scholarly journals The nuclear architecture of NGC 4151: on the path toward a universal outflow mechanism in light of NGC 1068

2020 ◽  
Vol 496 (2) ◽  
pp. 1488-1516
Author(s):  
D May ◽  
J E Steiner ◽  
R B Menezes ◽  
D R A Williams ◽  
J Wang
Keyword(s):  
High Velocity ◽  
Near Infrared ◽  
Nuclear Architecture ◽  
Low Velocity ◽  
Ionized Gas ◽  
Gas Phases ◽  
Ngc 4151 ◽  
Molecular Outflow ◽  
Ngc 1068 ◽  
The Difference

ABSTRACT We report near-infrared integral field spectroscopic observations of the active galactic nucleus NGC 4151 with archive data from the NIFS-Gemini North Telescope. We have selected best-seeing observations (≲0.3 arcsec) that, allied to our methodology of image processing techniques, show structures with spatial resolution comparable to those of the HST. The intricate outflow of NGC 4151 is revisited in light of the results found for NGC 1068, in a previous work, and a very similar dynamic is found: the low-velocity [Fe ii] emission depicts the glowing walls of an hourglass structure, while the high-velocity gas fills its volume. From this finding, we show that the misalignment between the jet and the NLR is not a projection effect, as previously thought. A molecular outflow is detected for the first time in this galaxy and, just like in NGC 1068, the transition between the molecular and the ionized gas phases comes from the fragmentation of molecular cavity walls into bullets of ionized gas exposed to the central source. Furthermore, it is suggestive that the same geometrical dichotomy between the cones seen in NGC 1068 is found here, with one side, where the cavity is disrupted by the AGN, being more extended than the other. Finally, a new spatial correlation between the high-velocity [Fe ii] and the soft X-ray emission of [Ne ix] is found, which is unexpected given the difference between their ionization potentials.

On the path toward a universal outflow mechanism in light of NGC 4151 and NGC 1068

2020 ◽  
Vol 15 (S359) ◽  
pp. 283-284
Author(s):  
D. May ◽  
J. E. Steiner ◽  
R. B. Menezes
Keyword(s):  
Near Infrared ◽  
Feedback Mechanism ◽  
Data Cube ◽  
Low Velocity ◽  
Ionized Gas ◽  
Ngc 4151 ◽  
Molecular Outflow ◽  
Ngc 1068 ◽  
Field Unit ◽  
First Time

AbstractWe use near-infrared Integral Field Unit (IFU) data to analyze the galaxies NGC 4151 and NGC 1068, which have very different Eddington ratios - ˜50 times lower for NGC 4151. Together with a detailed data cube treatment methodology, we reveal remarkable similarities between both AGN, such as the detection of the walls of an “hourglass” structure for the low-velocity [Fe ii] emission with the high-velocity emission within this hourglass; a molecular outflow - detected for the first time in NGC 4151; and the fragmentation of an expanding molecular bubble into bullets of ionized gas. Such observations suggest that NGC 4151 could represent a less powerful and more compact version of the outflow seen in NGC 1068, suggesting a universal feedback mechanism acting in quite different AGN.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

2021 ◽  
pp. 1-7
Author(s):  
Mercè Torra ◽  
Eduard Pujol ◽  
Anna Maiques ◽  
Salvador Quintana ◽  
Roser Garreta ◽  
...  
Keyword(s):  
High Velocity ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Low Velocity ◽  
Wrist Extensor ◽  
Submaximal Effort ◽  
The Difference ◽  
Muscle Groups ◽  
Maximal Effort ◽  
Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

scholarly journals The Molecular Outflow and CO Bullets in HH111

1997 ◽  
Vol 182 ◽  
pp. 141-152 ◽  
Author(s):  
J. Cernicharo ◽  
R. Neri ◽  
Bo Reipurth
Keyword(s):  
High Velocity ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Kinetic Temperature ◽  
Low Velocity ◽  
Molecular Outflow ◽  
Hh Objects ◽  
Physical Phenomena ◽  
First Time

We present high angular resolution observations of the molecular outflow associated with the optical jet and HH objects of the HH111 system. Interferometric observations in the CO J =2–1 and J =1–0 lines of the high velocity bullets associated with HH111 are presented for the first time. The molecular gas in these high velocity clumps has a moderate kinetic temperature and a mass of a few 10–4 M⊙ per bullet. We favor the view that HH jets and CO bullets, which represent different manifestations of the same physical phenomena, are driving the low-velocity molecular outflow.

scholarly journals Velocity Offsets Due to Mass Outflows in Active Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 387-392
Author(s):  
D. M. Crenshaw ◽  
S. B. Kraemer ◽  
H. R. Schmitt ◽  
R. F. Mushotzky ◽  
J. P. Dunn
Keyword(s):  
Seyfert Galaxies ◽  
Emission Lines ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Ionized Gas ◽  
Ngc 4151 ◽  
Spatially Resolved ◽  
Mass Outflow ◽  
Ngc 1068 ◽  
Narrow Emission

AbstractWe present a study of the radial velocity offsets between AGN-related narrow emission lines and host-galaxy emission and absorption lines in Seyfert galaxies with observed redshifts less than 0.043. We find that 35% of the Seyferts in the sample show [O iii] emission lines with blueshifts with respect to their host galaxies exceeding 50 km s−1, whereas only 6% show redshifts this large, in qualitative agreement with most previous studies. We also find that a greater percentage of Seyfert 1 galaxies show blueshifts than Seyfert 2 galaxies. Using HST/STIS spatially-resolved spectra of the Seyfert 2 galaxy NGC 1068 and the Seyfert 1 galaxy NGC 4151, we generate geometric models of their narrow-line regions (NLRs) and inner galactic disks and show how these models can explain the blueshifted [O iii] emission lines in collapsed STIS spectra of these two Seyferts. We conclude that the combination of mass outflow of ionized gas in the NLR and extinction by dust in the inner disk (primarily in the form of dust spirals) is primarily responsible for the velocity offsets in Seyfert galaxies.

scholarly journals Mid-Infrared Forbidden Lines of NGC 1068, NGC 4151, and NGC 5506

1997 ◽  
Vol 159 ◽  
pp. 308-309
Author(s):  
M.A. Greenhouse ◽  
T.L. Hayward ◽  
S. Satyapal ◽  
D.H. Wooden ◽  
J.W. Miles ◽  
...  
Keyword(s):  
Near Infrared ◽  
Seyfert Galaxies ◽  
Line Profiles ◽  
Mid Infrared ◽  
Ngc 4151 ◽  
Faint Object ◽  
Excitation Potential ◽  
Ngc 1068 ◽  
Infrared Array ◽  
Faint Object Spectrograph

We report near-infrared spectroscopy of three Seyfert galaxies. Velocity resolved spectra covering low excitation-potential transitions of [Ar III] 8.991 µm, [S IV] 10.514 µm, and [Ne II] 12.813 µm were obtained using the facility mid-infrared array spectrometer (SpectroCam) of the Palomar Observatory Hale 5-m Telescope, and low-resolution spectra covering [Mg V] 5.608 µm, [Ar II] 6.985 µm, and [Ne VI] 7.642 µm were obtained using the faint-object spectrograph (HIFOGS) of the Kuiper Airborne Observatory (KAO).We find high contrast [Ar III] and [S IV] in each galaxy, and [Ne II] in NGC 1068 and NGC 4151 (12.8 µm data were not obtained on NGC 5506). The line profiles are well resolved. In NGC 1068 and NGC 4151, they are fit by singlecomponent Gaussians. However, in NGC 5506, evidence for a broad pedestal is seen in the [Ar III] and [S IV] spectra, similar to the broad Paβ component reported by Blanco et al. (1990) and Rix et al. (1990).

scholarly journals Velocities Within 1 Arcsec of the Nucleus of NGC 4151 as Revealed by the HST Faint Object Camera

1994 ◽  
Vol 159 ◽  
pp. 441-441
Author(s):  
R.M. Catchpole ◽  
A. Boksenberg ◽  
Keyword(s):  
Velocity Component ◽  
High Velocity ◽  
Hubble Space Telescope ◽  
Position Angle ◽  
Emission Lines ◽  
Low Velocity ◽  
Strong Emission ◽  
Ngc 4151 ◽  
Zero Velocity ◽  
Faint Object

We have obtained a longslit spectrum at a position angle (PA) of 84.6° and passing within 0.38 arcsec of the nucleus of NGC 4151, using the FOC f/48 camera on the Hubble Space Telescope. The spectrum shows strong emission lines including [OII] λ 3727 and [OIII] λλ 4959, 5007. By fitting with Gaussian velocity profiles, we resolve the emission lines, within 1 arcsec of the nucleus, into a high and low velocity component. The low velocity component has a total range in radial velocity of 200 km s−1 and appears to be associated with material comprising the knots seen in the FOC, F501N [O III] image of NGC 4151, illustrated in Boksenberg (1993). The much weaker high velocity system has a range of 1000 km s−1, is more smoothly distributed in brightness and shows a peak brightness close to the nucleus. Because the slit did not intersect the nucleus it is possible to determine the PA at which the two velocity systems cross the zero velocity axis. This is at PA −26° for the low velocity system and PA +32° for the high velocity system. These PA values may be subject to a systematic error as the zero velocity is defined by the mean position of the line, in the absence of any external calibration.

NOTES ON REFRACTION PROSPECTING

Geophysics ◽  
1941 ◽  
Vol 6 (4) ◽  
pp. 378-396 ◽  
Author(s):  
Charles Hewitt Dix
Keyword(s):  
High Velocity ◽  
Linear Increase ◽  
Linear Velocity ◽  
Relative Depth ◽  
Low Velocity ◽  
Velocity Section ◽  
Air Interface ◽  
Machine Calculation ◽  
The Difference ◽  
Refraction Data

This is a series of notes dealing with several aspects of the problem of the interpretation of refraction data. A method of dealing with unreversed refraction lines is outlined. The case of a high velocity section with an overburden having a linear increase of velocity with depth is discussed. We show how the accuracy of the relative depth calculations depends upon the difference between the upper and lower velocities at the interface in question. A method of computing tables for the linear velocity depth case is given which is well adapted to machine calculation. Finally, reflections at the ground‐air interface and the formation of shadows by such obstacles as high or low velocity layers are considered.

scholarly journals The Phase Structure of the ISM in Galaxies

2009 ◽  
Vol 5 (H15) ◽  
pp. 409-410
Author(s):  
Mark G. Wolfire
Keyword(s):  
Molecular Clouds ◽  
Phase Distribution ◽  
Low Velocity ◽  
Ionized Gas ◽  
Gas Phases ◽  
Physical Conditions ◽  
Neutral Gas ◽  
The Galaxy ◽  
Transient Phases

AbstractDiffuse gas in the Galaxy is observed to exist as cold (T ~ 100 K) neutral atomic gas (CNM) and warm neutral atomic (T ~ 8000 K) gas (WNM). In addition to these “thermal” phases, gas can also exist as warm (T ~ 8000 K) ionized gas, cold (T ~ 10 K) molecular gas and in warm (T ~ 100 - 500 K) interface regions or Photodissociation Regions (PDRs) on the surfaces of molecular clouds. The same chemical and thermal processes that dominate in the PDRs associated with molecular clouds are also at work in the diffuse neutral gas. Two additional “phases” are gas associated with GMCs that has H2 but no or little CO, and short lived or transient phases such as shocks, shears, and turbulence. I will first review the different gas phases in the Galaxy, their physical conditions and their dominant cooling lines. I will also discuss the observations and theoretical modeling in support of turbulence versus thermal instability as the driving force in producing the “thermal” gas phase distributions. Rough estimates for the distribution of phases in the Galaxy and the origin of the dominant emission lines has been conducted by previous telescopes (e.g., COBE, BICE) but with low velocity and low spectral resolution. The distribution and mass of the various gas phases is important for sorting out the role of SN in setting ISM pressures and in driving ISM turbulence. In addition, understanding the Galactic phase distribution is important in interpreting observations of extragalactic systems in which beams encompass several emission components. I will review the potential for future observations by e.g., STO, SOFIA, and Herschel to detect and separate phases in Galactic and extragalactic systems.

scholarly journals Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 122
Author(s):  
Irina Medved ◽  
Elena Bataleva ◽  
Michael Buslov
Keyword(s):  
Seismic Tomography ◽  
High Velocity ◽  
Fault Zones ◽  
Magnetotelluric Sounding ◽  
Tien Shan ◽  
High Resistivity ◽  
Low Velocity ◽  
Low Resistivity ◽  
Velocity Models ◽  
Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

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