Turbulent and fast motions of H<sub>2</sub>gas in active galactic nuclei

Dasyra, K. M.; Combes, F.

doi:10.1051/0004-6361/201117730

Cited by 50 publications

(76 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An H i outflow in front of a bright radio knot (Morganti et al 2004) makes this scenario plausible for the neutral gas, and even for the molecular gas. A jet-ISM interaction can be responsible for the irregular H 2 kinematics (Dasyra & Combes 2011;Nesvadba et al 2011), the strong H 2 emission (Ogle et al 2010), and the high CO excitation (Papadopoulos et al 2008) of radio galaxies.…”

Section: Discussion: On the Properties Of A Multi-phase Agn-driven Oumentioning

confidence: 99%

Cold and warm molecular gas in the outflow of 4C 12.50

Dasyra

Combes

2012

A&A

Self Cite

View full text Add to dashboard Cite

We present deep observations of the 12 CO (1−0) and (3−2) lines in the ultra-luminous infrared and radio galaxy 4C 12.50, carried out with the 30 m telescope of the Institut de Radioastronomie Millimétrique. Our observations reveal the cold molecular gas component of a warm molecular gas outflow that was previously known from Spitzer Space Telescope data. The 12 CO(3−2) profile indicates the presence of absorption at −950 km s −1 from systemic velocity with a central optical depth of 0.22. Its profile is similar to that of the H i absorption that was seen in radio data of this source. A potential detection of the 0 → 1 absorption enabled us to place an upper limit of 0.03 on its central optical depth, and to constrain the excitation temperature of the outflowing CO gas to ≥65 K assuming that the gas is thermalized. If the molecular clouds fully obscure the background millimeter continuum that is emitted by the radio core, the H 2 column density is ≥1.8 × 10 22 cm −2 . The outflow then carries an estimated cold H 2 mass of at least 4.2 × 10 3 M along the nuclear line of sight. This mass will be even higher when integrated over several lines of sight, but if it were to exceed 3 × 10 9 M , the outflow would most likely be seen in emission. Since the ambient cold gas reservoir of 4C 12.50 is 1.0 × 10 10 M , the outflowing-to-ambient mass ratio of the warm gas (37%) could be elevated with respect to that of the cold gas.

show abstract

Section: Discussion: On the Properties Of A Multi-phase Agn-driven Oumentioning

confidence: 99%

Cold and warm molecular gas in the outflow of 4C 12.50

Dasyra

Combes

2012

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since the V(1-0) H 2 lines only probe the warmest, but not the bulk of the gas, this is difficult to turn into a mass outflow rateṀ. If we assume that the pure-rotational lines, which trace most of the mass, have a similar profile (as reported for AGN with high-resolution Spitzer spectroscopy, Dasyra & Combes 2011;Guillard et al 2011), we find ∼1 × 10 8 M of entrained dense, warm H 2 in the wind. For an outflow timescale of 10 7−8 yrs, this is consistent with or less than theṀ estimated from Na D, 30-40 M yr −1 (N10), which traces neutral (atomic and/or molecular) gas down to lower column densities.…”

Section: Introductionmentioning

confidence: 95%

Dense gas without star formation: the kpc-sized turbulent molecular disk in 3C 326 N

Nesvadba

Boulanger

Lehnert

et al. 2011

A&A

View full text Add to dashboard Cite

We report the discovery of a 3 kpc disk of few 10 9 M of dense, warm H 2 in the nearby radio galaxy 3C 326 N, which shows no signs of ongoing or recent star formation and falls a factor of 60 below the Schmidt-Kennicutt law. Our VLT/SINFONI imaging spectroscopy shows broad (FWHM ∼ 500 km s −1 ) ro-vibrational H 2 lines across the entire disk, with irregular profiles and line ratios consistent with shocks. The ratio of turbulent to gravitational energy suggests that the gas is highly turbulent and not gravitationally bound. In the absence of the driving by the jet, the short turbulent dissipation times indicate that the gas should collapse rapidly and form stars, at odds with the recent star-formation history. Motivated by hydrodynamic models of rapid H 2 formation boosted by turbulent compression, we propose that the molecules formed from diffuse atomic gas in the turbulent jet cocoon. Since the gas is not self-gravitating, it cannot form molecular clouds or stars while the jet is active, and is likely to disperse and become atomic again after the nuclear activity ceases. We speculate that very low star-formation rates are to be expected under such conditions, provided that the large-scale turbulence controls the gas dynamics in molecular clouds. Our results illustrate that jets may create large molecular reservoirs as expected in "positive feedback" scenarios of AGN-triggered star formation, but that this alone is insufficient to trigger star formation.

show abstract

“…Cold gas has been found to represent the dominant mass component of the outflows observed (see e.g. Morganti et al 2005aMorganti et al ,b, 2013aKanekar & Chengalur 2008;Holt et al 2009;Feruglio et al 2010;Alatalo et al 2011;Dasyra & Combes 2011Cicone et al 2014;García-Burillo et al 2014, for some examples). This makes them particularly interesting for their potential impact on the ISM of the host galaxy.…”

Section: Introductionmentioning

confidence: 99%

The fast molecular outflow in the Seyfert galaxy IC 5063 as seen by ALMA

Morganti

Oosterloo

Oonk

et al. 2015

A&A

222

269

View full text Add to dashboard Cite

We use high-resolution (0.5 arcsec) CO(2−1) observations performed with the Atacama Large Millimetre/submillimetre Array to trace the kinematics of the molecular gas in the Seyfert 2 galaxy IC 5063. The data reveal that the kinematics of the gas is very complex. A fast outflow of molecular gas extends along the entire radio jet (∼1 kpc), with the highest outflow velocities about 0.5 kpc from the nucleus, at the location of the brighter hot spot in the western lobe. The ALMA data show that a massive, fast outflow with velocities up to 650 km s −1 of cold molecular gas is present, in addition to the outflow detected earlier in warm H 2 , H i and ionized gas. All phases of the gas outflow show similar kinematics. IC 5063 appears to be one of the best examples of the multi-phase nature of AGN-driven outflows. Both the central AGN and the radio jet could energetically drive the outflow, however, the characteristics of the outflowing gas point to the radio jet being the main driver. This is an important result because IC 5063, although one of the most powerful Seyfert galaxies, is a relatively weak radio source (P 1.4 GHz = 3 × 10 23 W Hz −1 ). All the observed characteristics can be described by a scenario of a radio plasma jet expanding into a clumpy medium, interacting directly with the clouds and inflating a cocoon that drives a lateral outflow into the interstellar medium. This model is consistent with results obtained by recent simulations. A stronger, direct interaction between the jet and a gas cloud is present at the location of the brighter western lobe. This interaction may also be responsible for the asymmetry in the radio brightness of the two lobes. Even assuming the most conservative values for the conversion factor CO-to-H 2 , we find that the mass of the outflowing gas is between 1.9 and 4.8 × 10 7 M , of which between 0.5 and 1.3 × 10 7 M is associated with the fast outflow at the location of the western lobe. These amounts are much larger than those of the outflow of warm gas (molecular and ionized) and somewhat larger than of the H i outflow. This suggests that most of the observed cold molecular outflow is due to fast cooling after being shocked. This gas is the end product of the cooling process, although some of it could be the result of only partly dissociated clouds. Our CO observations demonstrate that fast outflows of substantial masses of molecular gas can be driven by relativistic jets, although in the case of IC 5063 the outflows are not fast enough to remove significant amounts of gas from the galaxy and the effects are limited to the central ∼0.5 kpc from the centre.

show abstract

Turbulent and fast motions of H₂gas in active galactic nuclei

Cited by 50 publications

References 41 publications

Cold and warm molecular gas in the outflow of 4C 12.50

Cold and warm molecular gas in the outflow of 4C 12.50

Dense gas without star formation: the kpc-sized turbulent molecular disk in 3C 326 N

The fast molecular outflow in the Seyfert galaxy IC 5063 as seen by ALMA

Contact Info

Product

Resources

About

Turbulent and fast motions of H2gas in active galactic nuclei

Cited by 50 publications

References 41 publications

Cold and warm molecular gas in the outflow of 4C 12.50

Cold and warm molecular gas in the outflow of 4C 12.50

Dense gas without star formation: the kpc-sized turbulent molecular disk in 3C 326 N

The fast molecular outflow in the Seyfert galaxy IC 5063 as seen by ALMA

Contact Info

Product

Resources

About

Turbulent and fast motions of H₂gas in active galactic nuclei