scholarly journals Tracing the Ionization Structure of the Shocked Filaments of NGC 6240

2021 ◽  
Vol 923 (2) ◽  
pp. 160
Author(s):  
Anne M. Medling ◽  
Lisa J. Kewley ◽  
Daniela Calzetti ◽  
George C. Privon ◽  
Kirsten Larson ◽  
...  
Keyword(s):  
Shock Front ◽  
Adaptive Optics ◽  
Hubble Space Telescope ◽  
Stellar Disk ◽  
Molecular Gas ◽  
Ionized Gas ◽  
Integral Field Spectroscopy ◽  
Ionization Structure ◽  
Systemic Velocity ◽  
The Galaxy

Abstract We study the ionization and excitation structure of the interstellar medium in the late-stage gas-rich galaxy merger NGC 6240 using a suite of emission-line maps at ∼25 pc resolution from the Hubble Space Telescope, Keck/NIRC2 with Adaptive Optics, and the Atacama Large Millimeter/submillimeter Array (ALMA). NGC 6240 hosts a superwind driven by intense star formation and/or one or both of two active nuclei; the outflows produce bubbles and filaments seen in shock tracers from warm molecular gas (H2 2.12 μm) to optical ionized gas ([O iii], [N ii], [S ii], and [O i]) and hot plasma (Fe XXV). In the most distinct bubble, we see a clear shock front traced by high [O iii]/Hβ and [O iii]/[O i]. Cool molecular gas (CO(2−1)) is only present near the base of the bubble, toward the nuclei launching the outflow. We interpret the lack of molecular gas outside the bubble to mean that the shock front is not responsible for dissociating molecular gas, and conclude that the molecular clouds are partly shielded and either entrained briefly in the outflow, or left undisturbed while the hot wind flows around them. Elsewhere in the galaxy, shock-excited H2 extends at least ∼4 kpc from the nuclei, tracing molecular gas even warmer than that between the nuclei, where the two galaxies’ interstellar media are colliding. A ridgeline of high [O iii]/Hβ emission along the eastern arm aligns with the southern nucleus’ stellar disk minor axis; optical integral field spectroscopy from WiFeS suggests this highly ionized gas is centered at systemic velocity and likely photoionized by direct line of sight to the southern active galactic nucleus.

scholarly journals The Narrow Line Region in 3D: mapping AGN feeding and feedback

2014 ◽  
Vol 10 (S309) ◽  
pp. 190-195 ◽  
Author(s):  
Thaisa Storchi Bergmann
Keyword(s):  
Seyfert Galaxies ◽  
Molecular Gas ◽  
Narrow Line ◽  
Ionized Gas ◽  
Gas Kinematics ◽  
Integral Field Spectroscopy ◽  
Line Region ◽  
The Galaxy ◽  
Mass Outflow ◽  
Narrow Line Region

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.

scholarly journals Survival of molecular gas in a stellar feedback-driven outflow witnessed with the MUSE TIMER project and ALMA

2019 ◽  
Vol 488 (3) ◽  
pp. 3904-3928 ◽  
Author(s):  
Ryan Leaman ◽  
Francesca Fragkoudi ◽  
Miguel Querejeta ◽  
Gigi Y C Leung ◽  
Dimitri A Gadotti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Mechanical Energy ◽  
Molecular Gas ◽  
Ionized Gas ◽  
Star Forming ◽  
Stellar Feedback ◽  
Dominant Component ◽  
The Galaxy ◽  
Field Lines

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.

scholarly journals CO J=2-1 observations toward the OH 1720 MHz maser in Kes 69

2002 ◽  
Vol 206 ◽  
pp. 221-224
Author(s):  
Estela M. Reynoso ◽  
Jeffrey G. Mangum
Keyword(s):  
Shock Front ◽  
Strong Evidence ◽  
Supernova Remnant ◽  
Molecular Gas ◽  
Conspicuous Feature ◽  
Systemic Velocity ◽  
The Difference ◽  
Small Clump

We present CO J=2-1 observations made with the 12 Meter Telescope of NRAO using the On-The-Fly technique, towards the OH 1720 MHz maser detected in direction to the supernova remnant (SNR) Kes 69. OH 1720 MHz masers associated to SNRs are strong evidence of shocked molecular gas, and are proposed to be tracers of SNRs kinematical distances. In our images, the most conspicuous feature positionally coincident with the maser is a cloud at ∼ +41 km s−1. The difference between the velocity of the OH 1720 MHz maser and this cloud is ∼ 30 km s−1. At the systemic velocity of the OH 1720 MHz maser, we detected a weak, small clump with the maser lying at its edge, in agreement with previous findings in other SNRs. We suggest that this small clump has been shocked by the expanding SNR, and the ∼ +41 km s−1 component probably corresponds to gas accelerated by the shock front. We do not discard, however, that the ∼ +41 km s−1 component be just a quiescent, foreground cloud unrelated to Kes 69.

scholarly journals Towards sub-kpc scale kinematics of molecular and ionized gas of star-forming galaxies at z ∼ 1

2019 ◽  
Vol 631 ◽  
pp. A91 ◽  
Author(s):  
M. Girard ◽  
M. Dessauges-Zavadsky ◽  
F. Combes ◽  
J. Chisholm ◽  
V. Patrício ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Rotation Curve ◽  
Velocity Dispersion ◽  
Major Axis ◽  
Stellar Disk ◽  
Molecular Gas ◽  
Ionized Gas ◽  
Rotation Curves ◽  
Star Forming ◽  
Gas Kinematics

We compare the molecular and ionized gas kinematics of two strongly lensed galaxies at z ∼ 1 that lie on the main sequence at this redshift. The observations were made with ALMA and MUSE, respectively. We derive the CO and [O II] rotation curves and dispersion profiles of these two galaxies. We find a difference between the observed molecular and ionized gas rotation curves for one of the two galaxies, the Cosmic Snake, for which we obtain a spatial resolution of a few hundred parsec along the major axis. The rotation curve of the molecular gas is steeper than the rotation curve of the ionized gas. In the second galaxy, A521, the molecular and ionized gas rotation curves are consistent, but the spatial resolution is only a few kiloparsec on the major axis. Using simulations, we investigate the effect of the thickness of the gas disk and effective radius on the observed rotation curves and find that a more extended and thicker disk smoothens the curve. We also find that the presence of a strongly inclined (> 70°) thick disk (> 1 kpc) can smoothen the rotation curve because it degrades the spatial resolution along the line of sight. By building a model using a stellar disk and two gas disks, we reproduce the rotation curves of the Cosmic Snake with a molecular gas disk that is more massive and more radially and vertically concentrated than the ionized gas disk. Finally, we also obtain an intrinsic velocity dispersion in the Cosmic Snake of 18.5 ± 7 km s−1 and 19.5 ± 6 km s−1 for the molecular and ionized gas, respectively, which is consistent with a molecular disk with a smaller and thinner disk. For A521, the intrinsic velocity dispersion values are 11 ± 8 km s−1 and 54 ± 11 km s−1, with a higher value for the ionized gas. This could indicate that the ionized gas disk is thicker and more turbulent in this galaxy. These results highlight the diversity of the kinematics of galaxies at z ∼ 1 and the different spatial distribution of the molecular and ionized gas disks. It suggests the presence of thick ionized gas disks at this epoch and that the formation of the molecular gas is limited to the midplane and center of the galaxy in some objects.

scholarly journals Powerful ionized gas outflows in the interacting radio galaxy 4C+29.30

2020 ◽  
Vol 497 (4) ◽  
pp. 5103-5117
Author(s):  
Guilherme S Couto ◽  
Thaisa Storchi-Bergmann ◽  
Aneta Siemiginowska ◽  
Rogemar A Riffel ◽  
Raffaella Morganti
Keyword(s):  
Radio Galaxy ◽  
Host Galaxy ◽  
Ionized Gas ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Integral Field Spectroscopy ◽  
The Galaxy ◽  
Outflow Rate ◽  
Mass Outflow ◽  
Integral Field

ABSTRACT We investigate the ionized gas excitation and kinematics in the inner $4.3\, \times \, 6.2$ kpc2 of the merger radio galaxy 4C+29.30. Using optical integral field spectroscopy with the Gemini North Telescope, we present flux distributions, line-ratio maps, peak velocities and velocity dispersion maps as well as channel maps with a spatial resolution of $\approx\! 955\,$ pc. We observe high blueshifts of up to $\sim\! -650\,$$\rm km\, s^{-1}$ in a region ∼1 arcsec south of the nucleus (the southern knot – SK), which also presents high velocity dispersions ($\sim\! 250\,$$\rm km\, s^{-1}$), which we attribute to an outflow. A possible redshifted counterpart is observed north from the nucleus (the northern knot – NK). We propose that these regions correspond to a bipolar outflow possibly due to the interaction of the radio jet with the ambient gas. We estimate a total ionized gas mass outflow rate of $\dot{M}_{\mathrm{ out}} = 25.4 ^{+11.5 }_{ -7.5}\,$ M⊙ yr−1with a kinetic power of $\dot{E} = 8.1 ^{+10.7 }_{ -4.0} \times 10^{42}\,$ erg s−1, which represents $5.8 ^{+7.6 }_{ -2.9} {{\ \rm per\ cent}}$ of the active galactic nucleus (AGN) bolometric luminosity. These values are higher than usually observed in nearby active galaxies with the same bolometric luminosities and could imply a significant impact of the outflows in the evolution of the host galaxy. The excitation is higher in the NK – that correlates with extended X-ray emission, indicating the presence of hotter gas – than in the SK, supporting a scenario in which an obscuring dust lane is blocking part of the AGN radiation to reach the southern region of the galaxy.

scholarly journals Study of the molecular gas in the central parsec of the Galaxy through regularized 3D spectroscopy

2013 ◽  
Vol 9 (S303) ◽  
pp. 83-85
Author(s):  
A. Ciurlo ◽  
T. Paumard ◽  
D. Rouan ◽  
Y. Clénet
Keyword(s):  
Molecular Gas ◽  
Imaging Data ◽  
Ionized Gas ◽  
Central Cavity ◽  
Neutral Gas ◽  
The Galaxy ◽  
Circumnuclear Disk ◽  
Cool Gas ◽  
Central Parsec ◽  
Spectro Imaging

AbstractThe cool gas in the central parsec of the Galaxy is organized in the surrounding circumnuclear disk, made of neutral gas, and the internal minispiral, composed of dust and ionized gas. In order to study the transition between them we have investigated the presence of H2 neutral gas in this area, through NIR spectro-imaging data observed with SPIFFI. To preserve the spatial resolution we implemented a new method consisting of a regularized 3D fit. We concentrated on the supposedly fully ionized central cavity and the very inner edge of the CND. H2 is detected everywhere: at the boundary of the CND and in the central cavity, where it seems to split in two components, one in the background of the minispiral and one inside the Northern arm.

scholarly journals 3D Spectroscopy of the Blue Compact Dwarf Galaxies IZw18 and IIZw70

2006 ◽  
Vol 2 (S237) ◽  
pp. 433-433
Author(s):  
C. Kehrig ◽  
J. M. Vílchez ◽  
S. F. Sanchez ◽  
L. Lopez-Martin ◽  
E. Telles ◽  
...  
Keyword(s):  
Data Cube ◽  
Ionized Gas ◽  
Data Set ◽  
Star Forming ◽  
La Palma ◽  
Integral Field Spectroscopy ◽  
Ongoing Work ◽  
Ionization Structure ◽  
Extended Object ◽  
Metal Abundances

AbstractBlue compact dwarf (BCD) galaxies are low-metallicity objects undergoing violent star formation (Searle & Sargent 1972). We present our ongoing work on integral field spectroscopy (IFS) of the two prototypical BCD galaxies IIZw70 and IZw18 (Papaderos et al. 2002). Two-dimensional spectroscopy allows us to collect simultaneously the spectra of many different regions of an extended object, combining photometry and spectroscopy in the same data set. The great advantage of using IFS for the investigation of galaxies is that it allows us to obtain data on the galaxies' positions, velocity fields and star-forming properties all in one data cube. The observations were taken with the instruments INTEGRAL/WYFFOS at the WHT (ORM, La Palma) and PMAS installed on the 3.5m telescope at the CAHA, covering a spectral range from λ 3600 to 6800 Å. The data are mainly used to study the ionized gas and stellar clusters. Our main goal is to investigate the presence of spatial variations in ionization structure indicators, physical conditions and gaseous metal abundances, in these galaxies (Vílchez & Iglesias-Páramo 1998). We also study the kinematical properties of the ionized gas, as well as systematic variations of ionization structure and physical-chemical parameters as a function of the surface-brightness in Hα emission. Maps of the relevant emission lines are presented.

scholarly journals Inflows and Outflows in Nearby AGN from Integral Field Spectroscopy

2009 ◽  
Vol 5 (S267) ◽  
pp. 290-298 ◽  
Author(s):  
Thaisa Storchi-Bergmann
Keyword(s):  
Near Infrared ◽  
Stellar Kinematics ◽  
Gas Emission ◽  
Ionized Gas ◽  
Integral Field Spectroscopy ◽  
Near Ir ◽  
Field Spectroscopy ◽  
The Galaxy ◽  
Mass Outflow ◽  
Integral Field

AbstractI report recent results on the kinematics of the inner few hundred parsecs (pc) around nearby active galactic nuclei (AGN) at a sampling of a few pc to a few tens of pc, using optical and near-infrared (near-IR) integral field spectroscopy obtained with the Gemini telescopes. The stellar kinematics of the hosts — comprised mostly of spiral galaxies — are dominated by circular rotation in the plane of the galaxy. Inflows with velocities of ~50 km s−1 have been observed along nuclear spiral arms in (optical) ionized gas emission for low-luminosity AGN and in (near-IR) molecular gas emission for higher-luminosity AGN. We have also observed gas rotating in the galaxy plane, sometimes in compact (few tens of pc) disks which may be fuelling the AGN. Outflows have been observed mostly in ionized gas emission from the narrow-line region, whose flux distributions and kinematics frequently correlate with radio flux distributions. Channel maps along the emission-line profiles reveal velocities as high as ~ 600 km s−1. Mass outflow rates in ionized gas range from 10−2 to 10−3M⊙ yr−1 and are 10–100 times larger than the mass accretion rates on to the AGN, supporting an origin for the bulk of the outflow in gas from the galaxy plane entrained by a nuclear jet or accretion disk wind.

scholarly journals A multiwavelength study of a massive, active galaxy at z ∼ 2: coupling the kinematics of the ionized and molecular gas

2019 ◽  
Vol 489 (1) ◽  
pp. 681-698 ◽  
Author(s):  
Federica Loiacono ◽  
Margherita Talia ◽  
Filippo Fraternali ◽  
Andrea Cimatti ◽  
Enrico M Di Teodoro ◽  
...  
Keyword(s):  
Near Infrared ◽  
Molecular Gas ◽  
Star Forming ◽  
Systemic Velocity ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Central Regions ◽  
Outflow Rate ◽  
Gas Consumption ◽  
Fisher Relation

ABSTRACTWe report a multiwavelength study of the massive ($M_{\star } \gtrsim 10^{11} \rm {M}_{\odot }$), z ∼ 2 star-forming galaxy GMASS 0953, which hosts an obscured AGN. We combined near-infrared observations of the GNIRS, SINFONI and KMOS spectrographs to study the kinematics of the [O  iii] λ5007 and H α emission lines. Our analysis shows that GMASS 0953 may host an ionized disc extending up to 13 kpc, which rotates at a velocity of $V_{\rm {ion}} = 203^{+17}_{-20}$  km s−1 at the outermost radius. Evidence of rotation on a smaller scale (R ∼ 1 kpc) arises from the CO(J = 6–5) line. The central velocity $V_{\rm {CO}} = 320^{+ 92}_{-53}$  km s−1 traced by the molecular gas is higher than Vion, suggesting that the galaxy harbours a multiphase disc with a rotation curve that peaks in the very central regions. The galaxy appears well located on the z = 0 baryonic Tully–Fisher relation. We also discuss the possibility that the [O  iii] λ5007 and H α velocity gradients are due to a galactic-scale wind. Besides, we found evidence of an AGN-driven outflow traced by a broad blueshifted wing affecting the [O  iii] λ5007 line, which presents a velocity offset Δv = −535 ± 152  km s−1 from the systemic velocity. Because of the short depletion time-scale (τdep ∼ 108 yr) due to gas ejection and gas consumption by star formation activity, GMASS 0953 may likely evolve into a passive galaxy. However, the role of the AGN in depleting the gas reservoir of the galaxy is quite unclear because of the uncertainties affecting the outflow rate.

scholarly journals Deep Spectroscopy of the Very Extended Ionized Gas of NGC 4388

2004 ◽  
Vol 217 ◽  
pp. 386-388
Author(s):  
Michitoshi Yoshida ◽  
M. Yagi ◽  
S. Okamura ◽  
Y. Ohyama ◽  
N. Kashikawa ◽  
...  
Keyword(s):  
Emission Line ◽  
Virgo Cluster ◽  
Ionized Gas ◽  
Shock Heating ◽  
Line Region ◽  
Systemic Velocity ◽  
Ram Pressure ◽  
The Galaxy ◽  
Solar Abundances ◽  
Extended Emission

We report here the results of deep optical spectroscopy of the very extended emission-line region (VEELR) found serendipitously around the Seyfert 2 galaxy NGC 4388 in the Virgo cluster. The Hα recession velocities of most of the filaments of the region observed are highly blue-shifted with respect to the systemic velocity of the galaxy. The velocity field is complicated, and there seem to be several streams of filaments ranging from ~ −100 km s−1 to ~ −700 km s−1 with respect to the systemic velocity of the galaxy. The emission-line ratios of the VEELR filaments are well explained by power-law photoionization models with solar abundances. In addition to photoionization, shock heating probably contributes to the ionization of the gas. We conclude that the VEELR was formerly the disk gas of NGC 4388, which has been stripped by ram pressure due to the interaction between the hot intra-cluster medium (ICM) and the galaxy.

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