Introducing the Texas Euclid Survey for Lyα (TESLA) Survey: Initial Study Correlating Galaxy Properties to Lyα Emission

We present the Texas Euclid Survey for Lyα (TESLA), a spectroscopic survey in the 10 deg2 of the Euclid North Ecliptic Pole (NEP) field. Using TESLA, we study how the physical properties of Lyα emitters (LAEs) correlate with Lyα emission to understand the escape of Lyα emission from galaxies at redshifts of 2–3.5. We present an analysis of 43 LAEs performed in the NEP field using early data from the TESLA survey. We use Subaru Hyper Suprime-Cam imaging in the grizy bands, Spitzer/IRAC channels 1 and 2 from the Hawaii 20 deg2 (H20) survey, and spectra acquired by the Visible Integral-Field Replicable Unit Spectrograph (VIRUS) on the Hobby–Eberly Telescope. We perform spectral energy distribution (SED) fitting to compute the galaxy properties of 43 LAEs, and study correlations between stellar mass, star formation rate (SFR), and dust to the Lyα rest-frame equivalent width (WLyα). We uncover marginal (1σ significance) correlations between stellar mass and WLyα, and SFR and WLyα, with a Spearman correlation coefficient of −0.34−.14+.17 and −0.37−.14+.16, respectively. We show that the WLyα distribution of the 43 LAEs is consistent with being drawn from an exponential distribution with an e-folding scale of W0 = 150 Å. Once complete the TESLA survey will enable the study of ≳50,000 LAEs to explore more correlations between galaxy properties and WLyα. The large sample size will allow the construction of a predictive model for WLyα as a function of SED-derived galaxy properties, which could be used to improve Lyα-based constraints on reionization

The Spitzer–HETDEX Exploratory Large-Area Survey. IV. Model-based Multiwavelength Photometric Catalog

We present a 0.3–4.5 μm 16-band photometric catalog for the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers an ∼27 deg2 field within the footprint of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX). Here we present new DECam imaging and an rizKs band–selected catalog of four million sources extracted using a fully model-based approach. We validate our photometry by comparing with the model-based DECam Legacy Survey. We analyze the differences between model-based and aperture photometry by comparing with the previous SHELA catalog, finding that our model-based photometry can measure point sources to fainter fluxes and better capture the full emission of resolved sources. The catalog is 80% (50%) complete at riz ∼ 24.7 (25.1) AB mag, and the optical photometry reaches a 5σ depth of ∼25.5 AB mag. We measure photometric redshifts and achieve a 1σ scatter of Δz/(1 + z) of 0.04 with available spectroscopic redshifts at 0 ≤ z ≤ 1. This large-area, multiwavelength photometric catalog, combined with spectroscopic information from HETDEX, will enable a wide range of extragalactic science investigations

Equitable Conversion in Washington: The Doctrine That Dares Not Speak Its Name

Since the 1925 decision of Ashford v. Reese, Washington has had the distinction of being the only American jurisdiction totally, albeit implicitly, to reject the doctrine of equitable conversion. Ashford was overruled in 1977, in a remarkable opinion which simultaneously, and explicitly, rejected the doctrine of equitable conversion, thus maintaining Washington\u27s unique status with respect to that doctrine. But the opinion failed to provide a substitute for either the rule of Ashford or the contrary doctrine of equitable conversion, both of which it emphatically abjured. The result is an unbroken line of Washington cases consistent with only one rule of law-the doctrine of equitable conversion. The effect of the opinion is thus de jure rejection and de facto adoption of equitable conversion. This article will analyze the process by which Washington has managed to achieve substantial conformity with the majority of American jurisdictions, while resolutely maintaining a unique stance

Equitable Conversion in Washington: The Doctrine That Dares Not Speak Its Name

Since the 1925 decision of Ashford v. Reese, Washington has had the distinction of being the only American jurisdiction totally, albeit implicitly, to reject the doctrine of equitable conversion. Ashford was overruled in 1977, in a remarkable opinion which simultaneously, and explicitly, rejected the doctrine of equitable conversion, thus maintaining Washington\u27s unique status with respect to that doctrine. But the opinion failed to provide a substitute for either the rule of Ashford or the contrary doctrine of equitable conversion, both of which it emphatically abjured. The result is an unbroken line of Washington cases consistent with only one rule of law-the doctrine of equitable conversion. The effect of the opinion is thus de jure rejection and de facto adoption of equitable conversion. This article will analyze the process by which Washington has managed to achieve substantial conformity with the majority of American jurisdictions, while resolutely maintaining a unique stance

A Method to Distinguish Quiescent and Dusty Star-forming Galaxies with Machine Learning

Large photometric surveys provide a rich source of observations of quiescent galaxies, including a surprisingly large population at z > 1. However, identifying large, but clean, samples of quiescent galaxies has proven difficult because of their near-degeneracy with interlopers such as dusty, star-forming galaxies. We describe a new technique for selecting quiescent galaxies based upon t-distributed stochastic neighbor embedding (t-SNE), an unsupervised machine-learning algorithm for dimensionality reduction. This t-SNE selection provides an improvement both over UVJ, removing interlopers that otherwise would pass color selection, and over photometric template fitting, more strongly toward high redshift. Due to the similarity between the colors of high- and low-redshift quiescent galaxies, under our assumptions, t-SNE outperforms template fitting in 63% of trials at redshifts where a large training sample already exists. It also may be able to select quiescent galaxies more efficiently at higher redshifts than the training sample

Can Regulation of Freshwater Runoff in Hudson Bay Affect the Climate of the North Atlantic?

A sequence of phenomena links anthropogenic changes in the timing of freshwater runoff in Hudson Bay to a possible impact on the North Atlantic thermohaline circulation. The chain of events starts with the spreading of estuarine plumes under ice and continues with the effect of lowered salinity on the rate of ice formation, regional effects on the scale of Hudson Bay, the export of freshwater to the Labrador Sea, its impact on deep convection in that area, and the relative importance of such changes to the North Atlantic circulation. At each step we compare anthropogenic effects with other factors and place them within the perspective of natural variability. Our conclusion does not support the contention that freshwater runoff regulation, even of all rivers in the basins of Hudson and James Bays, could have a significant or even a detectable effect on the climate of the North Atlantic.Une séquence de phénomènes relie des changements anthropiques dans le moment où les eaux douces commencent à s'écouler dans la baie d'Hudson à leur répercussion possible sur les courants thermiques des eaux marines. La séquence débute par la formation d'un panache estuarien sous la glace et se poursuit avec l'effet de la baisse de salinité sur la vitesse de formation de la glace, des répercussions régionales affectant toute la baie d'Hudson, l'exportation d'eau douce vers la mer du Labrador et ses retombées sur la convection profonde dans cette zone, ainsi qu'avec l'importance relative de tels changements sur les courants nord-atlantiques. À chaque étape, on compare les influences anthropiques avec d'autres facteurs pour les situer dans un contexte de variabilité. Notre conclusion n'appuie pas la thèse que la régulation de l'écoulement des eaux douces, même si elle s'étendait à tous les cours d'eau des bassins de la baie d'Hudson et de la baie James, pourrait avoir des répercussions notables ou même détectables sur le climat nord-atlantique

New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 JY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of ~0.02 arcsec (~700 km at 44 AU) and {\Delta}m less than or equal to 0.5.Comment: Pages: 11, Figures: 2, Tables: 3, Icarus, available online May 2014 (http://dx.doi.org/10.1016/j.icarus.2014.04.014

UNCOVER: The Growth of the First Massive Black Holes from JWST/NIRSpec—Spectroscopic Redshift Confirmation of an X-Ray Luminous AGN at z = 10.1

The James Webb Space Telescope is now detecting early black holes (BHs) as they transition from seeds to supermassive BHs. Recently, Bogdan et al. reported the detection of an X-ray luminous supermassive BH, UHZ-1, with a photometric redshift at z \u3e 10. Such an extreme source at this very high redshift provides new insights on seeding and growth models for BHs given the short time available for formation and growth. Harnessing the exquisite sensitivity of JWST/NIRSpec, here we report the spectroscopic confirmation of UHZ-1 at z = 10.073 ± 0.002. We find that the NIRSpec/Prism spectrum is typical of recently discovered z ≈ 10 galaxies, characterized primarily by star formation features. We see no clear evidence of the powerful X-ray source in the rest-frame UV/optical spectrum, which may suggest heavy obscuration of the central BH, in line with the Compton-thick column density measured in the X-rays. We perform a stellar population fit simultaneously to the new NIRSpec spectroscopy and previously available photometry. The fit yields a stellar-mass estimate for the host galaxy that is significantly better constrained than prior photometric estimates (�⋆∼1.4−0.4+0.3×108M⊙). Given the predicted BH mass (MBH ∼ 107–108M⊙), the resulting ratio of MBH/M⋆ remains 2 to 3 orders of magnitude higher than local values, thus lending support to the heavy seeding channel for the formation of supermassive BHs within the first billion years of cosmic evolution

UNCOVER: Illuminating the Early Universe—JWST/NIRSpec Confirmation of z \u3e 12 Galaxies

Observations of high-redshift galaxies provide a critical direct test to the theories of early galaxy formation, yet to date, only three have been spectroscopically confirmed at z \u3e 12. Due to strong gravitational lensing over a wide area, the galaxy cluster field A2744 is ideal for searching for the earliest galaxies. Here we present JWST/NIRSpec observations of two galaxies: a robust detection at zspec 12.393 0.001 0.004 = - + , and a plausible candidate at zspec 13.079 0.001 0.013 = - + . The galaxies are discovered in JWST/NIRCam imaging and their distances are inferred with JWST/NIRSpec spectroscopy, all from the JWST Cycle 1 UNCOVER Treasury survey. Detailed stellar population modeling using JWST NIRCam and NIRSpec data corroborates the primeval characteristics of these galaxies: low mass (∼108 Me), young, rapidly assembling, metal-poor, and star-forming. Interestingly, both galaxies are spatially resolved, having lensing-corrected rest-UV effective radii on the order of 300–400 pc, which are notably larger than other spectroscopically confirmed systems at similar redshifts. The observed dynamic range of z 10 sizes spans over 1 order of magnitude, implying a significant scatter in the size–mass relation at early times. Deep into the epoch of reionization, these discoveries elucidate the emergence of the first galaxies