Quasar outflows and AGN feedback in the extreme UV: HST/COS observations of HE 0238−1904★

Arav, Nahum; Borguet, B.; Chamberlain, Carter; Edmonds, Doug; Danforth, Charles W.

doi:10.1093/mnras/stt1812

Cited by 170 publications

(284 citation statements)

References 81 publications

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“…More generally, we simulate slow-massive-wide (SMW) outflows. Although the jets that are simulated here are not observed (because the medium is optically thick), such wide outflows are commonly observed from active galactic nuclei (e.g., Arav et al 2013). This, and the success of wide outflows to explain lobes observed in cooling flow clusters (e.g., Sternberg et al 2007) motivate us to consider wide outflows.…”

Section: Numerical Setupmentioning

confidence: 94%

Forming equatorial rings around dying stars

Akashi

Sabach

Yogev

et al. 2015

Mon. Not. R. Astron. Soc.

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We suggest that clumpy-dense outflowing equatorial rings around evolved giant stars, such as in supernova 1987A and the Necklace planetary nebula, are formed by bipolar jets that compress gas toward the equatorial plane. The jets are launched from an accretion disk around a stellar companion. Using the FLASH hydrodynamics numerical code we perform 3D numerical simulations, and show that bipolar jets expanding into a dense spherical shell can compress gas toward the equatorial plane and lead to the formation of an expanding equatorial ring. RayleighTaylor instabilities in the interaction region break the ring to clumps. Under the assumption that the same ring-formation mechanism operates in massive stars and in planetary nebulae, we find this mechanism to be more promising for ring formation than mass loss through the second Lagrangian point. The jets account also for the presence of a bipolar nebula accompanying many of the rings.

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Section: Numerical Setupmentioning

confidence: 94%

Forming equatorial rings around dying stars

Akashi

Sabach

Yogev

et al. 2015

Mon. Not. R. Astron. Soc.

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“…Dunn et al 2010) may be objects in the transition phase between the ULIRGs and unobscured QSO phase, where the outflowing wind in the ionized component is seen directly in optical-UV spectra (e.g., de Kool et al 2001;Hamann et al 2002). Extensive works in the past years uniquely contributed to our understanding of the winds physics, in terms of spatial location, ionization level and energetics involved (see, e.g., Moe et al 2009;Borguet et al 2013 andArav et al 2013). Recent works also suggest that ∼40% of IR selected and SDSS QSOs are BAL QSOs, pointing towards the fact that they are quite common (Dai et al 2008;Allen et al 2011) and that the outflow and unobscured phases may be of comparable length, in agreement with the Hopkins scenario (see also Glikman et al 2012).…”

Section: Introductionmentioning

confidence: 99%

X-shooter reveals powerful outflows in z ∼ 1.5 X-ray selected obscured quasi-stellar objects

Brusa

Bongiorno

Cresci

et al. 2014

Monthly Notices of the Royal Astronomical Society

156

218

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We present X-shooter@VLT observations of a sample of 10 luminous, X-ray obscured QSOs at z∼ 1.5 from the XMM-COSMOS survey, expected to be caught in the transitioning phase from starburst to AGN dominated systems. The main selection criterion is X-ray detection at bright fluxes (L X > ∼ 10 44 erg s −1 ) coupled to red optical-to-NIR-to-MIR colors. Thanks to its large wavelength coverage, X-shooter allowed us to determine accurate redshifts from the presence of multiple emission lines for five out of six targets for which we had only a photometric redshift estimate, with a 80% success rate, significantly larger than what is observed in similar programs of spectroscopic follow-up of red QSOs. We report the detection of broad and shifted components in the [OIII]λλ5007,4959 complexes for 6 out of 8 sources with these lines observable in regions free from strong atmospheric absorptions. The FWHM associated with the broad components are in the range FWHM∼ 900 − 1600 km s −1 , larger than the average value observed in SDSS Type 2 AGN samples at similar observed [OIII] luminosity, but comparable to those observed for QSO/ULIRGs systems for which the presence of kpc scale outflows have been revealed through IFU spectroscopy. Although the total outflow energetics (inferred under reasonable assumptions) may be consistent with winds accelerated by stellar processes, we favour an AGN origin for the outflows given the high outflow velocities oberved (v> 1000 km s −1 ) and the presence of strong winds also in objects undetected in the far infrared.

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“…There are some examples of outflows capable of feedback. Some of these include BAL winds (Moe et al 2009, Dunn et al 2010, Borguet et al 2013 or NAL winds , where the kinetic outflow rates represent up to a few percent of the bolometric luminosities of the system. The recently discovered X-ray ultra-fast outflow winds (X-ray detected winds with outflow velocities larger than 10,000 km s −1 ) also have high enough mass and kinetic outflow rates in order to produce feedback (e.g.…”

Section: Introductionmentioning

confidence: 99%

Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

Krongold¹,

Binette²,

Bohlin³

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Ton 34 recently transitioned from non-absorbing quasar into a BALQSO.Here, we report new HST-STIS observations of this quasar. Along with CIV absorption, we also detect absorption by NV+Lyα and possibly O VI+Lyβ. We follow the evolution of the CIV BAL, and find that, for the slower outflowing material, the absorption trough varies little (if at all) on a rest-frame timescale of ∼ 2 yr. However, we detect a strong deepening of the absorption in the gas moving at larger velocities (−20, 000 -−23, 000 km s −1 ). The data is consistent with a multistreaming flow crossing our line of sight to the source. The transverse velocity of the flow should be ∼ few thousand km s −1 , similar to the rotation velocity of the BLR gas (≈ 2, 600 km s −1 ). By simply assuming Keplerian motion, these two components must have similar locations, pointing to a common outflow forming the BLR and the BAL. We speculate that BALs, mini-BALs, and NALs, are part of a common, ubiquitous, accretion-disk outflow in AGN, but become observable depending on the viewing angle towards the flow. The absorption troughs suggests a wind covering only ∼20 % of the emitting source, implying a maximum size of 10 −3 pc for the clouds forming the BAL/BLR medium. This is consistent with constraints of the BLR clouds from X-ray occultations. Finally, we suggest that the low excitation broad emission lines detected in the spectra of this source lie beyond the wind, and this gas is probably excited by the shock of the BAL wind with the surrounding medium.

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Quasar outflows and AGN feedback in the extreme UV: HST/COS observations of HE 0238−1904★

Cited by 170 publications

References 81 publications

Forming equatorial rings around dying stars

Forming equatorial rings around dying stars

X-shooter reveals powerful outflows in z ∼ 1.5 X-ray selected obscured quasi-stellar objects

Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

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