Search Publications
Classification and Ranking of Fermi LAT Gamma-ray Sources from the 3FGL Catalog using Machine Learning Techniques
Marelli, M.; Saz Parkinson, P. M.; Falcone, A. D. +3 more
We apply a number of statistical and machine learning techniques to classify and rank gamma-ray sources from the Third Fermi Large Area Telescope Source Catalog (3FGL), according to their likelihood of falling into the two major classes of gamma-ray emitters: pulsars (PSR) or active galactic nuclei (AGNs). Using 1904 3FGL sources that have been id…
A Rich Globular Cluster System in Dragonfly 17: Are Ultra-diffuse Galaxies Pure Stellar Halos?
Peng, Eric W.; Lim, Sungsoon
Observations of nearby galaxy clusters at low surface brightness have identified galaxies with low luminosities, but sizes as large as L ⋆ galaxies, leading them to be dubbed “ultra-diffuse galaxies” (UDGs). The survival of UDGs in dense environments like the Coma cluster suggests that UDGs could reside in much more massive dark halos. …
Search for Gamma-Ray Emission from the Coma Cluster with Six Years of Fermi-LAT Data
Troja, E.; Caraveo, P. A.; Orlando, E. +109 more
We present results from γ-ray observations of the Coma cluster incorporating six years of Fermi-LAT data and the newly released “Pass 8” event-level analysis. Our analysis of the region reveals low-significance residual structures within the virial radius of the cluster that are too faint for a detailed investigation with the current data. Using a…
Deja Vu All Over Again: The Reappearance of Supernova Refsdal
Cenko, S. B.; Molino, A.; Zitrin, A. +19 more
In Hubble Space Telescope (HST) imaging taken on 2014 November 10, four images of supernova (SN) “Refsdal” (redshift z = 1.49) appeared in an Einstein-cross-like configuration (images S1-S4) around an early-type galaxy in the cluster MACS J1149.5+2223 (z = 0.54). Almost all lens models of the cluster have predicted that the SN should reappear with…
A New Approach to Analyzing HST Spatial Scans: The Transmission Spectrum of HD 209458 b
Tsiaras, A.; Waldmann, I. P.; Rocchetto, M. +4 more
The Wide Field Camera 3 on the Hubble Space Telescope is currently one of the most widely used instruments for observing exoplanetary atmospheres, especially with the use of the spatial scanning technique. An increasing number of exoplanets have been studied using this technique as it enables the observation of bright targets without saturating th…
The Space Density of Luminous Dusty Star-forming Galaxies at z > 4: SCUBA-2 and LABOCA Imaging of Ultrared Galaxies from Herschel-ATLAS
Pérez-Fournon, I.; Ivison, R. J.; Omont, A. +28 more
Until recently, only a handful of dusty, star-forming galaxies (DSFGs) were known at z > 4, most of them significantly amplified by gravitational lensing. Here, we have increased the number of such DSFGs substantially, selecting galaxies from the uniquely wide 250, 350, and 500 µm Herschel-ATLAS imaging survey on the basis of their extrem…
High-resolution Spectroscopy of a Young, Low-metallicity Optically Thin L = 0.02L* Star-forming Galaxy at z = 3.12
Schaerer, D.; Giavalisco, M.; Castellano, M. +29 more
We present VLT/X-Shooter and MUSE spectroscopy of a faint F814W = 28.60 ± 0.33 ({M}{UV}=-17.0), low-mass (≲{10}7{M}⊙ ), and compact (R eff = 62 pc) freshly star-forming galaxy at z = 3.1169 magnified (16×) by the Hubble Frontier Fields galaxy cluster Abell S1063. Gravitational lensing allows for a signif…
Iron-group Abundances in the Metal-poor Main-Sequence Turnoff Star HD~84937
Kobayashi, Chiaki; Sneden, Christopher; Cowan, John J. +4 more
We have derived new, very accurate abundances of the Fe-group elements Sc through Zn (Z = 21-30) in the bright main-sequence turnoff star HD 84937 based on high-resolution spectra covering the visible and ultraviolet spectral regions. New or recent laboratory transition data for 14 species of seven elements have been used. Abundances from more tha…
Possible Signatures of a Cold-flow Disk from MUSE Using a z ∼ 1 Galaxy-Quasar Pair toward SDSS J1422-0001
Carollo, C. M.; Lilly, S.; Kollatschny, W. +19 more
We use a background quasar to detect the presence of circumgalactic gas around a z=0.91 low-mass star-forming galaxy. Data from the new Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope show that the galaxy has a dust-corrected star formation rate (SFR) of 4.7 ± 2.0 M⊙ yr-1, with no companion down to 0.22 M…
The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Search for [CII] Line and Dust Emission in 6
Smail, I.; Magnelli, B.; Daddi, E. +29 more
We present a search for [C II] line and dust continuum emission from optical dropout galaxies at z > 6 using ASPECS, our Atacama Large Millimeter submillimeter Array Spectroscopic Survey in the Hubble Ultra-deep Field (UDF). Our observations, which cover the frequency range of 212-272 GHz, encompass approximately the range of 6 < z < 8 fo…