478 research outputs found

    Line Evolution of the Nova V5587 Sgr from Early to Nebula Phase

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    The spectral evolution of the nova V5587 Sgr has been monitored at Koyama Astronomical Observatory and Higashi-Hiroshima Observatory, Japan, from the early to nebula phase. The nova rebrightened several times. The spectra during the early phase showed emission lines of H α, H β, O I, He I, He II, N II, Fe II. Nova V5587 Sgr is classified into the Fe II type. The helium abundance of the nova is estimated as N(He)/N(H) = 0.134 ± 0.09. The light curve, the spectral evolution, and the helium abundance in V5587 Sgr are similar to those of the nova PW Vul

    Spectroscopic Monitoring Observations of Nova V1724 Aql in 2012

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    Spectroscopic and photometric monitoring observations of nova Apl 2012 (V1724 Apl) were conducted at Koyama Astronomical Observatory, Fujii-Kurosaki Observatory and Bisei Astronomical Observatory. The nova was initially considered as an outbursting pre-main-sequence young stellar object. Our monitoring observations have revealed the nova to be a Fe II type classical nova. The temporal evolution of spectra and light curves of the nova were similar to those of a slow nova (e.g., V1280 Sco and V5558 Sgr). We observed no evidence of molecule formation in V1724 Aql in contrast with V2676 Oph in which dust formation occurred after the molecular formation in the nova outflow

    Amniotic membrane transplantation for wound dehiscence after deep lamellar keratoplasty: a case report

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    <p>Abstract</p> <p>Purpose</p> <p>To report amniotic membrane (AM) transplantation in a patient with wound dehiscence 5 months after deep lamellar keratoplasty (DLKP)</p> <p>Methods</p> <p>The patient was an 84-year-old Japanese man who had undergone right DLKP 5 months earlier for central corneal scarring due to recurrent stromal herpetic keratitis. He developed wound dehiscence with corneal stromal melting due to recurrence of stromal herpes in both the donor and recipient sites. "AM roll-in filling technique" and AM patching were performed.</p> <p>Results</p> <p>Following AM transplantation, stromal inflammation subsided and complete epithelization occurred within 10 days of surgery.</p> <p>At 8 months postoperatively, biomicroscopy revealed stable wound apposition or stromal gain. Following AM transplantation, stromal inflammation subsided and complete epithelialization was achieved within 10 days after surgery.</p> <p>Conclusion</p> <p>AM transplantation may offer an effective treatment modality for herpetic corneal wound dehiscence after DLKP.</p

    Recent Searches for the Radio Lines of NH_3 in Comets

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    Radio observations in the ammonia inversion lines of four comets, C/2001 A2 (LINEAR), 153P/Ikeya-Zhang, C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR), were performed at the Effelsberg 100-m Radio Telescope during their respective close approaches to Earth. None of the four lowest energy metastable lines (J,K=J),J=1--4, could be detected in these comets. We derive the following 3 sigma upper bounds on the NH_3 production rate, and c omparing to the corresponding water production rates, percentage NH_3 abundances relative to H_2O: Q(NH_3) < 1.9x10^26 s^-1 (0.63%) for C/2001 A2 (LINEAR), Q(NH_3) < 2.7x10^26 s^-1 (0.13%) for C/2001 Q4 (NEAT), Q(NH_3) < 2.3x10^27 s^-1 (0.74%) for C/2002 T7 (LINEAR) and Q(NH_3) <= 6.3x10^26 s^-1 (0.63%) for Comet 153P/Ikeya-Zhang. At 0.74% or less, the ammonia-to-water ratios are factors of 2 below the value for C/1995 O1 (Hale-Bopp) and 1P/Halley, suggesting chemical diversity between comets. The 18-cm lines of OH were clearly detected in the two comets observed during the 2004 campaign, thereby validating the cometary ephemerides.Comment: 8 pages, 3 figure

    Chandra Observations of Type Ia Supernovae: Upper Limits to the X-ray Flux of SN 2002bo, SN 2002ic, SN 2005gj, and SN 2005ke

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    We set sensitive upper limits to the X-ray emission of four Type Ia supernovae (SNe Ia) using the Chandra X-ray Observatory. SN 2002bo, a normal, although reddened, nearby SN Ia, was observed 9.3 days after explosion. For an absorbed, high temperature bremsstrahlung model the flux limits are 3.2E-16 ergs/cm^2/s (0.5-2 keV band) and 4.1E-15 ergs/cm^2/s (2-10 keV band). Using conservative model assumptions and a 10 km/s wind speed, we derive a mass loss rate of \dot{M} ~ 2E-5 M_\odot/yr, which is comparable to limits set by the non-detection of Halpha lines from other SNe Ia. Two other objects, SN 2002ic and SN 2005gj, observed 260 and 80 days after explosion, respectively, are the only SNe Ia showing evidence for circumstellar interaction. The SN 2002ic X-ray flux upper limits are ~4 times below predictions of the interaction model currently favored to explain the bright optical emission. To resolve this discrepancy we invoke the mixing of cool dense ejecta fragments into the forward shock region, which produces increased X-ray absorption. A modest amount of mixing allows us to accommodate the Chandra upper limit. SN 2005gj is less well studied at this time. Assuming the same circumstellar environment as for SN 2002i, the X-ray flux upper limits for SN 2005gj are ~4 times below the predictions, suggesting that mixing of cool ejecta into the forward shock has also occurred here. Our reanalysis of Swift and Chandra data on SN 2005ke does not confirm a previously reported X-ray detection. The host galaxies NGC 3190 (SN 2002bo) and NGC 1371 (SN 2005ke) each harbor a low luminosity (L_X ~ 3-4E40 ergs/s) active nucleus in addition to wide-spread diffuse soft X-ray emission.Comment: 16 pages, to appear in ApJ (20 Nov 2007
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