Paul Martini
A5007857570- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- CCD and CMOS Imaging Sensors
- Scientific Research and Discoveries
- Dark Matter and Cosmic Phenomena
- Health and Medical Studies
- Pulsars and Gravitational Waves Research
- Spectroscopy and Laser Applications
- Calibration and Measurement Techniques
- Statistical and numerical algorithms
- Medical Practices and Rehabilitation
- Medical and Health Sciences Research
- Particle Detector Development and Performance
- Atmospheric Ozone and Climate
- SAS software applications and methods
- Black Holes and Theoretical Physics
State Library of Ohio
2006-2025
The Ohio State University
2015-2024
Aix-Marseille Université
2024
Austin Peay State University
2024
University of Zurich
2024
Stanford University
2024
Oak Ridge National Laboratory
2024
The Ohio State University at Lima
2024
California Consortium of Addiction Programs and Professionals
2024
Lancaster University
2024
We present early observations of the afterglow GRB 030329 and spectroscopic discovery its associated supernova SN 2003dh. obtained spectra each night from March 30.12 (0.6 days after burst) to April 8.13 (UT) (9.6 burst). The cover a wavelength range 350-850 nm. consist power-law continuum (Fν ∝ ν-0.9) with narrow emission lines originating H II regions in host galaxy, indicating low redshift z = 0.1687. However, our taken 2003 5 show broad peaks flux characteristic supernova. Correcting for...
We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Ly$\alpha$ forests completed Sloan Digital Sky Survey (SDSS) lineage experiments in large-scale structure. These experiments, composed data SDSS, SDSS-II, BOSS, eBOSS, offer independent baryon acoustic oscillation (BAO) angular-diameter distances Hubble relative to sound horizon, $r_d$, eight different samples six growth rate parameter, $f\sigma_8$, redshift-space distortions (RSD)....
This overview paper describes the legacy prospect and discovery potential of Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from DES early data.DES is using a wide-field camera (DECam) on 4 m Blanco Telescope in Chile to image 5000 sq deg sky five filters (grizY).
Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth supermassive black holes galaxies. Nuclear inflow gas attending collision triggers starburst and feeds hole growth, but for most duration starburst, heavily obscured by surrounding dust limits visibility quasar, especially at optical UV wavelengths. Eventually, feedback energy from accretion heats expels it powerful wind, leaving 'dead quasar'. Between...
We report the discovery of eight new ultra-faint dwarf galaxy candidates in second year optical imaging data from Dark Energy Survey (DES). Six these are detected at high confidence, while two lower-confidence identified regions non-uniform survey coverage. The stellar systems found by three independent automated search techniques and as overdensities stars, consistent with isochrone luminosity function an old metal-poor simple population. faint (Mv > -4.7 mag) span a range physical sizes...
The relation between galaxy stellar mass and gas-phase metallicity is a sensitive diagnostic of the main processes that drive evolution, namely cosmological gas inflow, metal production in stars, outflow via galactic winds. We employed direct method to measure metallicities ~200,000 star-forming galaxies from SDSS were stacked bins (1) (2) both star formation rate (SFR) significantly enhance signal-to-noise ratio weak [O III] 4363 II] 7320, 7330 auroral lines required apply method. These...
We report the discovery of eight new Milky Way companions in optical imaging data collected during first year Dark Energy Survey (DES). Each system is identified as a statistically significant over-density individual stars consistent with expected isochrone and luminosity function an old metal-poor stellar population. The objects span wide range absolute magnitudes (MV from to ), physical sizes (), heliocentric distances (). Based on low surface brightnesses, large sizes, and/or...
We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of extended Baryon Oscillation Spectroscopic (eBOSS). This comprises largest selection spectroscopically confirmed quasars to date. The full includes two sub-catalogs: a "superset" all SDSS-IV/eBOSS objects targeted as containing 1,440,615 observations and quasar-only 750,414 quasars, including 225,082 new appearing in an SDSS data release for first time, well known SDSS-I/II/III. automated...
We propose a model of quasar lifetimes in which longer periods rapid black hole accretion are distinguished from observationally inferred quasars owing to gas and dust obscuration. In our picture, powered by funneled galaxy centers, fueling starbursts feeding growth, but "buried" until feedback the disperses obscuring material, creating window is observable as an optical quasar. Eventually, activity ceases when rate drops below that required maintain luminosities. study this process...
ABSTRACT We search for excess γ -ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years data from Fermi Large Area Telescope (LAT). Our sample 45 stellar systems includes 28 kinematically dark-matter-dominated dwarf spheroidal (dSphs) 17 recently discovered that have photometric characteristics consistent population known dSphs. For each these targets, relative predicted flux due to dark matter annihilation is taken kinematic...
ABSTRACT We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large surveys. The updated algorithm is applied of Science Verification (SV) data from Dark Energy Survey (DES), and Sloan Digital Sky (SDSS) DR8 set. DES SV catalog locally volume limited contains 786 clusters with richness (roughly equivalent ) . consists 26,311 , sharply increasing threshold as function redshift performance both catalogs shown be excellent,...
We describe the creation, content, and validation of Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support upcoming cosmological analyses. The GOLD set is assembled from multiple epochs DES imaging consists calibrated photometric zeropoints, object catalogs, ancillary products - e.g., maps survey depth observing conditions, star-galaxy classification, redshift estimates that are necessary for accurate wide-area catalog ~137 million objects detected coadded...
We present an improved measurement of the Hubble constant (H_0) using 'inverse distance ladder' method, which adds information from 207 Type Ia supernovae (SNe Ia) Dark Energy Survey (DES) at redshift 0.018 < z 0.85 to existing measurements 122 low (z 0.07) SNe (Low-z) and Baryon Acoustic Oscillations (BAOs). Whereas traditional H_0 with use a ladder parallax Cepheid variable stars, inverse relies on absolute BAOs calibrate intrinsic magnitude Ia. find = 67.8 +/- 1.3 km s-1 Mpc-1...
Due to their proximity, high dark-matter content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection dark matter. Recently, eight new dSph candidates were discovered using first year data from Dark Energy Survey (DES). We searched gamma-ray emission coincident with positions these objects in six years Fermi Large Area Telescope data. found no significant excesses emission. Under assumption that...
We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 square degrees with a median redshift of $0.59$. The cover main fields: Stripe 82, and an area overlapping South Pole Telescope survey region. describe our analysis process in particular measurement using independent shear pipelines, METACALIBRATION IM3SHAPE. catalogue uses Gaussian model innovative internal calibration scheme, was applied to $riz$-bands, yielding 34.8M objects. IM3SHAPE...
We present constraints on extensions of the minimal cosmological models dominated by dark matter and energy, $\Lambda$CDM $w$CDM, using a combined analysis galaxy clustering weak gravitational lensing from first-year data Dark Energy Survey (DES Y1) in combination with external data. consider four energy-dominated scenarios: 1) nonzero curvature $\Omega_k$, 2) number relativistic species $N_{\rm eff}$ different standard value 3.046, 3) time-varying equation-of-state energy described...
We describe the derivation and validation of redshift distribution estimates their uncertainties for populations galaxies used as weak-lensing sources in Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (bpz) code is to assign four bins between z ≈ 0.2 ≈1.3, produce initial lensing-weighted distributions |$n^i_{\rm PZ}(z)\propto \mathrm{d}n^i/\mathrm{d}z$| members bin i. Accurate determination parameters depends critically on knowledge ni, but...
We present the first constraints on cosmology from Dark Energy Survey (DES), using weak lensing measurements preliminary Science Verification (SV) data. use 139 square degrees of SV data, which is less than 3% full DES survey area. Using cosmic shear 2-point over three redshift bins we find ${\ensuremath{\sigma}}_{8}({\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}/0.3{)}^{0.5}=0.81\ifmmode\pm\else\textpm\fi{}0.06$ (68% confidence), after marginalizing 7 systematics parameters and 3 other...
We introduce redMaGiC, an automated algorithm for selecting Luminous Red Galaxies (LRGs). The was specifically developed to minimize photometric redshift uncertainties in large-scale structure studies. redMaGiC achieves this by self-training the color-cuts necessary produce a luminosity-thresholded LRG sample of constant comoving density. demonstrate that photozs are very nearly as accurate best machine-learning based methods, yet they require minimal spectroscopic training, do not suffer...
We present weak lensing shear catalogues for 139 square degrees of data taken during the Science Verification (SV) time new Dark Energy Camera (DECam) being used Survey (DES). describe our object selection, point spread function estimation and measurement procedures using two independent pipelines, im3shape ngmix, which produce 2.12 million 3.44 galaxies, respectively. detail a set null tests measurements find that they pass requirements systematic errors at level necessary science...
We describe the Dark Energy Survey (DES) photometric data set assembled from first three years of science operations to support DES Year 3 cosmology analyses, and provide usage notes aimed at broad astrophysics community. Y3 Gold improves on previous releases DES, Y1 Data Release 1 (DES DR1), presenting an expanded curated that incorporates algorithmic developments in image detrending processing, calibration, object classification. comprises nearly 5000 square degrees grizY imaging south...
ABSTRACT We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in distribution of galaxies selected from first year Dark Energy Survey data. consider a sample over 1.3 million distributed footprint 1336 deg2 with 0.6 < $z$photo 1 and typical redshift uncertainty 0.03(1 + $z$). This was selected, as fully described companion paper, using colour/magnitude selection that optimizes trade-offs between number density uncertainty....
Abstract Over the next 5 yr, Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on 4 m Mayall Telescope at Kitt Peak National Observatory to conduct first Stage IV dark energy galaxy survey. At z < 0.6, DESI Bright Galaxy Survey (BGS) produce most detailed map of universe during dark-energy-dominated epoch redshifts >10 million galaxies spanning 14,000 deg 2 . In this work, we present and validate final BGS target selection survey design. From Legacy...
Determining the distribution of redshifts galaxies observed by wide-field photometric experiments like Dark Energy Survey is an essential component to mapping matter density field with gravitational lensing. In this work we describe methods used assign individual weak lensing source from Year 3 Weak Lensing Source Catalogue four tomographic bins and estimate redshift distributions in these bins. As first application data, validate that assumptions made apply DES Y3 develop a full treatment...
Abstract The Dark Energy Spectroscopic Instrument (DESI) is carrying out a five-year survey that aims to measure the redshifts of tens millions galaxies and quasars, including 8 million luminous red (LRGs) in redshift range 0.4 < z ≲ 1.0. Here we present selection DESI LRG sample assess its spectroscopic performance using data from Survey Validation (SV) first two months Main Survey. sample, selected g , r W 1 photometry Legacy Imaging Surveys, highly robust against imaging systematics....