³

et al. 2012

Monthly Notices of the Royal Astronomical Society

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“…There are different analytical forms of the temperature–radius relation for discs around black holes. Bregman () gives an expression for the temperature of gas near the last stable orbit. This will be at far smaller radii than the parts of the disc which emit in the far‐ultraviolet (FUV) and optical.…”

Section: Parameters and Geometry Of Cloudsmentioning

confidence: 99%

Intervening broad-line region clouds' effects on the optical/ultraviolet spectrum

Wang

Ferland

et al. 2012

Monthly Notices of the Royal Astronomical Society

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Recent X‐ray observations of Mrk 766 suggest that broad emission‐line region clouds cross our line of sight and produce variable X‐ray absorption. Here we investigate what optical/ultraviolet (UV) spectroscopic features would be produced by such ‘intervening broad‐line region (BLR) clouds' (IBC) crossing our line of sight to the accretion disc, the source of the optical/UV continuum. Although the emission spectrum produced by intervening clouds is identical to the standard BLR model, they may produce absorption features on the optical or UV continuum. Single clouds will have little effect on the optical/UV spectrum because BLR clouds are likely to be much smaller than the accretion disc. This is unlike the X‐ray case, where the radiation source is considerably smaller. However, an ensemble of intervening clouds will produce spectroscopic features in the far‐ultraviolet including a strong depression between the Lyman limit and Lyα. The amount of the depression will indicate the line‐of‐sight covering factor of clouds, an unknown quantity that is important for the ionization of the intergalactic medium and the energy budget of active galactic nuclei (AGNs). Comparison with observations suggests that the Spectral Energy Distribution (SED) of Mrk 766 may be affected by IBC that may exist in most of AGNs.

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Letter to the Editor

Cited by 2 publications

References 6 publications

PTF10iya: a short-lived, luminous flare from the nuclear region of a star-forming galaxy

PTF10iya: a short-lived, luminous flare from the nuclear region of a star-forming galaxy

Intervening broad-line region clouds' effects on the optical/ultraviolet spectrum

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