Haffner 16: A Young Moving Group in the Making

The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich population of PMS stars is identified, and comparisons with isochrones suggest an age < 10 Myr assuming a distance modulus of 13.5 (D = 5 kpc). When compared with the solar neighborhood, Haffner 16 is roughly a factor of two deficient in objects with sub-solar masses. PMS objects in the cluster are also more uniformly distributed on the sky than bright MS stars. It is suggested that Haffner 16 is dynamically evolved, and that it is shedding protostars with sub-solar masses. Young low mass clusters like Haffner 16 are one possible source of PMS stars in the field. The cluster will probably evolve on time scales of ~ 100 - 1000 Myr into a diffuse moving group with a mass function that is very different from that which prevailed early in its life.Comment: To appear in the Publications of the Astronomical Society of the Pacifi

Conceptual Art and the Continuing Quest for a New Social Context

In challenging the notion of formalist aesthetic taste during the late sixties, a scattered group of artists, centered primarily in New York City, began to reveal the wider implications of art which had been largely ignored by galleries and museums. Their efforts suggested that objects made and distributed within a somewhat limited art context become part of a much larger social context; that, although art reflects the concerns of a society at a particular time and through a particular artist\u27s interpretation, its attachment to that society is eminently clear. Whether art works exists in the form of objects, installations, propositions, or events, they have the power to effect and to be effected by the social structure which attributes meaning to them

Dense gas in IRAS 20343+4129: an ultracompact HII region caught in the act of creating a cavity

The intermediate- to high-mass star-forming region IRAS 20343+4129 is an excellent laboratory to study the influence of high- and intermediate-mass young stellar objects on nearby starless dense cores, and investigate for possible implications in the clustered star formation process. We present 3 mm observations of continuum and rotational transitions of several molecular species (C2H, c-C3H2, N2H+, NH2D) obtained with the Combined Array for Research in Millimetre-wave Astronomy, as well as 1.3 cm continuum and NH3 observations carried out with the Very Large Array, to reveal the properties of the dense gas. We confirm undoubtedly previous claims of an expanding cavity created by an ultracompact HII region associated with a young B2 zero-age main sequence (ZAMS) star. The dense gas surrounding the cavity is distributed in a filament that seems squeezed in between the cavity and a collimated outflow associated with an intermediate-mass protostar. We have identified 5 millimeter continuum condensations in the filament. All of them show column densities consistent with potentially being the birthplace of intermediate- to high-mass objects. These cores appear different from those observed in low-mass clustered environments in sereval observational aspects (kinematics, temperature, chemical gradients), indicating a strong influence of the most massive and evolved members of the protocluster. We suggest a possible scenario in which the B2 ZAMS star driving the cavity has compressed the surrounding gas, perturbed its properties and induced the star formation in its immediate surroundings.Comment: 17 pages, 13 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society (Main Journal

Editorial: Smart Objects and Technologies

Smart objects are entering everyday life and are heavily modifying it. Healthcare, communication, art, entertainment, safety, environment, education, democracy, and human rights, are just a few examples of scenarios that are radically changing thanks to the use of smart objects and technologies. In this context, the popularity of portable computing devices, such as smartphones, tablets, or smart watches combined with the emergence of many other small smart objects with computational, sensing and communication capabilities coupled with the popularity of social networks and new human-technology interaction paradigms is creating unprecedented opportunities for each of us to do something useful, ranging from a single person to the whole world. Furthermore, Internet of Things, Smart-cities, distributed sensing and Fog computing are representative examples of modern ICT paradigms that aim to describe a dynamic and globally cooperative infrastructure built upon objects intelligence and self-configuring capabilities. These connected objects are finding their way into our pockets, vehicles, urban areas and infrastructure, thus becoming the very texture of our society and providing us the possibility, but also the responsibility, to shape it

Representations of Practice- Distributed Sensemaking Using Boundary Objects

Aim/Purpose: This article examines how learning activities draw on resources in the work context to learn. Background The background is that if knowledge no longer is seen mainly as objects, but processes, how then to understand boundary objects? Our field study of learning activities reveals the use of pictures, documents and emotions for learning in the geographically distributed Norwegian Labor Inspection Authority Methodology: The study is a qualitative study consisting of interview data, observation data, and documents. Contribution: Contribute to practice based theorizing. Findings: Three ideal types of representing practices have been identified, i.e., ‘Visualizing’, ‘Documenting’ and ‘Testing’. All three are combined with storytelling, sensing, reflections and sensemaking, which point at the importance of processes in learning. The article also add insights about how emotions can be an important resource for boundary spanning – and sensemaking – by creating the capability of reflecting upon and integrating different knowledge areas in the in- practice context. Recommendations for Practitioners: Look for boundary objects within your field to promote online learning. Recommendation for Researchers: Study boundary objects in work context to understand learning. Impact on Society Role of objects in human learning. Future Research: Focus on how emotions can be used for online learning

Real-time multiple tracking using a combined technique

[[abstract]]This paper considers a real-time multi-object tracking algorithm for rigid and non-rigid objects. The major components of the tracking object system are extraction of the background image, adaptation of the background image, and identification of the extracted object. In each component, we improved existing methods without increasing the complexity of computation. The system was tested on our fish tank experiment that solves dynamic occlusions problems.[[sponsorship]]IEEE Computer Society Technical Committee on Distributed Processing (TCDP); Tamkung University[[notice]]補正完畢[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20050328~20050330[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北縣, 臺

Doppler optical frequency domain reflectometry for remote fiber sensing

Coherent optical frequency domain reflectometry has been widely used to locate static reflectors with high spatial resolution. Here, we present a new type of Doppler optical frequency domain reflectometry that offers simultaneous measurement of the position and speed of moving objects. The system is exploited to track optically levitated "flying" particles inside a hollow-core photonic crystal fiber. As an example, we demonstrate distributed temperature sensing with sub-mm-scale spatial resolution and a standard deviation of similar to 10 degrees C up to 200 degrees C. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Ultracool Spectroscopic Outliers in Gaia DR3

© The Author(s) 2023. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/).Gaia DR3 provided a first release of RP spectra and astrophysical parameters for ultracool dwarfs. We used these Gaia RP spectra and astrophysical parameters to select the most outlying ultracool dwarfs. These objects have spectral types of M7 or later and might be young brown dwarfs or low metallicity objects. This work aimed to find ultracool dwarfs which have Gaia RP spectra significantly different to the typical population. However, the intrinsic faintness of these ultracool dwarfs in Gaia means that their spectra were typically rather low signal-to-noise in Gaia DR3. This study is intended as a proof-of-concept for future iterations of the Gaia data releases. Based on well studied subdwarfs and young objects, we created a spectral type-specific color ratio, defined using Gaia RP spectra; this ratio is then used to determine which objects are outliers. We then used the objects kinematics and photometry external to Gaia to cut down the list of outliers into a list of 'prime candidates'. We produce a list of 58 Gaia RP spectra outliers, seven of which we deem as prime candidates. Of these, six are likely subdwarfs and one is a known young stellar object. Four of six subdwarf candidates were known as subdwarfs already. The two other subdwarf candidates: 2MASS J03405673+2633447 (sdM8.5) and 2MASS J01204397+6623543 (sdM9), are new classifications.Peer reviewe

Classification of Chandra X-Ray Sources in Cygnus OB2

© 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We have devised a predominantly Naive Bayes−based method to classify X-ray sources detected by Chandra in the Cygnus OB2 association into members, foreground objects, and background objects. We employ a variety of X-ray, optical, and infrared characteristics to construct likelihoods using training sets defined by well-measured sources. Combinations of optical photometry from the Sloan Digital Sky Survey (riz) and Isaac Newton Telescope Photometric Hα Survey (r I i I Hα), infrared magnitudes from United Kingdom Infrared Telescope Deep Sky Survey and Two-Micron All Sky Survey (JHK), X-ray quantiles and hardness ratios, and estimates of extinction A v are used to compute the relative probabilities that a given source belongs to one of the classes. Principal component analysis is used to isolate the best axes for separating the classes for the photometric data, and Gaussian component separation is used for X-ray hardness and extinction. Errors in the measurements are accounted for by modeling as Gaussians and integrating over likelihoods approximated as quartic polynomials. We evaluate the accuracy of the classification by inspection and reclassify a number of sources based on infrared magnitudes, the presence of disks, and spectral hardness induced by flaring. We also consider systematic errors due to extinction. Of the 7924 X-ray detections, 5501 have a total of 5597 optical/infrared matches, including 78 with multiple counterparts. We find that ≈6100 objects are likely association members, ≈1400 are background objects, and ≈500 are foreground objects, with an accuracy of 96%, 93%, and 80%, respectively, with an overall classification accuracy of approximately 95%.Peer reviewe