Cold Objects Research Articles

THE COLDEST BROWN DWARF (OR FREE-FLOATING PLANET)?: THE Y DWARF WISE 1828+2650

We have monitored the position of the cool Y dwarf WISEPA J182831.08+265037.8 using a combination of ground- and space-based telescopes and have determined its distance to be 11.2$_{-1.0}^{+1.3}$ pc. Its absolute H magnitude, M$_H=22.21^{+0.25}_{-0.22}$ mag, suggests a mass in the range 0.5-20 M$_{Jup}$ for ages of 0.1-10 Gyr with an effective temperature in the range 250-400 K. The broad range in mass is due primarily to the unknown age of the object. Since the high tangential velocity of the object, 51$\pm5$ km s$^{-1}$, is characteristic of an old disk population, a plausible age range of 2-4 Gyr leads to a mass range of 3-6 M$_{Jup}$ based on fits to the (highly uncertain) COND evolutionary models. The range in temperature is due to the fact that no single model adequately represents the 1-5 $\mu$m spectral energy distribution (SED) of the source, failing by factors of up to 5 at either the short or long wavelength portions of the spectral energy distribution. The appearance of this very cold object may be affected by non-equilibrium chemistry or low temperature condensates forming clouds, two atmospheric processes that are known to be important in brown dwarf atmospheres but have proven difficult to model. Finally, we argue that there would have to be a very steep upturn in the number density of late type Y-dwarfs to account for the putative population of objects suggested by by recent microlensing observations. Whether WISE 1828+2650 sits at the low mass end of the brown dwarf population or is the first example of a large number of "free-floating" planets is not yet known.

The Effects of Temperature Priming on Cooperation in the Iterated Prisoner's Dilemma

Based on initial research findings by Williams and Bargh (2008) and Kang, Williams, Clark, Gray and Bargh (2011) on the interaction between interpersonal and physical warmth, theoretical models such as cognitive scaffolding and the importance of evaluations of interpersonal warmth in trust-based decisions, this experiment investigated the effect of temperature priming on 30 pairs of British university students with hot and cold objects on frequency of cooperation in a game of iterated Prisoner's Dilemma. Participants were found to cooperate significantly more frequently when primed with hot objects than with cold objects, supporting the assertion that physical warmth sensation positively affects interpersonal trust evaluation. No support was found for the prediction that male-male pairs would cooperate less than female-female pairs. The implications of these findings to evolutionary and developmental theories of interpersonal warmth are discussed.

Deuterium burning in objects forming via the core accretion scenario

Aims. Our aim is to study deuterium burning in objects forming according to the core accretion scenario in the hot and cold start assumption and what minimum deuterium burning mass limit is found for these objects. We also study how the burning process influences the structure and luminosity of the objects. Furthermore we want to test and verify our results by comparing them to already existing hot start simulations which did not consider, however, the formation process. Methods. We present a new method to calculate deuterium burning of objects in a self-consistently coupled model of planet formation and evolution. We discuss which theory is used to describe the process of deuterium burning and how it was implemented. Results. We find that the objects forming according to a hot start scenario behave approximately in the same way as found in previous works of evolutionary calculations, which did not consider the formation. However, for cold start objects one finds that the objects expand during deuterium burning instead of being partially stabilized against contraction. In both cases, hot and cold start, the mass of the solid core has an influence on the minimum mass limit of deuterium burning. The general position of the mass limit, 13 MJ, stays however approximately the same. None of the investigated parameters was able to change this mass limit by more than 0.8 MJ. Due to deuterium burning, the luminosity of hot and cold start objects becomes comparable after ~ 200 Myrs.

Warmth, spatial proximity, and social attachment: The embodied perception of a social metaphor

Recent experiments in embodied social cognition suggest a fundamental link between physical warmth and social affiliation. Findings from two experiments support the hypothesis that physical warmth serves as a symbolic cue signaling the close proximity of a source of affiliation. In Experiment 1, participants perceived a warm object as being physically closer than a cold object. In Experiment 2, being primed with warmth led participants to display higher levels of self-reported social affiliative motivation. In both studies, effects were moderated by individual differences in attachment style; priming effects were pronounced among those low in attachment avoidance and those high in attachment anxiety. These findings contribute to a growing literature suggesting deep connections between perception, physical experience, and social cognition.

Risk factors for Raynaud's phenomenon in the workforce

To assess the prevalence of and risk factors for Raynaud's phenomenon (RP) in a French working population characterized by various levels of exposure to work-related constraints. The study population comprised 3,710 workers (2,161 men and 1,549 women) who were followed up by 83 occupational physicians and were representative of the region's workforce. RP, as diagnosed by a questionnaire and a standardized interview, was defined as the occurrence of at least occasional attacks of finger blanching triggered by exposure to environmental cold during the previous 12 months. Personal factors and work exposure were assessed by self-administered questionnaires. The associations between RP and personal and occupational factors were analyzed using logistic regression modeling. A total of 87 cases of RP (56 women and 31 men) were diagnosed. The population-based annual prevalence rates of RP were 3.6% (95% confidence interval [95% CI] 2.7-4.5%) for women and 1.4% (95% CI 0.9-1.9%) for men. Women had a higher risk of RP (odds ratio [OR] 2.1 [95% CI 1.3-3.4]) and the risk decreased continuously with body mass index (OR for 1-kg/m(2) increment 0.87 [95% CI 0.81-0.94]). The risk of RP increased consistently but moderately with age after 35 years (ORs ranging from 2.0 [95% CI 1.1-3.8] to 2.9 [95% CI 1.6-5.2]). Among the work-related factors studied, RP was associated with an exposure to a cold environment or objects (OR 2.2 [95% CI 1.0-4.6]), a high repetitiveness of a task (OR 1.7 [95% CI 1.0-2.7]), a high psychological demand at work (OR 1.7 [95% CI 1.0-2.7]), and low support from supervisors (OR 2.4 [95% CI 1.5-3.8]). Personal and work-related factors were associated with RP, with a clear difference between the sexes. Work-related psychosocial stressors played a significant role independently of biomechanical and environmental exposure.

Delayed-onset cold anaphylaxis after hymenoptera sting

Cold contact urticaria (CCU) is characterized by urticarial wheals and/or angioedema typically appearing in the exposed areas within minutes of contact with cold air, liquids, or objects. Serious anaphylactic reactions may occur during aquatic activities.1−4 Most cases of CCU are primary, but secondary CCU has been reported.5−8 We describe a patient who acquired CCU 12 days after a wasp sting.

THE HUBBLE WIDE FIELD CAMERA 3 TEST OF SURFACES IN THE OUTER SOLAR SYSTEM: THE COMPOSITIONAL CLASSES OF THE KUIPER BELT

We present the first results of the Hubble Wide Field Camera 3 Test of Surfaces in the Outer Solar System (H/WTSOSS). The purpose of this survey was to measure the surface properties of a large number of Kuiper belt objects and attempt to infer compositional and dynamical correlations. We find that the Centaurs and the low-perihelion scattered disk and resonant objects exhibit virtually identical bifurcated optical colour distributions and make up two well defined groups of object. Both groups have highly correlated optical and NIR colours which are well described by a pair of two component mixture models that have different red components, but share a common neutral component. The small, $H_{606}\gtrsim5.6$ high-perihelion excited objects are entirely consistent with being drawn from the two branches of the mixing model suggesting that the colour bifurcation of the Centaurs is apparent in all small excited objects. On the other hand, objects larger than $H_{606}\sim5.6$ are not consistent with the mixing model, suggesting some evolutionary process avoided by the smaller objects. The existence of a bifurcation amongst all excited populations argues that the two separate classes of object existed in the primordial disk before the excited Kuiper belt was populated. The cold classical objects exhibit a different type of surface which has colours that are consistent with being drawn from the red branch of the mixing model, but with much higher albedos.

The Jordan curve theorem is non-trivial

The formal mathematical definition of a Jordan curve (a non-self-intersecting continuous loop in the plane) is so simple that one is often lead to the unimaginative view that a Jordan curve is nothing more than a circle or an ellipse. In this paper, we pursue the theme that a Jordan curve can be quite fantastical in the sense that there are some bizarre properties such a curve might have (jagged at every point, space filling, etc.) or that such a curve can have a difficult to discover inside and outside as promised by the celebrated Jordan Curve Theorem (JCT). We explore the JCT theorem through its history and some hand drawings which not only challenge the viewer's preconceived notions of interior and exterior or that the JCT is a trivial result, but also challenge the reader's notion that a curve is a cold boring object, incapable of telling an interesting story.

Oxygen and nitrogen abundances in cold H II regions from Sloan Digital Sky Survey

Oxygen and nitrogen abundances for a selection of 113607 cold objects from the Sloan Digital Sky Survey (SDSS) spectra are derived. Values of oxygen abundances 12 + log(O/H) are obtained using three parametric N calibrations, one of which is constructed in this work. Values of nitrogen abundances 12 + log(N/H) are found with two N calibrations. The values of oxygen abundances that are derived using three parametric N calibrations are consistent within 0.05 dex for the vast majority of the objects. It is not improbable that there are systematic differences between the values of oxygen abundances which do not exceed 0.05 dex. The differences between the values of nitrogen abundances which are obtained using ON and NS calibrations reach 0.1 dex. We show that the vast majority of cold SDSS objects are in the same area of the diagram O/H—N/O as cold H2 regions of nearby galaxies, for which the oxygen and nitrogen abundances are derived through the Te-method. This is indirect evidence that the values of oxygen and nitrogen abundances that are found with parametric N calibrations are reliable.

Planckearly results. XXIII. The first all-sky survey of Galactic cold clumps

We present the statistical properties of the first version of the Cold Core Catalogue of Planck Objects (C3PO), in terms of their spatial distribution, temperature, distance, mass, and morphology. We also describe the statistics of the Early Cold Core Catalogue (ECC, delivered with the Early Release Compact Source Catalogue, ERCSC) that is the subset of the 915 most reliable detections of the complete catalogue. We have used the CoCoCoDeT algorithm to extract 10783 cold sources. Temperature and dust emission spectral index {\beta} values are derived using the fluxes in the IRAS 100 \mum band and the three highest frequency Planck bands. Temperature spans from 7K to 17K, and peaks around 13K. Data are not consistent with a constant value of {\beta} over the all temperature range. {\beta} ranges from 1.4 to 2.8 with a mean value around 2.1, and several possible scenarios are possible, including {\beta}(T) and the effect of multiple T components folded into the measurements. For one third of the objects the distances are obtained. Most of the detections are within 2 kpc in the Solar neighbourhood, but a few are at distances greater than 4 kpc. The cores are distributed from the deep Galactic plane, despite the confusion, to high latitudes (>30$^{\circle}$). The associated mass estimates range from 1 to $10^5$ solar masses. Using their physical properties these cold sources are shown to be cold clumps, defined as the intermediate cold sub-structures between clouds and cores. These cold clumps are not isolated but mostly organized in filaments associated with molecular clouds. The Cold Core Catalogue of Planck Objects (C3PO) is the first unbiased all-sky catalogue of cold objects. It gives an unprecedented statistical view to the properties of these potential pre-stellar clumps and offers a unique possibility for their classification in terms of their intrinsic properties and environment.

High resolution far-infrared Fourier transform spectroscopy of radicals at the AILES beamline of SOLEIL synchrotron facility

Experimental far-infrared (FIR) spectroscopy of transient species (unstable molecules, free radicals, and ions) has been limited so far in both emission and absorption (mainly by the low probability of spontaneous emission in that spectral range and the low brightness of continuum sources used for absorption measurements, respectively). Nevertheless, the FIR spectral range recently became of high astrophysical relevance thanks to several new observational platforms (HERSCHEL, ALMA...) dedicated to the study of this region suitable for the detection of the emission from cold objects of the interstellar medium. In order to complete the experimental dataset concerning transient species, three discharge experiments dedicated to the recording of high resolution FIR spectra of radicals have been developed at the Advanced Infrared Line Exploited for Spectroscopy (AILES) which extracts the bright FIR synchrotron continuum of the synchrotron facility SOLEIL. These experiments make use of a high resolution (R = 0.001 cm(-1)) Bruker IFS125 Fourier transform (FT) spectrometer. An emission setup (allowing to record spectra of radicals excited at high rotational and vibrational temperatures) and two absorption setups (exploiting the bright synchrotron source at the highest resolution available on the FT) are alternatively connected to the FT. The advantages and limitations of these techniques are discussed on the basis of the recent results obtained on OH and CH radicals. These results constitute the first FIR spectra of radicals using synchrotron radiation, and the first FIR spectrum of a C-bearing radical using FT-spectroscopy.

Frostbites in circumpolar areas

Circumpolar areas are associated with prolonged cold exposure where wind, precipitation, and darkness further aggravate the environmental conditions and the associated risks. Despite the climate warming, cold climatic conditions will prevail in circumpolar areas and contribute to adverse health effects. Frostbite is a freezing injury where localized damage affects the skin and other tissues. It occurs during occupational or leisure-time activities and is common in the general population among men and women of various ages. Industries of the circumpolar areas where frostbite occurs frequently include transportation, mining, oil, and gas industry, construction, agriculture, and military operations. Cold injuries may also occur during leisure-time activities involving substantial cold exposure, such as mountaineering, skiing, and snowmobiling. Accidental situations (occupational, leisure time) often contribute to adverse cooling and cold injuries. Several environmental (temperature, wind, wetness, cold objects, and altitude) and individual (behavior, health, and physiology) predisposing factors are connected with frostbite injuries. Vulnerable populations include those having a chronic disease (cardiovascular, diabetes, and depression), children and the elderly, or homeless people. Frostbite results in sequelae causing different types of discomfort and functional limitations that may persist for years. A frostbite injury is preventable, and hence, unacceptable from a public health perspective. Appropriate cold risk management includes awareness of the adverse effects of cold, individual adjustment of cold exposure and clothing, or in occupational context different organizational and technical measures. In addition, vulnerable population groups need customized information and care for proper prevention of frostbites.

Risk factors for Raynaud's phenomenon in the workforce: the French Pays de la Loire study

ObjectivesTo assess the prevalence and risk factors for Raynaud's phenomenon (RP) in a general French working population characterised by various levels of exposure to work-related constraints.MethodsThe study population comprised 3710...

Day-Night Side Cooling of a Strongly Irradiated Giant Planet

AbstractThe internal heat loss or cooling of a planet determines its structure and evolution. We address in a consistent fashion the coupling between the day and the night sides by means of model atmosphere calculations with heat redistribution. We assume that a strong convection leads to the same entropy on the day and night side and that the gravity is the same on both hemispheres. We argue that the core cooling rate from the two hemispheres of a strongly irradiated planet may not be the same and that the difference depends on several important parameters. If the day-night heat redistribution is very effective, or if it takes place at a large optical depth, then the day-side and the night-side cooling may be comparable. However, if the day-night heat transport is not effective, or if it takes place at a shallow optical depth, then there can be a big difference between the day-side and the night-side cooling and the night side may cool more effectively. If the stellar irradiation gets stronger e.g. due to the stellar evolution or migration, this will reduce both the day and the night side cooling. Enhanced metallicity in the atmosphere acts as a “blanket” and reduces both the day- and the night-side cooling. However, the stratosphere on the day side of the planet can enhance the day-side cooling since its opacity acts as a “shield” which screens the stellar irradiation. These results might affect the well known gravity darkening and bolometric albedo effects in interacting binaries, especially for strongly irradiated cold objects.

THE REFLECTION EFFECT IN INTERACTING BINARIES OR IN PLANET-STAR SYSTEMS

There are many similarities between interacting binary stars and stars with a close-in giant extrasolar planet. The reflection effect is a well-known example. Although the generally accepted treatment of this effect in interacting binaries is successful in fitting light curves of eclipsing binaries, it is not very suitable for studying cold objects irradiated by hot objects or extrasolar planets. The aim of this paper is to develop a model of the reflection effect which could be easily incorporated into the present codes for modeling of interacting binaries so that these can be used to study the aforementioned objects. Our model of the reflection effect takes into account the reflection (scattering), heating, and heat redistribution over the surface of the irradiated object. The shape of the object is described by the non-spherical Roche potential expected for close objects. Limb and gravity darkening are included in the calculations of the light output from the system. The model also accounts for the orbital revolution and rotation of the exoplanet with appropriate Doppler shifts for the scattered and thermal radiation. Subsequently, light curves and/or spectra of several exoplanets have been modeled and the effects of the heat redistribution, limb darkening/brightening, (non-)gray albedo, and non-spherical shape have been studied. Recent observations of planet-to-star flux ratio of HD189733b, WASP12b, and WASP-19b at various phases were reproduced with very good accuracy. It was found that HD189733b has a low Bond albedo and intense heat redistribution, while WASP-19b has a low Bond albedo and low heat redistribution. The exact Roche geometries and temperature distributions over the surface of all 78 transiting extrasolar planets have been determined. Departures from the spherical shape may vary considerably but departures of about 1% in the radius are common within the sample. In some cases, these departures can reach 8%, 12%, or 14%, for WASP-33b, WASP-19b, and WASP-12b, respectively. The mean temperatures of these planets also vary considerably from 300 K to 2600 K. The extreme cases are WASP-18b, WASP-12b, and WASP-33b, with mean temperatures of 2330 K, 2430 K, and 2600 K, respectively.

An all-sky catalogue of cold cores observed withPlanck-HFI: simulation and colour detection algorithms

Context. Planck will provide an unprecedented view of the (cold dust in both diffuse regions and dense cores and associated gas in the Galaxy), resulting in the observation of a large number of cold objects. Understanding the processes acting at the very earliest stages of star formation requires a detailed study of these cold cores. Aims. We present an algorithm which is able to compile a reliable catalogue of cold cores from the Planck High Frequency Instrument (HFI) data. We construct models of the cold cores and validate the extraction algorithm on simulated Planck data. Methods. We model cold cores along with their warmer envelopes which are then injected into a full sky simulation of Planck HFI data. These cold cores are mostly embedded in the relatively warmer Galactic background, in particular in the plane where there is a high level of confusion. We have developed two detection algorithms which make use of the colour of the cores rather than simply extracting compact sources from the individual frequency maps. The cold sources present a relative emission excess at wavelengths longer than 350 μm (i.e. 857 GHz), and thus provide the necessary signature to separate them from the diffuse Galactic emission and warmer cores. Furthermore, using an optimised photometry algorithm for embedded cold sources, reliable fluxes can be extracted. Results. We recover nearly 3% of our input sources, with 60% completeness at high latitude. This suggests that we will be able to compile a catalogue of nearly 5000 objects over the entire sky with a reliability of 98%. These detections cover the entire simulated mass range from 0.4 to 10 000 solar masses and cover the entire sky, including a small number of sources on the far side of the Galaxy. Conclusions. This algorithm is ready to be applied on Planck HFI data, and will be able to produce a reliable catalogue of sources ready for follow up observations, in particular for the Herschel open-time key-program on Galactic cold cores.

Adiabatic index of hot and cold compact objects

In the present work we calculate the adiabatic index of neutron stars formed by hadronic or quarkionic matter, under two possible conditions, with and without trapped neutrinos, and for two values of the entropy per baryon S = 0,2 kB/ baryon. We use the nonlinear Walecka model to describe hadronic stars, and the MIT bag model to describe quark stars. Particle fractions for each case are obtained and the appearance of particles are compared with drops in the adiabatic index, whenever possible.

COLORS OF INNER DISK CLASSICAL KUIPER BELT OBJECTS

We present new optical broadband colors, obtained with the Keck 1 and Vatican Advanced Technology telescopes, for six objects in the inner classical Kuiper Belt. Objects in the inner classical Kuiper Belt are of interest as they may represent the surviving members of the primordial Kuiper Belt that formed interior to the current position of the 3:2 resonance with Neptune, the current position of the plutinos, or, alternatively, they may be objects formed at a different heliocentric distance that were then moved to their present locations. The six new colors, combined with four previously published, show that the 10 inner belt objects with known colors form a neutral clump and a reddish clump in B-R color. Nonparametric statistical tests show no significant difference between the B-R color distribution of the inner disk objects compared to the color distributions of Centaurs, plutinos, or scattered disk objects. However, the B-R color distribution of the inner classical Kuiper belt objects does differ significantly from the distribution of colors in the cold (low inclination) main classical Kuiper belt. The cold main classical objects are predominately red, while the inner classical belt objects are a mixture of neutral and red. The color difference may reveal the existence of a gradient in the composition and /or surface processing history in the primordial Kuiper Belt, or indicate that the inner disk objects are not dynamically analogous to the cold main classical belt objects.

Atmospheres and surfaces of small bodies and dwarf planets in the Kuiper Belt

Kuiper Belt Objects (KBOs) are icy relics orbiting the sun beyond Neptune left over from the planetary accretion disk. These bodies act as unique tracers of the chemical, thermal, and dynamical history of our solar system. Over 1000 Kuiper Belt Objects (KBOs) and centaurs (objects with perihelia between the giant planets) have been discovered over the past two decades. While the vast majority of these objects are small ( 6-meter) telescopes, have allowed for the first detailed studies of their surfaces and atmospheres. Visible and near-infrared spectroscopy of KBOs and centaurs has revealed a great diversity of surface compositions. Only the largest and coldest objects are capable of retaining volatile ices and atmospheres. Knowledge of the dynamics, physical properties, and collisional history of objects in the Kuiper belt is important for understanding solar system formation and evolution.

Familial atypical cold urticaria: Description of a new hereditary disease

Acquired cold urticaria (ACU) is usually a self-limited, sporadic, cutaneous disease diagnosed based on history and a positive cold stimulation time test (CSTT) result. We describe 3 unrelated families (A, B, and C) with lifelong atypical cold urticaria distinguished from ACU and familial cold autoinflammatory syndrome. We sought to describe a new hereditary disease of cold urticaria and study its pathogenesis. Questionnaires, interviews, physical examinations, skin testing, and biopsies were performed. Absolute values, means, and prevalence percentages of data are reported. Thirty-five subjects are described with familial atypical cold urticaria (FACU; family A, 17; family B, 8; and family C, 10) displaying an autosomal dominant pattern of inheritance. All tested subjects had negative CSTT results. Completed questionnaires from affected and unaffected members of families A and B (n = 35) revealed that all affected subjects had lifelong symptoms that began in early childhood with pruritus, erythema, and urticaria after cold exposure. Angioedema (family A, 23%; family B, 42%) and syncope, near syncope, or both (family A, 46%; family B, 86%) were also present. Triggers included cold atmosphere (100%), aquatic activities (family A, 92%; family B, 100%), handling cold objects (family A, 54%; family B, 71%), and ingestion of cold foods or beverages (family A, 69%; family B, 100%). Skin biopsy specimens demonstrated a mast cell infiltrate with the appearance of degranulation after cold challenge. FACU is a new cold-induced inherited disease that is different than ACU in its natural history, atmospheric cold elicitation, severity of systemic reactions, and CSTT results. FACU differs from familial cold autoinflammatory syndrome in symptom timing and the absence of fever, chills, and joint pain. The cause is suspected to be mast cell related. Treatment of reactions is similar to that for ACU. Further evaluation of pathogenesis and genetics is warranted.