286 research outputs found
Seyfert Activity and Nuclear Star Formation in the Circinus Galaxy
We present high angular resolution (0".15-0".5) near infrared images and
spectroscopy of the Circinus galaxy, the closest Seyfert 2 galaxy known. The
data reveal a non-stellar nuclear source at 2.2 microns. The coronal line
region and the hot molecular gas emission extend for 20-50 pc in the ionization
cone. The data do not show evidence for a point-like concentration of dark
mass; we set an upper limit of 4*10^6 Mo to the mass of a putative black hole.
We find evidence for a young nuclear stellar population, with typical ages
between 4*10^7 and 1.5*10^8 yrs. The luminosity of the starburst inside a few
hundred pc is comparable to the intrinsic luminosity of the Seyfert nucleus,
and the two of them together account for most of the observed bolometric
luminosity of the galaxy. Within the central 12 pc the starburst has an age of
about 7*10^7 yrs and radiates about 2% of the luminosity of the active nucleus.
We discuss the implications of these results for models that have been proposed
for the starburst-AGN connection.Comment: 44 pages, Latex (including 11 Figures), Color Figures 1, 2 and 4 are
available at http://www.arcetri.astro.it/~maiolino/ , ApJ in pres
Infrared 3D Observations of Nearby Active Galaxies
We present multi-wavelength imaging observations of three nearby and famous
active galaxies obtained with NICMOS, ISOCAM and the MPE near-IR integral field
spectrometer. The data reveal a variety of features and properties that are
missed in optical studies and in traditional IR monodimensional spectroscopy.Comment: 6 pages, to appear in "Imaging the Universe in Three Dimensions:
Astrophysics with Advanced Multi-Wavelength Imaging Devices", eds. W. van
Breugel and J. Bland-Hawthorn, needs pasp3D.st
The Discovery of Quasisoft and Supersoft Sources in External Galaxies
We apply a uniform procedure to select very soft sources from point sources
observed by Chandra in 4 galaxies. This sample includes one elliptical galaxy
(NGC 4967), 2 face-on spirals (M101 and M83), and an interacting galaxy (M51).
We have found very soft X-ray sources (VSSs) in every galaxy. Some of these fit
the criteria for canonical supersoft sources (SSSs), while others are somewhat
harder. These latter have characteristic values of kT < 300 eV; we refer to
them as quasisoft sources (QSSs). We found a combined total of 149 VSSs in the
4 galaxies we considered; 77 were SSSs and 72 were QSSs. (See the paper for the
original long abstract)Comment: 20 pages, 6 figures. Accepted for publication in Ap
Stellar Dynamics and the implications on the merger evolution in NGC6240
We report near-infrared integral field spectroscopy of the luminous merging
galaxy NGC 6240. Stellar velocities show that the two K-band peaks separated by
1.6arcsec are the central parts of inclined, rotating disk galaxies with equal
mass bulges. The dynamical masses of the nuclei are much larger than the
stellar mass derived from the K-band light, implying that the progenitor
galaxies were galaxies with massive bulges. The K-band light is dominated by
red supergiants formed in the two nuclei in starbursts, triggered ~2x10^7 years
ago, possibly by the most recent perigalactic approach. Strong feedback effects
of a superwind and supernovae are responsible for a short duration burst
(~5x10^6 years) which is already decaying. The two galaxies form a
prograde-retrograde rotating system and from the stellar velocity field it
seems that one of the two interacting galaxies is subject to a prograde
encounter. Between the stellar nuclei is a prominent peak of molecular gas
(H_2, CO). The stellar velocity dispersion peaks there indicating that the gas
has formed a local, self-gravitating concentration decoupled from the stellar
gravitational potential. NGC 6240 has previously been reported to fit the
paradigm of an elliptical galaxy formed through the merger of two galaxies.
This was based on the near-infrared light distribution which follows a
r^1/4-law. Our data cast strong doubt on this conclusion: the system is by far
not relaxed, rotation plays an important role, as does self-gravitating gas,
and the near-infrared light is dominated by young stars.Comment: 34 pages, 11 figures, using AASTEX 5.0rc3.1, paper submitted to the
Astrophysical Journal, revised versio
Effects of a Supermassive Black Hole Binary on a Nuclear Gas Disk
We study influence of a galactic central supermassive black hole (SMBH)
binary on gas dynamics and star formation activity in a nuclear gas disk by
making three-dimensional Tree+SPH simulations. Due to orbital motions of SMBHs,
there are various resonances between gas motion and the SMBH binary motion. We
have shown that these resonances create some characteristic structures of gas
in the nuclear gas disk, for examples, gas elongated or filament structures,
formation of gaseous spiral arms, and small gas disks around SMBHs. In these
gaseous dense regions, active star formations are induced. As the result, many
star burst regions are formed in the nuclear region.Comment: 19 pages, 11 figures, accepted for publication in Ap
Young Clusters in the Nuclear Starburst of M 83
We present a photometric catalog of 45 massive star clusters in the nuclear
starburst of M 83 (NGC 5236), observed with the Hubble Space Telescope WFPC2,
in both broad-band (F300W, F547M, and F814W) and narrow-band (F656N and F487N)
filters. By comparing the photometry to theoretical population synthesis
models, we estimate the age and mass of each cluster. We find that over 75% of
the star clusters more massive than 2*10^4 Msun in the central 300 pc of M 83
are less than 10 Myr old. Among the clusters younger than 10 Myr and more
massive than 5*10^3 Msun, 70% are between 5 and 7 Myr old. We list an
additional 330 clusters that are detected in our F300W images, but not in the
shallower F547M and F814W images. The clusters are distributed throughout a
semicircular annulus that identifies the active region in the galaxy core,
between 50 and 130 pc from the optical center of M 83. Clusters younger than 5
Myr are preferentially found along the perimeter of the semicircular annulus.
We suggest that the 5-7 Myr population has evacuated much of the interstellar
material from the active ringlet region, and that star formation is continuing
along the edges of the region.Comment: 40 pages, 13 figures, accepted to ApJ
Emblica Officinalis: A Novel Therapy for Acute Pancreatitis — An Experimental Study
Acute necrotising pancreatitis is associated with an unacceptably high mortality for which no
satisfactory remedy exists. Emblica officinalis (E.o.) is a plant prescribed in Ayurveda, the
Indian traditional system of medicine, for pancreas-related disorders. This study was carried
out to evaluate the protective effect of E.o. against acute necrotising pancreatitis in dogs.
Pancreatitis was induced by injecting a mixture of trypsin, bile and blood into the duodenal
opening of the pancreatic duct. Twenty eight dogs were divided into 4 groups (n = 6-8 each):
GpI–control, GpII–acute pancreatitis, GpIII–sham-operated, GpIV–pretreatment with
28 mg E.o./kg/day for 15 days before inducing pancreatitis. Serum amylase increased from
541.99 ± 129.13 IU/ml to 1592.63 ± 327.83 IU (p<0.02) 2 hrs after the induction of pancreatitis
in GpII. The rise in serum amylase in both GpIII and GpIV was not significant. On
light microscopic examination, acinar cell damage was less and the total inflammatory score
was significantly lower in the E.o. treated group as compared to GpII. Electron microscopy
confirmed this and showed an increased amount of smooth, endoplasmic reticulum and small,
condensed granules embedded in a vacuole. More studies are needed to explore the clinical
potential of E.o. and its mechanism of action
Optical integral field spectroscopy of intermediate redshift infrared bright galaxies
The extreme infrared (IR) luminosity of local luminous and ultra-luminous IR
galaxies (U/LIRGs; 11 12,
respectively) is mainly powered by star-formation processes triggered by
mergers or interactions. While U/LIRGs are rare locally, at z > 1, they become
more common, they dominate the star-formation rate (SFR) density, and a
fraction of them are found to be normal disk galaxies. Therefore, there must be
an evolution of the mechanism triggering these intense starbursts with
redshift. To investigate this evolution, we present new optical SWIFT integral
field spectroscopic H{\alpha}+[NII] observations of a sample of 9
intermediate-z (0.2 < z < 0.4) U/LIRG systems selected from Herschel 250{\mu}m
observations. The main results are the following: (a) the ratios between the
velocity dispersion and the rotation curve amplitude indicate that 10-25% (1-2
out of 8) might be compatible with being isolated disks while the remaining
objects are interacting/merging systems; (b) the ratio between un-obscured and
obscured SFR traced by H{\alpha} and LIR, respectively, is similar in both
local and these intermediate-z U/LIRGs; and (c) the ratio between 250{\mu}m and
the total IR luminosities of these intermediate-z U/LIRGs is higher than that
of local U/LIRGs with the same LIR . This indicates a reduced dust temperature
in these intermediate-z U/LIRGs. This, together with their already measured
enhanced molecular gas content, suggests that the interstellar medium
conditions are different in our sample of intermediate-z galaxies when compared
to local U/LIRGs.Comment: Accepted for publication in MNRA
¿Qué leían los cruzados argentinos? : Las lecturas del nacionalismo católico a través de 'Cabildo' (1973-1976)
En el siguiente artículo se aborda la revista nacionalista católica Cabildo desde una perspectiva sensible a la historia intelectual. El objetivo es ampliar y completar, a partir de las lecturas promocionadas en las publicidades y de los libros reseñados, el universo de representaciones políticas y religiosas. Luego de presentar la revista, largamente estudiada por la historiografía, se analizan las publicidades identificando redes intelectuales locales, pero también transnacionales. En forma posterior se examinan tres reseñas dedicadas a la lectura de la historia, la ciencia ficción y la guerra contrarrevolucionaria. Se concluye que el nacionalismo católico, lejos de impugnar la modernidad en un nivel ontológico, trazó un diálogo práctico bajo la condición de corregir sus peligrosas derivas.En el següent article s'aborda la revista nacionalista catòlica Cabildo des d'una perspectiva sensible a la història intel·lectual. L'objectiu és ampliar i completar, a partir de les lectures promocionades en les publicitats i dels llibres ressenyats, l'univers de representacions polítiques i religioses. Després de presentar la revista, llargament estudiada per la historiografia, s'analitzen les publicitats tot identificant xarxes intel·lectuals locals, però també transnacionals. Més endavant s'examinen tres ressenyes dedicades a la lectura de la història, la ciència-ficció i la guerra contrarevolucionària. Es conclou que el nacionalisme catòlic, lluny d'impugnar la modernitat en un nivell ontològic, va traçar un diàleg pràctic sota la condició de corregir les seves perilloses derives.The following paper focuses on the Catholic nationalist magazine Cabildo from an Intellectual History standpoint. The aim is to expand and complete, from the reading matter promoted in its advertisements and the books reviewed, the universe of its political and religious representations. After a brief introduction to the magazine, long studied in the literature, the advertisements are analyzed and transnational as well as local intellectual networks are identified. Later, three book reviews, focusing on the interpretation of Argentine history, science fiction, and the counterrevolutionary war, are examined. It is concluded that, far from challenging modernity on an ontological level, Cabildo entered into a practical dialogue with it without accepting its dangerous deviations
Task sharing for family planning services, Burkina Faso
© 2019, World Health Organization. All rights reserved. Problem In Burkina Faso, the coverage of services for family planning is low due to shortage of qualified health staff and limited access to services. Approach Following the launch of the Ouagadougou Partnership, an alliance to catalyse the expansion of family planning services, the health ministry created a consortium of family planning stakeholders in 2011. The consortium adopted a collaborative framework to implement a pilot project for task sharing in family planning at community and primary health-care centre levels in two rural districts. Stakeholders were responsible for their areas of expertise. These areas included advocacy; monitoring and evaluation; and capacity development of community health workers (CHWs) to offer oral and injectable contraceptives to new users and of auxiliary nurses and auxiliary midwives to provide implants and intrauterine devices. The health ministry implemented supportive supervision cascades involving relevant planning and service levels. Local setting In Burkina Faso, only 15% (2563/17 087) of married women used modern contraceptives in 2010. Relevant changes Adoption of new policies and clinical care standards expanded task sharing roles in family planning. The consortium trained a total of 79 CHWs and 124 auxiliary nurses and midwives. Between January 2017 and December 2018, CHWs provided injectables to 3698 new users, and auxiliary nurses or midwives provided 726 intrauterine devices and 2574 implants to new users. No safety issues were reported. Lessons learnt The pilot project was feasible and safe, however, financial constraints are hindering scale-up efforts. Supportive supervision cascades were critical in ensuring success
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