Exploring X-ray Binary Populations in Compact Group Galaxies with ChandraChandra

We obtain total galaxy X-ray luminosities, $L_X$, originating from individually detected point sources in a sample of 47 galaxies in 15 compact groups of galaxies (CGs). For the great majority of our galaxies, we find that the detected point sources most likely are local to their associated galaxy, and are thus extragalactic X-ray binaries (XRBs) or nuclear active galactic nuclei (AGNs). For spiral and irregular galaxies, we find that, after accounting for AGNs and nuclear sources, most CG galaxies are either within the $\pm1\sigma$ scatter of the Mineo et al. (2012) $L_X$ - star formation rate (SFR) correlation or have higher $L_X$ than predicted by this correlation for their SFR. We discuss how these "excesses" may be due to low metallicities and high interaction levels. For elliptical and S0 galaxies, after accounting for AGNs and nuclear sources, most CG galaxies are consistent with the Boroson et al. (2011) $L_X$ - stellar mass correlation for low-mass XRBs, with larger scatter, likely due to residual effects such as AGN activity or hot gas. Assuming non-nuclear sources are low- or high-mass XRBs, we use appropriate XRB luminosity functions to estimate the probability that stochastic effects can lead to such extreme $L_X$ values. We find that, although stochastic effects do not in general appear to be important, for some galaxies there is a significant probability that high $L_X$ values can be observed due to strong XRB variability.Comment: Accepted by Ap

The Morpho-kinematic Architecture of Super Star Clusters in the Center of NGC 253

The center of the nearby galaxy NGC 253 hosts a population of more than a dozen super star clusters (SSCs) that are still in the process of forming. The majority of the star formation of the burst is concentrated in these SSCs, and the starburst is powering a multiphase outflow from the galaxy. In this work, we measure the 350 GHz dust continuum emission toward the center of NGC 253 at 47 mas (0.8 pc) resolution using data from the Atacama Large Millimeter/submillimeter Array. We report the detection of 350 GHz (dust) continuum emission in the outflow for the first time, associated with the prominent South-West streamer. In this feature, the dust emission has a width of approximate to 8 pc, is located at the outer edge of the CO emission, and corresponds to a molecular gas mass of similar to(8-17)x10(6) M (circle dot). In the starburst nucleus, we measure the resolved radial profiles, sizes, and molecular gas masses of the SSCs. Compared to previous work at the somewhat lower spatial resolution, the SSCs here break apart into smaller substructures with radii 0.4-0.7 pc. In projection, the SSCs, dust, and dense molecular gas appear to be arranged as a thin, almost linear, structure roughly 155 pc in length. The morphology and kinematics of this structure can be well explained as gas following x (2) orbits at the center of a barred potential. We constrain the morpho-kinematic arrangement of the SSCs themselves, finding that an elliptical, angular-momentum-conserving ring is a good description of both the morphology and kinematics of the SSCs

Outflows from Super Star Clusters in the Central Starburst of NGC253

Young massive clusters play an important role in the evolution of their host galaxies, and feedback from the high-mass stars in these clusters can have profound effects on the surrounding interstellar medium. The nuclear starburst in the nearby galaxy NGC253 at a distance of 3.5 Mpc is a key laboratory in which to study star formation in an extreme environment. Previous high resolution (1.9 pc) dust continuum observations from ALMA discovered 14 compact, massive super star clusters (SSCs) still in formation. We present here ALMA data at 350 GHz with 28 milliarcsecond (0.5 pc) resolution. We detect blueshifted absorption and redshifted emission (P-Cygni profiles) towards three of these SSCs in multiple lines, including CS 7$-$6 and H$^{13}$CN 4$-$3, which represents direct evidence for previously unobserved outflows. The mass contained in these outflows is a significant fraction of the cluster gas masses, which suggests we are witnessing a short but important phase. Further evidence of this is the finding of a molecular shell around the only SSC visible at near-IR wavelengths. We model the P-Cygni line profiles to constrain the outflow geometry, finding that the outflows must be nearly spherical. Through a comparison of the outflow properties with predictions from simulations, we find that none of the available mechanisms completely explains the observations, although dust-reprocessed radiation pressure and O star stellar winds are the most likely candidates. The observed outflows will have a very substantial effect on the clusters' evolution and star formation efficiency.Comment: Accepted to Ap

Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A

The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There has been no direct observation of this compact object. In this work, we observe the supernova remnant with JWST spectroscopy, finding narrow infrared emission lines of argon and sulfur. The line emission is spatially unresolved and blueshifted in velocity relative to the supernova rest frame. We interpret the lines as gas illuminated by a source of ionizing photons located close to the center of the expanding ejecta. Photoionization models show that the line ratios are consistent with ionization by a cooling neutron star or a pulsar wind nebula. The velocity shift could be evidence for a neutron star natal kick

PLoS One Spreadsheet Data

Tab 1 displays the bin contents (where each item from each participant ended up). This data was used for the "Accuracy" and "Bin Contents" analyses. Tab 2 displays the coding results of the two coders from the current experiment. This data was used for the "Receptacles used" and "Time spent at receptacles" analyses. Tab 3 displays the coding results of the two coders from the observational data in Wu et al. (2013). This data was used for the "Time spent at receptacles" analyses

Data from: Being in a “green” building elicits “greener” recycling, but not necessarily “better” recycling

Previous observational work revealed that transient populations in a sustainable building disposed of waste more accurately when compared to patrons in a non-sustainable building. The current study uses an experimental design to replicate this observed effect and to investigate whether or not the built environment influences motivational factors to impact behavior. We find support that a building designed and built to communicate an atmosphere of sustainability can influence waste disposal behavior. Participants in the sustainable building used the garbage receptacle significantly less and compensated by tending to select the containers and organics receptacle more, which actually resulted in more errors overall. Our findings suggest that building atmospherics can motivate people to recycle more. However, atmospherics alone do not appear to be sufficient to elicit the desired performance outcome

The duration of time spent at the receptacles in the current experimental study and in our observational study [26].

<p>Participants spent significantly more time at receptacles in the current study compared to patrons in Wu et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145737#pone.0145737.ref028" target="_blank">28</a>].</p

Examples of how the CIRS building conveys an atmosphere of sustainability to users.

<p>From top left to bottom right: water collection and purification system, signage in washroom about the water collection and purification system, 3D signage at waste receptacles in the café, extensive use of wood in the building’s construction, messaging on paper napkin holders in the café, LEED platinum certification display in the lobby, signage by the elevators to increase the use of stairs.</p

The room that participants were instructed to tidy up.

<p>The room that participants were instructed to tidy up.</p