1,071 research outputs found

    Palomar/TripleSpec Observations of Spitzer/MIPSGAL 24 μm Circumstellar Shells: Unveiling the Natures of Their Central Sources

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    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

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    WISE has discovered an extraordinary population of hyper-luminous dusty galaxies which are faint in the two bluer passbands (3.4μ3.4\, \mum and 4.6μ4.6\, \mum) but are bright in the two redder passbands of WISE (12μ12\, \mum and 22μ22\, \mum). 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 \sim 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 2.0×108M\times 10^{8} M_{\odot} for W0149+2350 and 3.9×108M\times 10^{8} M_{\odot} for W2238+2653, comparable to cold dust masses of luminous quasars. We obtain 2σ\sigma upper limits to the molecular gas masses traced by CO, which are 3.3×1010M\times 10^{10} M_{\odot} and 2.3×1010M\times 10^{10} M_{\odot} 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

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    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

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    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

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    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

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    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

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    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 1.4z51.4\leq z\leq5 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

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    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 BX(3872)(D0Dˉ0)KB\to X(3872)(\to D^{*0}\bar D^0)K decay

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    We present a study of BX(3872)KB\to X(3872)K with X(3872) decaying to D0Dˉ0D^{*0}\bar D^0 using a sample of 657 million BBˉB\bar B pairs recorded at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. Both D0D0γD^{*0}\to D^0\gamma and D0D0π0D^{*0}\to D^0\pi^0 decay modes are used. We find a peak of 50.111.1+14.850.1^{+14.8}_{-11.1} events with a mass of (3872.90.40.5+0.6+0.4)MeV/c2(3872.9^{+0.6 +0.4}_{-0.4 -0.5}){\rm MeV}/c^2, a width of (3.91.41.1+2.8+0.2)MeV/c2(3.9^{+2.8 +0.2}_{-1.4 -1.1}){\rm MeV}/c^2 and a product branching fraction B(BX(3872)K)×B(X(3872)D0Dˉ0)=(0.80±0.20±0.10)×104{\cal B}(B\to X(3872)K)\times{\cal B}(X(3872)\to D^{*0}\bar D^0)=(0.80\pm0.20\pm0.10)\times10^{-4}, where the first errors are statistical and the second ones are systematic. The significance of the signal is 6.4σ6.4\sigma. The difference between the fitted mass and the D0Dˉ0D^{*0}\bar D^0 threshold is calculated to be (1.10.40.3+0.6+0.1)MeV/c2(1.1^{+0.6 +0.1}_{-0.4 -0.3}){\rm MeV}/c^2. We also obtain an upper limit on the product of branching fractions B(BY(3940)K)×B(Y(3940)D0Dˉ0){\cal B}(B\to Y(3940)K)\times{\cal B}(Y(3940)\to D^{*0}\bar D^0) of 0.67×1040.67\times10^{-4} 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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