Time-Lapse Seismic Imaging of Oceanic Fronts and Transient Lenses within South Atlantic Ocean

Oceanic fronts play a pivotal role in controlling water mass transfer, although little is known about deep frontal structure on appropriate temporal and spatial scales. Here, we present a sequence of calibrated time-lapse images from a three-dimensional seismic survey that straddles the Brazil-Malvinas Confluence— a significant feature of the merid- ional overturning circulation. Eight vertical transects reveal the evolution of a major front. It is manifest as a discrete planar surface that dips at less than 2 ◦ and is traceable to 1.5–2 km depth. Its shape and surface expression are consistent with sloping isopycnal surfaces of the calculated potential density field and with coeval sea surface tempera- ture measurements, respectively. Within the top ∼1 km, where cold fresh water subducts beneath warm salty water, a series of tilted lenses are banked up against the sharply de- fined front. The largest of these structures is centered at 700 m depth and is cored by cold fresh water. Time-lapse imagery demonstrates that this tilted lens grows and de- cays over nine days. It has a maximum diameter of < 34 ± 0.13 km and a maximum height of < 750±10 m. Beneath 1 km, where horizontal density gradients are negligi- ble, numerous deforming lenses and filaments on length scales of 10–100 km are being swept toward the advecting front

A Simple Likelihood Method for Quasar Target Selection

We present a new method for quasar target selection using photometric fluxes and a Bayesian probabilistic approach. For our purposes we target quasars using Sloan Digital Sky Survey (SDSS) photometry to a magnitude limit of g=22. The efficiency and completeness of this technique is measured using the Baryon Oscillation Spectroscopic Survey (BOSS) data, taken in 2010. This technique was used for the uniformly selected (CORE) sample of targets in BOSS year one spectroscopy to be realized in the 9th SDSS data release. When targeting at a density of 40 objects per sq-deg (the BOSS quasar targeting density) the efficiency of this technique in recovering z>2.2 quasars is 40%. The completeness compared to all quasars identified in BOSS data is 65%. This paper also describes possible extensions and improvements for this techniqueComment: Updated to accepted version for publication in the Astrophysical Journal. 10 pages, 10 figures, 3 table

New Neutrino Mass Bounds from Sloan Digital Sky Survey III Data Release 8 Photometric Luminous Galaxies

We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release Eight (SDSS DR8). The galaxies have photometric redshifts between $z = 0.45$ and $z = 0.65$, and cover 10,000 square degrees and thus probe a volume of 3$h^{-3}$Gpc$^3$, enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos. A new bound on the sum of neutrino masses $\sum m_\nu < 0.26$ eV, at 95% confidence level (CL), is obtained after combining our sample of galaxies, which we call "CMASS", with WMAP 7 year Cosmic Microwave Background (CMB) data and the most recent measurement of the Hubble parameter from the Hubble Space Telescope (HST). This constraint is obtained with a conservative multipole range choice of $30 < \ell < 200$ in order to minimize non-linearities, and a free bias parameter in each of the four redshift bins. We study the impact of assuming this linear galaxy bias model using mock catalogs, and find that this model causes a small ($\sim 1-1.5 \sigma$) bias in $\Omega_{\rm DM} h^2$. For this reason, we also quote neutrino bounds based on a conservative galaxy bias model containing additional, shot noise-like free parameters. In this conservative case, the bounds are significantly weakened, e.g. $\sum m_\nu < 0.36$ eV (95% confidence level) for WMAP+HST+CMASS ($\ell_{\rm max}=200$). We also study the dependence of the neutrino bound on multipole range ($\ell_{\rm max}=150$ vs $\ell_{\rm max}=200$) and on which combination of data sets is included as a prior. The addition of supernova and/or Baryon Acoustic Oscillation data does not significantly improve the neutrino mass bound once the HST prior is included. [abridged]Comment: 14 pages, 8 figures, 1 tabl

The Student Movement Volume 107 Issue 20: Andrews Students Spring Back from Break: Six More Weeks to Go

HUMANS Meeting Dr. McCree, Interviewed by: Grace No Interview with Dr. Luxton: Saying Goodbye, Interviewed by: Grace No Spring Break Renovations & Relaxation, Caryn Cruz ARTS & ENTERTAINMENT Currently: The Last of Us, Solana Campbell Spring Break Spotlight, Amelia Stefanescu What Happened to Wang in the Costco Bathroom?, Nora Martin NEWS Experiences Living in Lamson Hall, Abigail Kim Time is Ticking for TikTok, Brendan Oh WEAAU x CFE Service Sabbath, Terika Williams IDEAS Inequality Drags on in Tennessee, Alexander J. Hess On Value: True Crime and the Search for Meaning, Nora Martin When Winds Change: The Legacy of President Luxton, Bella Hamann PULSE A Trip to the Museo , Chris Ngugi AUSA Senates Holds Bon Appétit Forum, Neesa Richards Speaking Up With Women Press Release, Nicholas C. Gunn LAST WORD A Week of Rest and Relaxation ... Almost, Grace Nohttps://digitalcommons.andrews.edu/sm-107/1019/thumbnail.jp

Think Outside the Color Box: Probabilistic Target Selection and the SDSS-XDQSO Quasar Targeting Catalog

We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 <~ z <~ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 <= z 3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45 mag in the 14,555 deg^2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available

Acoustic scale from the angular power spectra of SDSS-III DR8 photometric luminous galaxies

We measure the acoustic scale from the angular power spectra of the Sloan Digital Sky Survey III (SDSS-III) Data Release 8 imaging catalog that includes 872,921 galaxies over ~ 10,000 deg^2 between 0.45<z<0.65. The extensive spectroscopic training set of the Baryon Oscillation Spectroscopic Survey (BOSS) luminous galaxies allows precise estimates of the true redshift distributions of galaxies in our imaging catalog. Utilizing the redshift distribution information, we build templates and fit to the power spectra of the data, which are measured in our companion paper, Ho et al. 2011, to derive the location of Baryon acoustic oscillations (BAO) while marginalizing over many free parameters to exclude nearly all of the non-BAO signal. We derive the ratio of the angular diameter distance to the sound horizon scale D_A/r_s= 9.212 + 0.416 -0.404 at z=0.54, and therefore, D_A= 1411+- 65 Mpc at z=0.54; the result is fairly independent of assumptions on the underlying cosmology. Our measurement of angular diameter distance D_A is 1.4 \sigma higher than what is expected for the concordance LCDM (Komatsu et al. 2011), in accordance to the trend of other spectroscopic BAO measurements for z >~ 0.35. We report constraints on cosmological parameters from our measurement in combination with the WMAP7 data and the previous spectroscopic BAO measurements of SDSS (Percival et al. 2010) and WiggleZ (Blake et al. 2011). We refer to our companion papers (Ho et al. 2011; de Putter et al. 2011) for investigations on information of the full power spectrum.Comment: 16 pages, 14 figures, 3 tables, submitted to Ap

SDSS Standard Star Catalog for Stripe 82: the Dawn of Industrial 1% Optical Photometry

We describe a standard star catalog constructed using multiple SDSS photometric observations (at least four per band, with a median of ten) in the $ugriz$ system. The catalog includes 1.01 million non-variable unresolved objects from the equatorial stripe 82 ($|\delta_{J2000}|<$ 1.266$^\circ$) in the RA range 20h 34m to 4h 00m, and with the corresponding $r$ band (approximately Johnson V band) magnitudes in the range 14--22. The distributions of measurements for individual sources demonstrate that the photometric pipeline correctly estimates random photometric errors, which are below 0.01 mag for stars brighter than (19.5, 20.5, 20.5, 20, 18.5) in $ugriz$, respectively (about twice as good as for individual SDSS runs). Several independent tests of the internal consistency suggest that the spatial variation of photometric zeropoints is not larger than $\sim$0.01 mag (rms). In addition to being the largest available dataset with optical photometry internally consistent at the $\sim$1% level, this catalog provides practical definition of the SDSS photometric system. Using this catalog, we show that photometric zeropoints for SDSS observing runs can be calibrated within nominal uncertainty of 2% even for data obtained through 1 mag thick clouds, and demonstrate the existence of He and H white dwarf sequences using photometric data alone. Based on the properties of this catalog, we conclude that upcoming large-scale optical surveys such as the Large Synoptic Survey Telescope will be capable of delivering robust 1% photometry for billions of sources.Comment: 63 pages, 24 figures, submitted to AJ, version with correct figures and catalog available from http://www.astro.washington.edu/ivezic/sdss/catalogs/stripe82.htm

The Student Movement Volume 108 Issue 20: Breaking News: Curfew is Now Sunset: Effective Immediately

HUMANS Chivalry Not Dead: Students Spotted in Shining Armor, Grace No Interview with the Breakfast Burrito, Interviewed by Regan McCain VeggieTales Cast: Hot Takes From the Fridge, Interviewed by Savannah Tyler ARTS & ENTERTAINMENT Why the \u27Daughters of the Revolution\u27 Stay Mad, Madison Vath Jaws 6: The Jawsical, Corinna Bevier I UNDERSTAND MARY POPPINS\u27 ESSENCE MORE THAN THE FILM\u27S WRITERS, Nate Miller Pitagorical decision: Music Department opens Triangle Performance Major, Aiko J. Ayala Rivers Sabrina Carpenter Comes to Berrien, Reagan McCain NEWS Soccer (Football) Legend Lionel Messi to Visit Berrien County, Andrew Francis Satire: Severe Weather Stirs Mixed Emotions on Campus, Ana K. Zelidon The Fruits of Their Labor, Jonathan Clough IDEAS Curfew is Now Sunset, Abby Shim Lamson Hall: Summer Demolition Date Finalized, Bella Hamann Woof Woof, Abby Shim PULSE The Muppets: A Real-Life Musical, Anna Rybachek New Slogan: Seek Knowledge. Affirm Faith. Get a Tan!, Melissa Moore LETTERS TO THE EDITOR Nicholas Gunn LAST WORD The Beauty of Inconvenience, Abby Shimhttps://digitalcommons.andrews.edu/sm-108/1019/thumbnail.jp