Search Publications
Determining Ages of APOGEE Giants with Known Distances
Bovy, Jo; Majewski, Steven R.; Feuillet, Diane K. +4 more
We present a sample of 705 local giant stars observed using the New Mexico State University 1 m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R ∼ 22,500), near infrared …
SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova
Zitrin, A.; Filippenko, A. V.; Foley, R. J. +20 more
We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a br…
Origin of Molecular Oxygen in Comet 67P/Churyumov-Gerasimenko
Wurz, P.; Altwegg, K.; Bieler, A. +13 more
Molecular oxygen has been detected in the coma of comet 67P/Churyumov-Gerasimenko with abundances in the 1%-10% range by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis-Double Focusing Mass Spectrometer instrument on board the Rosetta spacecraft. Here we find that the radiolysis of icy grains in low-density environments such as the p…
A Distant Echo of Milky Way Central Activity Closes the Galaxy’s Baryon Census
Elvis, M.; Nicastro, F.; Krongold, Y. +2 more
We report on the presence of large amounts of million-degree gas in the Milky Way’s interstellar and circum-galactic medium. This gas (1) permeates both the Galactic plane and the halo, (2) extends to distances larger than 60-200 kpc from the center, and (3) its mass is sufficient to close the Galaxy’s baryon census. Moreover, we show that a vast,…
The Wind Nebula around Magnetar Swift J1834.9-0846
Lin, L.; Kouveliotou, C.; Baring, M. G. +12 more
We report on the analysis of two deep XMM-Newton observations of the magnetar Swift J1834.9-0846 and its surrounding extended emission taken in 2014 March and October, 2.5 and 3.1 yr after the source went into outburst. The magnetar is only weakly detected in the first observation, with an absorption-corrected flux {F}0.5-10{keV}≈ 4× {1…
Helical Kink Instability in a Confined Solar Eruption
Kliem, Bernhard; Hassanin, Alshaimaa
A model for strongly writhing confined solar eruptions suggests an origin in the helical kink instability of a coronal flux rope that remains stable against the torus instability. This model is tested against the well observed filament eruption on 2002 May 27 in a parametric MHD simulation study that comprises all phases of the event. Good agreeme…
Large-scale Structure around a z=2.1 Cluster
Casey, Caitlin M.; Kacprzak, Glenn G.; Tran, Kim-Vy H. +10 more
The most prodigious starburst galaxies are absent in massive galaxy clusters today, but their connection with large-scale environments is less clear at z≳ 2. We present a search of large-scale structure around a galaxy cluster core at z = 2.095 using a set of spectroscopically confirmed galaxies. We find that both color-selected star-forming galax…
The JCMT Gould Belt Survey: Evidence for Dust Grain Evolution in Perseus Star-forming Clumps
White, G. J.; Di Francesco, J.; Marsh, K. +56 more
The dust emissivity spectral index, β, is a critical parameter for deriving the mass and temperature of star-forming structures and, consequently, their gravitational stability. The β value is dependent on various dust grain properties, such as size, porosity, and surface composition, and is expected to vary as dust grains evolve. Here we present …
Homologous Jet-driven Coronal Mass Ejections from Solar Active Region 12192
Panesar, Navdeep K.; Moore, Ronald L.; Sterling, Alphonse C.
We report observations of homologous coronal jets and their coronal mass ejections (CMEs) observed by instruments onboard the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO) spacecraft. The homologous jets originated from a location with emerging and canceling magnetic field at the southeastern edge of the giant …
The MOSDEF Survey: The Strong Agreement between Hα and UV-to-FIR Star Formation Rates for z ~ 2 Star-forming Galaxies
Barro, Guillermo; Inami, Hanae; Siana, Brian +12 more
We present the first direct comparison between Balmer line and panchromatic spectral energy distribution (SED)-based star formation rates (SFRs) for z∼ 2 galaxies. For this comparison, we used 17 star-forming galaxies selected from the MOSFIRE Deep Evolution Field (MOSDEF) survey, with 3σ detections for Hα and at least two IR bands (Spitzer/MIPS 2…