Neutral Gas Outflows and Inflows in Infrared-Faint Seyfert Galaxies

Krug, H.; Rupke, David S. N.; Veilleux, Sylvain

doi:10.1088/0004-637x/708/2/1145

Cited by 47 publications

(64 citation statements)

References 78 publications

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“…Very high outflow speeds (many thousands of km s −1 ) are commonly observed in unobscured (Type 1) AGN (e.g., Rupke et al 2005;Krug et al 2010). However these same authors show that outflows similar to those we see in the DCOs (maximum outflow speeds of at least 1500 km s −1 ) are extremely rare in composite obscured-AGN/starburst systems and not seen at all in "pure" obscured AGN.…”

Section: Feedback From An Active Galactic Nucleus?mentioning

confidence: 63%

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Heckman

Borthakur

Overzier

et al. 2011

ApJ

291

405

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The source responsible for reionizing the universe at z > 6 remains uncertain. While an energetically adequate population of star-forming galaxies may be in place, it is unknown whether a large enough fraction of their ionizing radiation can escape into the intergalactic medium. Attempts to measure this escape fraction in intensely star-forming galaxies at lower redshifts have largely yielded upper limits. In this paper, we present new Hubble Space Telescope Cosmic Origins Spectrograph and archival Far-Ultraviolet Spectroscopic Explorer (FUSE) far-UV spectroscopy of a sample of 11 Lyman Break Analogs (LBAs), a rare population of local galaxies that strongly resemble the high-z Lyman Break galaxies. We combine these data with Sloan Digital Sky Survey optical spectra and Spitzer photometry. We also analyze archival FUSE observations of 15 typical UV-bright local starbursts. We find evidence of small covering factors for optically thick neutral gas in three cases. This is based on two independent pieces of evidence: a significant residual intensity in the cores of the strongest interstellar absorption-lines tracing neutral gas and a small ratio of extinction-corrected Hα to UV plus far-IR luminosities. These objects represent three of the four LBAs that contain a young, very compact (∼10 2 pc), and highly massive (∼10 9 M ) dominant central object (DCO). These three objects also differ from the other galaxies in showing a significant amount of blueshifted Lyα emission, which may be related to the low covering factor of neutral gas. All four LBAs with DCOs in our sample show extremely high velocity outflows of interstellar gas, with line centroids blueshifted by about 700 km s −1 and maximum outflow velocities reaching at least 1500 km s −1 . We show that these properties are consistent with an outflow driven by a powerful starburst that is exceptionally compact. We speculate that such extreme feedback may be required to enable the escape of ionizing radiation from star-forming galaxies.

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Section: Feedback From An Active Galactic Nucleus?mentioning

confidence: 63%

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Heckman

Borthakur

Overzier

et al. 2011

ApJ

291

405

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“…3.6 the possibility that an extended envelope around the nucleus of NGC 4418 is inflowing onto the nuclear region, thus feeding the nucleus and providing an external ram pressure that may further confine the nuclear gas. Krug et al (2010) have reported the detection of inflows in Seyferts based on absorption measurements of the Na I doublet at optical wavelengths.…”

Section: Inflowing Gas In Ngc 4418?mentioning

confidence: 99%

Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H₂O, H₂¹⁸O, OH,¹⁸OH, O I, HCN, and NH₃

González-Alfonso

Fischer

Graciá-Carpio

et al. 2012

A&A

157

166

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Full range Herschel/PACS spectroscopy of the (ultra)luminous infrared galaxies NGC 4418 and Arp 220, observed as part of the SHINING key programme, reveals high excitation in H 2 O, OH, HCN, and NH 3 . In NGC 4418, absorption lines were detected with E lower > 800 K (H 2 O), 600 K (OH), 1075 K (HCN), and 600 K (NH 3 ), while in Arp 220 the excitation is somewhat lower. While outflow signatures in moderate excitation lines are seen in Arp 220 as have been seen in previous studies, in NGC 4418 the lines tracing its outer regions are redshifted relative to the nucleus, suggesting an inflow withṀ 12 M yr −1 . Both galaxies have compact and warm (T dust 100 K) nuclear continuum components, together with a more extended and colder component that is much more prominent and massive in Arp 220. A chemical dichotomy is found in both sources: on the one hand, the nuclear regions have high H 2 O abundances, ∼10 −5 , and high HCN/H 2 O and HCN/NH 3 column density ratios of 0.1−0.4 and 2−5, respectively, indicating a chemistry typical of evolved hot cores where grain mantle evaporation has occurred. On the other hand, the high OH abundance, with OH/H 2 O ratios of ∼0.5, indicates the effects of X-rays and/or cosmic rays. The nuclear media have high surface brightnesses ( 10 13 L /kpc 2 ) and are estimated to be very thick (N H 10 25 cm −2 ). While NGC 4418 shows weak absorption in H 18 2 O and 18 OH, with a 16 O-to-18 O ratio of 250−500, the relatively strong absorption of the rare isotopologues in Arp 220 indicates 18 O enhancement, with 16 O-to-18 O of 70−130. Further away from the nuclear regions, the H 2 O abundance decreases to 10 −7 and the OH/H 2 O ratio is reversed relative to the nuclear region to 2.5−10. Despite the different scales and morphologies of NGC 4418, Arp 220, and Mrk 231, preliminary evidence is found for an evolutionary sequence from infall, hot-core like chemistry, and solar oxygen isotope ratio to high velocity outflow, disruption of the hot core chemistry and cumulative high mass stellar processing of 18 O.

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“…Outflows of neutral atomic and molecular gas have also been observed. The neutral atomic component has been probed by observations of the Na I D absorption doublet (Krug et al 2010) or by the [CII]158µm and HI 21cm fine structure emission lines (Maiolino et al 2012;Morganti et al 2016). The molecular component is mostly probed by observations of CO transitions (Feruglio et al 2010;Cicone et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Exponentially growing bubbles around early supermassive black holes

Gilli¹,

Calura²,

D’Ercole³

et al. 2017

A&A

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We address the as yet unexplored issue of outflows induced by exponentially growing power sources, focusing on early supermassive black holes (BHs). We assumed that these objects grow to 10 9 M by z=6 by Eddington-limited accretion and convert 5% of their bolometric output into a wind. We first considered the case of energy-driven and momentum-driven outflows expanding in a region where the gas and total mass densities are uniform and equal to the average values in the Universe at z > 6. We derived analytic solutions for the evolution of the outflow: for an exponentially growing power with e-folding time t S al , we find that the late time expansion of the outflow radius is also exponential, with e-folding time of 5t S al and 4t S al in the energy-driven and momentum-driven limit, respectively. We then considered energy-driven outflows produced by quasi-stellar objects (QSOs) at the centre of early dark matter halos of different masses and powered by BHs growing from different seeds. We followed the evolution of the source power and of the gas and dark matter density profiles in the halos from the beginning of the accretion until z = 6. The final bubble radius and velocity do not depend on the seed BH mass, but are instead smaller for larger halo masses. At z=6, bubble radii in the range 50-180 kpc and velocities in the range 400-1000 km s −1 are expected for QSOs hosted by halos in the mass range 3 × 10 11 − 10 13 M . These radius and velocity scales compare well with those measured for the outflowing gas in the z=6.4 QSO SDSS J1148+5251. By the time the QSO is observed, we found that the total thermal energy injected within the bubble in the case of an energy-driven outflow is E th ∼ 5 × 10 60 erg. This is in excellent agreement with the value of E th = (6.2 ± 1.7) × 10 60 erg measured through the detection of the thermal Sunyaev-Zeldovich effect around a large population of luminous QSOs at lower redshifts. This suggests that QSO outflows are closer to the energy-driven limit than to the momentum-driven limit. We investigated the stability of the expanding gas shell in the case of an energy-driven supersonic outflow propagating within a dark matter halo with M h = 3 × 10 11 M at z=6. We found that the shell is Rayleigh-Taylor unstable already at early times and, by means of a simple model, we investigated the fate of the fragments detaching from the shell. We found that these fragments should rapidly evaporate because of the extremely high temperature of the hot gas bubble if this does not cool. Since the only effective cooling mechanism for such a gas is inverse Compton by the cosmic microwave background (CMB) photons (IC-CMB), which is important only at z ≥ 6, we speculate that such shell fragments may be observed only around high-z QSOs, where IC-CMB cooling of the bubble gas can prevent their evaporation.

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Neutral Gas Outflows and Inflows in Infrared-Faint Seyfert Galaxies

Cited by 47 publications

References 78 publications

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H₂O, H₂¹⁸O, OH,¹⁸OH, O I, HCN, and NH₃

Exponentially growing bubbles around early supermassive black holes

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Neutral Gas Outflows and Inflows in Infrared-Faint Seyfert Galaxies

Cited by 47 publications

References 78 publications

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Extreme Feedback and the Epoch of Reionization: Clues in the Local Universe

Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H2O, H218O, OH,18OH, O I, HCN, and NH3

Exponentially growing bubbles around early supermassive black holes

Contact Info

Product

Resources

About

Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H₂O, H₂¹⁸O, OH,¹⁸OH, O I, HCN, and NH₃