scholarly journals Spectropolarimetry of the superwind filaments of the starburst galaxy M 82 II: Kinematics of the dust surrounding the nuclear starburst†

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Michitoshi Yoshida ◽  
Koji S Kawabata ◽  
Youichi Ohyama ◽  
Ryosuke Itoh ◽  
Takashi Hattori
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Position Angle ◽  
Polarization Degree ◽  
Starburst Galaxy ◽  
Molecular Gas ◽  
Light Sources ◽  
Systemic Velocity ◽  
The Galaxy ◽  
Hα Emission

Abstract We performed deep spectropolarimetric observations of the prototypical starburst galaxy M 82 with the Subaru Telescope in order to study the kinematics of the dust outflow. We obtained optical polarized emission-line spectra up to ∼4 kpc away from the nucleus of the galaxy along three position angles, 138°, 150°, and 179° within the conical outflowing wind (superwind). The Hα emission line in the superwind is strongly polarized and the polarization pattern shows dust scattering of central light sources, being consistent with the previous works. The intensity weighted polarization degree of the Hα line reaches ∼30% at maximum. There are at least two light sources at the central region of the galaxy; one is located at the near-infrared nucleus and the other resides at one of the peaks of the 3 mm radio and molecular gas emission. The outer (>1 kpc) dust is illuminated by the former, whereas the inner dust is scattering the light from the latter. We also investigated the dust motion from the velocity field of the polarized Hα emission line. The dust is accelerated outward on the northwest side of the nucleus. A simple bi-conical dust outflow model shows that the outflow velocity of the dust reaches ≳ 300–450 km s−1 at ∼4 kpc from the nucleus, suggesting that some portion of the dust escapes from the gravitational potential of M 82 into the intergalactic space. At some regions on the southeast side, in particular along the position angle of 138°, the dust has a radial velocity that is slower than the systemic velocity of the galaxy, apparently suggesting inflowing motion toward the nucleus. These components are spatially consistent with a part of the molecular gas stream, which is kinematically independent of the outflow gas; thus the apparent inflow motion of the dust reflects the streaming motion associated with the molecular gas stream.

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 Study of a Complete Sample of Hα Emission–Line Galaxies from the UCM Survey

1996 ◽  
Vol 171 ◽  
pp. 380-380 ◽  
Author(s):  
J. Gallego ◽  
J. Zamorano ◽  
M. Rego ◽  
A.G. Vitores ◽  
O. Alonso
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Energy Output ◽  
University Of Michigan ◽  
Complete Sample ◽  
Star Forming ◽  
The Galaxy ◽  
Hα Emission ◽  
Emission Line Galaxies ◽  
Galaxy Population

The Universidad Complutense de Madrid survey is a long-term project with the aim of finding and analyzing star forming galaxies using the Hα line as the tracer for star formation processes. In order to obtain a representative and complete sample of the population detected, spectroscopic observations were carried out for the full sample of Hα emission-line galaxy (ELG) candidates of the UCM lists 1 and 2. The ELGs types most commonly found (47%) are intermediate to low-luminosity objects with a very intense star-formation region which dominates the optical energy output of the galaxy. This kind of ELGs is similar to the galaxy population detected in the blue objective-prism surveys. And what is more important, a second population (43%) of star-forming galaxies with low ionization or high extinction properties has been found. This ELGs group is detected neither in the blue (University of Michigan survey, Case survey) nor in other surveys (Kiso, IRAS, Markarian) using other selection techniques.

scholarly journals Nuclear molecular gas in the Virgo Cluster S0 galaxy NGC 4710

1993 ◽  
Vol 153 ◽  
pp. 439-440
Author(s):  
J.M. Wrobel ◽  
J.D.P. Kenney
Keyword(s):  
Interstellar Medium ◽  
Emission Line ◽  
Optical Emission ◽  
Virgo Cluster ◽  
Gas Analysis ◽  
Molecular Gas ◽  
Star Forming ◽  
The Galaxy

The CO(J=1→0) emission from NGC 4710, a star–forming S0 galaxy in the Virgo Cluster, was synthesized with spatial and velocity resolutions of 7″ and 26 km s—1, respectively. The CO shows a compact morphology and co–rotates with the galaxy's stars and nuclear optical emission line gas. Analysis of the CO distribution and kinematics indicates that the nuclear molecular gas is probably gravitationally unstable, and this may explain why the galaxy is presently forming stars. Four possible origins for the nuclear molecular gas are considered. An origin via bulge star ejecta being deposited into a residual interstellar medium is favored.

scholarly journals Near-infrared observations of star formation and gas flows in the NUGA galaxy NGC 1365

2019 ◽  
Vol 622 ◽  
pp. A128 ◽  
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Mónica Valencia-S. ◽  
Andreas Eckart ◽  
Michal Zajaček ◽  
...  
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Near Infrared ◽  
Molecular Gas ◽  
Nuclear Region ◽  
Stellar Kinematics ◽  
Hydrogen Recombination ◽  
Ngc 1365

In the framework of understanding the gas and stellar kinematics and their relations to AGNs and galaxy evolution scenarios, we present spatially resolved distributions and kinematics of the stars and gas in the central ∼800 pc radius of the nearby Seyfert galaxy NGC 1365. We obtained H + K- and K-band near-infrared (NIR) integral-field observations from VLT/SINFONI. Our results reveal strong broad and narrow emission-line components of ionized gas (hydrogen recombination lines Paα and Brγ) in the nuclear region, as well as hot dust with a temperature of ∼1300 K, both typical for type-1 AGNs. From MBH − σ* and the broad components of hydrogen recombination lines, we find a black-hole mass of (5 − 10)×106 M⊙. In the central ∼800 pc, we find a hot molecular gas mass of ∼615 M⊙, which corresponds to a cold molecular gas reservoir of (2 − 8)×108 M⊙. However, there is a molecular gas deficiency in the nuclear region. The gas and stellar-velocity maps both show rotation patterns consistent with the large-scale rotation of the galaxy. However, the gaseous and stellar kinematics show deviations from pure disk rotation, which suggest streaming motions in the central < 200 pc and a velocity twist at the location of the ring which indicates deviations in disk and ring rotation velocities in accordance with published CO kinematics. We detect a blueshifted emission line split in Paα, associated with the nuclear region only. We investigate the star-formation properties of the hot spots in the circumnuclear ring which have starburst ages of ≲10 Myr and find indications for an age gradient on the western side of the ring. In addition, our high-resolution data reveal further substructure within this ring which also shows enhanced star forming activity close to the nucleus.

scholarly journals A spectroscopic study of the low redshift dwarf galaxy SDSS J134326.99+431118.7 to calculate star formation rate

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 100-107
Author(s):  
Daya Nidhi Chhatkuli ◽  
Sanjaya Paudel ◽  
Binil Aryal
Keyword(s):  
Star Formation ◽  
Spectroscopic Study ◽  
Emission Line ◽  
Star Formation Rate ◽  
Dwarf Galaxy ◽  
Formation Rate ◽  
Flux Ratio ◽  
Starburst Galaxy ◽  
Characteristic Lines ◽  
The Galaxy

We present a spectroscopic study of an interacting emission-line dwarf galaxy SDSS J134326.99+431118.7. We analyzed eight-strong emission lines of wavelength in a range of 3902.1Å to 6619.1Å. Among them, the strongest emission line is OIII, with an intensity of 1043.6 x 10-17 erg/s/cm2/Å. These characteristic lines show a perfect Gaussian fit with a coefficient of regression greater than 98%, where the derived full width half maximum (FWHM) is less than 3.8 Å. The line ratio between Ha  and Hb, (Ha/ Hb), is  2.73. This suggests that the galaxy is a starburst galaxy. Star Formation Rate (SFR) of the galaxy derived from Ha  emission line flux is 0.019  and emission line metallicity derived from flux ratio between NII and Ha is 7.85 dex. These morphological and physical properties of SDSSJ134326.99+431118.7 are very similar to those of a typical Blue Compact Dwarf (BCD) galaxy. We conclude that we have presented another evidence of forming a BCD-type galaxy through a merger. BIBECHANA 18 (2021) 100-107

scholarly journals Outflows in the Seyfert 2 galaxy NGC 5643 traced by the [S iii] emission

2018 ◽  
Vol 35 ◽  
Author(s):  
Rogemar A. Riffel ◽  
C. Hekatelyne ◽  
Izabel C. Freitas
Keyword(s):  
Emission Line ◽  
Flux Distribution ◽  
Major Axis ◽  
Position Angle ◽  
Stellar Kinematics ◽  
The Galaxy ◽  
Stellar Velocity ◽  
Outflow Rate ◽  
Field Unit ◽  
East West

AbstractWe use Gemini Multi-Object Spectrograph integral Field Unit observations of the inner 285 × 400 pc2 region of the Seyfert 2 galaxy NGC 5643 to map the [S iii]λ9069 emission line flux distribution and kinematics, as well as the stellar kinematics, derived by fitting the Ca iiλλλ8498,8542,8662 triplet, at a spatial resolution of 45 pc. The stellar velocity field shows regular rotation, with a projected velocity of 100 km s−1 and kinematic major axis along a position angle of –36°. A ring of low stellar velocity dispersion values (∼70 km s−1), attributed to young/intermediate age stellar populations, is seen surrounding the nucleus with a radius of 50 pc. We found that the [S iii] flux distribution shows an elongated structure along the east–west direction and its kinematics is dominated by outflows within a bi-cone at an ionised gas outflow rate of 0.3 M⊙ yr−1. In addition, velocity slices across the [S iii]λ9069 emission line reveal a kinematic component attributed to rotation of gas in the plane of the galaxy.

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.

scholarly journals Starburst galaxy NGC 7673: a minor merger remnant

1999 ◽  
Vol 193 ◽  
pp. 743-744
Author(s):  
Nicole L. Homeier ◽  
John S. Gallagher
Keyword(s):  
Rotating Disk ◽  
Starburst Galaxy ◽  
Stellar Winds ◽  
H Ii Regions ◽  
Irregular Galaxy ◽  
Narrow Component ◽  
Broad Component ◽  
The Galaxy ◽  
Hα Emission ◽  
A Minor

We investigate the kinematics of the luminous starburst galaxy NGC 7673 = Mrk 325, a nearby example of a ‘clumpy irregular galaxy’. Images with the WIYN 3.5m telescope reveal outer wisps associated with mergers, and we suggest NGC 7673 is the survivor of a minor merger. DensePak spectroscopy of the Hα kinematics shows that the H II regions are confined to a rotating disk. The Hα emission line velocity field indicates that although there is widespread star formation across the inner disk, it is still rotating smoothly. The Hα emission profiles over the brightest regions of the galaxy have two components: narrow, FWHM ≈ 50kms−1 lines, and broad, FWHMW ≈ 150 km s−1 lines. The width of the narrow lines is likely due to a combination of averaging effects, stellar winds and SNRs, and possibly gravitational motions within the disk. The origin of the broad component, which eclipses the narrow component in flux over much of the galaxy's inner regions, is still unclear. We may be looking at turbulent gas encased in bubbles carved out by massive stars and their descendants, or possibly some localized outflows from the disk.

The birth of an AGN: NGC 4111

2020 ◽  
Vol 15 (S359) ◽  
pp. 362-363
Author(s):  
Gabriel R. H. Roier ◽  
Thaisa Storchi-Bergmann
Keyword(s):  
Near Infrared ◽  
Dwarf Galaxy ◽  
Molecular Gas ◽  
Stellar Kinematics ◽  
Gas Kinematics ◽  
Integral Field Spectroscopy ◽  
Optical Images ◽  
Counter Rotation ◽  
The Galaxy ◽  
Nearby Galaxies

AbstractWe have used near-infrared and optical Integral Field Spectroscopy along with optical images to study the inner 100 pc of NGC 4111 in a project to investigate the stellar and gas kinematics in the surroundings of Supermassive Black Holes in nearby galaxies. We have compared the inner stellar and gas kinematics with data of the outer regions of the galaxy. We found larger scale hot ionized gas and warm molecular gas within the inner 100 pc that is in counter-rotation relative to the stellar kinematics, a sign of inflowing material that is probably triggering an Active Galactic Nucleus. This is supported by the nuclear X-ray emission which is heating the molecular gas and causing it to emit. The presence of large amounts of dust in a polar ring suggests that this is a fairly recent event probably due to the capture of a dwarf galaxy.

scholarly journals Near-IR Integral Field Spectroscopy of the central region of NGC 5929

2014 ◽  
Vol 10 (S309) ◽  
pp. 339-339
Author(s):  
Rogemar A. Riffel ◽  
Thaisa Storchi-Bergmann ◽  
Rogério Riffel
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Line Emission ◽  
Linear Structure ◽  
Emission Lines ◽  
Line Profiles ◽  
Gas Kinematics ◽  
Systemic Velocity ◽  
Integral Field Spectrograph ◽  
Integral Field

AbstractWe present two-dimensional (2D) near-infrared spectra of the inner 300×300 pc2 of the Seyfert 2 galaxy NGC 5929 at a spatial resolution of ~20 pc obtained with the Gemini Near infrared Integral Field Spectrograph (NIFS). We present 2D maps for the emission line flux distributions and kinematics and report the discovery of a linear structure ~300 pc in extent and of ~50 pc in width oriented perpendicular to the radio jet, showing broadened emission-line profiles.While over most of the field the emission-line profiles have full-widths-at-half-maximum (FWHM) of ~210 km/s, at a linear structure perpendicular do the radio jet the emission-line FWHMs are twice this value, and are due to two velocity components, one blueshifted and the other redshifted relative to the systemic velocity. We attribute these velocities to an outflow from the nucleus which is launched perpendicular to the radio jet. We reported the detection of this peculiar outflow in Riffel, Storchi-Bergmann & Riffel (2014a), where more details of the analysis can be found. Since, NGC 5929 has a Type 2 nucleus, this detection implies that: (1) both ionizing radiation and relativistic particles are escaping through holes in the torus perpendicular to the radio jet; and/or (2) the torus is also outflowing, as proposed by recent models of tori as winds from the outer parts of an accretion flow; or (3) the torus is absent in NGC 5929.At other locations the gas kinematics is dominated by rotation in a disk, although some evidences of interaction of the radio jet with the emitting gas are seen as a broadening of the line profiles at the locations of the radio structures.The flux distributions for the [P ii], [Fe ii], H i and H2 emission lines show that the line emission is more extended along the PA = 60/240^, extending to up to 1.5” to both sides of the nucleus, while to the perpendicular direction (PA = -30/150^) the emission is extended to 0.7” from the nucleus. The flux distributions of all emission lines show a good correlation with radio the radio structures, with the two peak of emission associated to the soutwestern and northeastern radio knots. Some differences are observed among distinct emission lines. While the [Fe ii] and H2 emission peak at the location of the soutwestern radio structure at 0.6” from the nucleus, the H i recombination lines present the their highest fluxes at the location of the northeastern radio hotspot at 0.5” from the nucleus. Another difference is that the H2 emission is less collimated than that for other lines, being more extended perpendicularly to the radio jet. A detailed analysis of the line emission and kinematics will be presented in Riffel, Storchi-Bergmann & Riffel (2014b).

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