Stellar and Ionized Gas Kinematics in the Circumnuclear Region of the Galaxy NGC 7331

1997 ◽  
Vol 488 (2) ◽  
pp. 682-693 ◽  
Author(s):  
E. Mediavilla ◽  
S. Arribas ◽  
B. Garcia‐Lorenzo ◽  
C. del Burgo
2019 ◽  
Vol 487 (3) ◽  
pp. 3679-3692 ◽  
Author(s):  
Dania Muñoz-Vergara ◽  
Neil M Nagar ◽  
Venkatessh Ramakrishnan ◽  
Carolina Finlez ◽  
Thaisa Storchi-Bergmann ◽  
...  

ABSTRACT As part of a high-resolution observational study of feeding and feedback processes occurring in the vicinity of the active galactic nucleus in 40 galaxies, we observed the inner 3${^{\prime\prime}_{.}}$5 × 5 arcsec of the nearby spiral and Seyfert 2 galaxy UGC 2024 with the integral field unit of the Gemini-South Telescope. The observations enabled a study of the stellar and gas kinematics in this region at a spatial resolution of 0${^{\prime\prime}_{.}}$5 (218 pc), and a spectral resolution of 36  km s−1 over the wavelength range 4100–7300 Å. For the strongest emission-lines (H β, [$\rm{O\,{\small III}}$] λ5007 Å, H α, [$\rm{N\,{\small II}}$] λ6584 Å, and [$\rm{S\,{\small II}}$] λλ6717,6731 Å) we derived maps of the flux, radial velocity, and velocity dispersion. The flux distribution and kinematics of the [$\rm{O\,{\small III}}$] emission line are roughly symmetric around the nucleus: the radial velocity is close to systemic over the full field of view. The kinematics of the other strong emission lines trace both this systemic velocity component, and ordered rotation (with kinematic centre 0${^{\prime\prime}_{.}}$2 north-west of the nucleus). The stellar continuum morphology and kinematics are, however, asymmetrical around the nucleus. We interpret these unusual kinematics as the superposition of a component of gas rotating in the galaxy disc plus a ‘halo’ component of highly ionized gas. This halo either traces a quasi-spherical fountain with average radial velocity 200 km s−1, in which case the total nuclear outflow mass and momentum are 2 × 105 M⊙ and 4 × 107 M⊙ km s−1, respectively, or a dispersion supported halo created by a past nuclear starburst.


2020 ◽  
Vol 643 ◽  
pp. A127 ◽  
Author(s):  
A. J. Domínguez-Fernández ◽  
A. Alonso-Herrero ◽  
S. García-Burillo ◽  
R. I. Davies ◽  
A. Usero ◽  
...  

Active galactic nucleus (AGN) driven outflows are believed to play an important role in regulating the growth of galaxies, mostly via negative feedback. However, their effects on their hosts are far from clear, especially for low- and moderate-luminosity Seyferts. To investigate this issue, we obtained cold molecular gas observations, traced by the CO(2-1) transition, using the NOEMA interferometer of five nearby (distances between 19 and 58 Mpc) Seyfert galaxies. The resolution of ∼0.3–0.8 (∼30–100 pc) and field of view of NOEMA allowed us to study the CO(2-1) morphology and kinematics in the nuclear regions (∼100 pc) and up to radial distances of ∼900 pc. We detected CO(2-1) emission in all five galaxies with disky or circumnuclear ring-like morphologies. We derived cold molecular gas masses on nuclear (∼100 pc) and circumnuclear (∼650 pc) scales in the range from 106 to 107 M⊙ and from 107 to 108 M⊙, respectively. In all of our galaxies, the bulk of this gas is rotating in the plane of the galaxy. However, noncircular motions are also present. In NGC 4253, NGC 4388, and NGC 7465, we can ascribe the streaming motions to the presence of a large-scale bar. In Mrk 1066 and NGC 4388, the noncircular motions in the nuclear regions are explained as outflowing material due to the interaction of the AGN wind with molecular gas in the galaxy disk. We conclude that for an unambiguous and precise interpretation of the kinematics of the cold molecular gas, we need detailed knowledge of the host galaxy (i.e., presence of bars, interactions, etc.), and also of the ionized gas kinematics and ionization cone geometry.


2014 ◽  
Vol 10 (S309) ◽  
pp. 190-195 ◽  
Author(s):  
Thaisa Storchi Bergmann

AbstractEarly studies of nearby Seyfert galaxies have led to the picture that the Narrow Line Region is a cone-shaped region of gas ionized by radiation from a nuclear source collimated by a dusty torus, where the gas is in outflow. In this contribution, I discuss a 3D view of the NLR obtained via Integral Field Spectroscopy, showing that: (1) although the region of highest emission is elongated (and in some cases cone-shaped), there is also lower level emission beyond the “ionization cone”, indicating that the AGN radiation leaks through the torus; (2) besides outflows, the gas kinematics include also rotation in the galaxy plane and inflows; (3) in many cases the outflows are compact and restricted to the inner few 100pc; we argue that these may be early stages of an outflow that will evolve to an open-ended, cone-like one. Inflows are observed in ionized gas in LINERs, and in warm molecular gas in more luminous AGN, being usually found on hundred of pc scales. Mass outflow rates in ionized gas are of the order of a few M⊙ yr−1, while the mass inflow rates are of the order of tenths of M⊙ yr−1. Mass inflow rates in warm molecular gas are ≈ 4–5 orders of magnitude lower, but these inflows seem to be only tracers of more massive inflows in cold molecular gas that should be observable at mm wavelengths.


2019 ◽  
Vol 15 (S359) ◽  
pp. 272-273
Author(s):  
M. A. Fonseca-Faria ◽  
A. Rodríguez-Ardila

AbstractWe employ Multi Unit Spectroscopic Explorer (MUSE) data to study the ionized and very ionized gas phase of the feedback in Circinus, the closest Seyfert 2 galaxy. The analysis of the nebular emission allowed us to detect a remarkable high-ionization gas outflow, out of the galaxy plane, traced by the coronal lines [Fe viii] 6089Å and [Fe x] 6374Å, extending up to 700 parsecs north-west from the nucleus. The gas kinematics reveal expanding gas shells with velocities of a few hundred km s-1, spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionization gas is characterized by a temperature of up to 18000 K and a gas density of ne > 102 cm−3. We propose two scenarios consistent with the observations to explain the high-ionization component of the outflow: an active galactic nuclei (AGN) ejection that took place ⁓105 yr ago or local gas excitation by shocks produced by the passage of a radio jet.


1997 ◽  
Vol 490 (1) ◽  
pp. 227-237 ◽  
Author(s):  
S. Arribas ◽  
E. Mediavilla ◽  
B. Garcia‐Lorenzo ◽  
C. del Burgo
Keyword(s):  

2020 ◽  
Vol 635 ◽  
pp. A41
Author(s):  
Jan Florian ◽  
Bodo Ziegler ◽  
Michaela Hirschmann ◽  
Polychronis Papaderos ◽  
Ena Choi ◽  
...  

Context. Powerful active galactic nuclei (AGN) are supposed to play a key regulatory role on the evolution of their host galaxies by shaping the thermodynamic properties of their gas component. However, little is known as to the nature and the visibility timescale of the kinematical imprints of AGN-driven feedback. Gaining theoretical and observational insights into this subject is indispensable for a thorough understanding of the AGN-galaxy coevolution and could yield empirical diagnostics for the identification of galaxies that have experienced a major AGN episode in the past. Aims. We present an investigation of kinematical imprints of AGN feedback on the warm ionized gas medium (WIM) of massive early-type galaxies (ETGs). To this end, we take a two-fold approach that involves a comparative analysis of Hα velocity fields in 123 local ETGs from the CALIFA (Calar Alto Legacy Integral Field Area Survey) integral field spectroscopy survey with 20 simulated galaxies from high-resolution hydrodynamic cosmological SPHgal simulations. The latter were resimulated for two modeling setups, one with and another without AGN feedback. Methods. In order to quantify the effects of AGN feedback on gas kinematics, we measured three parameters that probe deviations from simple regular rotation by using the kinemetry package. These indicators trace the possible presence of distinct kinematic components in Fourier space (k3, 5/k1), variations in the radial profile of the kinematic major axis (σPA), and offsets between the stellar and gas velocity fields (Δϕ). These quantities were monitored in the simulations from a redshift 3 to 0.2 to assess the connection between black hole accretion history, stellar mass growth, and the kinematical perturbation of the WIM. Results. Observed local massive galaxies show a broad range of irregularities, indicating disturbed warm gas motions, which is irrespective of being classified via diagnostic lines as AGN or not. Simulations of massive galaxies with AGN feedback generally exhibit higher irregularity parameters than without AGN feedback, which is more consistent with observations. Besides AGN feedback, other processes like major merger events or infalling gas clouds can lead to elevated irregularity parameters, but they are typically of shorter duration. More specifically, k3, 5/k1 is most sensitive to AGN feedback, whereas Δϕ is most strongly affected by gas infall. Conclusions. We conclude that even if the general disturbance of the WIM velocity is not a unique indicator for AGN feedback, irregularity parameters that are high enough to be consistent with observations can only be reproduced in simulations with AGN feedback. Specifically, an elevated value for the deviation from simple ordered motion is a strong sign for previous events of AGN activity and feedback.


2019 ◽  
Vol 15 (S359) ◽  
pp. 413-414
Author(s):  
María P. Agüero ◽  
Rubén Díaz ◽  
Mischa Schirmer

AbstractThis work is focused on the characterization of the Seyfert-2 galaxies hosting very large, ultra-luminous narrow-line regions (NLRs) at redshifts z = 0.2−0.34. With a space density of 4.4 Gcp−3 at z ∼ 0.3, these “Low Redshift Lyman-α Blob” (LAB) host galaxies are amongst the rarest objects in the universe, and represent an exceptional and short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). We present the study of GMOS spectra for 13 LAB galaxies covering the rest frame spectral range 3700–6700 Å. Predominantly, the [OIII]λ5007 emission line radial distribution is as widespread as that of the continuum one. The emission line profiles exhibit FWHM between 300–700 Km s−1. In 7 of 13 cases a broad kinematical component is detected with FWHM within the range 600–1100 Km s−1. The exceptionally high [OIII]λ5007 luminosity is responsible for very high equivalent width reaching 1500 Å at the nucleus.


Science ◽  
2021 ◽  
pp. eabe9680
Author(s):  
Takafumi Tsukui ◽  
Satoru Iguchi

Spiral galaxies have distinct internal structures including a stellar bulge, disk and spiral arms. It is unknown when in cosmic history these structures formed. We analyze observations of BRI 1335–0417, an intensely star-forming galaxy in the distant Universe, at redshift 4.41. The [C ii] gas kinematics show a steep velocity rise near the galaxy center and have a two-armed spiral morphology, which extends from about 2 to 5 kiloparsecs in radius. We interpret these features as due to a central compact structure, such as a bulge; a rotating gas disk; and either spiral arms or tidal tails. These features had formed within 1.4 billion years after the Big Bang, long before the peak of cosmic star formation.


2019 ◽  
Vol 488 (3) ◽  
pp. 3904-3928 ◽  
Author(s):  
Ryan Leaman ◽  
Francesca Fragkoudi ◽  
Miguel Querejeta ◽  
Gigi Y C Leung ◽  
Dimitri A Gadotti ◽  
...  

ABSTRACT Stellar feedback plays a significant role in modulating star formation, redistributing metals, and shaping the baryonic and dark structure of galaxies – however, the efficiency of its energy deposition to the interstellar medium is challenging to constrain observationally. Here we leverage HST and ALMA imaging of a molecular gas and dust shell ($M_{\mathrm{ H}_2} \sim 2\times 10^{5}\, {\rm M}_{\odot }$) in an outflow from the nuclear star-forming ring of the galaxy NGC 3351, to serve as a boundary condition for a dynamical and energetic analysis of the outflowing ionized gas seen in our MUSE TIMER survey. We use starburst99 models and prescriptions for feedback from simulations to demonstrate that the observed star formation energetics can reproduce the ionized and molecular gas dynamics – provided a dominant component of the momentum injection comes from direct photon pressure from young stars, on top of supernovae, photoionization heating, and stellar winds. The mechanical energy budget from these sources is comparable to low luminosity active galactic neuclei, suggesting that stellar feedback can be a relevant driver of bulk gas motions in galaxy centres – although here ≲10−3 of the ionized gas mass is escaping the galaxy. We test several scenarios for the survival/formation of the cold gas in the outflow, including in situ condensation and cooling. Interestingly, the geometry of the molecular gas shell, observed magnetic field strengths and emission line diagnostics are consistent with a scenario where magnetic field lines aided survival of the dusty ISM as it was initially launched (with mass-loading factor ≲1) from the ring by stellar feedback. This system’s unique feedback-driven morphology can hopefully serve as a useful litmus test for feedback prescriptions in magnetohydrodynamical galaxy simulations.


2006 ◽  
Vol 2 (S235) ◽  
pp. 230-230
Author(s):  
Ivelina Momcheva ◽  
Kurtis Williams ◽  
Ann Zabludoff ◽  
Charles Keeton

AbstractPoor groups are common and interactive environments for galaxies, and thus are important laboratories for studying galaxy evolution. Unfortunately, little is known about groups at z ≥ 0.1, because of the difficulty in identifying them in the first place. Here we present results from our ongoing survey of the environments of strong gravitational lenses, in which we have so far discovered six distant (z ≥ 0.5) groups of galaxies. As in the local Universe, the highest velocity dispersion groups contain a brightest member spatially coincident with the group centroid, whereas lower-dispersion groups tend to have an offset brightest group galaxy. This suggests that higher-dispersion groups are more dynamically relaxed than lower-dispersion groups and that at least some evolved groups exist by z ~ 0.5. We also compare the galaxy and hot gas kinematics with those of similarly distant clusters and of nearby groups.


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