370 research outputs found
An outflow perpendicular to the radio jet in the Seyfert nucleus of NGC5929
We report the observation of an outflow perpendicular to the radio jet in
near-infrared integral field spectra of the inner 250 pc of the Seyfert 2
galaxy NGC 5929. The observations were obtained with the Gemini Near infrared
Integral Field Spectrograph at a spatial resolution of ~20 pc and spectral
resolution R~5300 and reveal a region 50 pc wide crossing the nucleus and
extending by 300 pc perpendicularly to the known radio jet in this galaxy.
Along this structure - which we call SE-NW strip - the emission-line profiles
show two velocity components, one blueshifted and the other redshifted by -150
km/s and 150 km/s, respectively, relative to the systemic velocity. We
interpret these two components as due to an outflow perpendicular to the radio
jet, what is supported by low frequency radio emission observed along the same
region. We attribute this feature to the interaction of ambient gas with an
"equatorial outflow" predicted in recent accretion disk and torus wind models.
Perpendicularly to the SE-NW strip, thus approximately along the radio jet,
single component profiles show blueshifts of ~-150 km/s to the north-east and
similar redshifts to the south-west, which can be attributed to gas
counter-rotating relative to the stellar kinematics. More double-peaked
profiles are observed in association with the two radio hot-spots, attributed
to interaction of the radio jet with surrounding gas.Comment: Accepted for publication in ApJL; 5 page
Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk79
We have mapped the gaseous kinematics and the emission-line flux
distributions and ratios from the inner ~680pc radius of the Seyfert 1 galaxy
Mrk79, using two-dimensional (2D) near-IR J- and Kl-band spectra obtained with
the Gemini instrument NIFS at a spatial resolution of ~100pc and velocity
resolution of ~40km/s. The molecular hydrogen flux distribution presents two
spiral arms extending by ~700pc, one to the north and another to the south of
the nucleus, with an excitation indicating heating by X-rays from the central
source. The low velocity dispersion (sigma~50km/s) and rotation pattern
supports a location of the H2 gas in the disk of the galaxy. Blueshifts
observed along the spiral arm in the far side of the galaxy and redshifts in
the spiral arm in the near side, suggest that the spiral arms are feeding
channels of H2 to the inner 200pc. From channel maps along the H2 l2.1218um
emission-line profile we estimate a mass inflow rate of ~4E-3 M_Sun/year, which
is one order of magnitude smaller than the mass accretion rate necessary to
power the AGN of Mrk79. The emission from the ionized gas (traced by Pabeta and
[FeII]l1.2570um emission lines) is correlated with the radio jet and with the
narrow-band [OIII] flux distribution. Its kinematics shows both rotation and
outflows to the north and south of the nucleus. The ionized gas mass outflow
rate through a cross section with radius ~320pc located at a distance of ~455pc
from the nucleus is 3.5 MSun/year, which is much larger than the AGN mass
accretion rate, indicating that most of the outflowing gas originates in the
interstellar medium surrounding the galaxy nucleus, which is pushed away by a
nuclear jet.Comment: Accepted by MNRA
Outflows, Inflows and Young Stars in the inner 200 pc of the Seyfert galaxy NGC 2110
We present a two-dimensional mapping of stellar population age components,
emission-line fluxes, gas excitation and kinematics within the inner
pc of the Seyfert 2 galaxy NGC 2110. We used the Gemini North Integral Field
Spectrograph (NIFS) in the J and K bands at a spatial resolution of
pc. The unresolved nuclear continuum is originated in combined contributions of
young stellar population (SP; age Myr), a featureless AGN continuum
and hot dust emission. The young-intermediate SP (age Myr) is
distributed in a ring-shaped structure at pc from the nucleus,
which is roughly coincident with the lowest values of the stellar velocity
dispersion. In the inner pc the old SP (age Gyr) is dominant.
The [FeII]1.25m emission-line flux distribution is correlated with the
radio emission and its kinematics comprise two components, one from gas
rotating in the galaxy plane and another from gas in outflow within a bicone
oriented along north-south. These outflows seem to originate in the interaction
of the radio jet with the ambient gas producing shocks that are the main
excitation mechanism of the [FeII] emission. We estimate: (1) an ionized gas
mass outflow rate of M/yr at 70 pc from the nucleus;
and (2) a kinetic power for the outflow of only 0.05% of the AGN bolometric
luminosity implying weak feedback effect on the galaxy.Comment: Accepted for publication in MNRA
PROFIT: a new alternative for emission-line PROfile FITting
I briefly describe a simple routine for emission-line profiles fitting by
Gaussian curves or Gauss-Hermite series. The PROFIT (line-PROfile FITting)
routine represent a new alternative for use in fits data cubes, as those from
Integral Field Spectroscopy or Fabry-Perot Interferometry, and may be useful to
better study the emission-line flux distributions and gas kinematics in
distinct astrophysical objects, such as the central regions of galaxies and
star forming regions. The PROFIT routine is written in IDL language and is
available at http://www.ufsm.br/rogemar/software.html.
The PROFIT routine was used to fit the [Fe II]1.257um emission-line profiles
for about 1800 spectra of the inner 350 pc of the Seyfert galaxy Mrk1066
obtained with Gemini NIFS and shows that the line profiles are better
reproduced by Gauss-Hermite series than by the commonly used Gaussian curves.
The two-dimensional map of the h_3 Gauss-Hermite moment shows its highest
absolute values in regions close to the edge of the radio structure. These high
values may be originated in an biconical outflowing gas associated with the
radio jet - previously observed in the optical [O III] emission. The analysis
of this kinematic component indicates that the radio jet leaves the center of
the galaxy with the north-west side slightly oriented towards us and the
south-east side away from us, being partially hidden by the disc of the galaxy.Comment: Accepted for publication Astrophysics & Space Science - 7 pges; 4
Fig
The fiftieth anniversary of physics at UFSM: a gender analysis of graduates
The Federal University of Santa Maria (UFSM - Universidade Federal de Santa
Maria) has trained more than 600 undergraduate and 200 Ph.D. students, becoming
a reference in physics training at the Rio Grande do Sul central region. In
this work we present a gender analysis of the UFSM graduated students from both
levels. The number of graduated students of the female gender has been rising
with time and is significatively bigger than the number observed nationally in
both levels. The mean values are 35%, 37%, 28%, 42% e 39% for the courses
physics teaching (daytime), physics teaching (nightime), physics, master and
doctorate, respectively. We also observe an increase in the participation of
female students in graduate courses, when comparing to undergraduate courses,
unlike what is observed in the national average numbers. Considering only the
last 5 years the number of graduated students reaches 50% in the physics
teaching (daytime) and master courses. Although this study is of a local
nature, it reinforces the need for the dissemination of data regarding the
gender of graduates by all universities, allowing to conduct general gender
studies.Comment: Main text in Portuguese; Published in Ci\^encia e Natura
(https://periodicos.ufsm.br/cienciaenatura/article/view/31793
Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk 766
We have mapped the emission-line flux distributions and ratios as well as the
gaseous kinematics of the inner 450 pc radius of the Seyfert 1 galaxy Mrk 766
using integral field near-IR J- and Kl-band spectra obtained with the Gemini
nifs at a spatial resolution of 60 pc and velocity resolution of 40 km/s.
Emission-line flux distributions in ionized and molecular gas extend up to ~
300 pc from the nucleus. Coronal [S IX]{\lambda}1.2523{\mu}m line emission is
resolved, being extended up to 150 pc from the nucleus. At the highest flux
levels, the [Fe II]{\lambda}1.257{\mu}m line emission is most extended to the
south-east, where a radio jet has been observed.The emission-line ratios [Fe
II]{\lambda}1.2570{\mu}m/Pa{\beta} and {\lambda}2.1218{\mu}m/Br{\gamma}
show a mixture of Starburst and Seyfert excitation; the Seyfert excitation
dominates at the nucleus, to the north-west and in an arc-shaped region between
0.2" and 0.6" to the south-east at the location of the radio jet. A
contribution from shocks at this location is supported by enhanced [Fe II]/[P
II] line ratios and increased [Fe II] velocity dispersion. The gas velocity
field is dominated by rotation that is more compact for than for
Pa{\beta}, indicating that the molecular gas has a colder kinematics and is
located in the galaxy plane. There is about solar masses of hot ,
implying ~ solar masses of cold molecular gas. At the location of the
radio jet, we observe an increase in the [Fe II] velocity dispersion (150
km/s), as well as both blueshift and redshifts in the channel maps, supporting
the presence of an outflow there. The ionized gas mass outflow rate is
estimated to be ~ 10 solar masses/yr, and the power of the outflow ~ 0.08
Intermediate age stars as origin of the low velocity dispersion nuclear ring in Mrk1066
We report the first two-dimensional stellar population synthesis in the
near-infrared of the nuclear region of an active galaxy, namely Mrk1066.
We have used integral field spectroscopy with adaptive optics at the Gemini
North Telescope to map the to map the age distribution of the stellar
population in the inner 300 pc at a spatial resolution of 35 pc. An old stellar
population component (age >5Gyr) is dominant within the inner ~160pc, which we
attribute to the galaxy bulge. Beyond this region, up to the borders of the
observation field (~300 pc), intermediate age components (0.3-0.7Gyr) dominate.
We find a spatial correlation between this intermediate age component and a
partial ring of low stellar velocity dispersions (sigma). Low-sigma nuclear
rings have been observed in other active galaxies and our result for Mrk1066
suggests that they are formed by intermediate age stars. This age is consistent
with an origin for the low-sigma rings in a past event which triggered an
inflow of gas and formed stars which still keep the colder kinematics (as
compared to that of the bulge) of the gas from which they have formed. At the
nucleus proper we detect, in addition, two unresolved components: a compact
infrared source, consistent with an origin in hot dust with mass ~1.9x10^{-2}
M_Sun, and a blue featureless power-law continuum, which contributes with only
~15% of the flux at 2.12 microns.Comment: 6 pages, 2 figs, accepted by Ap
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