5,169 research outputs found
Management of incidentally detected heart murmurs in dogs and cats
A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient
A Megacam Survey of Outer Halo Satellites. IV. Two foreground populations possibly associated with the Monoceros substructure in the direction of NGC2419 and Koposov2
The origin of the Galactic halo stellar structure known as the Monoceros ring
is still under debate. In this work, we study that halo substructure using deep
CFHT wide-field photometry obtained for the globular clusters NGC2419 and
Koposov2, where the presence of Monoceros becomes significant because of their
coincident projected position. Using Sloan Digital Sky Survey photometry and
spectroscopy in the area surrounding these globulars and beyond, where the same
Monoceros population is detected, we conclude that a second feature, not likely
to be associated with Milky Way disk stars along the line-of-sight, is present
as foreground population. Our analysis suggests that the Monoceros ring might
be composed of an old stellar population of age t ~ 9Gyr and a new component ~
4Gyr younger at the same heliocentric distance. Alternatively, this detection
might be associated with a second wrap of Monoceros in that direction of the
sky and also indicate a metallicity spread in the ring. The detection of such a
low-density feature in other sections of this halo substructure will shed light
on its nature.Comment: 10 pages, 10 figures, accepted for publication in Ap
Photoassociative spectroscopy at long range in ultracold strontium
We report photoassociative spectroscopy of Sr in a magneto-optical
trap operating on the intercombination line at 689 nm.
Photoassociative transitions are driven with a laser red-detuned by 600-2400
MHz from the atomic resonance at 461 nm. Photoassociation
takes place at extremely large internuclear separation, and the
photoassociative spectrum is strongly affected by relativistic retardation. A
fit of the transition frequencies determines the atomic lifetime
( ns) and resolves a discrepancy between experiment and
recent theoretical calculations.Comment: 4 pages, 4 figures, submitte
The Environment of M85 optical transient 2006-1: constraints on the progenitor age and mass
M85 optical transient 2006-1 (M85 OT 2006-1) is the most luminous member of
the small family of V838 Mon-like objects, whose nature is still a mystery.
This event took place in the Virgo cluster of galaxies and peaked at an
absolute magnitude of I~-13. Here we present Hubble Space Telescope images of
M85 OT 2006-1 and its environment, taken before and after the eruption, along
with a spectrum of the host galaxy at the transient location. We find that the
progenitor of M85 OT 2006-1 was not associated with any star forming region.
The g and z-band absolute magnitudes of the progenitor were fainter than about
-4 and -6 mag, respectively. Therefore, we can set a lower limit of ~50 Myr on
the age of the youngest stars at the location of the progenitor that
corresponds to a mass of <7 solar mass. Previously published line indices
suggest that M85 has a mean stellar age of 1.6+/-0.3 Gyr. If this mean age is
representative of the progenitor of M85 OT 2006-1, then we can further
constrain its mass to be less than 2 solar mass. We compare the energetics and
mass limit derived for the M85 OT 2006-1 progenitor with those expected from a
simple model of violent stellar mergers. Combined with further modeling, these
new clues may ultimately reveal the true nature of these puzzling events.Comment: 4 pages, accepted to Ap
Is Extension Relevant for the 21st Century?
As a 90-year-old artifact of the days when an agrarian economy dominated society, is it possible for Extension to still be relevant? As the primary outreach and public service function of land-grant universities, the relevance of Extension is tied to the perception and reality of the relevance of these host institutions. Did the recent ECOP report A Vision for the 21st Century and other ECOP statements address whether Extension remains relevant to the 21st century context? Extension educators are assisting communities of place and of interest and involving more university and agency colleagues in responding to changing citizen education needs
The properties of the Malin 1 galaxy giant disk: A panchromatic view from the NGVS and GUViCS surveys
Low surface brightness galaxies (LSBGs) represent a significant percentage of
local galaxies but their formation and evolution remain elusive. They may hold
crucial information for our understanding of many key issues (i.e., census of
baryonic and dark matter, star formation in the low density regime, mass
function). The most massive examples - the so called giant LSBGs - can be as
massive as the Milky Way, but with this mass being distributed in a much larger
disk. Malin 1 is an iconic giant LSBG, perhaps the largest disk galaxy known.
We attempt to bring new insights on its structure and evolution on the basis of
new images covering a wide range in wavelength. We have computed surface
brightness profiles (and average surface brightnesses in 16 regions of
interest), in six photometric bands (FUV, NUV, u, g, i, z). We compared these
data to various models, testing a variety of assumptions concerning the
formation and evolution of Malin 1. We find that the surface brightness and
color profiles can be reproduced by a long and quiet star-formation history due
to the low surface density; no significant event, such as a collision, is
necessary. Such quiet star formation across the giant disk is obtained in a
disk model calibrated for the Milky Way, but with an angular momentum
approximately 20 times larger. Signs of small variations of the star-formation
history are indicated by the diversity of ages found when different regions
within the galaxy are intercompared.For the first time, panchromatic images of
Malin 1 are used to constrain the stellar populations and the history of this
iconic example among giant LSBGs. Based on our model, the extreme disk of Malin
1 is found to have a long history of relatively low star formation (about 2
Msun/yr). Our model allows us to make predictions on its stellar mass and
metallicity.Comment: Accepted in Astronomy and Astrophysic
Hall Crystal States at and Moderate Landau Level Mixing
The quantum Hall state at low Zeeman coupling is well-known to be a
translationally invariant singlet if Landau level mixing is small. At zero
Zeeman interaction, as Landau level mixing increases, the translationally
invariant state becomes unstable to aninhomogeneous state. This is the first
realistic example of a full Hall crystal, which shows the coexistence of
quantum Hall order and density wave order. The full Hall crystal differs from
the more familiar Wigner crystal by a topological property, which results in it
having only linearly dispersing collective modes at small , and no
magnetophonon. I present calculations of the topological number and the
collective modes.Comment: Final version to appear in PRL. Two references added, minor changes
to figures and tex
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