1,071 research outputs found
Palomar/TripleSpec Observations of Spitzer/MIPSGAL 24 μm Circumstellar Shells: Unveiling the Natures of Their Central Sources
We present near-IR spectroscopic observations of the central sources in 17 circumstellar shells from a sample of more than 400 "bubbles" discovered in the Spitzer/MIPSGAL 24 μm survey of the Galactic plane and in the Cygnus-X region. To identify the natures of these shells, we have obtained J, H, and K band spectra with a resolution of ~2600 of the stars at their centers. We observed 14 MIPSGAL bubbles (MBs), WR149, and 2 objects in the Cygnus-X region (WR138a and BD+43 3710), our sample being about 2.5 mag fainter in the K band than previous studies of the central sources of MBs. We use spectroscopic diagnostics and spectral libraries of late- and early-type stars to constrain the natures of our targets. We find five late-type giants. The equivalent widths of their CO 2.29 μm features allow us to determine the spectral types of the stars and hence derive the extinction along the line of sight, distance, and physical size of the shells. We also find 12 early-type stars: in 9 MBs and the 3 comparison objects. We find that the subtype inferred from the near-IR for WR138a (WN9h) and WR149 (WN5h) agrees with that derived from optical observations. A careful analysis of the literature and the environment of BD+43 3710 allows us to rule out the carbon star interpretation previously suggested. Our near-IR spectrum suggests that it is a B5 supergiant. At the centers of the nine MBs, we find a WC5-6 star possibly of low mass, a candidate O5-6 V star, a B0 supergiant, a B/A-type giant, and five luminous blue variable (LBV) candidates. We also report the detections of emission lines arising from at least two shells with typical extents (~10"), in agreement with those in the mid-IR. We summarize the findings on the natures of the MBs since their discovery, with 30% of them now known. Most MBs with central sources detected in the near- to mid-IR have been identified and are red and blue giants, supergiants, or stars evolving toward these phases, including, in particular, a handful of newly discovered Wolf–Rayet stars and a significant number of LBV candidates
Interferometric Follow-Up of WISE Hyper-Luminous Hot, Dust-Obscured Galaxies
WISE has discovered an extraordinary population of hyper-luminous dusty
galaxies which are faint in the two bluer passbands (m and m) but are bright in the two redder passbands of WISE (m and
m). We report on initial follow-up observations of three of these
hot, dust-obscured galaxies, or Hot DOGs, using the CARMA and SMA
interferometer arrays at submm/mm wavelengths. We report continuum detections
at 1.3 mm of two sources (WISE J014946.17+235014.5 and WISE
J223810.20+265319.7, hereafter W0149+2350 and W2238+2653, respectively), and
upper limits to CO line emission at 3 mm in the observed frame for two sources
(W0149+2350 and WISE J181417.29+341224.8, hereafter W1814+3412). The 1.3 mm
continuum images have a resolution of 1-2 arcsec and are consistent with single
point sources. We estimate the masses of cold dust are 2.0 for W0149+2350 and 3.9 for W2238+2653,
comparable to cold dust masses of luminous quasars. We obtain 2 upper
limits to the molecular gas masses traced by CO, which are 3.3 and 2.3 for W0149+2350 and W1814+3412,
respectively. We also present high-resolution, near-IR imaging with WFC3 on the
Hubble Space Telescope for W0149+2653 and with NIRC2 on Keck for W2238+2653.
The near-IR images show morphological structure dominated by a single,
centrally condensed source with effective radius less than 4 kpc. No signs of
gravitational lensing are evident.Comment: 13 pages, 3 figures. ApJ in pres
A demand-driven approach for a multi-agent system in Supply Chain Management
This paper presents the architecture of a multi-agent decision support system for Supply Chain Management (SCM) which has been designed to compete in the TAC SCM game. The behaviour of the system is demand-driven and the agents plan, predict, and react dynamically to changes in the market. The main strength of the system lies in the ability of the Demand agent to predict customer winning bid prices - the highest prices the agent can offer customers and still obtain their orders. This paper investigates the effect of the ability to predict customer order prices on the overall performance of the system. Four strategies are proposed and compared for predicting such prices. The experimental results reveal which strategies are better and show that there is a correlation between the accuracy of the models' predictions and the overall system performance: the more accurate the prediction of customer order prices, the higher the profit. © 2010 Springer-Verlag Berlin Heidelberg
A sample of radio-loud QSOs at redshift ~ 4
We obtained spectra of 60 red, starlike objects (E< 18.8) identified with
FIRST radio sources, S_{1.4GHz} > 1 mJy. Eight are QSOs with redshift z>
3.6.Combined with our pilot search (Benn et al 2002), our sample of 121
candidates yields a total of 18 z > 3.6 QSOs (10 of these with z > 4.0). 8% of
candidates with S_{1.4GHz} 10
mJy are QSOs with z > 3.6. The surface density of E 1mJy,
z> 4 QSOs is 0.003 deg^{-2}. This is currently the only well-defined sample of
radio-loud QSOs at z ~ 4 selected independently of radio spectral index. The
QSOs are highly luminous in the optical (8 have M_B < -28, q_0 = 0.5, H_0 = 50
kms^{-1}Mpc^{-1}). The SEDs are as varied as those seen in optical searches for
high-redshift QSOs, but the fraction of objects with weak (strongly
self-absorbed) Ly alpha emission is marginally higher (3 out of 18) than for
high-redshift QSOs from SDSS (5 out of 96).Comment: Accepted for publication in MNRAS, 9 pages, Latex, 5 postscript
figures, 1 landscape table (postscript
Les temps de la consultation du comité d’entreprise
The DD4HEP detector description toolkit offers a flexible and easy-to-use solution for the consistent and complete description of particle physics detectors in a single system. The sub-component DDREC provides a dedicated interface to the detector geometry as needed for event reconstruction. With DDREC there is no need to define an additional, separate reconstruction geometry as is often done in HEP, but one can transparently extend the existing detailed simulation model to be also used for the reconstruction. Based on the extension mechanism of DD4HEP, DDREC allows one to attach user defined data structures to detector elements at all levels of the geometry hierarchy. These data structures define a high level view onto the detectors describing their physical properties, such as measurement layers, point resolutions, and cell sizes. For the purpose of charged particle track reconstruction, dedicated surface objects can be attached to every volume in the detector geometry. These surfaces provide the measurement directions, local-to-global coordinate transformations, and material properties. The material properties, essential for the correct treatment of multiple scattering and energy loss effects in charged particle reconstruction, are automatically averaged from the detailed geometry model along the normal of the surface. Additionally, a generic interface allows the user to query material properties at any given point or between any two points in the detector's world volume. In this paper we will present DDREC and how it is used together with the linear collider tracking software and the particle-flow package PANDORAPFA for full event reconstruction of the ILC detector concepts ILD and SiD, and of CLICdp. This flexible tool chain is also well suited for other future accelerator projects such as FCC and CEPC
Safety and efficacy of apremilast through 104 weeks in patients with moderate to severe psoriasis who continued on apremilast or switched from etanercept treatment: findings from the LIBERATE study
Background Apremilast, an oral phosphodiesterase‐4 inhibitor, has demonstrated efficacy in patients with moderate to severe psoriasis. Objective To evaluate long‐term efficacy and safety of apremilast in biologic‐naive patients with moderate to severe plaque psoriasis and safety of switching from etanercept to apremilast in the phase 3b LIBERATE trial. Methods Two hundred fifty patients were randomized to placebo, apremilast 30 mg BID or etanercept 50 mg QW through Week 16; thereafter, all patients continued or switched to apremilast through Week 104 (extension phase). Skin, scalp and nail involvement at Weeks 16, 52 and 104 were assessed using the Psoriasis Area and Severity Index (PASI; 0–72), Scalp Physician Global Assessment (ScPGA; 0–5) and Nail Psoriasis Severity Index (NAPSI; 0–8); patient‐reported outcomes (PROs) were assessed using the Dermatology Life Quality Index (DLQI; 0–32) and pruritus visual analog scale (VAS; 0–100 mm). Results The apremilast‐extension phase (Weeks 16–104) included 226 patients in the placebo/apremilast (n = 73), apremilast/apremilast (n = 74) and etanercept/apremilast (n = 79) groups, and at Week 104, 50.7%, 45.9% and 51.9% of these patients, respectively, maintained ≥75% reduction from baseline in PASI score (based on last‐observation‐carried‐forward analysis). Across treatment groups, ScPGA 0 (clear) or 1 (minimal) was achieved by 50.0%–59.2% of patients; NAPSI mean change from baseline was −48.1% to −51.1%; DLQI score ≤5 was achieved by 66.0%–72.5% of patients; and pruritus VAS mean change from baseline was −24.4 to −32.3. AEs in ≥5% of patients (diarrhoea, nausea, nasopharyngitis, upper respiratory tract infection and headache) did not increase with prolonged apremilast exposure. Conclusions Apremilast demonstrated significant and sustained improvements in skin, scalp, nails and PROs (pruritus and quality of life) over 104 weeks in patients with moderate to severe plaque psoriasis. Safety was consistent with the known safety profile of apremilast
Molecular Gas in Redshift 6 Quasar Host Galaxies
We report our new observations of redshifted carbon monoxide emission from
six z~6 quasars, using the PdBI. CO (6-5) or (5-4) line emission was detected
in all six sources. Together with two other previous CO detections, these
observations provide unique constraints on the molecular gas emission
properties in these quasar systems close to the end of the cosmic reionization.
Complementary results are also presented for low-J CO lines observed at the GBT
and the VLA, and dust continuum from five of these sources with the SHARC-II
bolometer camera at the CSO. We then present a study of the molecular gas
properties in our combined sample of eight CO-detected quasars at z~6. The
detections of high-order CO line emission in these objects indicates the
presence of highly excited molecular gas, with estimated masses on the order of
10^10 M_sun within the quasar host galaxies. No significant difference is found
in the gas mass and CO line width distributions between our z~6 quasars and
samples of CO-detected quasars and submillimeter galaxies.
Most of the CO-detected quasars at z~6 follow the far infrared-CO luminosity
relationship defined by actively star-forming galaxies at low and high
redshifts. This suggests that ongoing star formation in their hosts contributes
significantly to the dust heating at FIR wavelengths. The result is consistent
with the picture of galaxy formation co-eval with supermassive black hole
(SMBH) accretion in the earliest quasar-host systems. We investigate the black
hole--bulge relationships of our quasar sample, using the CO dynamics as a
tracer for the dynamical mass of the quasar host. The results place important
constraints on the formation and evolution of the most massive SMBH-spheroidal
host systems at the highest redshift.Comment: 34 pages, 8 figures, accepted for publication in Ap
Extended [CII] Emission in Local Luminous Infrared Galaxies
We present Herschel/PACS observations of extended [CII]157.7{\mu}m line
emission detected on ~ 1 - 10 kpc scales in 60 local luminous infrared galaxies
(LIRGs) from the Great Observatories All-sky LIRG Survey (GOALS). We find that
most of the extra-nuclear emission show [CII]/FIR ratios >~ 4 x 10^-3, larger
than the mean ratio seen in the nuclei, and similar to those found in the
extended disks of normal star-forming galaxies and the diffuse inter-stellar
medium (ISM) of our Galaxy. The [CII] "deficits" found in the most luminous
local LIRGs are therefore restricted to their nuclei. There is a trend for
LIRGs with warmer nuclei to show larger differences between their nuclear and
extra-nuclear [CII]/FIR ratios. We find an anti-correlation between [CII]/FIR
and the luminosity surface density, {\Sigma}_IR, for the extended emission in
the spatially-resolved galaxies. However, there is an offset between this trend
and that found for the LIRG nuclei. We use this offset to derive a beam
filling-factor for the star-forming regions within the LIRG disks of ~ 6 %
relative to their nuclei. We confront the observed trend to photo-dissociation
region (PDR) models and find that the slope of the correlation is much
shallower than the model predictions. Finally, we compare the correlation found
between [CII]/FIR and {\Sigma}_IR with measurements of high-redshift
starbursting IR-luminous galaxies.Comment: Accepted for publication in ApJ Letters. 5 pages, 2 figure
Study of the decay
We present a study of with X(3872) decaying to using a sample of 657 million pairs recorded at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider. Both and decay
modes are used. We find a peak of events with a mass of
, a width of and a product branching fraction , where the first errors are statistical
and the second ones are systematic. The significance of the signal is
. The difference between the fitted mass and the
threshold is calculated to be . We
also obtain an upper limit on the product of branching fractions of at
90% CL.Comment: 7 pages, 3 figures, BELLE-CONF-0832 contributed to ICHEP 2008,
revised and submitted to Phys. Rev. D R
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