28 research outputs found
Listening through hearing aids affects spatial perception and speech intelligibility in normal-hearing listeners
Photon Dominated Regions in NGC 3603
Aims: We aim at deriving the excitation conditions of the interstellar gas as
well as the local FUV intensities in the molecular cloud surrounding NGC 3603
to get a coherent picture of how the gas is energized by the central stars.
Methods: The NANTEN2-4m submillimeter antenna is used to map the [CI] 1-0, 2-1
and CO 4-3, 7-6 lines in a 2' x 2' region around the young OB cluster NGC 3603
YC. These data are combined with C18O 2-1 data, HIRES-processed IRAS 60 and 100
micron maps of the FIR continuum, and Spitzer/IRAC maps. Results: The NANTEN2
observations show the presence of two molecular clumps located south-east and
south-west of the cluster and confirm the overall structure already found by
previous CS and C18O observations. We find a slight position offset of the peak
intensity of CO and [CI], and the atomic carbon appears to be further extended
compared to the molecular material. We used the HIRES far-infrared dust data to
derive a map of the FUV field heating the dust. We constrain the FUV field to
values of \chi = 3 - 6 \times 10^3 in units of the Draine field across the
clouds. Approximately 0.2 to 0.3 % of the total FUV energy is re-emitted in the
[CII] 158 {\mu}m cooling line observed by ISO. Applying LTE and escape
probability calculations, we derive temperatures (TMM1 = 43 K, TMM2 = 47 K),
column densities (N(MM1) = 0.9 \times 10^22 cm^-2, N(MM2) = 2.5 \times 10^22
cm^-2) and densities (n(MM1) = 3 \times 10^3 cm^-3, n(MM2) = 10^3 -10^4 cm^-3)
for the two observed molecular clumps MM1 and MM2. Conclusions: The cluster is
strongly interacting with the ambient molecular cloud, governing its structure
and physical conditions. A stability analysis shows the existence of
gravitationally collapsing gas clumps which should lead to star formation.
Embedded IR sources have already been observed in the outskirts of the
molecular cloud and seem to support our conclusions.Comment: 13 pages, 10 figures, accepted for publication by A&
Submillimeter Line Emission from LMC 30Dor: The Impact of a Starburst on a Low Metallicity Environment
(Abridged) The 30 Dor region in the Large Magellanic Cloud (LMC) is the most
vigorous star-forming region in the Local Group. Star formation in this region
is taking place in low-metallicity molecular gas that is exposed to an extreme
far--ultraviolet (FUV) radiation field powered by the massive compact star
cluster R136. We used the NANTEN2 telescope to obtain high-angular resolution
observations of the 12CO 4-3, 7-6, and 13CO 4-3 rotational lines and [CI]
3P1-3P0 and 3P2-3P1 fine-structure submillimeter transitions in 30Dor-10, the
brightest CO and FIR-emitting cloud at the center of the 30Dor region. We
derived the properties of the low-metallicity molecular gas using an
excitation/radiative transfer code and found a self-consistent solution of the
chemistry and thermal balance of the gas in the framework of a clumpy cloud PDR
model. We compared the derived properties with those in the N159W region, which
is exposed to a more moderate far-ultraviolet radiation field compared with
30Dor-10, but has similar metallicity. We also combined our CO detections with
previously observed low-J CO transitions to derive the CO spectral-line energy
distribution in 30Dor-10 and N159W. The separate excitation analysis of the
submm CO lines and the neutral carbon fine structure lines shows that the mid-J
CO and [CI]-emitting gas in the 30Dor-10 region has a temperature of about 160
K and a H2 density of about 10^4 cm^-3. We find that the molecular gas in
30Dor-10 is warmer and has a lower beam filling factor compared to that of
N159W, which might be a result of the effect of a strong FUV radiation field
heating and disrupting the low--metallicity molecular gas. We use a clumpy PDR
model (including the [CII] line intensity reported in the literature) to
constrain the FUV intensity to about chi_0 ~ 3100 and an average total H
density of the clump ensemble of about 10^5 cm^-3 in 30Dor-10.Comment: 11 pages, 8 figures. Accepted for publication in A&
The Photon Dominated Region in the IC 348 molecular cloud
In this paper we discuss the physical conditions of clumpy nature in the IC
348 molecular cloud.
We combine new observations of fully sampled maps in [C I] at 492 GHz and
12CO 4--3, taken with the KOSMA 3 m telescope at about 1' resolution, with
FCRAO data of 12CO 1--0, 13CO 1--0 and far-infrared continuum data observed by
HIRES/IRAS. To derive the physical parameters of the region we analyze the
three different line ratios. A first rough estimate of abundance is obtained
from an LTE analysis. To understand the [C I] and CO emission from the PDRs in
IC 348, we use a clumpy PDR model. With an ensemble of identical clumps, we
constrain the total mass from the observed absolute intensities. Then we apply
a more realistic clump distribution model with a power law index of 1.8 for
clump-mass spectrum and a power law index of 2.3 for mass-size relation.
We provide detailed fits to observations at seven representative positions in
the cloud, revealing clump densities between 4 10 cm and 4
10 cm and C/CO column density ratios between 0.02 and 0.26. The
derived FUV flux from the model fit is consistent with the field calculated
from FIR continuum data, varying between 2 and 100 Draine units across the
cloud. We find that both an ensemble of identical clumps and an ensemble with a
power law clump mass distribution produce line intensities which are in good
agreement (within a factor ~ 2) with the observed intensities. The models
confirm the anti-correlation between the C/CO abundance ratio and the hydrogen
column density found in many regions.Comment: 11 pages, 8 figures, accepted by A&
A clumpy-cloud PDR model of the global far-infrared line emission of the Milky Way
The fractal structure of the interstellar medium suggests that the
interaction of UV radiation with the ISM as described in the context of
photon-dominated regions (PDR) dominates most of the physical and chemical
conditions, and hence the far-infrared and submm emission from the ISM in the
Milky Way. We investigate to what extent the Galactic FIR line emission of the
important species CO, C, C+, and O, as observed by the Cosmic Background
Explorer (COBE) satellite can be modeled in the framework of a clumpy,
UV-penetrated cloud scenario. The far-infrared line emission of the Milky Way
is modeled as the emission from an ensemble of clumps with a power law clump
mass spectrum and mass-size relation with power-law indices consistent with the
observed ISM structure. The individual clump line intensities are calculated
using the KOSMA-tau PDR-model for spherical clumps. The model parameters for
the cylindrically symmetric Galactic distribution of the mass density and
volume filling factor are determined by the observed radial distributions. A
constant FUV intensity, in which the clumps are embedded, is assumed. We show
that this scenario can explain, without any further assumptions and within a
factor of about 2, the absolute FIR-line intensities and their distribution
with Galactic longitude as observed by COBE.Comment: 14 pages, 13 figures, accepted by A&A at the 7th of July, 200
The origin of the [C II] emission in the S140 PDRs - new insights from HIFI
Using Herschel's HIFI instrument we have observed [C II] along a cut through
S140 and high-J transitions of CO and HCO+ at two positions on the cut,
corresponding to the externally irradiated ionization front and the embedded
massive star forming core IRS1. The HIFI data were combined with available
ground-based observations and modeled using the KOSMA-tau model for photon
dominated regions. Here we derive the physical conditions in S140 and in
particular the origin of [C II] emission around IRS1. We identify three
distinct regions of [C II] emission from the cut, one close to the embedded
source IRS1, one associated with the ionization front and one further into the
cloud. The line emission can be understood in terms of a clumpy model of
photon-dominated regions. At the position of IRS1, we identify at least two
distinct components contributing to the [C II] emission, one of them a small,
hot component, which can possibly be identified with the irradiated outflow
walls. This is consistent with the fact that the [C II] peak at IRS1 coincides
with shocked H2 emission at the edges of the outflow cavity. We note that
previously available observations of IRS1 can be well reproduced by a
single-component KOSMA-tau model. Thus it is HIFI's unprecedented spatial and
spectral resolution, as well as its sensitivity which has allowed us to uncover
an additional hot gas component in the S140 region.Comment: accepted for publication in Astronomy and Astrophysics (HIFI special
issue
Sustained Release Myofascial Release as Treatment for a Patient with Complications of Rheumatoid Arthritis and Collagenous Colitis: A Case Report
Background: Myofascial release (MFR) is a manual therapeutic technique used to release fascial restrictions, which may cause neuromusculoskeletal and systemic pathology.
Purpose: This case report describes the use of sustained release MFR techniques in a patient with a primary diagnosis of rheumatoid arthritis (RA) and a secondary diagnosis of collagenous colitis. Changes in pain, cervical range of motion, fatigue, and gastrointestinal tract function, as well as the impact of RA on daily activities, were assessed.
Methods: A 54-year-old white woman presented with signs and symptoms attributed to RA and collagenous colitis. Pre and post measurements were taken with each treatment and during the interim between the initial and final treatment series. The patient recorded changes in pain, fatigue, gastrointestinal tract function, and quality of life. Cervical range of motion was assessed. Six sustained release MFR treatment sessions were provided over a 2-week period. Following an 8-week interim, two more treatments were performed.
Results: The patient showed improvements in pain, fatigue, gastrointestinal tract function, cervical range of motion, and quality of life following the initial treatment series of six sessions. The patient maintained positive gains for 5 weeks following the final treatment, after which her symptoms returned to near baseline measurements. Following two more treatments, positive gains were achieved once again.
Conclusions: In a patient with RA and collagenous colitis, the application of sustained release MFR techniques in addition to standard medical treatment may provide short-term and long-term improvements in comorbid symptoms and overall quality of life
Clumpy photon-dominated regions in Carina. I. [CI] and mid-J CO lines in two 4'x4' fields
The Carina region is an excellent astrophysical laboratory for studying the
feedback mechanisms of newly born, very massive stars within their natal giant
molecular clouds (GMCs) at only 2.35 kpc distance. We use a clumpy PDR model to
analyse the observed intensities of atomic carbon and CO and to derive the
excitation conditions of the gas. The NANTEN2-4m submillimeter telescope was
used to map the [CI] 3P1-3P0, 3P2-3P1 and CO 4-3, 7-6 lines in two 4'x4'
regions of Carina where molecular material interfaces with radiation from the
massive star clusters. One region is the northern molecular cloud near the
compact OB cluster Tr14, and the second region is in the molecular cloud south
of etaCar and Tr16. These data were combined with 13CO SEST spectra, HIRES/IRAS
60um and 100um maps of the FIR continuum, and maps of 8um IRAC/Spitzer and MSX
emission. We used the HIRES far-infrared dust data to create a map of the FUV
field heating the gas. The northern region shows an FUV field of a few 1000 in
Draine units while the field of the southern region is about a factor 10
weaker. We constructed models consisting of an ensemble of small spherically
symmetric PDR clumps within the 38" beam (0.43pc), which follow canonical
power-law mass and mass-size distributions. We find that an average local clump
density of 2x10**5 cm-3 is needed to reproduce the observed line emission at
two selected interface positions. Stationary, clumpy PDR models reproduce the
observed cooling lines of atomic carbon and CO at two positions in the Carina
Nebula.Comment: accepted by A&