Radio-Infrared Correlation for Local Dusty Galaxies and Dusty AGNs from the AKARI All Sky Survey

We use the new release of the AKARI Far-Infrared all sky Survey matched with the NVSS radio database to investigate the local ($z<0.25$) far infrared-radio correlation (FIRC) of different types of extragalactic sources. To obtain the redshift information for the AKARI FIS sources we crossmatch the catalogue with the SDSS DR8. This also allows us to use emission line properties to divide sources into four categories: i) star-forming galaxies (SFGs), ii) composite galaxies (displaying both star-formation and active nucleus components), iii) Seyfert galaxies, and iv) low-ionization nuclear emission-line region (LINER) galaxies. We find that the Seyfert galaxies have the lowest FIR/radio flux ratios and display excess radio emission when compared to the SFGs. We conclude that FIRC can be used to separate SFGs and AGNs only for the most radio-loud objects.Comment: 9 pages, accepted to PAS

Morphometric parameters of cardiac implantable electronic device (CIED) pocket walls observed on device replacement

Background: The final stage of a conventional de-novo cardiac implantable electronic device (CIED) implantation procedure with transvenous lead insertion involves the formation of a pocket by tissue separation superficial to the pectoralis major muscle in the right or left infraclavicular region, where the device is subsequently placed. Over time, a scar “capsule” is formed around the CIED as a result of normal biological remodelling. Materials and methods: The purpose of this study was to analyse the structure and present the variations of CIED capsules observed during device replacement. The nature and extent of this local tissue remodelling, which had occurred from the time of device implantation to its replacement in 2016 (10 ± 3.1 years), was analysed in 100 patients (mean age 77.1 ± 14.5 years), including 45 women and 55 men. Results: The most prevalent types of “capsules” (70% of cases) were those with similar thickness of both walls or a slightly thicker posterior (&lt; 1.0 mm) than anterior wall (&lt; 0.5 mm). The second most common capsule type (23% of cases) was characterised by a significantly thicker posterior wall of scar tissue (&gt; 1.0 mm). The third group of capsules was characterised by various degrees of wall calcification (7% of cases). Conclusions: The extent and nature of scar tissue structure in the CIED pocket walls seem to correlate with the relative position of cardiac lead loops with respect to the device itself; where the more extensive scarring is likely to result from pocket wall irritation in the capsule formation phase due to lead movements underneath the device. The group of cases with calcified capsules was characterised by “old” device pockets (&gt; 13 years) and the oldest population (patients in their 80s and 90s)

An artificial protein cage made from a 12-membered ring

Artificial protein cages have great potential in diverse fields including as vaccines and drug delivery vehicles. TRAP-cage is an artificial protein cage notable for the way in which the interface between its ring-shaped building blocks can be modified such that the conditions under which cages disassemble can be controlled. To date, TRAP-cages have been constructed from homo-11mer rings, i.e., hendecamers. This is interesting as convex polyhedra with identical regular faces cannot be formed from hendecamers. TRAP-cage overcomes this limitation due to intrinsic flexibility, allowing slight deformation to absorb any error. The resulting TRAP-cage made from 24 TRAP 11mer rings is very close to regular with only very small errors necessary to allow the cage to form. The question arises as to the limits of the error that can be absorbed by a protein structure in this way before the formation of an apparently regular convex polyhedral becomes impossible. Here we use a naturally occurring TRAP variant consisting of twelve identical monomers (i.e., a dodecamer) to probe these limits. We show that it is able to form an apparently regular protein cage consisting of twelve TRAP rings. Comparison of the cryo-EM structure of the new cage with theoretical models and related cages gives insight into the rules of cage formation and allows us to predict other cages that may be formed given TRAP-rings consisting of different numbers of monomers

The AMANDA Neutrino Telescope and the Indirect Search for Dark Matter

With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.Comment: Latex2.09, 16 pages, uses epsf.sty to place 15 postscript figures. Talk presented at the 3rd International Symposium on Sources and Detection of Dark Matter in the Universe (DM98), Santa Monica, California, Feb. 199

Star-galaxy separation in the AKARI NEP Deep Field

Context: It is crucial to develop a method for classifying objects detected in deep surveys at infrared wavelengths. We specifically need a method to separate galaxies from stars using only the infrared information to study the properties of galaxies, e.g., to estimate the angular correlation function, without introducing any additional bias. Aims. We aim to separate stars and galaxies in the data from the AKARI North Ecliptic Pole (NEP) Deep survey collected in nine AKARI / IRC bands from 2 to 24 {\mu}m that cover the near- and mid-infrared wavelengths (hereafter NIR and MIR). We plan to estimate the correlation function for NIR and MIR galaxies from a sample selected according to our criteria in future research. Methods: We used support vector machines (SVM) to study the distribution of stars and galaxies in the AKARIs multicolor space. We defined the training samples of these objects by calculating their infrared stellarity parameter (sgc). We created the most efficient classifier and then tested it on the whole sample. We confirmed the developed separation with auxiliary optical data obtained by the Subaru telescope and by creating Euclidean normalized number count plots. Results: We obtain a 90% accuracy in pinpointing galaxies and 98% accuracy for stars in infrared multicolor space with the infrared SVM classifier. The source counts and comparison with the optical data (with a consistency of 65% for selecting stars and 96% for galaxies) confirm that our star/galaxy separation methods are reliable. Conclusions: The infrared classifier derived with the SVM method based on infrared sgc- selected training samples proves to be very efficient and accurate in selecting stars and galaxies in deep surveys at infrared wavelengths carried out without any previous target object selection.Comment: 8 pages, 8 figure

The AMANDA Neutrino Telescope: Principle of Operation and First Results

AMANDA is a high-energy neutrino telescope presently under construction at the geographical South Pole. In the Antarctic summer 1995/96, an array of 80 optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths between 1.5 and 2 km. In this paper we describe the design and performance of the AMANDA-B4 prototype, based on data collected between February and November 1996. Monte Carlo simulations of the detector response to down-going atmospheric muon tracks show that the global behavior of the detector is understood. We describe the data analysis method and present first results on atmospheric muon reconstruction and separation of neutrino candidates. The AMANDA array was upgraded with 216 OMs on 6 new strings in 1996/97 (AMANDA-B10), and 122 additional OMs on 3 strings in 1997/98.Comment: 36 pages, 23 figures, submitted to Astroparticle Physic

Clustering of the AKARI NEP deep field 24<i>μ</i>m selected galaxies

Aims. We present a method of selection of 24 μm galaxies from the AKARI north ecliptic pole (NEP) deep field down to 150 μJy and measurements of their two-point correlation function. We aim to associate various 24 μm selected galaxy populations with present day galaxies and to investigate the impact of their environment on the direction of their subsequent evolution. Methods. We discuss using of Support Vector Machines (SVM) algorithm applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy higher than 80%. The photometric redshift information, obtained through the CIGALE code, is used to explore the redshift dependence of the correlation function parameter (r0) as well as the linear bias evolution. This parameter relates galaxy distribution to the one of the underlying dark matter. We connect the investigated sources to their potential local descendants through a simplified model of the clustering evolution without interactions. Results. We observe two different populations of star-forming galaxies, at zmed ∼ 0.25, zmed ∼ 0.9. Measurements of total infrared luminosities (LTIR) show that the sample at zmed ∼ 0.25 is composed mostly of local star-forming galaxies, while the sample at zmed ∼ 0.9 is composed of luminous infrared galaxies (LIRGs) with LTIR ∼ 1011.62 L⨀. We find that dark halo mass is not necessarily correlated with the LTIR: for subsamples with LTIR = 1011.15 L⨀ at zmed ∼ 0.7 we observe a higher clustering length (r0 = 6.21 ± 0.78 [h−1Mpc]) than for a subsample with mean LTIR = 1011.84 L⨀ at zmed ∼ 1.1 (r0 = 5.86 ± 0.69 h−1Mpc). We find that galaxies at zmed ∼ 0.9 can be ancestors of present day L∗ early type galaxies, which exhibit a very high r0 ∼ 8h−1 Mpc.</p

Effect of symmetry reduction on the electronic transitions in polytypic GdAl3(BO3)4:Eu:Tb crystals

The existence of a recently described monoclinic phase (C2/c, Z=8) in addition to the well-known Huntite type rhombohedral (R32) polytypic modification of the GdAl3(BO3)4 (GAB) crystal at room temperature provides a unique possibility to investigate the incorporation of rare earth dopants into slightly modified crystal lattice by spectroscopic methods. In these characteristic GAB structures the dopant ions, e.g Tb3+ or Eu3+ , possess slightly different neighbor geometries and local symmetries. The Tb3+:7F6 → 5D4 and Eu3+:7F0,1,2 → 5D0,1,2 electronic transitions were successfully identified in the absorption spectra using polarization, concentration and temperature dependent measurements in both polytypic modifications. The positions of the investigated Tb lines are shifted by up to 10 cm−1 due to symmetry changes. In addition, some of the Eu lines show splittings of about 4–30 cm−1 as a consequence of the change of the local environment. From the room temperature absorption measurements some of the low energy crystal field levels of 7F and 5D states of the Eu3+ ions were successfully determined for both modifications

The AMANDA Neutrino Telescope

With an effective telescope area of order $10^4$ m$^2$ for TeV neutrinos, a threshold near $\sim$50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript files included. Talk presented at the 18th International Conference on Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199

Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector

Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon-neutrinos, as predicted from, e.g., the sum of all active galaxies in the universe. This search yielded no excess events above those expected from the background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux. For an assumed E^-2 spectrum, a 90% classical confidence level upper limit has been placed at a level E^2 Phi(E) = 8.4 x 10^-7 GeV cm^-2 s^-1 sr^-1 (for a predominant neutrino energy range 6-1000 TeV) which is the most restrictive bound placed by any neutrino detector. When specific predicted spectral forms are considered, it is found that some are excluded.Comment: Submitted to Physical Review Letter