A5088256603- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Dark Matter and Cosmic Phenomena
- Inertial Sensor and Navigation
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Advanced Vision and Imaging
- CCD and CMOS Imaging Sensors
- Species Distribution and Climate Change
- Remote Sensing in Agriculture
- Silicon and Solar Cell Technologies
Lawrence Berkeley National Laboratory
2014-2023
Space Telescope Science Institute
2019-2023
University of California, Berkeley
2015-2021
University of British Columbia
2018-2020
University of Notre Dame
2010-2016
We present an analysis of 15 Type Ia supernovae (SNe Ia) at redshift z > 1 (9 1.5 < 2.3) recently discovered in the CANDELS and CLASH Multi-Cycle Treasury programs using WFC3 on Hubble Space Telescope. combine these SNe with a new compilation 1050 Ia, jointly calibrated corrected for simulated survey biases to produce accurate distance measurements. unbiased constraints expansion rate six redshifts range 0.07 based only this combined SN sample. The added leverage our sample leads factor ~3...
Previously we used the Nearby Supernova Factory sample to show that Type Ia supernovae (SNe Ia) having locally star-forming environments are dimmer than SNe passive environments. Here use Constitution together with host galaxy data from GALEX independently confirm result. The effect is seen using both SALT2 and MLCS2k2 lightcurve fitting standardization methods, brightness differences of 0.094 ± 0.037 mag for 0.155 0.041 RV = 2.5. When combined our previous measurement 0.025 SALT2. If ratio...
As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization Type Ia supernovae (SNIa) cosmology, we have statistically classified a large sample nearby SNeIa into those located predominantly younger or older environments. This classification is based on specific star formation rate measured within projected distance 1kpc from each SN location (LsSFR). important refinement compared using local directly as it provides normalization relative...
This paper describes the data release of Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, ancillary are presented for 10,258 variable transient sources discovered through repeat ugriz imaging SDSS Stripe 82, a 300 deg2 area along celestial equator. is comprised all brighter than r~22.5 mag with no history variability prior to 2004. Dedicated spectroscopic observations were performed on subset 889 transients, as...
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed total area of ~0.25 deg^2 with ~900 HST orbits spread across 5 fields over 3 years. Within these survey images we discovered 65 supernovae (SN) all types, out to z~2.5. We classify ~24 as Type Ia SN (SN Ia) based host-galaxy redshifts and photometry (supplemented by grism spectroscopy 6 SN). Here present measurement volumetric rate...
The accelerating expansion of the universe is one most profound discoveries in modern cosmology, pointing to a which 70% mass-energy density has an unknown form spread uniformly across universe. This result been well established using combination cosmological probes (e.g., Planck Collaboration et al. 2016), resulting "standard model" cosmology that constant with cold dark matter and baryons. first compelling evidence for acceleration came late 1990's, when two independent teams studying type...
We analyze the rise and fall times of Type Ia supernova (SN Ia) light curves discovered by Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. From a set 391 k-corrected to rest-frame B V bands, we find smaller dispersion in rising portion curve compared decline. This is qualitative agreement with computer models which predict that variations radioactive nickel yield have less impact on than spread decline rates. The differences properties suggest single "stretch" correction phase does...
While recent supernova cosmology research has benefited from improved measurements, current analysis approaches are not statistically optimal and will prove insufficient for future surveys. This paper discusses the limitations of cosmological analyses in treating outliers, selection effects, shape- color-standardization relations, unexplained dispersion, heterogeneous observations. We present a new Bayesian framework, called UNITY (Unified Nonlinear Inference Type-Ia cosmologY), that...
We present the Massive and Distant Clusters of WISE Survey (MaDCoWS), a search for galaxy clusters at 0.7<z<1.5 based upon data from Wide-field Infrared Explorer (WISE) mission. MaDCoWS is first cluster survey capable discovering massive these redshifts over full extragalactic sky. The divided into two regions -- region sky covered by Pan-STARRS (Dec>-30 degrees) remainder southern Dec<-30 degrees which shallower optical SuperCOSMOS Sky are available. In this paper we describe algorithm,...
Using a sample of 4 galaxy clusters at $1.35 < z 1.65$ and 10 $0.85 1.35$, we measure the environmental quenching timescale, $t_Q$, corresponding to time required after is accreted by cluster for it fully cease star formation. Cluster members are selected photometric-redshift criterion, categorized as star-forming, quiescent, or intermediate according their dust-corrected rest-frame colors magnitudes. We employ "delayed-then-rapid" model that relates simulated mass accretion rate observed...
From the set of nearly 500 spectroscopically confirmed type~Ia supernovae and around 10,000 unconfirmed candidates from SDSS-II, we select a subset 108 SNe Ia with well-observed early-time light curves to search for signatures shock interaction supernova companion star. No evidence emission is seen; however, cadence photometric noise could hide weak signal. We simulate shocked using SN templates simple, Gaussian model emulate properties SDSS-II sample estimate detectability signal as...
We present the discovery of a Type Ia supernova (SN) at redshift z = 1.914 from CANDELS multi-cycle treasury program on Hubble Space Telescope (HST). This SN was discovered in infrared using Wide-Field Camera 3, and it is highest-redshift yet observed. classify this object as by comparing its light curve spectrum with those large sample core-collapse SNe. Its apparent magnitude consistent that expected ΛCDM concordance cosmology. discuss use spectral evidence for classification > 1.5 SNe HST...
Type Ia supernova cosmology depends on the ability to fit and standardize observations of magnitudes with an empirical model. We present here a series new models Supernova spectral time that capture greater amount diversity than possible are currently customary. These entitled SuperNova Empirical MOdels (\textsc{SNEMO}\footnote{https://snfactory.lbl.gov/snemo}). The constructed using spectrophotometric from $172$ individual supernovae Nearby Factory, comprising more $2000$ spectra. Using...
We present ALMA CO (2-1) detections in 11 gas-rich cluster galaxies at z~1.6, constituting the largest sample of molecular gas measurements z>1.5 clusters to date. The observations span three galaxy clusters, derived from Spitzer Adaptation Red-sequence Cluster Survey. augment >5sigma fluxes with multi-band photometry, yielding stellar masses and infrared-derived star formation rates, place some first constraints on properties z~1.6 environments. measure sizable reservoirs 0.5-2x10^11 solar...
We constrain the evolution of brightest cluster galaxy plus intracluster light (BCG+ICL) using an ensemble 42 groups and clusters that span redshifts z = 0.05-1.75 masses $M_{500,c}=2\times10^{13}-10^{15}$ M$_\odot$ Specifically, we measure relationship between BCG+ICL stellar mass $M_\star$ $M_{500,c}$ at projected radii 10 < r 100 kpc for three different epochs. At intermediate redshift (z 0.40), where have best data, find $M_\star\propto M_{500,c}^{0.48\pm0.06}$. Fixing exponent this...
Abstract We present a new empirical Type Ia supernova (SN Ia) model with three chromatic flux variation templates: one phase dependent and two independent. No underlying dust extinction or patterns of intrinsic variability are assumed. Implemented S tan trained using spectrally binned Nearby Supernova Factory spectrophotometry, we examine this model's 2D, phase-independent space motivated basis representations. In both, the first template captures that appears dust-like, while second...
Type Ia Supernova Hubble residuals have been shown to correlate with host galaxy mass, imposing a major obstacle for their use in measuring dark energy properties. Here, we calibrate the fundamental metallicity relation (FMR) of Mannucci et al. (2010) mass and star formation rates measured from broad-band colors alone. We apply FMR large number hosts SDSS-II sample Gupta (2011) find that scatter is significantly reduced when compared using only stellar (or mass-metallicity relation) as fit...
We have discovered an optically rich galaxy cluster at z=1.7089 with star formation occurring in close proximity to the central galaxy. The system, SpARCS104922.6+564032.5, was detected within Spitzer Adaptation of red-sequence Cluster Survey, (SpARCS), and confirmed through Keck-MOSFIRE spectroscopy. rest-frame optical richness Ngal(500kpc) = 30+/-8 implies a total halo mass, 500kpc, ~3.8+/-1.2 x 10^14 Msun, comparable other clusters or above this redshift. There is wealth ancillary data...
We present two supernovae (SNe) discovered with the Hubble Space Telescope (HST) in Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, an HST multi-cycle treasury program. classify both objects as SNe Ia and find redshifts of z = 1.80 ± 0.02 2.26+0.02−0.10, latter which is highest redshift SN yet seen. Using light curve fitting we determine luminosity distances that are consistent a standard ΛCDM cosmological model. These were observed using Wide Field Camera 3 infrared...
We report the discovery of a Type Ia supernova (SNIa) at redshift z=1.55 with infrared detector Wide Field Camera 3 (WFC3-IR) on Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data Ultra Deep Field, and followed as part CANDELS+CLASH Supernova project, comprising SN search components from those two HST multi-cycle treasury programs. is highest SNIa direct spectroscopic evidence for classification. It also first z>1 found infrared, providing full light curve...
Abstract The morphology–density relationship states that dense cosmic environments such as galaxy clusters have an overabundance of quiescent elliptical galaxies, but it is unclear at which redshift this first established. We study the morphology four with 1.2 < z 1.8 using Hubble Space Telescope imaging and computation code statmorph . By comparing median cluster galaxies to CANDELS field Monte Carlo analysis, we find two out (at = 1.19 1.75) established more than 3 σ significance....
We introduce a method for identifying "twin" Type Ia supernovae, and using them to improve distance measurements. This novel approach supernova standardization is made possible by spectrophotometric time series observations from the Nearby Supernova Factory (SNfactory). begin with well-measured set of find pairs whose spectra match well across entire optical window, then test whether this leads smaller dispersion in their absolute brightnesses. analysis completed blinded fashion, ensuring...
Abstract Hot, dust-obscured galaxies, or “Hot DOGs,” are a rare, dusty, hyperluminous galaxy population discovered by the WISE mission. Predominantly at redshifts 2–3, they include most luminous known galaxies in universe. Their high luminosities likely come from accretion onto highly obscured supermassive black holes (SMBHs). We have conducted pilot survey to measure SMBH masses of five <?CDATA $z\sim 2$?> Hot DOGs via broad H α emission lines, using Keck/MOSFIRE and Gemini/FLAMINGOS-2....
We present confirmation of the cluster MOO J1142+1527, a massive galaxy discovered as part Massive and Distant Clusters WISE Survey. The is confirmed to lie at z = 1.19, using Combined Array for Research in Millimeter-wave Astronomy we robustly detect Sunyaev–Zel'dovich (SZ) decrement 13.2σ. SZ data imply mass M200m (1.1 ± 0.2) × 1015M⊙, making J1142+1527 most known > 1.15 second 1. For standard ΛCDM cosmology it further expected be one ∼5 clusters exist ≥ 1.19 over entire sky. Our ongoing...