533 research outputs found
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
Disentangling the near infrared continuum spectral components of the inner 500 pc of Mrk 573: two-dimensional maps
We present a near infrared study of the spectral components of the continuum
in the inner 500500 pc of the nearby Seyfert galaxy Mrk573 using
adaptive optics near-infrared integral field spectroscopy with the instrument
NIFS of the Gemini North Telescope at a spatial resolution of 50 pc. We
performed spectral synthesis using the {\sc starlight} code and constructed
maps for the contributions of different age components of the stellar
population: young ( Myr), young-intermediate (
Myr), intermediate-old ( Myr Gyr) to the
near-IR K-band continuum, as well as their contribution to the total stellar
mass. We found that the old stellar population is dominant within the inner 250
pc, while the intermediate age components dominate the continuum at larger
distances. A young stellar component contributes up to 20% within the
inner 70 pc, while hot dust emission and featureless continuum components
are also necessary to fit the nuclear spectrum, contributing up to 20% of the
K-band flux there. The radial distribution of the different age components in
the inner kiloparsec of Mrk573 is similar to those obtained by our group for
the Seyfert galaxies Mrk1066, Mrk1157 and NGC1068 in previous works using a
similar methodology. Young stellar populations (100 Myr) are seen in the
inner 200-300 pc for all galaxies contributing with 20% of the K-band
flux, while the near-IR continuum is dominated by the contribution of
intermediate-age stars (100 Myr-2 Gyr) at larger distances. Older stellar
populations dominate in the inner 250 pc
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
The first 62 AGN observed with SDSS-IV MaNGA -- III: stellar and gas kinematics
We investigate the effects of Active Galactic Nuclei (AGN) on the gas
kinematics of their host galaxies, using MaNGA data for a sample of 62 AGN
hosts and 109 control galaxies (inactive galaxies). We compare orientation of
the line of nodes (kinematic Position Angle - PA) measured from the gas and
stellar velocity fields for the two samples. We found that AGN hosts and
control galaxies display similar kinematic PA offsets between gas and stars.
However, we note that AGN have larger fractional velocity dispersion
differences between gas and stars [] when compared to their controls, as
obtained from the velocity dispersion values of the central (nuclear) pixel
(2.5" diameter). The AGN have a median value of of
, while the the median value for the control
galaxies is . 75% of the AGN show
, while 75% of the normal galaxies show , thus we suggest that the parameter can be
used as an indicative of AGN activity. We find a correlation between the
[OIII]5007 luminosity and for our sample. Our main
conclusion is that the AGN already observed with MaNGA are not powerful enough
to produce important outflows at galactic scales, but at 1-2 kpc scales, AGN
feedback signatures are always present on their host galaxies.Comment: 19 pages, 8 figures, published in MNRA
Optical/NIR stellar absorption and emission-line indices from luminous infrared galaxies
We analyze a set of optical-to-near-infrared long-slit nuclear spectra of 16
infrared-luminous spiral galaxies. All of the studied sources present H
emission, which reflects the star-forming nature of our sample, and they
clearly display H I emission lines in the optical. Their continua contain many
strong stellar absorption lines, with the most common features due to Ca I, Ca
II, Fe I, Na I, Mg I, in addition to prominent absorption bands of TiO, VO,
ZrO, CN and CO. We report a homogeneous set of equivalent width (EW)
measurements for 45 indices, from optical to NIR species for the 16
star-forming galaxies as well as for 19 early type galaxies where we collected
the data from the literature. This selected set of emission and
absorption-feature measurements can be used to test predictions of the
forthcoming generations of stellar population models. We find correlations
among the different absorption features and propose here correlations between
optical and NIR indices, as well as among different NIR indices, and compare
them with model predictions. While for the optical absorption features the
models consistently agree with the observations,the NIR indices are much harder
to interpret. For early-type spirals the measurements agree roughly with the
models, while for star-forming objects they fail to predict the strengths of
these indices.Comment: accepted for publication in MNRA
Feeding and Feedback in the Inner Kiloparsec of the Active Galaxy NGC2110
We present two-dimensional gaseous kinematics of the inner 1.1 x 1.6kpc^2 of
the Seyfert 2 galaxy NGC2110, from optical spectra obtained with the GMOS
integral field spectrograph on the Gemini South telescope at a spatial
resolution of 100pc. Gas emission is observed over the whole field-of-view,
with complex - and frequently double - emission-line profiles. We have
identified four components in the emitting gas, according to their velocity
dispersion (sigma), which we refer to as: (1) warm gas disk (sigma =
100-220km/s); (2) cold gas disk (sigma = 60-90km/s); (3) nuclear component
(sigma = 220-600km/s); and (4) northern cloud (sigma = 60-80km/s). Both the
cold and warm disk components are dominated by rotation and have similar gas
densities, but the cold gas disk has lower velocity dispersions and reaches
higher rotation velocities. We attribute the warm gas disk to a thick gas layer
which encompasses the cold disk as observed in some edge-on spiral galaxies.
After subtraction of a rotation model from the cold disk velocity field, we
observe excess blueshifts of 50km/s in the far side of the galaxy as well as
similar excess redshifts in the near side. These residuals can be interpreted
as due to nuclear inflow in the cold gas, with an estimated ionized gas mass
inflow rate of 2.2 x 10^(-2)Msun/yr. We have also subtracted a rotating model
from the warm disk velocity field and found excess blueshifts of 100km/s to the
SW of the nucleus and excess redshifts of 40km/s to the NE, which we attribute
to gas disturbed by an interaction with a nuclear spherical outflow. This
nuclear outflow is the origin of the nuclear component observed within the
inner 300pc and it has a mass outflow rate of 0.9Msun/yr. In a region between
1" and 4" north of the nucleus we find a new low sigma component of ionized gas
which we attribute to a high latitude cloud photoionized by the nuclear source.Comment: 17 pages, 13 figures, 1 table; accepted for publication in MNRA
The first 62 AGN observed with SDSS-IV MaNGA - IV: gas excitation and star-formation rate distributions
We present maps of the ionized gas flux distributions, excitation,
star-formation rate SFR, surface mass density , and obtain total
values of SFR and ionized gas masses {\it M} for 62 Active Galactic Nuclei
(AGN) observed with SDSS-IV MaNGA and compare them with those of a control
sample of 112 non-active galaxies. The most luminous AGN -- with
L(\rm{[OIII]}\lambda 5007) \ge 3.8\times 10^{40}\,\mbox{erg}\,\mbox{s}^{-1},
and those hosted by earlier-type galaxies are dominated by Seyfert excitation
within 0.2 effective radius from the nucleus, surrounded by LINER
excitation or transition regions, while the less luminous and hosted by
later-type galaxies show equally frequent LINER and Seyfert excitation within
. The extent of the region ionized by the AGN follows the
relation -- as in the case of the Broad-Line
Region. The SFR distribution over the region ionized by hot stars is similar
for AGN and controls, while the integrated SFR -- in the range
\,M\,yr is also similar for the late-type
sub-sample, but higher in the AGN for 75\% of the early-type sub-sample. We
thus conclude that there is no signature of AGN quenching star formation in the
body of the galaxy in our sample. We also find that 66\% of the AGN have higher
ionized gas masses than the controls -- in the range
10\,M -- while 75\% of the AGN have higher
within than the control galaxies
Infrared identification of IGR J09026-4812 as a Seyfert 1 galaxy
IGR J09026-4812 was discovered by INTEGRAL in 2006 as a new hard X-ray
source. Thereafter, an observation with Chandra pinpointed a single X-ray
source within the ISGRI error circle, showing a hard spectrum, and improving
its high-energy localisation to a subarcsecond accuracy. Thus, the X-ray source
was associated to the infrared counterpart 2MASS J09023731-4813339 whose JHKs
photometry indicated a highly reddened source. The high-energy properties and
the counterpart photometry suggested a high-mass X-ray binary with a main
sequence companion star located 6.3-8.1 kpc away and with a 0.3-10 keV
luminosity of 8e34 erg/s. New optical and infrared observations were needed to
confirm the counterpart and to reveal the nature of IGR J09026-4812. We
performed optical and near infrared observations on the counterpart 2MASS
J09023731-4813339 with the ESO/NTT telescope on March 2007. We achieved
photometry and spectroscopy in near infrared wavelengths and photometry in
optical wavelengths. The accurate astrometry at both optical and near infrared
wavelengths confirmed 2MASS J09023731-4813339 to be the counterpart of IGR
J09026-4812. However, the near infrared images show that the source is
extended, thus excluding any Galactic compact source possibility. The source
spectrum shows three main emission lines identified as the HeI lambda 1.0830
micron line, and the HI Pa_beta and Pa_alpha lines, typical in galaxies with an
active galactic nucleus. The broadness of these lines reached values as large
as 4000 km/s pointing towards a type 1 Seyfert galaxy. The redshift of the
source is z=0.0391(4). Thus, the near infrared photometry and spectroscopy
allowed us to classify IGR J09026-4812 as a Seyfert galaxy of type 1.Comment: 4 pages, 3 figures, Astronomy and Astrophysics in pres
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