Publications (39)
Project Dinos I: A joint lensing-dynamics constraint on the deviation from the power law in the mass profile of massive ellipticals
Chin Yi Tan, Anowar J. Shajib, Simon Birrer +7
The mass distribution in massive elliptical galaxies encodes their evolutionary history, thus providing an avenue to constrain the baryonic astrophysics in their evolution. The pow…
Mirror Dark Sector Solution of the Hubble Tension with Time-varying Fine-structure Constant
John Zhang, Joshua Frieman
We explore a model introduced by Cyr-Racine, Ge, and Knox (arXiv:2107.13000(2)) that resolves the Hubble tension by invoking a ``mirror world" dark sector with energy density a fix…
Incorporating galaxy cluster triaxiality in stacked cluster weak lensing analyses
Zhuowen Zhang, Hao-Yi Wu, Yuanyuan Zhang +10
Counts of galaxy clusters offer a high-precision probe of cosmology, but control of systematic errors will determine the accuracy of this measurement. Using Buzzard simulations, we…
The Multi-Object, Fiber-Fed Spectrographs for SDSS and the Baryon Oscillation Spectroscopic Survey
Stephen Smee, James E. Gunn, Alan Uomoto +61
We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Sur…
TDCOSMO XVII. New time delays in 22 lensed quasars from optical monitoring with the ESO-VST 2.6m and MPG 2.2m telescopes
Frédéric Dux, Martin Millon, Aymeric Galan +29
We present new time delays, the main ingredient of time delay cosmography, for 22 lensed quasars resulting from high-cadence r-band monitoring on the 2.6 m ESO VLT Survey Telescope…
Loop Corrections in Non-Linear Cosmological Perturbation Theory
Roman Scoccimarro, Joshua Frieman
Using a diagrammatic approach to Eulerian perturbation theory, we analytically calculate the variance and skewness of the density and velocity divergence induced by gravitational e…
Constraining the Scatter in the Mass-Richness Relation of maxBCG Clusters With Weak Lensing and X-ray Data
Eduardo Rozo, Eli S. Rykoff, August Evrard +10
We measure the logarithmic scatter in mass at fixed richness for clusters in the maxBCG cluster catalog, an optically selected cluster sample drawn from SDSS imaging data. Our meas…
The Spectroscopic Stage-5 Experiment
Robert Besuner, Arjun Dey, Alex Drlica-Wagner +106
The existence, properties, and dynamics of the dark sectors of our universe pose fundamental challenges to our current model of physics, and large-scale astronomical surveys may be…
Candidate Periodically Variable Quasars from the Dark Energy Survey and the Sloan Digital Sky Survey
Yu-Ching Chen, Xin Liu, Wei-Ting Liao +62
Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confir…
Facilities for Dark Energy Investigations
David Weinberg, Deborah Bard, Kyle Dawson +5
The discovery of cosmic acceleration has inspired ambitious experimental and observational efforts to understand its origin. Many of these take the form of large astronomical surve…
Probing the Fundamental Nature of Dark Matter with the Large Synoptic Survey Telescope
Alex Drlica-Wagner, Yao-Yuan Mao, Susmita Adhikari +97
Astrophysical and cosmological observations currently provide the only robust, empirical measurements of dark matter. Future observations with Large Synoptic Survey Telescope (LSST…
Eigenspectra of the SDSS DR1 quasars
Ching-Wa Yip, Andrew Connolly, Daniel Vanden Berk +4
We construct eigenspectra from the DR1 quasars in the SDSS using the Karhunen-Loève (KL) transform (or Principal Component Analysis, PCA) in different redshift and luminosity bins…
Natural Inflation: Particle Physics Models, Power Law Spectra for Large Scale Structure, and Constraints from COBE
Fred Adams, J. R. Bond, Katherine Freese +2
A pseudo-Nambu-Goldstone boson, with a potential of the form f \sim M_{Pl}Î\sim M_{GUT}$. We show how…
Primordial non-Gaussianity and Dark Energy constraints from Cluster Surveys
Emiliano Sefusatti, Chris Vale, Kenji Kadota +1
Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundance is sensitive to any non-Gaussianity of the primordial density field. It is there…
TDCOSMO. XVI. Measurement of the Hubble Constant from the Lensed Quasar WGD20384008
Kenneth C. Wong, Frédéric Dux, Anowar J. Shajib +17
Time-delay cosmography is a powerful technique to constrain cosmological parameters, particularly the Hubble constant (). The TDCOSMO collaboration is performing an ongoing…
Spectroscopic Determination of the Low Redshift Type Ia Supernova Rate from the Sloan Digital Sky Survey
K. Simon Krughoff, Andrew Connolly, Joshua Frieman +3
Supernova rates are directly coupled to high mass stellar birth and evolution. As such, they are one of the few direct measures of the history of cosmic stellar evolution. In this…
Deep inference of simulated strong lenses in ground-based surveys
Jason Poh, Ashwin Samudre, Aleksandra ÄiprijanoviÄ +3
The large number of strong lenses discoverable in future astronomical surveys will likely enhance the value of strong gravitational lensing as a cosmic probe of dark energy and dar…
Optimizing galaxy samples for clustering measurements in photometric surveys
Dimitrios Tanoglidis, Chihway Chang, Joshua Frieman
When analyzing galaxy clustering in multi-band imaging surveys, there is a trade-off between selecting the largest galaxy samples (to minimize the shot noise) and selecting samples…
Extreme variability quasars from the Sloan Digital Sky Survey and the Dark Energy Survey
Nick Rumbaugh, Yue Shen, Eric Morganson +49
We perform a systematic search for long-term extreme variability quasars (EVQs) in the overlapping Sloan Digital Sky Survey (SDSS) and 3-Year Dark Energy Survey (DES) imaging, whic…
dolphin: A fully automated forward modeling pipeline powered by artificial intelligence for galaxy-scale strong lenses
Anowar J. Shajib, Nafis Sadik Nihal, Chin Yi Tan +4
Strong gravitational lensing is a powerful tool for probing the internal structure and evolution of galaxies, the nature of dark matter, and the expansion history of the Universe,…
Estimating the Redshift Distribution of Photometric Galaxy Samples II. Applications and Tests of a New Method
Carlos E. Cunha, Marcos Lima, Hiroaki Oyaizu +2
In Lima et al. 2008 we presented a new method for estimating the redshift distribution, N(z), of a photometric galaxy sample, using photometric observables and weighted sampling fr…
The SDSS-II Supernova Survey: Parameterizing the Type Ia Supernova Rate as a Function of Host Galaxy Properties
Mathew Smith, Robert C Nichol, Benjamin Dilday +11
Using data from the Sloan Digital Sky Supernova Survey-II, we measure the rate of Type Ia Supernovae (SNe Ia) as a function of galaxy properties at intermediate redshift. A sample…
Dust Reverberation Mapping in Distant Quasars from Optical and Mid-Infrared Imaging Surveys
Qian Yang, Yue Shen, Xin Liu +47
The size of the dust torus in Active Galactic Nuclei (AGN) and their high-luminosity counterparts, quasars, can be inferred from the time delay between UV/optical accretion disk co…
A Galaxy Photometric Redshift Catalog for the Sloan Digital Sky Survey Data Release 6
Hiroaki Oyaizu, Marcos Lima, Carlos E. Cunha +3
We present and describe a catalog of galaxy photometric redshifts (photo-z's) for the Sloan Digital Sky Survey (SDSS) Data Release 6 (DR6). We use the Artificial Neural Network (AN…
Modeling the three-point correlation function
Felipe Marin, Risa Wechsler, Joshua Frieman +1
We present new predictions for the galaxy three-point correlation function (3PCF) using high-resolution dissipationless cosmological simulations of a flat LCDM Universe which resol…
Discovery and Physical Characterization of a Large Scattered Disk Object at 92 AU
David Gerdes, Masao Sako, Stephanie Hamilton +65
We report the observation and physical characterization of the possible dwarf planet \UZ\ ("DeeDee"), a dynamically detached trans-Neptunian object discovered at 92 AU. This object…
Distributions of Galaxy Spectral Types in the Sloan Digital Sky Survey
Ching-Wa Yip, Andrew Connolly, Alex Szalay +12
We perform an objective classification of 170,000 galaxy spectra in the Sloan Digital Sky Survey (SDSS) using the Karhunen-Loève (KL) transform. With about one-sixth of the total…
Photometric Supernova Cosmology with BEAMS and SDSS-II
Renée Hlozek, Martin Kunz, Bruce Bassett +16
Supernova cosmology without spectroscopic confirmation is an exciting new frontier which we address here with the Bayesian Estimation Applied to Multiple Species (BEAMS) algorithm…
Testing Models of Intrinsic Brightness Variations in Type Ia Supernovae, and their Impact on Measuring Cosmological Parameters
Richard Kessler, Julien Guy, John Marriner +8
For spectroscopically confirmed Type Ia supernovae we evaluate models of intrinsic brightness variations with detailed data/Monte Carlo comparisons of the dispersion in the followi…
The Effect of Nonlinear Gravity on the Cosmological Background During Preheating
Ryn Grutkoski, Hayley J. Macpherson, John T. Giblin +1
We use numerical relativity to study the violent preheating era at the end of inflation. This epoch can result in highly nonlinear fluctuations in density and gravitational potenti…
LensingETC: a tool to optimize multi-filter imaging campaigns of galaxy-scale strong lensing systems
Anowar J. Shajib, Karl Glazebrook, Tania Barone +7
Imaging data is the principal observable required to use galaxy-scale strong lensing in a multitude of applications in extragalactic astrophysics and cosmology. In this paper, we d…
Hubble Space Telescope and Ground-Based Observations of the Type Iax Supernovae SN 2005hk and SN 2008A
Curtis McCully, Saurabh W. Jha, Ryan J. Foley +24
We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe)…
Photometric SN Ia Candidates from the Three-Year SDSS-II SN Survey Data
Masao Sako, Bruce Bassett, Brian Connolly +12
We analyze the three-year SDSS-II Superernova (SN) Survey data and identify a sample of 1070 photometric SN Ia candidates based on their multi-band light curve data. This sample co…
Dark Matter Science in the Era of LSST
Keith Bechtol, Alex Drlica-Wagner, Kevork N. Abazajian +177
Astrophysical observations currently provide the only robust, empirical measurements of dark matter. In the coming decade, astrophysical observations will guide other experimental…
Estimating the Redshift Distribution of Faint Galaxy Samples
Marcos Lima, Carlos E. Cunha, Hiroaki Oyaizu +3
We present an empirical method for estimating the underlying redshift distribution N(z) of galaxy photometric samples from photometric observables. The method does not rely on phot…
Impact of Property Covariance on Cluster Weak lensing Scaling Relations
Zhuowen Zhang, Arya Farahi, Daisuke Nagai +5
We present an investigation into a hitherto unexplored systematic that affects the accuracy of galaxy cluster mass estimates with weak gravitational lensing. Specifically, we study…
Type Ia Supernova Properties as a Function of the Distance to the Host Galaxy in the SDSS-II SN Survey
Lluis Galbany, Ramon Miquel, Linda Ostman +22
We use type-Ia supernovae (SNe Ia) discovered by the SDSS-II SN Survey to search for dependencies between SN Ia properties and the projected distance to the host galaxy center, usi…
Photometric Redshift Error Estimators
Hiroaki Oyaizu, Marcos Lima, Carlos E. Cunha +2
Photometric redshift (photo-z) estimates are playing an increasingly important role in extragalactic astronomy and cosmology. Crucial to many photo-z applications is the accurate q…
Dark Energy and the Accelerating Universe
Joshua Frieman, Michael Turner, Dragan Huterer
The discovery ten years ago that the expansion of the Universe is accelerating put in place the last major building block of the present cosmological model, in which the Universe i…