Development of scenarios for land cover, population density, impervious cover, and conservation in New Hampshire, 2010–2100

Future changes in ecosystem services will depend heavily on changes in land cover and land use, which, in turn, are shaped by human activities. Given the challenges of predicting long-term changes in human behaviors and activities, scenarios provide a framework for simulating the long-term consequences of land-cover change on ecosystem function. As input for process-based models of terrestrial and aquatic ecosystem function, we developed scenarios for land cover, population density, and impervious cover for the state of New Hampshire for 2020–2100. Key drivers of change were identified through information gathered from six sources: historical trends, existing plans relating to New Hampshire’s land-cover future, surveys, existing population scenarios, key informant interviews with diverse stakeholders, and input from subject-matter experts. Scenarios were developed in parallel with information gathering, with details added iteratively as new questions emerged. The final scenarios span a continuum from spatially dispersed development with a low value placed on ecosystem services (Backyard Amenities) to concentrated development with a high value placed on ecosystem services (the Community Amenities family). The Community family includes two population scenarios (Large Community and Small Community), to be combined with two scenarios for land cover (Protection of Wildlands and Promotion of Local Food), producing combinations that bring the total number of scenarios to six. Between Backyard Amenities and Community Amenities is a scenario based on linear extrapolations of current trends (Linear Trends). Custom models were used to simulate decadal change in land cover, population density, and impervious cover. We present raster maps and proportion of impervious cover for HUC10 watersheds under each scenario and discuss the trade-offs of our translation and modeling approach within the context of contemporary scenario projects

The Clustering of Ha Emitters at z=2.23 from HiZELS

We present a clustering analysis of 370 high-confidence Hα emitters (HAEs) at z = 2.23. The HAEs are detected in the Hi-Z Emission Line Survey (HiZELS), a large-area blank field 2.121 μm narrow-band survey using the United Kingdom Infrared Telescope Wide Field Camera (WFCAM). Averaging the two-point correlation function of HAEs in two ∼1° scale fields [United Kingdom Infrared Deep Sky Survey/Ultra Deep Survey (UDS) and Cosmological Evolution Survey (COSMOS) fields] we find a clustering amplitude equivalent to a correlation length of r0 = 3.7 ± 0.3 h−1 Mpc for galaxies with star formation rates of ≳7 M⊙ yr−1. The data are also well-fitted by the expected correlation function of cold dark matter (CDM), scaled by a bias factor: ωHAE = b2ωDM where . The corresponding ‘characteristic’ mass for the haloes hosting HAEs is log (Mh/[h−1 M⊙]) = 11.7 ± 0.1. Comparing to the latest semi-analytic galform predictions for the evolution of HAEs in a ΛCDM cosmology, we find broad agreement with the observations, with galform predicting an HAE correlation length of ∼4 h−1 Mpc. Motivated by this agreement, we exploit the simulations to construct a parametric model of the halo occupation distribution (HOD) of HAEs, and use this to fit the observed clustering. Our best-fitting HOD can adequately reproduce the observed angular clustering of HAEs, yielding an effective halo mass and bias in agreement with that derived from the scaled ωDM fit, but with the relatively small sample size the current data provide a poor constraint on the HOD. However, we argue that this approach provides interesting hints into the nature of the relationship between star-forming galaxies and the matter field, including insights into the efficiency of star formation in massive haloes. Our results support the broad picture that ‘typical’ (≲L⋆) star-forming galaxies have been hosted by dark matter haloes with Mh ≲ 1012 h−1 M⊙ since z ≈ 2, but with a broad occupation distribution and clustering that is likely to be a strong function of luminosity

Modeling the color evolution of luminous red galaxies - improvements with empirical stellar spectra

Predicting the colors of Luminous Red Galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) has been a long-standing problem. The g,r,i colors of LRGs are inconsistent with stellar population models over the redshift range 0.1<z<0.7. The g-r colors in the models are on average redder than the data while the r-i colors in the models are bluer towards low redshift. Beyond redshift 0.4, the predicted r-i color becomes instead too red, while the predicted g-r agrees with the data. We provide a solution to this problem, through a combination of new astrophysics and a fundamental change to the stellar population modeling. We find that the use of the empirical library of Pickles (1998) instead of theoretical spectra modifies the predicted colors exactly in the way suggested by the data. The reason is a lower flux in the empirical libraries, with respect to the theoretical ones, in the wavelength range 5500-6500 AA. The discrepancy increases with decreasing effective temperature independently of gravity. This result has general implications for a variety of studies from globular clusters to high-redshift galaxies. The astrophysical part of our solution regards the composition of the stellar populations of these massive Luminous Red Galaxies. We find that on top of the previous effect one needs to consider a model in which ~3% of the stellar mass is in old metal-poor stars. Other solutions such as substantial blue Horizontal Branch at high metallicity or young stellar populations can be ruled out by the data. Our new model provides a better fit to the g-r and r-i colors of LRGs and gives new insight into the formation histories of these most massive galaxies. Our model will also improve the k- and evolutionary corrections for LRGs which are critical for fully exploiting present and future galaxy surveys.Comment: Submitted to ApJ Letters. High resolution version available at http://www.maraston.eu/Maraston_etal_2008.pd

Spatially Extended Low Ionization Emission Regions (LIERs) at z∼0.9z\sim0.9

We present spatially resolved emission diagnostics for eight $z\sim0.9$ galaxies that demonstrate extended low ionization emission-line regions (LIERs) over kpc scales. Eight candidates are selected based on their spatial extent and emission line fluxes from slitless spectroscopic observations with the HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra X-Ray Observatory} Deep Fields. We modify the traditional Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use [SII]/(H$\alpha$+[NII]) instead of [NII]/H$\alpha$ to overcome the blending of [NII] and H$\alpha$+[NII] in the low resolution slitless grism spectra. We construct emission line ratio maps and place the individual pixels in the modified BPT. The extended LINER-like emission present in all of our candidates, coupled with X-Ray properties consistent with star-forming galaxies and weak [OIII]$\lambda$5007\AA\ detections, is inconsistent with purely nuclear sources (LINERs) driven by active galactic nuclei. While recent ground-based integral field unit spectroscopic surveys have revealed significant evidence for diffuse LINER-like emission in galaxies within the local universe $(z\sim0.04)$, this work provides the first evidence for the non-AGN origin of LINER-like emission out to high redshifts.Comment: 11 pages, 1 table, 6 figures, accepted for publication in the Astrophysics Journal (ApJ

The environmental dependence of galaxy colors in intermediate-redshift X‐ray–selected clusters

We present a wide-field imaging study of the colors of bright galaxies (∗ + 2) in a sample of 12 X-ray–selected clusters and groups of galaxies at z ~ 0:3. The systems cover one of the largest ranges in X-ray luminosity (Lx ~ 1043 1045 ergs s-1), and hence mass, of any sample studied at this redshift. We find that the ‘‘red’’ galaxies form a tight color-magnitude relation (CMR) and that neither the slope nor zero point of this relation changes significantly over the factor of 100 in X-ray luminosity covered by our sample. Using stellar population synthesis models, we find that our data allow a maximum possible change of 2 Gyr in the typical age of the ‘‘red’’ galaxies on the CMR over the range of Lx of our sample.We also measure the fraction of blue galaxies (fb) relative to the CMR in our clusters and find a low value of fb ~ 0.1 consistent with other X-ray–selected cluster samples.We find that there is no correlation between fb and Lx over our large Lx range. However, we do find that both the CMR and fb depend significantly on cluster radius, with the zero point of the CMR shifting blueward in B - R by 0.10 ± 0.036 mag out to a radius of 0.75 times the virial radius. This color change is equivalent to a luminosity-weighted age gradient of ~2.5 Gyr per log (radius) and is consistent with previous studies of the radial change in the zero point of the CMR. It thus appears that the global cluster environment, in the form of cluster mass (Lx), has little influence on the properties of the bright cluster galaxies, whereas the local environment, in the form of galaxy density (radius), has a strong effect. The range of ~100 in Lx corresponds to a factor of ~40 in ram pressure efficiency, thus suggesting that ram pressure stripping or other mechanisms that depend on cluster mass, like tidal stripping or harassment, are unlikely to be solely responsible for changing the galaxy population from the ‘‘blue’’ star-forming galaxies, which dominate low-density environments, to the ‘‘red’’ passive galaxies, which dominate cluster cores

Divergence of thermal physiological traits in terrestrial breeding frogs along a tropical elevational gradient

Critical thermal limits are thought to be correlated with the elevational distribution of species living in tropical montane regions, but with upper limits being relatively invariant compared to lower limits. To test this hypothesis, we examined the variation of thermal physiological traits in a group of terrestrial breeding frogs (Craugastoridae) distributed along a tropical elevational gradient. We measured the critical thermal maximum (CTmax; n = 22 species) and critical thermal minimum (CTmin; n = 14 species) of frogs captured between the Amazon floodplain (250 m asl) and the high Andes (3,800 m asl). After inferring a multilocus species tree, we conducted a phylogenetically informed test of whether body size, body mass, and elevation contributed to the observed variation in CTmax and CTmin along the gradient. We also tested whether CTmax and CTmin exhibit different rates of change given that critical thermal limits (and their plasticity) may have evolved differently in response to different temperature constraints along the gradient. Variation of critical thermal traits was significantly correlated with speciesâ elevational midpoint, their maximum and minimum elevations, as well as the maximum air temperature and the maximum operative temperature as measured across this gradient. Both thermal limits showed substantial variation, but CTmin exhibited relatively faster rates of change than CTmax, as observed in other taxa. Nonetheless, our findings call for caution in assuming inflexibility of upper thermal limits and underscore the value of collecting additional empirical data on speciesâ thermal physiology across elevational gradients.A widely held assumption is that climatic niches have not changed along the history of species, both within and among closely related species. Using a phylogenetic framework, this study documents high variability in both elevational distribution and tolerance to heat among closely related species. Our findings suggest that thermal traits in ectotherms can adjust rapidly and so cannot be simply extrapolated from relatives.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136724/1/ece32929_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136724/2/ece32929.pd

Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements

Cosmic shear constrains cosmology by exploiting the apparent alignments of pairs of galaxies due to gravitational lensing by intervening mass clumps. However galaxies may become (intrinsically) aligned with each other, and with nearby mass clumps, during their formation. This effect needs to be disentangled from the cosmic shear signal to place constraints on cosmology. We use the linear intrinsic alignment model as a base and compare it to an alternative model and data. If intrinsic alignments are ignored then the dark energy equation of state is biased by ~50 per cent. We examine how the number of tomographic redshift bins affects uncertainties on cosmological parameters and find that when intrinsic alignments are included two or more times as many bins are required to obtain 80 per cent of the available information. We investigate how the degradation in the dark energy figure of merit depends on the photometric redshift scatter. Previous studies have shown that lensing does not place stringent requirements on the photometric redshift uncertainty, so long as the uncertainty is well known. However, if intrinsic alignments are included the requirements become a factor of three tighter. These results are quite insensitive to the fraction of catastrophic outliers, assuming that this fraction is well known. We show the effect of uncertainties in photometric redshift bias and scatter. Finally we quantify how priors on the intrinsic alignment model would improve dark energy constraints.Comment: 14 pages and 9 figures. Replaced with final version accepted in "Gravitational Lensing" Focus Issue of the New Journal of Physics at http://www.iop.org/EJ/abstract/1367-2630/9/12/E0