Probing the birth of fast rotating magnetars through high-energy neutrinos

We investigate the high-energy neutrino emission expected from newly born magnetars surrounded by their stellar ejecta. Protons might be accelerated up to 0.1-100 EeV energies possibly by, e.g., the wave dissipation in the winds, leading to hadronic interactions in the stellar ejecta. The resulting PeV-EeV neutrinos can be detected by IceCube/KM3Net with a typical peak time scale of a few days after the birth of magnetars, making the characteristic soft-hard-soft behavior. Detections would be important as a clue to the formation mechanism of magnetars, although there are ambiguities coming from uncertainties of several parameters such as velocity of the ejecta. Non-detections would also lead to useful constraints on the scenario.Comment: 5 pages, 3 figures, accepted for publication in PR

Gapless formation in the K0K^0 condensed color-flavor locked quark matter : a model-independent treatment

The electric/color neutral solution and the critical conditions for gapless formation are investigated in the $K^0$ condensed color-flavor locked matter. We point out that there exist no longer gapless modes for down-strange quark pairing while the gapless phenomenon for up-strange one is dominated in the $K^0$ condensed environment. In a model-independent way, the phase transition to the resulting gapless phase is found to be of first-order. The novel phase structure implies that the chromomagnetic instability happens in the previous-predicted gapless phase might be removed at least partly.Comment: 2 figure

ALMA Observations of Ethyl Formate toward Orion KL

Orion KL is one of the prime templates of astrochemical and prebiotic chemical studies. We wish to explore more organic molecules with increasing complexity in this region. In particular, we have searched for one of the most complex organic molecules detected in space so far, ethyl formate (C$_{2}$H$_{5}$OCHO). This species is the next step in chemical complexity after the simplest member of esters (methyl formate, CH$_{3}$OCHO). The mechanisms leading to its formation are still poorly known. We have used high angular resolution ($\sim$ 1.$^{\prime\prime}$5) ALMA observations covering a large bandwidth from 214 to 247 GHz. We have detected 82 unblended lines of C$_{2}$H$_{5}$OCHO (49 and 33 of the trans and gauche conformers, respectively). The line images showed that C$_{2}$H$_{5}$OCHO arises mainly from the compact ridge and the hot core-southwest regions. The derived rotational temperatures and column densities are 122 $\pm$ 34 K, (0.9 $\pm$ 0.3) $\times$ 10$^{16}$ cm$^{-2}$ for the hot core-SW, and 103 $\pm$ 13 K, (0.6 $\pm$ 0.3) $\times$ 10$^{16}$ cm$^{-2}$ for the compact ridge. The comparison of spatial distribution and abundance ratios with chemically related molecules (methyl formate, ethanol and formic acid) indicates that C$_{2}$H$_{5}$OCHO is likely formed on the surface of dust grains by addition of CH$_{3}$ to functional-group radicals (CH$_{2}$OCHO) derived from methyl formate (CH$_{3}$OCHO)

Identification of Two categories of optically bright gamma-ray bursts

We present the results of a systematical analysis of the intrinsic optical afterglow light curves for a complete sample of gamma-ray bursts (GRBs) observed in the period from Feb. 1997 to Aug. 2005. These light curves are generally well-sampled, with at least four detections in the $R$ band. The redshifts of all the bursts in the sample are available. We derive the intrinsic $R$ band afterglow lightcurves (luminosity versus time within the cosmic proper rest frame) for these GRBs, and discover a fact that they essentially follow two universal tracks after 2 hours since the GRB triggers. The optical luminosities at 1 day show a clear bimodal distribution, peaking at 1.4*10^{46} ergs~s^{-1} for the luminous group and 5.3*10^{44} ergs~s^{-1} for the dim group. About 75% of the GRBs are in the luminous group, and the other 25% belong to the dim group. While the luminous group has a wide range of redshift distribution, the bursts in the dim group all appear at a redshift lower than 1.1.Comment: 10 pages, 2 figures, emulateapj style, accepted for publication by ApJ Letter

Late-Time Optical Afterglow Observations with LBT and MDM

Using the 2.4m MDM and 8.4m Large Binocular Telescope, we observed nine GRB afterglows to systematically probe the late time behaviors of afterglows including jet breaks, flares, and supernova bumps. In particular, the LBT observations have typical flux limits of 25-26 mag in the Sloan r' band, which allows us to extend the temporal baseline for measuring jet breaks by another decade in time scale. We detected four jet breaks (including a "textbook" jet break in GRB070125) and a fifth candidate, all of which are not detectable without deep, late time optical observations. In the other four cases, we do not detect the jet breaks either because of contamination from the host galaxy light, the presence of a supernova bump, or the intrinsic faintness of the optical afterglow. This suggests that the basic picture that GRBs are collimated is still valid and that the apparent lack of Swift jet breaks is due to poorly sampled afterglow light curves, particularly at late times. Besides the jet breaks, we also detected late time flares, which could attribute to late central engine activities, and two supernova bumps.Comment: 5 pages, 5 figures, 2008 NANJING GAMMA-RAY BURST CONFERENCE. AIP Conference Proceedings, Volume 1065, pp. 93-97 (2008), Eds. Y.F. Huang, Z.G. Dai, B. Zhan

Nature and Nurture: a model for soft gamma-ray repeaters

During supernova explosions, strange stars with almost bare quark surfaces may be formed. Under certain conditions, these stars could be rapidly spun down by the torque exerted by the fossil disks formed from the fall-back materials. They may also receive large kicks and hence, have large proper motion velocities. When these strange stars pass through the spherical ``Oort'' comet cloud formed during the pre-supernova era, they will capture some small-scale comet clouds and collide with some comet-like objects occasionally. These impacts can account for the repeating bursts as observed from the soft gamma repeaters (SGRs). According to this picture, it is expected that SGR 1900+14 will become active again during 2004-2005.Comment: emulateapj, 5 pages, accepted by ApJ Letter

A Case Study on the Impact of Personal Characteristics on Residents’ Support for Tourism Development

A Case Study on the Impact of Personal Characteristics on Residents’ Support for Tourism Development Abstract This research assessed resident attitudes towards tourism including those areas that residents believe impact their quality of life. Specifically, the purpose of this study was to find how personal characteristics (distance from tourism zone, length of residency, and employment in the tourism sector) influence residents’ attitudes towards supporting tourism and the need for broader regulations to manage the sector’s impact on residents’ quality of life. Framed in social exchange theory and based on the works, this research proposes a serious of hypotheses and a structural equation model which examines the relationships among personal characteristics, the perceived positive/negative impact, and subsequent support for tourism development. Data were collected from a stratified random sample of residents of Charleston, SC in April 2014. AMOS program was utilized to test the conceptual model. Results reveal the existence of an indirect relationship between living distance to tourism district and residents’ attitude to tourism development, which is mediated by residents’ perception on the impact of tourism