926 research outputs found
Spatially resolved observations of warm ionized gas and feedback in local ULIRGs
We present VLT/VIMOS-IFU emission-line spectroscopy of a volume limited
sample of 18 southern ULIRGs selected with z<0.09 and dec<10. By covering a
wide range of ULIRG types, this dataset provides an important set of templates
for comparison with high-redshift galaxies. We employed an automated Gaussian
line fitting program to decompose the emission line profiles of Halpha, [NII],
[SII], and [OI] into individual components, and chart the Halpha kinematics,
and the ionized gas excitations and densities. 11/18 of our galaxies show
evidence for outflowing warm ionized gas with speeds between 500 and a few 1000
km/s, with the fastest outflows associated with systems that contain an AGN.
Our spatially resolved spectroscopy has allowed us to map the outflows, and in
some cases determine for the first time to which nucleus the wind is
associated. In three of our targets we find line components with widths >2000
km/s over spatially extended regions in both the recombination and forbidden
lines; in two of these three, they are associated with a known Sy2 nucleus.
Eight galaxies have clear rotating gaseous disks, and for these we measure
rotation velocities, virial masses, and calculate Toomre Q parameters. We find
radial gradients in the emission line ratios in a significant number of systems
in our study. We attribute these gradients to changes in ionizing radiation
field strength, most likely due to an increasing contribution of shocks with
radius. We conclude with a detailed discussion of the results for each
individual system, with reference to the existing literature.
Our observations demonstrate that the complexity of the kinematics and gas
properties in ULIRGs can only be disentangled with high sensitivity, spatially
resolved IFU observations. Many of our targets are ideal candidates for future
high spatial resolution follow-up observations.Comment: 44 pages, 8 figures, 3 tables, accepted to MNRA
Especiação química do cobre e concentração de nutrientes na Lagoa da Conceição, Florianópolis, SC
TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Química.Nos dias 18 de dezembro de 1998 e dia 19 fevereiro de 1999 foram coletadas amostras de agua de superfície em 6 pontos da Lagoa da Conceição (area 19,2 km 2 ) e um no mar com o objetivo de caracterizar algumas das mais importantes formas do elemento cobre, além de identificar possíveis fontes de contaminação por esgotos através das análises de nitrato e fosfato. A estação Marina foi a que apresentou a maior concentração de cobre nas duas amostragens (23,4 nmo/L e dezembro e 8,1 nmol/L em fevereiro), podendo ser este oriundo das tintas utilizadas nos cascos dos barcos e dos esgotos domésticos. Em dezembro a estação Marina foi a que apresentou a menor concentração de clorofila-a (0,5 _ig/L) e maior concentração de cobre lábil (11,2 nmol/L), já em fevereiro houve um decréscimo na concentração de cobre (5,2 nmol/L) e um aumento na concentração de clorofila-a (5,5 1.ig/L) indicando que o excesso de cobre presente no local poderia estar prejudicando o desenvolvimento da comunidade fitoplanctônica da região. Cerca de 50% do cobre dissolvido nas Lagoas da Conceição e do Pen i encontra-se na forma de fortes complexos com a matéria orgânica, o que diminui sua toxicidade para a biota e ressalta a importância de se avaliar a especiação química para se avaliar a qualidade das aguas. A Lagoa do Pen, mesmo tendo uma concentração de material particulado menor que a Lagoa da Conceição, apresentou a maior fração de cobre lixiviável (37%) que pode ser proveniente dos organismos clorofilados. As concentragóes média de nitrato (0,43 ± 0,32 nmol/L) e fosfato (0,12 ± 0,11 nmol/L) encontradas são características de ambientes oligotróficos e meso-eutrófico, respectivamente. As concentrações de cobre encontradas na Lagoa da Conceição são bem inferiores ao maxima tolerável, na resolução do Conselho Nacional do Meio Ambiente n° 20 de 1986. As análises da agua do mar certi fi cada CRM-403 demonstraram que o método utilizado neste trabalho para a determinação de cobre tem boa exatidão e precisão. As faixas de concentrações para as diversas espécies de cobre em dezembro de 1998 foram: cobre lábil de 1,7 a 11,2 nmol/L, iv cobre dissolvido total de 3,0 a 23,3 nmol/L, cobre dissolvido mais particulado lixiviável de 3,7 a 25,7 nmol/L. Já na amostragem de fevereiro de 1999 os valores foram: cobre lábil de 1,0 a 5,2 nmol/L, cobre dissolvido total de 2,6 a 8,1 nmol/L e cobre dissolvido mais particulado lixiviável de 4,4 a 7,4 nmol/L. Neste trabalho utilizou-se a voltametria de redissolução catódica para avaliar as concentrações de cobre nas amostras. Sua principal vantagem é que a fração lábil do metal pode ser avaliada sem nenhum tratamento prévio das amostras, minimizando assim riscos de contaminação
THE ROLE OF PHYSICAL ACTIVITY IN ANTHROPOMETRIC PARAMETERS AT TEENAGE GIRLS IN DIFFERENT KIND OF SPORTS
The aim of the study is to compare the levels of physical activity and anthropometric parameters during the curricular time of a 45 minutes physical education lesson three time a week, in different kind of sports: volleyboll, basketball and athletics. A total of 88 teenage girls aged from 13-14 years old from “Pjetër Budi” elementary school in Tirana, have taken part volunteering in this study. The study period lasted from September to June 2014. The body mass index (BMI) significantly decreased in the group which was engaged with basketball (p < 0.000), which was associated from a decreased in body weight. A significant increase in height, body weight and BMI (p < 0.005) was observed in both volleyball and athletic groups. No significant changes were detected comparing between groups by paired t-test for equality. The t-test within groups revealed that some anthropometric parameters significantly were changed during this period in all three groups of sports. The Anova analysis showed that no significant changes were observed comparing these groups to each-other (p > 0.005), except the height parameter between volleyball and athletic groups (p < 0.05). Although an addition of an hour a week increase in physical activity, accordingly to the new curricular program of physical education lesson, a clear improvement in health fitness parameters will help the children to achieve better results of motor performance in the future. Article visualizations
OhioLINK’s Affordable Learning Initiatives – Making a Collaborative Commitment to Affordability for Students
Since 2016, OhioLINK, Ohio\u27s higher education library consortium, has defined affordable learning as a strategic initiative. Our affordable learning initiatives have evolved from advocacy and outreach largely around open educational resources to a multi-pronged approach that includes many different strategies for reducing the cost of course materials. At our recent Ohio Affordable Learning Summit, OhioLINK and its member libraries presented on a diverse array of strategic affordable learning initiatives and a menu of options that colleges and universities could choose from in order to pursue making learning more affordable. This second Ohio Affordable Learning Summit was an evolution from previous affordable learning events which intentionally divided efforts to promote open educational resources from efforts to negotiate with commercial publishers to provide deals on inclusive access materials. This year, OhioLINK combined the two and promoted a comprehensive affordable learning strategy led by our collaborative relationship with member librarians. If the goal is making college more affordable for students by reducing the cost of textbooks and course materials, OhioLINK, as a network of libraries, is well-positioned to promote many different paths toward that goal and to give librarians options as they work with faculty to find the best way to make learning more affordable
The Herschel Space Observatory view of dust in M81
We use Herschel Space Observatory data to place observational constraints on the peak and Rayleigh-Jeans slope of dust emission observed at 70−500 μm in the nearby spiral galaxy M81. We find that the ratios of wave bands between 160 and 500 μm are primarily dependent on radius but that the ratio of 70 to 160 μm emission shows no clear dependence on surface brightness or radius. These
results along with analyses of the spectral energy distributions imply that the 160−500 μm emission traces 15−30 K dust heated by evolved stars in the bulge and disc whereas the 70 μm emission includes dust heated by the active galactic nucleus and young stars in star forming regions
DPOAE measurements in comparison to audiometric measurements in hemodialyzed patients
AbstractObjectiveTo investigate the early detection of the damage of cochlear activity by using distortion product otoacoustic emissions (DPOAE) (DP-gram) comparing to the results of the impedance audiometry.MethodsWe examined 53 patients including 43 hemodialyzed patients, and 10 controls. First it was applied a tympanometry, and then in normal results we applied impedance audiometry and DPOAE (DP-gram).ResultsWe found sensorineural hearing loss in 67% of audiometric results of the hemodialyzed patients and there was a decrease of the DPOAE amplitude in 77% of hemodialyzed patients. In the control group there was one patient (10%) with neurosensorial in high frequencies hearing loss in both measurements with audiometry and DPOAE.ConclusionsThere is a sensorineural hearing loss observed in most of the patients with chronic renal failure. DPOAE audiogram shows lower amplitudes than impedance audiometry and it can be used for the early detection of cochlear damage
Free-free and H42alpha emission from the dusty starburst within NGC 4945 as observed by ALMA
We present observations of the 85.69 GHz continuum emission and H42alpha line
emission from the central 30 arcsec within NGC 4945. Both sources of emission
originate from nearly identical structures that can be modelled as exponential
discs with a scale length of ~2.1 arcsec (or ~40 pc). An analysis of the
spectral energy distribution based on combining these data with archival data
imply that 84% +/- 10% of the 85.69 GHz continuum emission originates from
free-free emission. The electron temperature is 5400 +/- 600 K, which is
comparable to what has been measured near the centre of the Milky Way Galaxy.
The star formation rate (SFR) based on the H42alpha and 85.69 GHz free-free
emission (and using a distance of 3.8 Mpc) is 4.35 +/- 0.25 M/yr. This is
consistent with the SFR from the total infrared flux and with previous
measurements based on recombination line emission, and it is within a factor of
~2 of SFRs derived from radio data. The Spitzer Space Telescope 24 micron data
and Wide-field Infrared Survey Explorer 22 micron data yield SFRs ~10x lower
than the ALMA measurements, most likely because the mid-infrared data are
strongly affected by dust attenuation equivalent to A_V=150. These results
indicate that SFRs based on mid-infrared emission may be highly inaccurate for
dusty, compact circumnuclear starbursts.Comment: 19 pages, 9 figures, accepted for publication in MNRA
LABOCA and MAMBO-2 imaging of the dust ring of the Sombrero galaxy (NGC 4594)
The Sombrero galaxy (NGC 4594) is an Sa galaxy with a symmetric dust ring. We
have used the Large APEX BOlometer CAmera (LABOCA) at 870 micron and the
MAx-Planck Millimeter BOlometer (MAMBO-2) at 1.2 mm to detect the dust ring for
the first time at submillimetre and millimetre wavelengths. We have constructed
a model of the galaxy to separate the active galactic nucleus (AGN) and dust
ring components. The ring radius at both 870 micron and 1.2 mm agrees well with
the radius determined from optical absorption and atomic gas studies. The
spectral energy distribution of the ring is well fitted by a single grey-body
with dust emissivity index beta=2 and a dust temperature T_d=18.4 K. The dust
mass of the ring is found to be 1.6\pm0.2x10^7Msun which, for a Galactic
gas-to-dust ratio, implies a gas mass that is consistent with measurements from
the literature.Comment: 4 pages including 3 figures and 2 tables. Accepted for publication in
A&A Letters. Full resolution version at
http://www.strw.leidenuniv.nl/~vlahakis/vlahakis-highres.pd
Kathryns Wheel: A spectacular galaxy collision discovered in the Galactic neighbourhood
We report the discovery of the closest collisional ring galaxy to the Milky
Way. Such rare systems occur due to "bulls-eye" encounters between two
reasonably matched galaxies. The recessional velocity of about 840 km/s is low
enough that it was detected in the AAO/UKST Survey for Galactic H
emission. The distance is only 10.0 Mpc and the main galaxy shows a full ring
of star forming knots, 6.1 kpc in diameter surrounding a quiescent disk. The
smaller assumed "bullet" galaxy also shows vigorous star formation. The
spectacular nature of the object had been overlooked because of its location in
the Galactic plane and proximity to a bright star and even though it is the
60 brightest galaxy in the HI Parkes All Sky Survey (HIPASS) HI
survey.
The overall system has a physical size of 15 kpc, a total mass of
M (stars + HI), a metallicity of
[O/H], and a star formation rate of 0.2-0.5 M\,yr,
making it a Magellanic-type system. Collisional ring galaxies therefore extend
to much lower galaxy masses than commonly assumed. We derive a space density
for such systems of , an order of magnitude
higher than previously estimated. This suggests Kathryn's Wheel is the nearest
such system. We present discovery images, CTIO 4-m telescope narrow-band
follow-up images and spectroscopy for selected emission components. Given its
proximity and modest extinction along the line of sight, this spectacular
system provides an ideal target for future high spatial resolution studies of
such systems and for direct detection of its stellar populations.Comment: 18 pages, 12 figures, accepted for publication in MNRA
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