116 research outputs found

    Shakhbazian compact galaxy groups. II. Photometric and spectroscopic study of ShCG 376

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    The results of the redshift measurements and of the detailed surface photometry in BVR of the compact group ShCG 376 are presented. The radial velocity dispersion, the virial mass, the total luminosity, the M/L ratio, and the crossing time of the group are estimated. The group consists of eight accordant redshift spiral galaxies. Four (or possibly five) of the group members have emission-line spectra. Such morphological content and the number of emission-line galaxies are very atypical for compact galaxy groups. There are signs of interaction between some members of the group. It is suggested that the irregular shape of the brightest galaxy No. 4 is probably due to interaction with other members of the group, particularly, the emission line galaxy No. 6 with a discordant redshift (Delta v = 2600 km/s). It is speculated that the latter galaxy may be a infalling intruder to the group.Comment: accepted A&A, 7 pages, 6 figures are in separate file

    Zero-Transmission Law for Multiport Beam Splitters

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    The Hong-Ou-Mandel effect is generalized to a configuration of n bosons prepared in the n input ports of a Bell multiport beam splitter. We derive a strict suppression law for most possible output events, consistent with a generic bosonic behavior after suitable coarse graining.Comment: Version accepted by PR

    Quantum transport efficiency and Fourier's law

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    We analyze the steady-state energy transfer in a chain of coupled two-level systems connecting two thermal reservoirs. Through an analytic treatment we find that the energy current is independent of the system size, hence violating Fourier's law of heat conduction. The classical diffusive behavior in Fourier's law of heat conduction can be recovered by introducing decoherence to the quantum systems constituting the chain. Implications of these results on energy transfer in biological light harvesting systems, and the role of quantum coherences and entanglement are discussed.Comment: 6 pages, 4 figure

    Design and Cost Analysis of a Self-contained Mobile Laboratory for Commercial-scale Aquatic Species Cryopreservation

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    © Copyright by the World Aquaculture Society 2018 Although aquatic species cryopreservation protocols have been studied around the world over the past 60 yr., germplasm repository development efforts and commercialization have begun only recently. The goal of this project was to develop a self-contained mobile laboratory for on-site high-throughput cryopreservation of aquatic species. The objectives of this study were to: (1) identify how a mobile laboratory would function in different operational scenarios, (2) customize an enclosed cargo trailer to function as a mobile laboratory, (3) evaluate the laboratory layout and ability of cryopreservation equipment to operate from generator power, and (4) document the investment costs for private and public groups to integrate a mobile laboratory into an existing cryopreservation facility at three levels of automation and estimate the total cost per trip based on hypothetical assumptions for two scenarios (aquaculture production and repository development). There were three operational designs identified for the mobile laboratory: (1) self-contained work inside the unit using generator power, (2) work inside the unit using external facility power, and (3) using the equipment inside of a host facility. The investment costs for a base-level mobile laboratory ranged between US5670andUS5670 and US5787 for private groups and between US5208andUS5208 and US5315 for public groups. With the addition of a range of automated processing equipment, total investment costs ranged from US13,616toUS13,616 to US103,529 for private groups and US12,494toUS12,494 to US94,891 for public groups. The total cost per trip to cryopreserve sperm of 59 blue catfish, Ictalurus furcatus, males to produce 6300 0.5-mL French straws was estimated to range from US6089toUS6089 to US14,633 for private and between US5703andUS5703 and US16,938 for public groups depending on the level of automation. Total cost per trip to cryopreserve sperm of 500 males of five different species in the genus Xiphophorus to produce 641 0.25-mL French straws was estimated to range from US6653toUS6653 to US7640 for private and US7582toUS7582 to US8088 for public groups depending on level of automation. Overall, a commercial-scale mobile laboratory was developed that can assist current germplasm activities and support future repository and industry development, and the layout information provided can help others to design and build comparable units

    Radio emission of Shakhbazian Compact Galaxy Groups

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    Three hundred fifty three radio sources from the NRAO VLA Sky Survey (NVSS) (Condon et al. 1998) and the FIRST Survey (White et al. 1997}, are detected in the areas of 179 Shakhbazian Compact Groups (ShCGs) of galaxies. Ninety three of them are identified with galaxies in 74 ShCGs. Six radio sources have complex structure. The radio spectra of 22 sources are determined. Radio luminosities of galaxies in ShCGs are in general higher than that of galaxies in Hickson Compact Groups (HCGs). The comparison of radio (at 1.4 GHz) and FIR (at 60 μ\mum) fluxes of ShCG galaxies with that of HCG galaxies shows that galaxies in ShCGs are relatively stronger emitters at radio wavelengths, while galaxies in HCGs have relatively stronger FIR emission. The reasons of such difference is discussed.Comment: 35 pages, 6 Postscript figures, ApJS in pres

    Approaches to Measuring Entanglement in Chemical Magnetometers

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    Chemical magnetometers are radical pair systems such as solutions of pyrene and N,N-dimethylaniline (Py–DMA) that show magnetic field effects in their spin dynamics and their fluorescence. We investigate the existence and decay of quantum entanglement in free geminate Py–DMA radical pairs and discuss how entanglement can be assessed in these systems. We provide an entanglement witness and propose possible observables for experimentally estimating entanglement in radical pair systems with isotropic hyperfine couplings. As an application, we analyze how the field dependence of the entanglement lifetime in Py–DMA could in principle be used for magnetometry and illustrate the propagation of measurement errors in this approach

    On the X-ray emission of the low-mass galaxy groups

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    It is shown that the low-mass groups obey the Lxσv4L_{x}\sim\sigma_v^{4} law deduced for galaxy clusters. The impression of the more shallow slope of the LxσvL_x-\sigma_{v} correlation for groups is created not by enhanced X-ray emission, but by underestimation of the radial velocity dispersion of some groups.Comment: 4 pages, 2 figures, accepted in ApJ

    Measurement-based quantum computing with a spin ensemble coupled to a stripline cavity

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    Recently a new form of quantum memory has been proposed. The storage medium is an ensemble of electron spins, coupled to a stripline cavity and an ancillary readout system. Theoretical studies suggest that the system should be capable of storing numerous qubits within the ensemble, and an experimental proof-of-concept has already been performed. Here we show that this minimal architecture is not limited to storage but is in fact capable of full quantum processing by employing measurement-based entanglement. The technique appears to be remarkably robust against the anticipated dominant error types. The key enabling component, namely a readout technology that non-destructively determines "are there n photons in the cavity?", has already been realised experimentally.Comment: 17 pages, 8 figure

    Far-infrared emission from Shakhbazian Compact Galaxy Groups

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    Using the IRAS archives, we searched for far-infrared (FIR) counterparts of Shakh bazian Compact Groups of Galaxies (SCGGs). Reliable IRAS detections are identified at the positions of 24 out of 367 SCGGs; another 10 IRAS sources, located within ~2 arcmin of SCGGs, are possibly associated with the corresponding galaxy groups. Some of these sources are not very reliable. Previous work has shown that the fraction of E and S0 galaxies in a representative sample of SCGGs is 77%, while E and S0 galaxies comprise about 51% of galaxies in Hickson Compact Groups (HCGs). The higher fraction of early Hubble types, combined with their greater distances, explains the low IRAS detection rate of SCGGs (7-8%) compared to HCGs (64%). The FIR colors and morphological types of galaxies in the groups suggest that active star formation or Seyfert galaxies may be the main source of the FIR emission in the SCGGs detected by IRAS, perhaps originating as the result of tidal interactions in the dense environments of these groups
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