Evidence of joint commitment in great apes’ natural joint actions

Human joint action seems special, as it is grounded in joint commitment—a sense of mutual obligation participants feel towards each other. Comparative research with humans and non-human great apes has typically investigated joint commitment by experimentally interrupting joint actions to study subjects’ resumption strategies. However, such experimental interruptions are human-induced, and thus the question remains of how great apes naturally handle interruptions. Here, we focus on naturally occurring interruptions of joint actions, grooming and play, in bonobos and chimpanzees. Similar to humans, both species frequently resumed interrupted joint actions (and the previous behaviours, like grooming the same body part region or playing the same play type) with their previous partners and at the previous location. Yet, the probability of resumption attempts was unaffected by social bonds or rank. Our data suggest that great apes experience something akin to joint commitment, for which we discuss possible evolutionary origins

Low-energy quantum dynamics of atoms at defects. Interstitial oxygen in silicon

The problem of the low-energy highly-anharmonic quantum dynamics of isolated impurities in solids is addressed by using path-integral Monte Carlo simulations. Interstitial oxygen in silicon is studied as a prototypical example showing such a behavior. The assignment of a "geometry" to the defect is discussed. Depending on the potential (or on the impurity mass), there is a "classical" regime, where the maximum probability-density for the oxygen nucleus is at the potential minimum. There is another regime, associated to highly anharmonic potentials, where this is not the case. Both regimes are separated by a sharp transition. Also, the decoupling of the many-nuclei problem into a one-body Hamiltonian to describe the low-energy dynamics is studied. The adiabatic potential obtained from the relaxation of all the other degrees of freedom at each value of the coordinate associated to the low-energy motion, gives the best approximation to the full many-nuclei problem.Comment: RevTeX, 6 pages plus 4 figures (all the figures were not accesible before

First Astronomical Use of Multiplexed Transition Edge Bolometers

We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE'S detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Δλ/λ= 1/7 at a resolution of δλ/λ ≈ 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 µm and 450 µm bands. These bands cover line emission from the important star formation tracers neutral carbon [Cl] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry

The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)

AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 microns, was installed at the South Pole during the 1994-1995 Austral summer. The telescope operates continuously through the Austral winter, and is being used primarily for spectroscopic studies of neutral atomic carbon and carbon monoxide in the interstellar medium of the Milky Way and the Magellanic Clouds. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Four heterodyne receivers, an array receiver, three acousto-optical spectrometers, and an array spectrometer are installed. A Fabry-Perot spectrometer using a bolometric array and a Terahertz receiver are in development. Telescope pointing, focus, and calibration methods as well as the unique working environment and logistical requirements of the South Pole are described.Comment: 57 pages, 15 figures. Submitted to PAS

The NIKA instrument: results and perspectives towards a permanent KID based camera for the Pico Veleta observatory

The New IRAM KIDs Array (NIKA) is a pathfinder instrument devoted to millimetric astronomy. In 2009 it was the first multiplexed KID camera on the sky; currently it is installed at the focal plane of the IRAM 30-meters telescope at Pico Veleta (Spain). We present preliminary data from the last observational run and the ongoing developments devoted to the next NIKA-2 kilopixels camera, to be commissioned in 2015. We also report on the latest laboratory measurements, and recent improvements in detector cosmetics and read-out electronics. Furthermore, we describe a new acquisition strategy allowing us to improve the photometric accuracy, and the related automatic tuning procedure.Comment: 24th International Symposium on Space Terahertz Technology, ISSTT 2013, April 8 to 10, 2013, Groningen, the Netherland

Latest NIKA results and the NIKA-2 project

NIKA (New IRAM KID Arrays) is a dual-band imaging instrument installed at the IRAM (Institut de RadioAstronomie Millimetrique) 30-meter telescope at Pico Veleta (Spain). Two distinct Kinetic Inductance Detectors (KID) focal planes allow the camera to simultaneously image a field-of-view of about 2 arc-min in the bands 125 to 175 GHz (150 GHz) and 200 to 280 GHz (240 GHz). The sensitivity and stability achieved during the last commissioning Run in June 2013 allows opening the instrument to general observers. We report here the latest results, in particular in terms of sensitivity, now comparable to the state-of-the-art Transition Edge Sensors (TES) bolometers, relative and absolute photometry. We describe briefly the next generation NIKA-2 instrument, selected by IRAM to occupy, from 2015, the continuum imager/polarimeter slot at the 30-m telescope.Comment: Proceedings of Low Temperature Detectors 15 (LTD-15), Pasadena, June 201

High resolution SZ observations at the IRAM 30-m telescope with NIKA

High resolution observations of the thermal Sunyaev-Zel'dovich (tSZ) effect are necessary to allow the use of clusters of galaxies as a probe for large scale structures at high redshifts. With its high resolution and dual-band capability at millimeter wavelengths, the NIKA camera can play a significant role in this context. NIKA is based on newly developed Kinetic Inductance Detectors (KIDs) and operates at the IRAM 30m telescope, Pico Veleta, Spain. In this paper, we give the status of the NIKA camera, focussing on the KID technology. We then present observations of three galaxy clusters: RX J1347.5-1145 as a demonstrator of the NIKA capabilities and the recent observations of CL J1226.9+3332 (z = 0.89) and MACS J0717.5+3745 (z = 0.55). We also discuss prospects for the final NIKA2 camera, which will have a 6.5 arcminute field of view with about 5000 detectors in two bands at 150 and 260 GHz

Detection of the tSZ effect with the NIKA camera

We present the first detection of the thermal Sunyaev-Zel'dovich (tSZ) effect from a cluster of galaxies performed with a KIDs (Kinetic Inductance Detectors) based instrument. The tSZ effect is a distortion of the black body CMB (Cosmic Microwave Background) spectrum produced by the inverse Compton interaction of CMB photons with the hot electrons of the ionized intra-cluster medium. The massive, intermediate redshift cluster RX J1347.5-1145 has been observed using NIKA (New IRAM KIDs arrays), a dual-band (140 and 240 GHz) mm-wave imaging camera, which exploits two arrays of hundreds of KIDs: the resonant frequencies of the superconducting resonators are shifted by mm-wave photons absorption. This tSZ cluster observation demonstrates the potential of the next generation NIKA2 instrument, being developed for the 30m telescope of IRAM, at Pico Veleta (Spain). NIKA2 will have 1000 detectors at 140GHz and 2x2000 detectors at 240GHz, providing in that band also a measurement of the linear polarization. NIKA2 will be commissioned in 2015.Comment: SF2A Proceedings 201

Non-parametric deprojection of NIKA SZ observations: Pressure distribution in the Planck-discovered cluster PSZ1 G045.85+57.71

The determination of the thermodynamic properties of clusters of galaxies at intermediate and high redshift can bring new insights into the formation of large-scale structures. It is essential for a robust calibration of the mass-observable scaling relations and their scatter, which are key ingredients for precise cosmology using cluster statistics. Here we illustrate an application of high resolution $(< 20$ arcsec) thermal Sunyaev-Zel'dovich (tSZ) observations by probing the intracluster medium (ICM) of the \planck-discovered galaxy cluster \psz\ at redshift $z = 0.61$, using tSZ data obtained with the NIKA camera, which is a dual-band (150 and 260~GHz) instrument operated at the IRAM 30-meter telescope. We deproject jointly NIKA and \planck\ data to extract the electronic pressure distribution from the cluster core ($R \sim 0.02\, R_{500}$) to its outskirts ($R \sim 3\, R_{500}$) non-parametrically for the first time at intermediate redshift. The constraints on the resulting pressure profile allow us to reduce the relative uncertainty on the integrated Compton parameter by a factor of two compared to the \planck\ value. Combining the tSZ data and the deprojected electronic density profile from \xmm\ allows us to undertake a hydrostatic mass analysis, for which we study the impact of a spherical model assumption on the total mass estimate. We also investigate the radial temperature and entropy distributions. These data indicate that \psz\ is a massive ($M_{500} \sim 5.5 \times 10^{14}$ M$_{\odot}$) cool-core cluster. This work is part of a pilot study aiming at optimizing the treatment of the NIKA2 tSZ large program dedicated to the follow-up of SZ-discovered clusters at intermediate and high redshifts. (abridged)Comment: 16 pages, 10 figure

NIKA 2: next-generation continuum/polarized camera at the IRAM 30 m telescope and its prototype

NIKA 2 (New Instrument of Kids Array) is a next generation continuum and polarized instrument successfully installed in October 2015 at the IRAM 30 m telescope on Pico-Veleta (Granada, Spain). NIKA 2 is a high resolution dual-band camera, operating with frequency multiplexed LEKIDs (Lumped Element Kinetic Inductance Detectors) cooled at 100 mK. Dual color images are obtained thanks to the simultaneous readout of a 1020 pixels array at 2 mm and 1140 x 2 pixels arrays at 1.15 mm with a final resolution of 18 and 12 arcsec respectively, and 6.5 arcmin of Field of View (FoV). The two arrays at 1.15 mm allow us to measure the linear polarization of the incoming light. This will place NIKA 2 as an instrument of choice to study the role of magnetic fields in the star formation process. The NIKA experiment, a prototype for NIKA 2 with a reduced number of detectors (about 400 LEKIDs) and FoV (1.8 arcmin), has been successfully operated at the IRAM 30 telescope in several open observational campaigns. The performance of the NIKA 2 polarization setup has been successfully validated with the NIKA prototype.Comment: 5 pages, 4 figures, proceeding for the conference: Extragalactic radio surveys 201