Molecular Gas Streamers Feeding and Obscuring the Active Nucleus of NGC 1068

Sánchez, F.; Davies, R. I.; Genzel, R.; Tacconi, L. J.; Eisenhauer, F.; Hicks, E. K. S.; Friedrich, Susanne; Sternberg, A.

doi:10.1088/0004-637x/691/1/749

Cited by 128 publications

(79 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The outflow rate in warm molecular gas is about three orders of magnitude smaller than mass outflow rates we have observed in ionized gas for other Seyfert galaxies (e.g. Riffel et al 2008Sánchez et al 2009) and up to 6 orders of magnitude smaller than those observed for high luminosity Seyfert 2 galaxies (e.g. McElroy et al 2014).…”

Section: Agn Accretion Ratecontrasting

confidence: 72%

Feeding versus feedback in AGN from near-infrared IFU observations XI: NGC 2110

Diniz

Riffel

Storchi‐Bergmann

et al. 2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We present a two-dimensional mapping of the gas flux distributions, as well as of the gas and stellar kinematics in the inner 220 pc of the Seyfert galaxy NGC 2110, using K-band integral field spectroscopy obtained with the Gemini NIFS at a spatial resolution of ≈ 24 pc and spectral resolution of ≈ 40 km s −1 . The H 2 λ 2.1218 µm emission extends over the whole field-of-view and is attributed to heating by X-rays from the AGN and/or by shocks, while the Brγ emission is restricted to a bi-polar region extending along the South-East-NorthWest direction. The masses of the warm molecular gas and of the ionized gas are M H 2 ≈ 1.4 × 10 3 M ⊙ and M H II ≈ 1.8 × 10 6 M ⊙ , respectively. The stellar kinematics present velocity dispersions reaching 250 km s −1 , and a rotation pattern reaching an amplitude of 200 km s −1 . The gas velocity fields present a similar rotation pattern but also additional components that we attribute to inflows and outflows most clearly observed in the molecular gas emission. The inflows are observed beyond the inner 70 pc and are associated to a spiral arm seen in blueshift to the North-East and another in redshift to the South-West. We have estimated a mass inflow rate in warm molecular gas of ≈ 4.6 × 10 −4 M ⊙ yr −1 . Within the inner 70 pc, another kinematic component is observed in the H 2 emission that can be interpreted as due to a bipolar nuclear outflow oriented along the East-West direction, with a mass-outflow rate of ≈ 4.3 × 10 −4 M ⊙ yr −1 in warm H 2 .

show abstract

Section: Agn Accretion Ratecontrasting

confidence: 72%

Feeding versus feedback in AGN from near-infrared IFU observations XI: NGC 2110

Diniz

Riffel

Storchi‐Bergmann

et al. 2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…Bicknell et al (1998) found that the deviation of the jet, at 0.3 from the core, is caused by its interaction with a giant molecular cloud. Sánchez et al (2009) confirmed that the "northern tongue" correlates with the mid-IR emission and coincides with a knot of radio continuum, providing direct evidence of interaction between the jet and the molecular cloud. Rouan et al (2004) and Gratadour et al (2005Gratadour et al ( , 2006 observed the nearest regions from the core of NGC 1068 (<70 pc) at the diffraction limits of the VLT with NaCo.…”

Section: Introductionsupporting

confidence: 56%

Star formation and jet-induced coronal lines near the core of NGC 1068

Exposito

Gratadour

Clénet

et al. 2011

A&A

View full text Add to dashboard Cite

Context. Active galactic nuclei (AGNs) are very luminous galaxies from the ultraviolet (UV) to the far infrared (FIR). To study regions near the core, which are dominated by dust, IR is the perfect spectral range because of the lower optical depth of the dust. However, these galaxies are usually distant, and the structures near the core are faint compared to the central source. High resolution and high contrast are mandatory to study the inner structures of AGNs and better understand the interaction between the central core and its surroundings. Aims. Our goal is to propose an explanation for the coronal lines in our spectra of NGC 1068 at a far distance (few tens of parsec) from the central source inside wave-like structures that we call nodules. Methods. NGC 1068 was observed with NaCo at ESO/VLT, using long-slit spectroscopy at 2.2 μm and 3.5 μm. Reduced spectra were compared to the output of Cloudy, using various ionizing continua: the continuum of the central source, young stars, and radiative shocks caused by the jet. Results. For the first time, thanks to the resolution provided by NaCo, near-IR coronal emission can be precisely associated to structures observable in the IR broad-band images. We found that coronal lines observed in the nodules cannot be caused by photoionization by the central source but are instead caused by a local jet-induced ionizing continuum. In addition, studying the Brackett-γ line (Brγ) and CO 2-0 band head, we deduced a star density within the four nodules (∼800 000 stars) compatible with super star cluster (hereafter SSC) models.

show abstract

“…This limitation is even more severe in single dish observations for which, depending on the lines observed, the emitting regions (or clouds) can be of a much smaller scale (∼1 order of magnitude) than the beam size of the telescope. In particular, our single dish observations of HCN, HNC, CN and HCO + are sensitive to the high density (∼10 5 cm −3 ) clouds that can be embedded even inside the feeding streamers observed by Sánchez et al (2009). The size of these dense clumps is expected to be from <1 pc up to a few pc, embedded in large molecular clouds of the order of tens of parsecs.…”

Section: Structure Of the Cnd And Limitations Of The Modelmentioning

confidence: 86%

“…However, in some previous works (e.g., Schinnerer et al 2000) it was speculated that the classical (large-scale) molecular torus is not always needed to explain the occultation of the nuclear regions. Recent mid-IR observations have shown the existence of two molecular streamers feeding the galactic nucleus of NGC 1068 (Tomono et al 2006;Sánchez et al 2009). These observations suggest that the occultation of the nuclear region can also be associated with a nuclear concentration of molecular gas and dust that forms an optically thick amorphous clumpy structure (Sánchez et al 2009).…”

Section: Structure Of the Cnd And Limitations Of The Modelmentioning

confidence: 99%

“…Recent mid-IR observations have shown the existence of two molecular streamers feeding the galactic nucleus of NGC 1068 (Tomono et al 2006;Sánchez et al 2009). These observations suggest that the occultation of the nuclear region can also be associated with a nuclear concentration of molecular gas and dust that forms an optically thick amorphous clumpy structure (Sánchez et al 2009). Although it is very likely that this structure encloses smaller infalling clouds, they are not resolved at the 0.075 (scale size ∼5 pc at a distance of 14.4 Mpc) resolution of the Very Large Telescope (VLT).…”

Section: Structure Of the Cnd And Limitations Of The Modelmentioning

confidence: 99%

See 1 more Smart Citation

Probing X-ray irradiation in the nucleus of NGC 1068 with observations of high-Jlines of dense gas tracers

Pérez-Beaupuits¹,

Spaans²,

Tak

et al. 2009

A&A

View full text Add to dashboard Cite

Context. Single-dish observations of molecular tracers have suggested that both star formation and an AGN can drive the gas chemistry of the central ∼kpc of active galaxies. The irradiation by UV photons from an starburst or by X-rays from an AGN is expected to produce different signatures in molecular chemistry, which existing data on low-J lines cannot distinguish, as they do not trace gas at high temperature and density. Depending on the angular scale of a galaxy, the observed low-J lines can be dominated by the emission coming from the starburst ring rather than from the central region. Aims. With the incorporation of high-J molecular lines, we aim to constrain the physical conditions of the dense gas in the central region of the Seyfert 2 galaxy NGC 1068 and to determine signatures of the AGN or the starburst contribution. Methods. We used the James Clerk Maxwell Telescope to observe the J = 4−3 transition of HCN, HNC, and HCO + , as well as the CN N J = 2 5/2 − 1 3/2 and N J = 3 5/2 − 2 5/2 , in NGC 1068. We estimate the excitation conditions of HCN, HNC, and CN, based on the line intensity ratios and radiative transfer models. We discuss the results in the context of models of irradiation of the molecular gas by UV light and X-rays. Results. A first-order estimate leads to starburst contribution factors of 0.58 and 0.56 for the CN and HCN J = 1−0 lines, respectively. We find that the bulk emission of HCN, HNC, CN, and the high-J HCO + emerge from dense gas (n(H 2 ) ≥ 10 5 cm −3 ). However, the low-J HCO + lines (dominating the HCO + column density) trace less dense (n(H 2 ) < 10 5 cm −3 ) and colder (T K ≤ 20 K) gas, whereas the high-J HCO + emerges from warmer (>30 K) gas than the other molecules. We also find that the HNC/HCN and CN/HCN line intensity ratios decrease with increasing rotational quantum number J.

show abstract

Molecular Gas Streamers Feeding and Obscuring the Active Nucleus of NGC 1068

Cited by 128 publications

References 52 publications

Feeding versus feedback in AGN from near-infrared IFU observations XI: NGC 2110

Feeding versus feedback in AGN from near-infrared IFU observations XI: NGC 2110

Star formation and jet-induced coronal lines near the core of NGC 1068

Probing X-ray irradiation in the nucleus of NGC 1068 with observations of high-Jlines of dense gas tracers

Contact Info

Product

Resources

About