1,439 research outputs found
To see or not to see a Bow Shock: Identifying Bow Shocks with H-Alpha Allsky Surveys
OB-stars have the highest luminosities and strongest stellar winds of all
stars, which enables them to interact strongly with their surrounding ISM, thus
creating bow shocks. These offer us an ideal opportunity to learn more about
the ISM. They were first detected and analysed around runaway OB-stars using
the IRAS allsky survey by van Buren et al. (1995). Using the geometry of such
bow shocks information concerning the ISM density and its fluctuations can be
gained from such infrared observations. As to help to improve the bow shock
models, additional observations at other wavelengths, e.g. H-Alpha, are most
welcome. However due to their low velocity these bow shocks have a size of ~1
degrees, and could only be observed as a whole with great difficulties. In the
light of the new H-Alpha allsky surveys (SHASSA/VTSS) this is no problem any
more. We developed different methods to detect bow shocks, e.g. the improved
determination of their symmetry axis with radial distance profiles. Using two
H-Alpha-allsky surveys (SHASSA/VTSS), we searched for bow shocks and compared
the different methods. From our sample we conclude, that the correlation
between the direction of both proper motion and the symmetry axis determined
with radial distance profile is the most promising detection method. We found
eight bow shocks around HD 17505, HD 24430, HD 48099, HD 57061, HD 92206, HD
135240, HD 149757, and HD 158186 from 37 candidates taken from van Buren et al.
(1995). Additionally to the traditional determination of ISM parameters using
the standoff distance of the bow shock, another approach was chosen, using the
thickness of the bow-shock layer. Both methods lead to the same results,
yielding densities (~1 cm^{-3}) and the maximal temperatures (~10^4 K), that
fit well to the up-to-date picture of the Warm Ionised Medium.Comment: 12 pages, 12 figures, Accepted, A&A 04/28/200
A Candidate Protoplanet in the Taurus Star Forming Region
HST/NICMOS images of the class I protostar TMR-1 (IRAS04361+2547) reveal a
faint companion with 10.0" = 1400 AU projected separation. The central
protostar is itself resolved as a close binary with 0.31" = 42 AU separation,
surrounded by circumstellar reflection nebulosity. A long narrow filament seems
to connect the protobinary to the faint companion TMR-1C, suggesting a physical
association. If the sources are physically related then we hypothesize that
TMR-1C has been ejected by the protobinary. If TMR-1C has the same age and
distance as the protobinary then current models indicate its flux is consistent
with a young giant planet of several Jovian masses.Comment: 16 pages, 1 figure, Accepted by Astrophysical Journal Letters,
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Comparison of Visual Analog Pain Score Reported to Physician vs Nurse in Nonoperatively Treated Foot and Ankle Patients
Background: Patient reported outcome measures (PROMs) are taking a more prominent role in Orthopedics as health care seeks to define treatment outcomes. The Visual Analogue Scale (VAS) is considered a reliable measure of acute pain. A previous study found that operative candidates’ VAS pain score was significantly higher when reported to the surgeon compared to the nurse. This study’s aim is to examine whether this phenomenon occurs in nonoperative patients. We hypothesize that patients’ VAS scores reported to the surgeon and a nurse will be the same
Methods: This study is a retrospective cohort of 201 consecutive nonoperative patients treated by a single surgeon. Patients were asked to rate pain intensity by a nurse followed by the surgeon using a horizontal VAS, 0 “no pain” to 10 worst pain”. Differences in reported pain levels were compared with data from the previous cohort of 201 consecutive operative patients.
Results: The mean VAS score reported to the nurse was 3.2 whereas the mean VAS score reported to the surgeon was 4.2 (p\u3c.001). The mean difference in VAS scores reported for operative patients was 2.9, whereas the mean difference for nonoperative patients was 1.0 (p \u3c .001).
Conclusion: This study found statistically significant differences between VAS scores reported to the surgeon versus the nurse in nonoperative patients which support the trend found in our previous study, where operative patients reported significantly higher scores to the surgeon. The mean difference between reported pain scores is significantly higher for operative patients compared to nonoperative patients
Case-Control Study of Risk Factors Associated with Feline and Canine Chronic Kidney Disease
An age-matched case-control study was initiated to determine the major risk factors associated with CKD in cats and dogs and to determine what clinical signs cat and dog owners observed before their veterinarian diagnosed their pet with CKD. When compared to controls, the feline cases were more likely to have had polydipsia and polyuria in the year before the owners' cats were diagnosed with CKD. In the dogs, increased water intake, increased urination, small size and a recent history of weight loss and bad breath were noticed by the dog owners before veterinary CKD diagnosis. Dog owners recognized abnormal drinking and urination behavior over half a year before their pet's veterinary diagnosis with CKD, and they recognized weight loss almost 4 months before CKD diagnosis. Bad breath was noticed 1.2 years before recognition of CKD by a veterinarian. Given that earlier CKD diagnosis should have been possible in most cases, clinical trials should proceed to measure the efficacy of early interventions
Development and test of an IR camera for astronomical observation at the Palomar 200-inch observatory using the NICMOS II array
A NICMOS II array, a NIR (0.80 - 2.6 micron) imaging system, was integrated into the California Institute of Technology Palomar Observatory camera. The Palomar camera system which consists of six discrete subsystems including a focal plane, an electrical interface, data acquisition electronics, a dewar, dewar optics, and the software is described. The performance and calibration data for each subsystem are presented. Emphasis is placed on test data on the focal plane performance
An IR Search for Extinguished Supernovae in Starburst Galaxies
IR and Radio band observations of heavily extinguished regions in starburst
galaxies suggest a very high SN rate associated with such regions. Optically
measured supernova (SN) rates may therefore underestimate the total SN rate by
factors of up to 10, due to the high extinction to SNe in starburst regions.
The IR/radio SN rates come from a variety of indirect means, however, which
suffer from model dependence and other problems.
We describe a direct measurement of the SN rate from a regular patrol of
starburst galaxies done with K' band imaging to minimize the effects of
extinction. A collection of K' measurements of core-collapse SNe near maximum
light is presented. Results of a preliminary SN search using the MIRC camera at
the Wyoming IR Observatory (WIRO), and an improved search using the ORCA optics
are described. A monthly patrol of starburst galaxies within 25 Mpc should
yield 1.6 - 9.6 SNe/year. Our MIRC search with low-resolution (2.2" pixels)
failed to find extinguished SNe, limiting the SN rate outside the nucleus (at >
15" radius) to less than 3.8 Supernova Rate Units (SRU or SNe/century/10^10
L(solar); 90% confidence). The MIRC camera had insufficient resolution to
search nuclear starburst regions, where SN activity is concentrated, explaining
why we found no heavily obscured SNe. We conclude that high-resolution, small
field SN searches in starburst nuclei are more productive than low resolution,
large-field searches, even for our large galaxies. With our ORCA
high-resolution optics, we could limit the total SN rate to < 1.3 SRU at 90%
confidence in 3 years of observations, lower than the most pessimistic
estimate.Comment: AJ Submitted 1998 Dec. 13. View figures and download all as one file
at http://panisse.lbl.gov/public/bruce/irs
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