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We describe the survey design and science goals for One-hundred-deg2 DECam Imaging in Narrowbands (ODIN), a NOIRLab survey using the Dark Energy Camera (DECam) to obtain deep (AB ∼ 25.7) narrowband images over an unprecedented area of sky. The three custom-built narrowband filters, N419, N501, and N673, have central wavelengths of 419, 501, and 673 nm and respective FWHM of 7.5, 7.6, and 10.0 nm, corresponding to Lyα at z = 2.4, 3.1, and 4.5 and cosmic times of 2.8, 2.1, and 1.4 Gyr, respectively. When combined with even deeper, public broadband data from the Hyper Suprime-Cam, DECam, and in the future, the Legacy Survey of Space and Time, the ODIN narrowband images will enable the selection of over 100,000 Lyα-emitting (LAE) galaxies at these epochs. ODIN-selected LAEs will identify protoclusters as galaxy overdensities, and the deep narrowband images enable detection of highly extended Lyα blobs (LABs). Primary science goals include measuring the clustering strength and dark matter halo connection of LAEs, LABs, and protoclusters, and their respective relationship to filaments in the cosmic web. The three epochs allow for the redshift evolution of these properties to be determined during the period known as Cosmic Noon, where star formation was at its peak. The narrowband filter wavelengths are designed to enable interloper rejection and further scientific studies by revealing [O ii] and [O iii] at z = 0.34, Lyα and He ii 1640 at z = 3.1, and Lyman continuum plus Lyα at z = 4.5. Ancillary science includes similar studies of the lower-redshift emission-line galaxy samples and investigations of nearby star-forming galaxies resolved into numerous [O iii] and [S ii] emitting regions.

As the progenitors of present-day galaxy clusters, protoclusters are excellent laboratories to study galaxy evolution. Since existing observations of protoclusters are limited to the detected constituent galaxies at UV and/or infrared wavelengths, the details of how typical galaxies grow in these young, pre-virialized structures remain uncertain. We measure the total stellar mass and star formation within protoclusters, including the contribution from faint undetected members by performing a stacking analysis of 211 z = 2–4 protoclusters selected as Planck cold sources. We stack Wide-field Infrared Survey Explorer and Herschel/SPIRE images to measure the angular size and the spectral energy distribution of the integrated light from the protoclusters. The fluxes of protoclusters selected as Planck cold sources can be contaminated by line-of-sight interlopers. Using the WebSky simulation, we estimate that a single protocluster contributes 33% ± 15% of the flux of a Planck cold source on average. After this correction, we obtain a total star formation rate of 7.3 ± 3.2 × 103 M ⊙yr−1 and a total stellar mass of 4.9 ± 2.2 × 1012 M ⊙. Our results indicate that protoclusters have, on average, 2× more star formation and 4× more stellar mass than the total contribution from individually detected galaxies in spectroscopically confirmed protoclusters. This suggests that much of the total flux within z = 2–4 protoclusters comes from galaxies with luminosities lower than the detection limit of SPIRE (L IR < 3 × 1012 L ⊙). Lastly, we find that protoclusters subtend a half-light radius of 2.′8 (4.2–5.8 cMpc), which is consistent with simulations. [ABSTRACT FROM AUTHOR]

The present model revisits the issue of unit and ad valorem taxes in a model of monopolistic competition. It is shown that if the assumption of full employment is relaxed, then taxation can increase employment conditionally when the elasticity of substitution among varieties is low. Moreover, with the same level of initial unemployment, ad valorem tax is better than unit tax in terms of employment, when the targeted tax revenue is relatively high and scale economies are strong. [ABSTRACT FROM AUTHOR]

Massive galaxy clusters undergo strong evolution from z ∼ 1.6 to z ∼ 0.5, with overdense environments at high- z characterized by abundant dust-obscured star formation and stellar mass growth which rapidly give way to widespread quenching. Data spanning the near- to far-infrared (IR) can directly trace this transformation; however, such studies have largely been limited to the massive galaxy end of cluster populations. In this work, we present 'total light' stacking techniques spanning |$3.4\!-\!500\, \mu$| m aimed at revealing the total cluster emission, including low-mass members and potential intracluster dust. We detail our procedures for  WISE, Spitzer , and  Herschel imaging, including corrections to recover the total stacked emission in the case of high fractions of detected galaxies. We apply our techniques to 232 well-studied log |$\, M_{200}/\mathrm{M}_{\odot }\sim 13.8$| clusters in multiple redshift bins, recovering extended cluster emission at all wavelengths. We measure the averaged IR radial profiles and spectral energy distributions (SEDs), quantifying the total stellar and dust content. The near-IR profiles are well described by an NFW model with a high (c ∼ 7) concentration. Dust emission is similarly concentrated, albeit suppressed at  |$r\lesssim 0.3\,$| Mpc. The measured SEDs lack warm dust, consistent with the colder SEDs of low-mass galaxies. We derive total stellar masses consistent with the theoretical M halo− M ⋆ relation and specific star formation rates that evolve strongly with redshift, echoing that of log |$\, M_{\star }/\mathrm{M}_{\odot }\gtrsim 10$| cluster galaxies. Separating out the massive population reveals the majority of cluster far-IR emission (⁠|$\sim 70\!-\!80{{\ \rm per\ cent}}$|⁠) is provided by the low-mass constituents, which differs from field galaxies. This effect may be a combination of mass-dependent quenching and excess dust in low-mass cluster galaxies. [ABSTRACT FROM AUTHOR]

Core-collapse supernovae (SNe) expand into a medium created by winds from the pre-SN progenitor. The SN explosion and resulting shock wave(s) heat up the surrounding plasma, giving rise to thermal X-ray emission, which depends on the density of the emitting material. Tracking the variation of the X-ray luminosity over long periods of time thus allows for investigation of the kinematics of the SN shock waves, the structure of the surrounding medium, and the nature of the progenitor star. In this paper, X-ray observations of five of the oldest known X-ray SNe—SN 1970G, SN 1968D, SN 1959D, SN 1957D, and SN 1941C—are analyzed, with the aim of reconstructing their light curves over several decades. For those SNe for which we can extract multiepoch data, the X-ray luminosity appears to decline with time, although with large error bars. No increase in the X-ray emission from SN 1970G is found at later epochs, contrary to previous reports. All five SNe show X-ray luminosities that are of comparable magnitude. We compare the late-time X-ray luminosities of these SNe to those of supernova remnants (SNRs) in the Galaxy, which are a few hundred years old, and find that when the tentative decline is taken into account, the luminosity of the old SNe studied herein could fall below the luminosity of some of the younger SNRs within a few hundred years. However, the X-ray luminosity should begin to increase as the SNe expand in the Sedov phase, thus reaching that of the observed SNRs. [ABSTRACT FROM AUTHOR]