357 research outputs found
Multi-Symptom Management in Hospice Patients during End-of-Life Transition
The purpose of this quality improvement project is to compare the provider’s perception following an educational model of using single symptom management versus multi-symptom management during the end-of-life transition in adult patients for improved quality of life outcomes. The appraised evidence indicates that it is critical to have anticipatory medications at the patient’s residence to manage multiple symptoms rather than focusing exclusively on a single symptom management such as pain management. In February 2016, the author conducted an educational model among hospice providers for increasing knowledge and awareness of multi-symptom management. Thirty (n = 30) Clinical Nursing Directors, Licensed Practical Nurses, Medical Directors, and Registered Nurse Case Managers from hospice organizations located in South Carolina were surveyed pre and post intervention regarding their perception of symptoms, the most prominent distressful symptoms that are experienced by hospice patients, and the pharmaceutical preference to manage distressful symptoms. With a response rate of 77%; (n=23) participants pre-test responses indicated that pain (35%) was the most prominent symptom among patients; Dyspnea/SOB (44%) was identified as the most distressful symptom for patients; and anxiety/restlessness and increased respiratory secretions received (35%) as the most distressful symptoms for patients’ families and/ or caregivers witnessed during a patient’s last two weeks of life. Hospice provider’s post-test responses indicated that the most prominent symptom was dyspnea/SOB (30%) followed by pain (22%). Additionally, the presence of anxiety/restlessness had increased by almost (10%) in the post-test results (26%). Healthcare providers reported the most distressful symptom for the patient was dyspnea/SOB (44%) with the same response rate both pre-test and post-test. However, the prevalence of pain as the most distressful symptom’s response rate decreased from pre-test (17%) to post-test (9%). The presence of perceived increased respiratory secretions response rate increased from pre-test (13%) to post-test (22%). This project was consistent with the evidence that multi-symptom management is critical in end of life transitions and care providers must focus on multi-symptoms rather than single symptom
Baryonic Tully-Fisher Relation for Extremely Low Mass Galaxies
We study Tully-Fisher relations for a sample that combines extremely faint
(M_B > -14.0) galaxies along with bright (i.e. L_*) galaxies. Accurate (~ 10%)
distances, I band photometry, and B-V colors are known for the majority of the
galaxies in our sample. The faint galaxies are drawn from the Faint Irregular
Galaxy GMRT survey (FIGGS), and we have HI rotation velocities derived from
aperture synthesis observations for all of them. For the faint galaxies, we
find that even though the median HI and stellar masses are comparable, the HI
mass correlates significantly better with the circular velocity indicators than
the stellar mass. We also find that W correlates better with mass than
the rotation velocity, although the difference is not statistically
significant. The faint galaxies lie systematically below the I band TF relation
defined by bright galaxies, and also show significantly more intrinsic scatter.
This implies that the integrated star formation in these galaxies has been both
less efficient and also less regulated than in large galaxies. We find that
while the faint end deviation is greatly reduced in Baryonic Tully-Fisher (BTF)
relations, the existence of a break at the faint end of the BTF is subject to
systematics such as the assumed stellar mass to light ratio. If we assume that
there is an intrinsic BTF and try to determine the baryonic mass by searching
for prescriptions that lead to the tightest BTF, we find that scaling the HI
mass leads to a much more significant tightening than scaling the stellar mass
to light ratio. The most significant tightening that we find however, is if we
scale the entire baryonic mass of the faint (but not the bright) galaxies. Such
a scenario would be consistent with models where dwarf (but not large) galaxies
have a large fraction of dark or ``missing'' baryons (Slightly abridged)Comment: 7 pages, 7 figures. Accepted for publication in MNRA
Medium Resolution 0.97-5.3 micron spectra of Very Young Benchmark Brown Dwarfs with NIRSpec onboard the James Webb Space Telescope
Spectra of young benchmark brown dwarfs with well-known ages are vital to
characterize other brown dwarfs, for which ages are in general not known. These
spectra are also crucial to test atmospheric models which have the potential to
provide detailed information about the atmospheres of these objects. However,
to optimally test atmospheric models, medium-resolution, long-wavelength
coverage spectra with well-understood uncertainties are ideal, such as the
spectra provided by the NIRSpec instrument onboard the James Webb Space
Telescope. In this paper, we present the medium-resolution JWST/NIRSpec spectra
of two young brown dwarfs, TWA 28 (M9.0) and TWA 27A (M9.0), and one
planetary-mass object, TWA 27B (L6.0), members of the TW Hydrae Association
(~10 Myr). We show the richness of the atomic lines and molecular bands present
in the spectra. All objects show signs of a circumstellar disk, via
near-infrared excess and/or via emission lines. We matched a set of cloudless
atmospheric spectra (ATMO), and cloudy atmospheric spectra (BT-Settl) to our
NIRSpec spectra, and analyzed which wavelength ranges and spectral features
both models reproduce best. Both models derive consistent parameters for the
three sources, and predict the existence of CH4 at 3.35 microns in TWA 27B.
Nonetheless, in contrast to other slightly older objects with similar spectral
type, like PSO 318.5-22 and VHS 1256b, this feature is not present in the
spectrum of TWA 27B. The lack of the CH4 feature might suggest that the L/T
transition of very young dwarfs starts at later spectral types than for older
brown dwarfs.Comment: Accepted in A
An HST/ACS View of the Inhomogeneous Outer Halo of M31
We present a high precision photometric view of the stellar populations in
the outer halo of M31, using data taken with the Hubble Space Telescope
Advanced Camera for Surveys (HST/ACS). We analyse the field populations
adjacent to 11 luminous globular clusters which sample the galactocentric
radial range 18 < R < 100 kpc and reach a photometric depth of ~2.5 magnitudes
below the horizontal branch (m_F814W ~27 mag). The colour-magnitude diagrams
(CMDs) are well populated out to ~60 kpc and exhibit relatively metal-rich red
giant branches, with the densest fields also showing evidence for prominent red
clumps. We use the Dartmouth isochrones to construct metallicity distribution
functions (MDFs) which confirm the presence of dominant populations with
= -0.6 to -1.0 dex and considerable metallicity dispersions of 0.2 to
0.3 dex (assuming a 10 Gyr population and scaled-Solar abundances). The average
metallicity over the range 30 - 60 kpc is [Fe/H] = -0.8 +/- 0.14 dex, with no
evidence for a significant radial gradient. Metal-poor stars ([Fe/H] <= -1.3)
typically account for < 10-20 % of the population in each field, irrespective
of radius. Assuming our fields are unbiased probes of the dominant stellar
populations in these parts, we find that the M31 outer halo remains
considerably more metal-rich than that of the Milky Way out to at least 60 kpc.Comment: Accepted for publication in MNRAS. 10 pages, 6 figure
JWST/NIRSpec Observations of the Planetary Mass Companion TWA 27B
We present 1-5um spectroscopy of the young planetary mass companion TWA 27B
(2M1207B) performed with NIRSpec on board the James Webb Space Telescope. In
these data, the fundamental band of CH_4 is absent and the fundamental band of
CO is weak. The nondetection of CH_4 reinforces a previously observed trend of
weaker CH_4 with younger ages among L dwarfs, which has been attributed to
enhanced non-equilibrium chemistry among young objects. The weakness of CO may
reflect an additional atmospheric property that varies with age, such as the
temperature gradient or cloud thickness. We are able to reproduce the broad
shape of the spectrum with an ATMO cloudless model that has T=1300 K,
non-equilibrium chemistry, and a temperature gradient reduction caused by
fingering convection. However, the fundamental bands of CH_4 and CO are
somewhat stronger in the model. In addition, the model temperature of 1300 K is
higher than expected from evolutionary models given the luminosity and age of
TWA 27B (T=1200 K). Previous models of young L-type objects suggest that the
inclusion of clouds could potentially resolve these issues; it remains to be
seen whether cloudy models can provide a good fit to the 1-5um data from
NIRSpec. TWA 27B exhibits emission in Paschen transitions and the He I triplet
at 1.083um, which are signatures of accretion that provide the first evidence
of a circumstellar disk. We have used the NIRSpec data to estimate the
bolometric luminosity of TWA 27B (log L/L_sun=-4.466+/-0.014), which implies a
mass of 5-6 MJup according to evolutionary models.Comment: Astrophysical Journal Letters, in pres
Advanced Camera for Surveys Observations of Young Star Clusters in the Interacting Galaxy UGC 10214
We present the first Advanced Camera for Surveys (ACS) observations of young
star clusters in the colliding/merging galaxy UGC 10214. The observations were
made as part of the Early Release Observation (ERO) program for the newly
installed ACS during service mission SM3B for the Hubble Space Telescope (HST).
Many young star clusters can be identified in the tails of UGC 10214, with ages
ranging from ~3 Myr to 10 Myr. The extreme blue V-I (F606W-F814W) colors of the
star clusters found in the tail of UGC 10214 can only be explained if strong
emission lines are included with a young stellar population. This has been
confirmed by our Keck spectroscopy of some of these bright blue stellar knots.
The most luminous and largest of these blue knots has an absolute magnitude of
M_V = -14.45, with a half-light radius of 161 pc, and if it is a single star
cluster, would qualify as a super star cluster (SSC). Alternatively, it could
be a superposition of multiple scaled OB associations or clusters. With an
estimated age of ~ 4-5 Myr, its derived mass is < 1.3 x 10^6 solar masses. Thus
the young stellar knot is unbound and will not evolve into a normal globular
cluster. The bright blue clusters and associations are much younger than the
dynamical age of the tail, providing strong evidence that star formation occurs
in the tail long after it was ejected. UGC 10214 provides a nearby example of
processes that contributed to the formation of halos and intra-cluster media in
the distant and younger Universe.Comment: 6 pages with embedded figures, ApJ in pres
Star formation in 30 Doradus
Using observations obtained with the Wide Field Camera 3 (WFC3) on board the
Hubble Space Telescope (HST), we have studied the properties of the stellar
populations in the central regions of 30 Dor, in the Large Magellanic Cloud.
The observations clearly reveal the presence of considerable differential
extinction across the field. We characterise and quantify this effect using
young massive main sequence stars to derive a statistical reddening correction
for most objects in the field. We then search for pre-main sequence (PMS) stars
by looking for objects with a strong (> 4 sigma) Halpha excess emission and
find about 1150 of them over the entire field. Comparison of their location in
the Hertzsprung-Russell diagram with theoretical PMS evolutionary tracks for
the appropriate metallicity reveals that about one third of these objects are
younger than ~4Myr, compatible with the age of the massive stars in the central
ionising cluster R136, whereas the rest have ages up to ~30Myr, with a median
age of ~12Myr. This indicates that star formation has proceeded over an
extended period of time, although we cannot discriminate between an extended
episode and a series of short and frequent bursts that are not resolved in
time. While the younger PMS population preferentially occupies the central
regions of the cluster, older PMS objects are more uniformly distributed across
the field and are remarkably few at the very centre of the cluster. We
attribute this latter effect to photoevaporation of the older circumstellar
discs caused by the massive ionising members of R136.Comment: 15 pages, 12 figures. Accepted for publication in The Astrophysical
Journa
The XMM-Newton serendipitous ultraviolet source survey catalogue
The XMM-Newton Serendipitous Ultraviolet Source Survey (XMM-SUSS) is a
catalogue of ultraviolet (UV) sources detected serendipitously by the Optical
Monitor (XMM-OM) on-board the XMM-Newton observatory. The catalogue contains
ultraviolet-detected sources collected from 2,417 XMM-OM observations in 1-6
broad band UV and optical filters, made between 24 February 2000 and 29 March
2007. The primary contents of the catalogue are source positions, magnitudes
and fluxes in 1 to 6 passbands, and these are accompanied by profile
diagnostics and variability statistics. The XMM-SUSS is populated by 753,578 UV
source detections above a 3 sigma signal-to-noise threshold limit which relate
to 624,049 unique objects. Taking account of substantial overlaps between
observations, the net sky area covered is 29-54 square degrees, depending on UV
filter. The magnitude distributions peak at 20.2, 20.9 and 21.2 in UVW2, UVM2
and UVW1 respectively. More than 10 per cent of sources have been visited more
than once using the same filter during XMM-Newton operation, and > 20 per cent
of sources are observed more than once per filter during an individual visit.
Consequently, the scope for science based on temporal source variability on
timescales of hours to years is broad. By comparison with other astrophysical
catalogues we test the accuracy of the source measurements and define the
nature of the serendipitous UV XMM-OM source sample. The distributions of
source colours in the UV and optical filters are shown together with the
expected loci of stars and galaxies, and indicate that sources which are
detected in multiple UV bands are predominantly star-forming galaxies and stars
of type G or earlier.Comment: Accepted for publication in MNRA
Evolution in the Cluster Early-type Galaxy Size-Surface Brightness Relation at z =~ 1
We investigate the evolution in the distribution of surface brightness, as a
function of size, for elliptical and S0 galaxies in the two clusters RDCS
J1252.9-2927, z=1.237 and RX J0152.7-1357, z=0.837. We use multi-color imaging
with the Advanced Camera for Surveys on the Hubble Space Telescope to determine
these sizes and surface brightnesses. Using three different estimates of the
surface brightnesses, we find that we reliably estimate the surface brightness
for the galaxies in our sample with a scatter of < 0.2 mag and with systematic
shifts of \lesssim 0.05 mag. We construct samples of galaxies with early-type
morphologies in both clusters. For each cluster, we use a magnitude limit in a
band which closely corresponds to the rest-frame B, to magnitude limit of M_B =
-18.8 at z=0, and select only those galaxies within the color-magnitude
sequence of the cluster or by using our spectroscopic redshifts. We measure
evolution in the rest-frame B surface brightness, and find -1.41 \+/- 0.14 mag
from the Coma cluster of galaxies for RDCS J1252.9-2927 and -0.90 \+/- 0.12 mag
of evolution for RX J0152.7-1357, or an average evolution of (-1.13 \+/- 0.15)
z mag. Our statistical errors are dominated by the observed scatter in the
size-surface brightness relation, sigma = 0.42 \+/- 0.05 mag for RX
J0152.7-1357 and sigma = 0.76 \+/- 0.10 mag for RDCS J1252.9-2927. We find no
statistically significant evolution in this scatter, though an increase in the
scatter could be expected. Overall, the pace of luminosity evolution we measure
agrees with that of the Fundamental Plane of early-type galaxies, implying that
the majority of massive early-type galaxies observed at z =~ 1 formed at high
redshifts.Comment: Accepted in ApJ, 16 pages in emulateapj format with 15 eps figures, 6
in colo
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