Mass Loss from the Nuclei of Active Galaxies

Crenshaw, D. Michael; Kraemer, S. B.; George, I. M.

doi:10.1146/annurev.astro.41.082801.100328

Cited by 495 publications

(561 citation statements)

References 205 publications

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“…We assume that the opening angle factor C (a fraction of 4 ) is given by the detection rate (which is the case if the frequency of occurrence of winds is 100%) and that the local clumping is given by the measured covering fraction along the line of sight, C f . The global covering factor is then given by /4 ¼ C hC f i ¼ DhC f i (see x 2.6.2 and Crenshaw et al 2003). In the more general case, where F is not necessarily unity, we can set lower limits to F and C using our detection rate: D < F < 1 and D < C < 1.…”

Section: Frequency Of Occurrence and Global Covering Factormentioning

confidence: 99%

Outflows in Infrared‐Luminous Starbursts at z < 0.5. II. Analysis and Discussion

Rupke

Veilleux

Sanders

2005

ASTROPHYS J SUPPL S

518

612

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We have performed an absorption-line survey of outflowing gas in 78 starburst-dominated, infrared-luminous galaxies. This is the largest study of superwinds at z P 3. Superwinds are found in almost all infrared-luminous galaxies, and changes in detection rate with SFR-winds are found twice as often in ultraluminous infrared galaxies (ULIRGs) as in less-luminous galaxies-reflect different wind geometries. The maximum velocities we measure are 600 km s À1 , though most of the outflowing gas has lower velocities (100-200 km s À1 ). (One galaxy has velocities exceeding 1000 km s À1 .) Velocities in LINERs are higher than in H ii galaxies, and outflowing ionized gas often has higher velocities than the neutral gas. Wind properties (velocity, mass, momentum, and energy) scale with galaxy properties (SFR, luminosity, and galaxy mass), consistent with ram-pressure driving of the wind. Wind properties increase strongly with increasing galactic mass, contrary to expectation. These correlations flatten at high SFR (k10-100 M yr À1 ), luminosities, and masses. This saturation is due to a lack of gas remaining in the wind's path, a common neutral gas terminal velocity, and/or a decrease in the efficiency of thermalization of the supernovae energy. It means that mass entrainment efficiency, rather than remaining constant, declines in galaxies with SFR > 10 M yr À1 and M K < À24. Half of our sample consists of ULIRGs, which host as much as half of the star formation in the universe at z k 1. The powerful, ubiquitous winds we observe in these galaxies imply that superwinds in massive galaxies at redshifts above unity play an important role in the evolution of galaxies and the intergalactic medium.

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Section: Frequency Of Occurrence and Global Covering Factormentioning

confidence: 99%

Outflows in Infrared‐Luminous Starbursts at z < 0.5. II. Analysis and Discussion

Rupke

Veilleux

Sanders

2005

ASTROPHYS J SUPPL S

518

612

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“…While in this work these have been considered contaminants, the prevalence and measurement of these lines could be used to infer properties of the metallicities within intervening absorbers (e.g Ryan-Weber et al 2006;Becker et al 2009;D'Odorico et al 2013) and to reveal the presence of massive outflows of ionised gas from their nuclei (e.g. Crenshaw et al 2003, and reference therein). For example, we have thrown out any QSOs with strong intervening absorption from systems such as DLAs, however, analysing these sources with our MCMC fitting algorithm could yield measurements on the internal properties of these absorption systems.…”

Section: Potential Applicationsmentioning

confidence: 99%

Lyα emission-line reconstruction for high-zQSOs

Greig

Mesinger

McGreer

et al. 2016

Mon. Not. R. Astron. Soc.

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We introduce an intrinsic Lyα emission line profile reconstruction method for high-z quasars (QSOs). This approach utilises a covariance matrix of emission line properties obtained from a large, moderate-z (2 ≤ z ≤ 2.5), high signal to noise (S/N> 15) sample of BOSS QSOs. For each QSO, we complete a Monte Carlo Markov Chain fitting of the continuum and emission line properties and perform a visual quality assessment to construct a large database of robustly fit spectra. With this dataset, we construct a covariance matrix to describe the correlations between the high ionisation emission lines Lyα, C IV, Si IV +O IV] and C III], and find it to be well approximated by an N -dimensional Gaussian distribution. This covariance matrix characterises the correlations between the line width, peak height and velocity offset from systemic while also allowing for the existence of broad and narrow line components for Lyα and C IV. We illustrate how this covariance matrix allows us to statistically characterise the intrinsic Lyα line solely from the observed spectrum redward of 1275Å. This procedure can be used to reconstruct the intrinsic Lyα line emission profile in cases where Lyα may otherwise be obscured. Applying this reconstruction method to our sample of QSOs, we recovered the Lyα line flux to within 15 per cent of the measured flux at 1205Å (1220Å) ∼ 85 (90) per cent of the time.

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“…This theoretical picture has been supported by numerous observations. The strongest evidence comes from the brightest cluster galaxies (BCGs) of cool core clusters, whose powerful radio jets have swept out cavities in the intracluster medium (ICM; Rosner & Tucker 1989;Allen et al 2001;McNamara & Nulsen 2007), while in some individual galaxies, energy transportation into the ISM via AGN-driven outflows is observed to remove gas from the central regions of the galaxy (Crenshaw et al 2003;Nesvadba et al 2007;Alexander et al 2010;Morganti et al 2013). All these show the negative effect of AGN feedback by removing/heating up the gas and eventually suppressing the star formation and regulating the galaxy growth.…”

Section: Introductionmentioning

confidence: 99%

Constraints on Feedback in the Local Universe: The Relation Between Star Formation and Agn Activity in Early-Type Galaxies

Vaddi

O’Dea

Baum

et al. 2016

ApJ

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We address the relation between star formation and active galactic nucleus (AGN) activity in a sample of 231 nearby (0.0002 < z < 0.0358) early-type galaxies by carrying out a multi-wavelength study using archival observations in the UV, IR, and radio. Our results indicate that early-type galaxies in the current epoch are rarely powerful AGNs, with P 10 WHz 22 1 < -for a majority of the galaxies. Only massive galaxies are capable of hosting powerful radio sources while less massive galaxies are hosts to lower radio power sources. Evidence of ongoing star formation is seen in approximately 7% of the sample. The star formation rate (SFR) of these galaxies is less than 0.1 M e yr −1 . They also tend to be radio faint (P 10 WHzThere is a nearly equal fraction of star-forming galaxies in radio faint (P 10 WHz 22 1 < -) and radio bright galaxies (P 10 WHz 22 1  -) suggesting that both star formation and radio mode feedback are constrained to be very low in our sample. We notice that our galaxy sample and the Brightest Cluster Galaxies follow similar trends in radio power versus SFR. This may be produced if both radio power and SFR are related to stellar mass.

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Mass Loss from the Nuclei of Active Galaxies

Cited by 495 publications

References 205 publications

Outflows in Infrared‐Luminous Starbursts at z < 0.5. II. Analysis and Discussion

Outflows in Infrared‐Luminous Starbursts at z < 0.5. II. Analysis and Discussion

Lyα emission-line reconstruction for high-zQSOs

Constraints on Feedback in the Local Universe: The Relation Between Star Formation and Agn Activity in Early-Type Galaxies

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