tipa -- 11/8/2011

The first Infrared study of the close environment of a long Gamma-Ray Burst

• Authors: E.Le Floc'h (1), V.Charmandaris (2,3,4), K.Gordon (5), W.J.Forrest (6), B.Brandl (7), D.Schaerer (8,9), M.Dessauges-Zavadsky (8), L.Armus (10) ((1) CEA/AIM, France, (2) Univ.of Crete, Greece, (3) Obs.de Paris, France, (4) IESL, Greece, (5) STScI, Baltimore, USA, (6) Univ.of Rochester, USA, (7) Leiden Obs., Netherlands, (8) Geneva Obs., Switzerland, (9) CNRS/IRAP, France, (10) Spitzer Science Center, Pasadena, USA)

A nearby GRB host galaxy: VLT/X-shooter observations of HG 031203

• Authors: N. G. Guseva (1,2), Y. I. Izotov (1,2), K. J. Fricke (1,3), C. Henkel (1) ((1) Max-Planck-Institute for Radioastronomy, Bonn, Germany, (2) Main Astronomical Observatory, Kyiv, Ukraine, (3) Institute for Astrophysics, University of Goettingen, Goettingen, Germany)

Effect of Population III Multiplicity on Dark Star Formation

• Authors: Athena Stacy, Andreas H. Pawlik, Volker Bromm, Abraham Loeb

Enhancing the Relative Fe-to-Proton Abundance in Ultra-High-Energy Cosmic Rays

• Authors: Carl Blaksley, Etienne Parizot

Pulsar Pair Cascades in Magnetic Fields with Offset Polar Caps

• Authors: Alice K. Harding, Alex G. Muslimov

A comparison between star formation rate diagnostics and rate of core collapse supernovae within 11 Mpc

• Authors: M. T. Botticella, S. J. Smartt, R. C. Kennicutt Jr., E. Cappellaro, M. Sereno, J. C. Lee

Black hole-neutron star mergers for 10 solar mass black holes

• Authors: Francois Foucart, Matthew D. Duez, Lawrence E. Kidder, Mark A. Scheel, Bela Szilagyi, Saul A. Teukolsky

Neutrino mass in cosmology: status and prospects

• Authors: Yvonne Y. Y. Wong

Nuclear condensate and helium white dwarfs

• Authors: Paulo F. Bedaque, Evan Berkowitz, Aleksey Cherman

Shining a Gluon Beam Through Quark-Gluon Plasma

• Authors: Paul M. Chesler, Ying-Yu Ho, Krishna Rajagopal

tipa -- 11/7/2011

A Compact Degenerate Primary-Star Progenitor of SN 2011fe

• Authors: Joshua S. Bloom, Daniel Kasen, Ken J. Shen, Peter E. Nugent, Nathaniel R. Butler, Melissa L. Graham, D. Andrew Howell, Ulrich Kolb, Stefan Holmes, Carole Haswell, Vadim Burwitz, Juan Rodriguez, Mark Sullivan

Unifying the Zoo of Jet-Driven Stellar Explosions

• Authors: Davide Lazzati (NCSU), Brian J. Morsony (UWi Madison), Christopher H. Blackwell (NCSU & UAH), Micthell C. Begelman (CU Boulder)

tipa -- 11/4/2011

Cosmic flows in the nearby universe from Type Ia Supernovae

• Authors: Stephen J. Turnbull, Michael J. Hudson, Hume A. Feldman, Malcolm Hicken, Robert P. Kirshner, Richard Watkin

Hydrodynamics of Core-Collapse Supernovae at the Transition to Explosion. I. Spherical Symmetry

• Authors: Rodrigo Fernández (IAS)

Discovery of a giant, highly-collimated jet from Sanduleak's star in the Large Magellanic Cloud

• Authors: R. Angeloni (1), F. Di Mille (2), J. Bland-Hawthorn (3), D. Osip (4)- ((1) Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, (2) Australian Astronomical Observatory - Carnegie Observatories, (3) Sydney Institute for Astronomy, School of Physics, University of Sydney, (4) Las Campanas Observatory, Carnegie Observatories)

A measurement of secondary cosmic microwave background anisotropies with two years of South Pole Telescope observations

• Authors: C. L. Reichardt, L. Shaw, O. Zahn, K. A. Aird, B. A. Benson, L. E. Bleem, J. E. Carlstrom, C. L. Chang, H. M. Cho, T. M. Crawford, A. T. Crites, T. de Haan, M. A. Dobbs, J. Dudley, E. M. George, N. W. Halverson, G. P. Holder, W. L. Holzapfel, S. Hoover, Z. Hou, J. D. Hrubes, M. Joy, R. Keisler, L. Knox, A. T. Lee, E. M. Leitch, M. Lueker, D. Luong-Van, J. J. McMahon, J. Mehl, S. S. Meyer, M. Millea, J. J. Mohr, T. E. Montroy, T. Natoli, S. Padin, T. Plagge, C. Pryke, J. E. Ruhl, K. K. Schaffer, E. Shirokoff, H. G. Spieler, Z. Staniszewski, A. A. Stark, K. Story, A. van Engelen, K. Vanderlinde, J. D. Vieira, R. Williamson

High-Energy Emission Induced by Ultra-high-Energy Photons as a Probe of Ultra-high-Energy Cosmic-Ray Accelerators Embedded in the Cosmic Web

• Authors: Kohta Murase

tipa -- 11/3/2011

Discovery of Nine Gamma-Ray Pulsars in Fermi-LAT Data Using a New Blind Search Method

• Authors: H. J. Pletsch, L. Guillemot, B. Allen, M. Kramer, C. Aulbert, H. Fehrmann, P. S. Ray, E. D. Barr, A. Belfiore, F. Camilo, P. A. Caraveo, O. Celik, D. J. Champion, M. Dormody, R. P. Eatough, E. C. Ferrara, P. C. C. Freire, J. W. T. Hessels, M. Keith, M. Kerr, A. de Luca, A. G. Lyne, M. Marelli, M. A. McLaughlin, D. Parent, S. M. Ransom, M. Razzano, W. Reich, P. M. Saz Parkinson, B. W. Stappers, M. T. Wolff

Improved distance determination to M51 from supernovae 2011dh and 2005cs

• Authors: J. Vinko, K. Takats, T. Szalai, G. H. Marion, J. C. Wheeler, K. Sarneczky, P. M. Garnavich, J. Kelemen, P. Klagyivik, A. Pal, N. Szalai, K. Vida

Dark Radiation from Particle Decays during Big Bang Nucleosynthesis

• Authors: Justin L. Menestrina, Robert J. Scherrer

tipa -- 11/2/2011

A Revised View of the Transient Radio Sky

• Authors: D. A. Frail, S. R. Kulkarni, E. O. Ofek, G. C. Bower, E. Nakar

The VLT-FLAMES Tarantula Survey: The fastest rotating O-type star and shortest period LMC pulsar - remnants of a supernova disrupted binary?

• Authors: P. L. Dufton, P. R. Dunstall, C. J. Evans, I. Brott, M. Cantiello, A. de Koter, S.E. de Mink, M. Fraser, V. Hénault-Brunet, I. D. Howarth, N. Langer, D. J. Lennon, N. Markova, H. Sana, W. D. Taylor

tipa -- 11/1/2011

The Hubble Space Telescope Cluster Supernova Survey: VI. The Volumetric Type Ia Supernova Rate

• Authors: K. Barbary, G. Aldering, R. Amanullah, M. Brodwin, N. Connolly, K. S. Dawson, M. Doi, P. Eisenhardt, L. Faccioli, V. Fadeyev, H. K. Fakhouri, A. S. Fruchter, D. G. Gilbank, M. D. Gladders, G. Goldhaber, A. Goobar, T. Hattori, E. Hsiao, X. Huang, Y. Ihara, N. Kashikawa, B. Koester, K. Konishi, M. Kowalski, C. Lidman, L. Lubin, J. Meyers, T. Morokuma, T. Oda, N. Panagia, S. Perlmutter, M. Postman, P. Ripoche, P. Rosati, D. Rubin, D. J. Schlegel, A. L. Spadafora, S. A. Stanford, M. Strovink, N. Suzuki, N. Takanashi, K. Tokita, N. Yasuda, for the Supernova Cosmology Project

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background

• Authors: George M. Fuller, Chad T. Kishimoto, Alexander Kusenko

A new analytic solution for 2nd-order Fermi acceleration

• Authors: Philipp Mertsch (Oxford)

Probing Novel Scalar and Tensor Interactions from (Ultra)Cold Neutrons to the LHC

• Authors: Tanmoy Bhattacharya, Vincenzo Cirigliano, Saul D. Cohen, Alberto Filipuzzi, Martin Gonzalez-Alonso, Michael L. Graesser, Rajan Gupta, Huey-Wen Lin

tipa -- 10/31/2011

Mapping the Galactic Center with Gravitational Wave measurements using Pulsar Timing

• Authors: Bence Kocsis, Alak Ray, Simon Portegies Zwart

On The Origin Of High Energy Correlations in Gamma-ray Bursts

• Authors: Daniel Kocevski

On The Lack of Time Dilation Signatures in Gamma-ray Burst Light Curves

• Authors: Daniel Kocevski, Vahe Petrosian

Supernova 2011fe from an Exploding Carbon-Oxygen White Dwarf Star

• Authors: Peter E. Nugent, Mark Sullivan, S. Bradley Cenko, Rollin C. Thomas, Daniel Kasen, D. Andrew Howell, David Bersier, Joshua S. Bloom, S. R. Kulkarni, Michael T. Kandrashoff, Alexei V. Filippenko, Jeffrey M. Silverman, Geoffrey W. Marcy, Andrew W. Howard, Howard T. Isaacson, Kate Maguire, Nao Suzuki, James E. Tarlton, Yen-Chen Pan, Lars Bildsten, Benjamin J. Fulton, Jerod T. Parrent, David Sand, Philipp Podsiadlowski, Federica B. Bianco, Benjamin Dilday, Melissa L. Graham, Joe Lyman, Phil James, Mansi M. Kasliwal, Nicholas M. Law, Robert M. Quimby, Isobel M. Hook, Emma S. Walker, Paolo Mazzali, Elena Pian, Eran O. Ofek, Avishay Gal-Yam, Dovi Poznanski

tipa -- 10/28/2011

Andromeda XXVIII: A Dwarf Galaxy More Than 350 kpc from Andromeda

• Authors: Colin T. Slater, Eric F. Bell, Nicolas F. Martin

Andromeda XXIX: A New Dwarf Spheroidal Galaxy 200kpc from Andromeda

• Authors: Eric F. Bell, Colin T. Slater (University of Michigan), Nicolas F. Martin (MPIA Heidelberg)

Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster

• Authors: Fabio Antonini, Roberto Capuzzo-Dolcetta, Alessandra Mastrobuono-Battisti, David Merritt

The cosmic-ray and gas content of the Cygnus region as measured in gamma rays by the Fermi Large Area Telescope

• Authors: the Fermi LAT collaboration

Constraints on WIMP and Sommerfeld-Enhanced Dark Matter Annihilation from HESS Observations of the Galactic Center

• Authors: Kevork N. Abazajian, J. Patrick Harding

tipa -- 10/27/2011

Evidence for Type Ia Supernova Diversity from Ultraviolet Observations with the Hubble Space Telescope

• Authors: Xiaofeng Wang, Lifan Wang, Alexei V. Filippenko, Greg Aldering, Pierre Antilogus, David Arnett, Dietrich Baade, Eddie Baron, Brian J. Barris, Stefano Benetti, Patrice Bouchet, Adam S. Burrows, Ramon Canal, Enrico Cappellaro, Raymond Carlberg, Elisa di Carlo, Peter Challis, Arlin Crotts, John I. Danziger, Massimo Della Valle, Dennis Jack, Michael Fink, Ryan J. Foley, Claes Fransson, Avishay Gal-Yam, Peter Garnavich, Chris L. Gerardy, Mario Hamuy, Wolfgang Hillebrandt, Peter A. Hoeflich, Stephen T. Holland, Daniel E. Holz, John P. Hughes, David J. Jeffrey, Saurabh W. Jha, Dan Kasen, Alexei M. Khokhlov, Robert P. Kirshner, Robert Knop, Cecilia Kozma, Kevin Krisciunas, Markus Kromer, Brian C. Lee, Bruno Leibundgut, Eric J. Lentz, Douglas C. Leonard, Walter H. G. Lewin, Weidong Li, Mario Livio, Peter Lundqvist, Dan Maoz, Thomas Matheson, Paolo Mazzali, Peter Meikle, Gajus Miknaitis, Peter Milne, Stefan Mochnacki, Ken'Ichi Nomoto, Peter E. Pugent, Elaine Oran, Nino Panagia, Ferdinando Patat, Saul Perlmutter, Mark M. Phillips, Philip Pinto, Dovi Poznanski, Christopher J. Pritchet, Martin Reinecke, Adam Riess, Pilar Ruiz-Lapuente, Richard Scalzo, Eric M. Schlegel, Brian Schmidt, James Siegrist, Alicia M. Soderberg, Jesper Sollerman, George Sonneborn, Jason Spyromilio, Richard A. Sramek, Sumner G. Starrfield, Louis G. Strolger, Nicholas B. Suntzeff, Rollin Thomas, John L. Tonry, Amedeo Tornambe, James W. Truran, Massimo Turatto, Michael Turner, Schuyler D. Van Dyk, Kurt Weiler, J. Craig Wheeler, Michael Wood-Vasey, Stan Woosley, Hitoshi Yamaoka, Tianmeng Zhang

tipa -- 10/26/2011

Evidence for a compact Wolf-Rayet progenitor for the Type Ic supernova PTF 10vgv

• Authors: A. Corsi, E. O. Ofek, A. Gal-Yam, D. A. Frail, D. Poznanski, P. A. Mazzali, S. R. Kulkarni, M. M. Kasliwal, I. Arcavi, S. Ben-Ami, S. B. Cenko, A. V. Filippenko, D. B. Fox, A. Horesh, J. L. Howell, I. K. W. Kleiser, E. Nakar, I. Rabinak, R. Sari, J. M. Silverman, D. Xu, J. S. Bloom, N. M. Law, P. Nugent, R. M. Quimby

Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

• Authors: Chris B. D'Andrea, Ravi R. Gupta, Masao Sako, Matt Morris, Robert C. Nichol, Peter J. Brown, Heather Campbell, Matthew D. Olmstead, Joshua A. Frieman, Peter Garnavich, Saurabh W. Jha, Richard Kessler, Hubert Lampeitl, John Marriner, Donald P. Schneider, Mathew Smith

Analysis of WMAP 7-year Temperature Data: Astrophysics of the Galactic Haze

• Authors: Davide Pietrobon, Krzysztof M. Gorski, James Bartlett, Anthony J. Banday, Gregory Dobler, Loris P. L. Colombo, Luca Pagano, Graca Rocha, Rajib Saha, Jeffrey B. Jewell, Sergi R. Hildebrandt, Hans Kristian Eriksen, Charles R. Lawrence

Proton-Helium Spectral Anomaly as a Signature of Cosmic Ray Accelerator

• Authors: M. A. Malkov, P. H. Diamond, R. Z. Sagdeev

Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei

• Authors: A. Knecht, R. Hong, D.W. Zumwalt, B.G. Delbridge, A. Garcia, P. Mueller, H.E. Swanson, I.S. Towner, S. Utsuno, W. Williams, C. Wrede

tipa -- 10/25/2011

Freeze-out yields of radioactivities in core-collapse supernovae

• Authors: Georgios Magkotsios, F. X. Timmes, Michael Wiescher

Gamma-ray burst afterglow broadband fitting based directly on hydrodynamics simulations

• Authors: H. J. van Eerten, A. J. van der Horst, A. I. MacFadyen

VLBI observations of SN2011dh: imaging of the youngest radio supernova

• Authors: I. Marti-Vidal, V. Tudose, Z. Paragi, J. Yang, J. M. Marcaide, J. C. Guirado, E. Ros, A. Alberdi, M. A. Perez-Torres, M. K. Argo, A. J. van der Horst, M. A. Garrett, C. J. Stockdale, K. W. Weiler

tipa -- 10/24/2011

Stellar Feedback in Galaxies and the Origin of Galaxy-scale Winds

• Authors: Philip F. Hopkins (Berkeley), Eliot Quataert (Berkeley), Norman Murray (CITA)

WIMP-nucleon cross-section results from the second science run of ZEPLIN-III

• Authors: D. Yu. Akimov, H. M. Araujo, E. J. Barnes, V. A. Belov, A. Bewick, A. A. Burenkov, V. Chepel, A. Currie, L. DeViveiros, B. Edwards, C. Ghag, A. Hollingsworth, M. Horn, W. G. Jones, G. E. Kalmus, A. S. Kobyakin, A. G. Kovalenko, V. N. Lebedenko, A. Lindote, M. I. Lopes, R. Luscher, P. Majewski, A. StJ. Murphy, F. Neves, S. M. Paling, J. Pinto da Cunha, R. Preece, J. J. Quenby, L. Reichhart, P. R. Scovell, C. Silva, V. N. Solovov, N. J. T. Smith, V. N. Stekhanov, T. J. Sumner, C. Thorne, R.J. Walker

Three Dimensional MHD Simulation of Circumbinary Accretion Disks -1. Disk Structures and Angular Momentum Transport

• Authors: Ji-Ming Shi, Julian H. Krolik, Stephen H. Lubow, John F. Hawley

Probing Lorentz Violation in Neutrino Propagation from a Core-Collapse Supernova

• Authors: John Ellis, Hans-Thomas Janka, Nikolaos E. Mavromatos, Alexander S. Sakharov, Edward K. G. Sarkisyan

tipa -- 10/21/2011

Effects of hyperons in binary neutron star mergers

• Authors: Yuichiro Sekiguchi, Kenta Kiuchi, Koutarou Kyutoku, Masaru Shibata

tipa -- 10/20/2011

Toward a Unification of Star Formation Rate Determinations in the Milky Way and Other Galaxies

• Authors: Laura Chomiuk, Matthew S. Povich

The Fast Evolution of SN 2010bh associated with XRF 100316D

• Authors: Felipe Olivares E., Jochen Greiner, Patricia Schady, Arne Rau, Sylvio Klose, Thomas Krühler, Paulo M. J. Afonso, Adria C. Updike, Marco Nardini, Robert Filgas, Ana Nicuesa Guelbenzu, Christian Clemens, Jonny Elliott, D. Alexander Kann, Andrea Rossi, Vladimir Sudilovsky

A Radio-Selected Sample of Gamma Ray Burst Afterglows

• Authors: Poonam Chandra (1), Dale A. Frail (2) ((1) Royal Military College of Canada, Kingston, (2) National Radio Astronomy Observatory, Socorro)

Systematic Investigation of Solar Modulation of Galactic Protons for Solar Cycle 23 using a Monte Carlo Approach with Particle Drift Effects and Latitudinal Dependence

• Authors: P. Bobik, G. Boella, M.J. Boschini, C. Consolandi, S. Della Torre, M. Gervasi, D. Grandi, K. Kudela, S. Pensotti, P.G. Rancoita, M. Tacconi

Connecting Neutron Star Observations to Three-Body Forces in Neutron Matter and to the Nuclear Symmetry Energy

• Authors: A. W. Steiner, S. Gandolfi

Updated BBN bounds on the cosmological lepton asymmetry for non-zero theta13

• Authors: Gianpiero Mangano, Gennaro Miele, Sergio Pastor, Ofelia Pisanti, Srdjan Sarikas

Spectrum and Charge Ratio of Vertical Cosmic Ray Muons up to Momenta of 2.5 TeV/c

• Authors: CosmoALEPH Collaboration

Revisiting the 'LSND anomaly' I: impact of new data

• Authors: The HARP-CDP Group

tipa -- 10/19/2011

The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars

• Authors: M. Ajello, M. S. Shaw, R. W. Romani, C. D. Dermer, L. Costamante, O. G. King, W. Max-Moerbeck, A. Readhead, A. Reimer, J. L. Richards, M. Stevenson

Unburned Material in the Ejecta of Type Ia Supernovae

• Authors: Gastón Folatelli, M. M. Phillips, Nidia Morrell, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto, Maximilian Stritzinger, Christopher R. Burns, Mario Hamuy, Paolo Mazzali, Luis Boldt, Abdo Campillay, Carlos Contreras, Sergio Gonzalez, Miguel Roth, Francisco Salgado, W. L. Freedman, Barry F. Madore, S. E. Persson, Nicholas B. Suntzeff

Diversity of Luminous Supernovae from Non-Steady Mass Loss

• Authors: Takashi J. Moriya, Nozomu Tominaga

Long Gamma-Ray Transients from Collapsars

• Authors: S. E. Woosley, Alexander heger

Measurement of the cosmic electron plus positron spectrum with the MAGIC telescopes

• Authors: D. Borla Tridon, P. Colin, L. Cossio, M. Doro, V. Scalzotto, for the MAGIC Collaboration

tipa -- 10/18/2011

A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS

• Authors: ICARUS Collaboration

Nature of the Unidentified TeV Source HESS J1614-518, Revealed by Suzaku and XMM-Newton Observations

• Authors: Michito Sakai, Yukie Yajima, Hironori Matsumoto

Cepheid Period-Luminosity Relations in the Near-Infrared and the Distance to M31 from the Hubble Space Telescope Wide Field Camera 3

• Authors: Adam G. Riess (JHU/STScI), Juergen Fliri (OBSPM), David Valls-Gabaud (OBSPM)

Supersymmetry in Light of 1/fb of LHC Data

• Authors: O. Buchmueller, R. Cavanaugh, A. De Roeck, M.J. Dolan, J.R. Ellis, H. Flacher, S. Heinemeyer, G. Isidori, D. Martinez Santos, K.A. Olive, S. Rogerson, F.J. Ronga, G. Weiglein

Laboratory Tests of Low Density Astrophysical Equations of State

• Authors: L. Qin, K. Hagel, R. Wada, J. B. Natowitz, S. Shlomo, A. Bonasera, G. Roepke, S. Typel, Z. Chen, M. Huang, J. Wang, H. Zheng, S. Kowalski, M. Barbui, M. R. D. Rodrigues, K. Schmidt, D. Fabris, M. Lunardon, S. Moretto, G. Nebbia, S. Pesente, V. Rizzi, G. Viesti, M. Cinausero, G. Prete, T. Keutgen, Y. El Masri, Z. Majka

Study of wavelength-shifting chemicals for use in large-scale water Cherenkov detectors

• Authors: M. Sweany, A. Bernstein, S. Dazeley, J. Dunmore, J. Felde, R. Svoboda, M. Tripathi

tipa -- 10/17/2011

First evidence of pep solar neutrinos by direct detection in Borexino

• Authors: The Borexino Collaboration

The Dust Extinction Curves of Gamma-Ray Burst Host Galaxies

• Authors: P.Schady, T.Dwelly, M.J.Page, T.Krühler, J.Greiner, S.R.Oates, M.De Pasquale, M.Nardini, P.W.A.Roming, A.Rossi, M.Still

The Role of Structured Magnetic Fields on Constraining Properties of Transient Sources of Ultra-high-energy Cosmic Rays

• Authors: Hajime Takami, Kohta Murase

tipa -- 10/14/2011

Low-mass X-ray binaries indicate a top-heavy stellar initial mass function in ultra compact dwarf galaxies

• Authors: Jörg Dabringhausen, Pavel Kroupa, Jan Pflamm-Altenburg, Steffen Mieske

Discovery of Variability of the Progenitor of SN 2011dh in M51 Using the Large Binocular Telescope

• Authors: D. M. Szczygieł, J. R. Gerke, C. S. Kochanek, K. Z. Stanek

Low-Mach-number turbulence in interstellar gas revealed by radio polarization gradients

• Authors: Bryan M. Gaensler, Marijke Haverkorn, Blakesley Burkhart, Katherine J. Newton-McGee, Ronald D. Ekers, Alex Lazarian, Naomi M. McClure-Griffiths, Timothy Robishaw, John M. Dickey, Anne J. Green

Tenth-Order QED Lepton Anomalous Magnetic Moment --- Eighth-Order Vertices Containing a Second-Order Vacuum Polarization

• Authors: Tatsumi Aoyama, Masashi Hayakawa, Toichiro Kinoshita, Makiko Nio