Search Publications
The Remarkable Similarity of Massive Galaxy Clusters from z ∼ 0 to z ∼ 1.9
Gladders, M. D.; Gaspari, M.; Hlavacek-Larrondo, J. +12 more
We present the results of a Chandra X-ray survey of the eight most massive galaxy clusters at z > 1.2 in the South Pole Telescope 2500 deg2 survey. We combine this sample with previously published Chandra observations of 49 massive X-ray-selected clusters at 0 < z < 0.1 and 90 Sunyaev-Zel’dovich-selected clusters at 0.25 < z…
ISM Properties of a Massive Dusty Star-forming Galaxy Discovered at z ∼ 7
Menten, K. M.; Béthermin, M.; Murphy, E. J. +28 more
We report the discovery and constrain the physical conditions of the interstellar medium of the highest-redshift millimeter-selected dusty star-forming galaxy to date, SPT-S J031132-5823.4 (hereafter SPT0311-58), at z=6.900+/- 0.002. SPT0311-58 was discovered via its 1.4 mm thermal dust continuum emission in the South Pole Telescope (SPT)-SZ surve…
Solution of Heliospheric Propagation: Unveiling the Local Interstellar Spectra of Cosmic-ray Species
Orlando, E.; Jóhannesson, G.; Moskalenko, I. V. +14 more
Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosm…
Molecular Outflows in Local ULIRGs: Energetics from Multitransition OH Analysis
Sturm, E.; Veilleux, S.; Farrah, D. +11 more
We report on the energetics of molecular outflows in 14 local ultraluminous infrared galaxies (ULIRGs) that show unambiguous outflow signatures (P Cygni profiles or high-velocity absorption wings) in the far-infrared lines of OH measured with the Herschel/PACS spectrometer. All sample galaxies are gas-rich mergers at various stages of the merging …
Extensive Globular Cluster Systems Associated with Ultra Diffuse Galaxies in the Coma Cluster
Mowla, Lamiya; van Dokkum, Pieter; Romanowsky, Aaron J. +7 more
We present Hubble Space Telescope (HST) imaging of two ultra diffuse galaxies (UDGs) with measured stellar velocity dispersions in the Coma cluster. The galaxies, Dragonfly 44 and DFX1, have effective radii of 4.7 kpc and 3.5 kpc and velocity dispersions of {47}-6+8 km s-1 and {30}-7+7 km s
Statistical Studies of Solar White-light Flares and Comparisons with Superflares on Solar-type Stars
Notsu, Yuta; Maehara, Hiroyuki; Namekata, Kosuke +9 more
Recently, many superflares on solar-type stars have been discovered as white-light flares (WLFs). The statistical study found a correlation between their energies (E) and durations (τ): τ \propto {E}0.39, similar to those of solar hard/soft X-ray flares, τ \propto {E}0.2{--0.33}. This indicates a universal mechanism of energy…
Simultaneous X-Ray, Gamma-Ray, and Radio Observations of the Repeating Fast Radio Burst FRB 121102
Ransom, S. M.; Chatterjee, S.; Cordes, J. M. +19 more
We undertook coordinated campaigns with the Green Bank, Effelsberg, and Arecibo radio telescopes during Chandra X-ray Observatory and XMM-Newton observations of the repeating fast radio burst FRB 121102 to search for simultaneous radio and X-ray bursts. We find 12 radio bursts from FRB 121102 during 70 ks total of X-ray observations. We detect no …
The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. VII. Properties of the Host Galaxy and Constraints on the Merger Timescale
Berger, E.; Rest, A.; Annis, J. +21 more
We present the properties of NGC 4993, the host galaxy of GW170817, the first gravitational-wave (GW) event from the merger of a binary neutron star (BNS) system and the first with an electromagnetic (EM) counterpart. We use both archival photometry and new optical/near-IR imaging and spectroscopy, together with stellar population synthesis models…
Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster
Mukai, K.; Yamaguchi, H.; Koyama, K. +215 more
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E≈ 3.5 {keV} emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The e…
Global Energetics of Solar Flares. V. Energy Closure in Flares and Coronal Mass Ejections
Xu, Yan; Jing, Ju; Warren, Harry P. +11 more
In this study we synthesize the results of four previous studies on the global energetics of solar flares and associated coronal mass ejections (CMEs), which include magnetic, thermal, nonthermal, and CME energies in 399 solar M- and X-class flare events observed during the first 3.5 yr of the Solar Dynamics Observatory (SDO) mission. Our findings…