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Heckman, Carey; Wobbrock, Jacob O.

doi:10.1023/a:1010087325358

Cited by 47 publications

(55 citation statements)

References 6 publications

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“…4). The same conclusion also holds if we use the classical definition of LINERs (Heckman 1980) fig. 1b of Filippenko & Terlevich 1992) but, again, close to the borderline with LINERs.…”

Section: O P T I C a L S P E C T Ro S C O P I C C L A S S I F I C At supporting

confidence: 63%

“…4). The same conclusion also holds if we use the classical definition of LINERs (Heckman 1980) which only makes use of oxygen emission‐line ratios. For LINERs, [O ii ]λ3727/[O iii ]λ5007 > 1 and [O i ]λ6300/[O iii ]λ5007 > 1/3 (and lower for ‘[O i ]‐weak’ LINERS), whereas NGC 7589 shows [O ii ]λ3727/[O iii ]5007λ≈ 0.5 and [O i ]λ6300/[O iii ]λ5007 = 0.1.…”

Section: Optical Spectroscopic Classificationsupporting

confidence: 55%

“…About 40 per cent of nearby galaxies exhibit LLAGN activity (Ho, Filippenko & Sargent 1997), the majority of which belong to a class known as low‐ionization nuclear emission‐line regions (LINER, Heckman 1980). Large‐amplitude X‐ray variability is sometimes seen in low‐luminosity Seyferts (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC 7589

Yuan¹,

Komossa²,

Xu³

et al. 2004

Monthly Notices of the Royal Astronomical Society

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We present the first result of a programme to search for large flux variations in the X‐ray sources of the XMM Serendipitous Survey compared to previous ROSAT observations. An increase in X‐ray flux by a factor >10 was discovered from the nucleus of the galaxy NGC 7589 on a time‐scale of less than 5 yr. The 0.4–10 keV XMM spectrum can be approximated by a power law with photon index of 1.7–1.8, though it seems to flatten above 5 keV, suggesting a possible complex model, such as partial covering or disc reflection. A classification based on an analysis of its optical spectrum places NGC 7589 in the Seyfert region, but close to the Seyfert–LINER (low‐ionization nuclear emission‐line region) borderline on the active galactic nucleus (AGN) diagnostic diagrams. We classify NGC 7589 as either Seyfert 1.9 or LINER I, in the light of the detection of a broad Hα line, which makes NGC 7589 an AGN in the low‐luminosity regime. We interpret the observed variability in terms of either changes in covering factor of absorbing gas in the AGN, or variability in the intrinsic X‐ray luminosity. Should the latter be the case, the inferred Eddington accretion rate increased from the radiatively inefficient accretion‐dominated regime to a value close to the putative critical value, at which a transition of the accretion mode is supposed to take place. This possibility presents a new prospect of studying accretion physics in the central black holes of external galaxies by direct observing changes of ‘spectral state’, as is common in stellar black hole binary systems.

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“…4). The same conclusion also holds if we use the classical definition of LINERs (Heckman 1980) fig. 1b of Filippenko & Terlevich 1992) but, again, close to the borderline with LINERs.…”

Section: O P T I C a L S P E C T Ro S C O P I C C L A S S I F I C At supporting

confidence: 63%

Section: Optical Spectroscopic Classificationsupporting

confidence: 55%

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Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC 7589

Yuan¹,

Komossa²,

Xu³

et al. 2004

Monthly Notices of the Royal Astronomical Society

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“…Thus, in almost all the borders of the shells of IRAS 04505−2958, the GMOS‐IFU [S ii ]/Hα and [N ii ]/Hα maps show high values, which are consistent with an ionization process produced mainly by shock‐heating in the outflowing gas of the expanding supergiant shells (Heckman 1980, 1996; Heckman et al 1987, 1990; Dopita 1994, 1995; Dopita & Sutherland 1995; Lípari et al 2004a,d, 2005).…”

Section: The Ionization Structure Of the Hyper+super Shellsmentioning

confidence: 60%

Gemini 3D spectroscopy of BAL+IR+Fe ii QSOs - II. IRAS 04505−2958, an explosive QSO with hypershells and a new scenario for galaxy formation and galaxy end phase

Lípari¹,

Bergmann²,

Sanchez³

et al. 2009

Monthly Notices of the Royal Astronomical Society

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From a study of broad absorption line (BAL) + infrared (IR) + Fe ii quasi‐stellar objects (QSOs) [using deep Gemini Multi‐Object Spectrograph Integral Field Unit (GMOS‐IFU) spectroscopy], new results are presented for IRAS 04505−2958. Specifically, we have studied in detail the outflow (OF) process at two large galactic scales: (i) two blobs/shells at radius r∼ 1.1 and 2.2 kpc, and (ii) an external hypergiant shell at r∼ 11 kpc. In addition, the presence of two very extended hypergiant shells at r∼ 60–80 kpc is also discussed. From this GMOS study the following main results were obtained. (i) For the external hypergiant shell, the kinematics GMOS maps of the ionized gas ([O ii], [Ne iii], [O iii], Hβ) show a small‐scale bipolar OF, with similar properties to those observed in the prototype of exploding external supershells: NGC 5514. (ii) Three main knots – of this hypershell S3 – show the presence of a young starburst. (iii) The two internal shells show OF components with typical properties of nuclear shells. (iv) The two blobs and the hypershell are aligned at PA ∼ 131° showing bipolar OF shape at ∼10–15 kpc scale. In addition, the more external shells (at ∼60–80 kpc scale) are aligned at PA ∼ 40° also with bipolar OF shape (perpendicular to the more internal OF). (v) A strong blue continuum and multiple emission‐line components were detected in all the GMOS fields. The new GMOS data show a good agreement with an extreme + explosive OF scenario for IRAS 04505−2958, in which part of the interstellar medium (ISM) of the host galaxy was ejected (in multiple shells). This extreme OF could also be associated with two main processes in the evolution of QSOs: (i) the formation of companion/satellite galaxies by giant explosions; and (ii) to define the final mass of the host galaxy, and even if the explosive nuclear OF is extremely energetic, this process could disrupt an important fraction of the host galaxy. Finally, the generation of ultra‐high‐energy cosmic rays and neutrino/dark matter – associated with HyNe in explosive BAL + IR + Fe ii QSOs – is discussed.

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“…We have known since the early 1980s that nearly all galaxies show nuclear emission lines, and that a third of all galaxies, and most early Hubble types, show LINER spectra, hinting at but not proving that some kind of weak quasar-like activity is extremely common (Heckman 1980). The heroic high S/N spectral survey of 486 galaxies by Ho Filippenko and Sargent (1997 and references therein) has strengthened this suspicion, showing that ∼ 10% of galaxies show weak broad Hα lines, and almost half show AGN-like narrow lines.…”

Section: Do All Galaxies Contain Agn?mentioning

confidence: 99%

The AGN/normal galaxy connection: Summary

Lawrence

1999

Advances in Space Research

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The connection between normal and active galaxies is reviewed, by summarizing our progress on answering nine key questions. (1) Do all galaxies contain massive dark objects (MDOs)? (2) Are these MDOs actually supermassive black holes? (3) Why are the dark objects so dark? (4) Do all galaxies contain an Active Galactic Nucleus (AGN)? (5) Are the "dwarf AGN " really AGN? (6) Does AGN activity correlate with host galaxy properties? (7) How are AGN fuelled? (8) Is AGN activity related to starburst activity? (9) How do quasars relate to galaxy formation?

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Untitled

Cited by 47 publications

References 6 publications

Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC 7589

Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC 7589

Gemini 3D spectroscopy of BAL+IR+Fe ii QSOs - II. IRAS 04505−2958, an explosive QSO with hypershells and a new scenario for galaxy formation and galaxy end phase

The AGN/normal galaxy connection: Summary

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