Search Publications
The Dragonfly Nearby Galaxies Survey. II. Ultra-Diffuse Galaxies near the Elliptical Galaxy NGC 5485
van Dokkum, Pieter; Abraham, Roberto; Danieli, Shany +4 more
We present the unexpected discovery of four ultra-diffuse galaxies (UDGs) in a group environment. We recently identified seven extremely low surface brightness galaxies in the vicinity of the spiral galaxy M101, using data from the Dragonfly Telephoto Array. The galaxies have effective radii of 10″-38″ and central surface brightnesses of 25.6-27.7…
Neutrino mass limits: Robust information from the power spectrum of galaxy surveys
Verde, Licia; Cuesta, Antonio J.; Niro, Viviana
We present cosmological upper limits on the sum of active neutrino masses using large-scale power spectrum data from the WiggleZ Dark Energy Survey and from the Sloan Digital Sky Survey - Data Release 7 (SDSS-DR7) sample of Luminous Red Galaxies (LRG). Combining measurements on the Cosmic Microwave Background temperature and polarisation anisotrop…
Filamentary structure and magnetic field orientation in Musca
Prusti, T.; Pilbratt, G. L.; André, Ph. +17 more
Herschel has shown that filamentary structures are ubiquitous in star-forming regions, in particular in nearby molecular clouds associated with Gould's Belt. High dynamic range far-infrared imaging of the Musca cloud with SPIRE and PACS reveals at least two types of filamentary structures: (1) the main ~10-pc scale high column-density linear filam…
Evolution of Stellar-to-Halo Mass Ratio at z = 0 - 7 Identified by Clustering Analysis with the Hubble Legacy Imaging and Early Subaru/Hyper Suprime-Cam Survey Data
Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +15 more
We present clustering analysis results from 10,381 Lyman break galaxies (LBGs) at z ∼ 4-7, identified in the Hubble legacy deep imaging and new complimentary large-area Subaru/Hyper Suprime-Cam data. We measure the angular correlation functions of these LBGs at z ∼ 4, 5, 6, and 7 and fit these measurements using halo occupation distribution (HOD) …
Resolving the Discrepancy of Galaxy Merger Fraction Measurements at z ∼ 0-3
Zirm, Andrew W.; Toft, Sune; Man, Allison W. S.
We measure the merger fraction of massive galaxies using the UltraVISTA/COSMOS catalog, complemented with the deeper, higher resolution 3DHST+CANDELS catalog, presenting the largest mass-complete photometric merger sample up to z∼ 3. We find that the variation in the mass ratio probe can explain the discrepant redshift evolution of the merger frac…
History and development of coronal mass ejections as a key player in solar terrestrial relationship
Gopalswamy, N.
Coronal mass ejections (CMEs) are relatively a recently discovered phenomenon—in 1971, some 15 years into the Space Era. It took another two decades to realize that CMEs are the most important players in solar terrestrial relationship as the root cause of severe weather in Earth's space environment. CMEs are now counted among the major natural haz…
Interstellar Hydrides
Neufeld, David A.; Gerin, Maryvonne; Goicoechea, Javier R.
Interstellar hydrides—that is, molecules containing a single heavy element atom with one or more hydrogen atoms—were among the first molecules detected outside the solar system. They lie at the root of interstellar chemistry, being among the first species to form in initially atomic gas, along with molecular hydrogen and its associated ions. Becau…
The Connection Between Reddening, Gas Covering Fraction, and the Escape of Ionizing Radiation at High Redshift
Pettini, Max; Shapley, Alice E.; Steidel, Charles C. +2 more
Using a large sample of spectroscopically confirmed z∼ 3 galaxies, we establish an empirical relationship between reddening (E(B-V)), neutral gas covering fraction ({f}{{cov}}({{H}} {{I}})), and the escape of ionizing (Lyman continuum, LyC) photons. Our sample includes 933 galaxies at z∼ 3,121 of which have deep spectroscopic observatio…
Detection of the kinematic Sunyaev-Zel'dovich effect with DES Year 1 and SPT
Benoit-Lévy, A.; Efstathiou, G.; D'Andrea, C. B. +82 more
We detect the kinematic Sunyaev-Zel'dovich (kSZ) effect with a statistical significance of 4.2σ by combining a cluster catalogue derived from the first year data of the Dark Energy Survey with cosmic microwave background temperature maps from the South Pole Telescope Sunyaev-Zel'dovich Survey. This measurement is performed with a differential stat…
Eliminating the optical depth nuisance from the CMB with 21 cm cosmology
Sherwin, Blake D.; Liu, Adrian; Pritchard, Jonathan R. +3 more
Amongst standard model parameters that are constrained by cosmic microwave background (CMB) observations, the optical depth τ stands out as a nuisance parameter. While τ provides some crude limits on reionization, it also degrades constraints on other cosmological parameters. Here we explore how 21 cm cosmology—as a direct probe of reionization—ca…