Search Publications
Spatial Distribution of the Milky Way Hot Gaseous Halo Constrained by Suzaku X-Ray Observations
Nakashima, Shinya; Inoue, Yoshiyuki; Kataoka, Jun +3 more
The formation mechanism of the hot gaseous halo associated with the Milky Way is still under debate. We report new observational constraints on the gaseous halo using 107 lines of sight of the Suzaku X-ray observations at 75° < l < 285° and | b| > 15^\circ with a total exposure of 6.4 Ms. The gaseous halo spectra are represented by a sing…
Discovery of Extended Main Sequence Turnoffs in Galactic Open Clusters
Di Criscienzo, M.; Balaguer-Núñez, L.; Milone, A. P. +5 more
The color-magnitude diagrams (CMDs) of Galactic open clusters are widely considered to be the prototypes of single stellar populations. By using photometry in ultraviolet and optical bands we discovered that the nearby young cluster NGC 6705 (M11) exhibits an extended main-sequence turnoff (eMSTO) and a broadened main sequence (MS). This is the fi…
Magnetic Flux Cancelation as the Trigger of Solar Coronal Jets in Coronal Holes
Panesar, Navdeep K.; Moore, Ronald L.; Sterling, Alphonse C.
We investigate in detail the magnetic cause of minifilament eruptions that drive coronal-hole jets. We study 13 random on-disk coronal-hole jet eruptions, using high-resolution X-ray images from the Hinode/X-ray telescope(XRT), EUV images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), and magnetograms from the SDO/He…
Quasar Accretion Disk Sizes from Continuum Reverberation Mapping from the Dark Energy Survey
Benoit-Lévy, A.; Smith, M.; D'Andrea, C. B. +70 more
We present accretion disk size measurements for 15 luminous quasars at 0.7 ≤ z ≤ 1.9 derived from griz light curves from the Dark Energy Survey. We measure the disk sizes with continuum reverberation mapping using two methods, both of which are derived from the expectation that accretion disks have a radial temperature gradient and the continuum e…
Solar Energetic Particle Events Observed by the PAMELA Mission
de Nolfo, G. A.; Christian, E. R.; Ryan, J. M. +55 more
Despite the significant progress achieved in recent years, the physical mechanisms underlying the origin of solar energetic particles (SEPs) are still a matter of debate. The complex nature of both particle acceleration and transport poses challenges to developing a universal picture of SEP events that encompasses both the low-energy (from tens of…
On the 1/f Spectrum in the Solar Wind and Its Connection with Magnetic Compressibility
Matteini, L.; Horbury, T. S.; Chen, C. H. K. +1 more
We discuss properties of Alfvénic fluctuations with large amplitude in plasmas characterized by low magnetic field compression. We note that in such systems power laws cannot develop with arbitrarily steep slopes at large scales, i.e., when | δ {\boldsymbol{B}}| becomes of the order of the background field | {\boldsymbol{B}}| . In such systems the…
A Near-infrared Period-Luminosity Relation for Miras in NGC 4258, an Anchor for a New Distance Ladder
Casertano, Stefano; Jones, David O.; Riess, Adam G. +8 more
We present year-long, near-infrared (NIR) Hubble Space Telescope (HST) WFC3 observations of Mira variables in the water megamaser host galaxy NGC 4258. Miras are asymptotic giant branch variables that can be divided into oxygen- (O-) and carbon- (C-) rich subclasses. Oxygen-rich Miras follow a tight (scatter ∼0.14 mag) period-luminosity relation (…
SHINING, A Survey of Far-infrared Lines in Nearby Galaxies. I. Survey Description, Observational Trends, and Line Diagnostics
Lutz, D.; Genzel, R.; Maiolino, R. +12 more
We use the Herschel/PACS spectrometer to study the global and spatially resolved far-infrared (FIR) fine-structure line emission in a sample of 52 galaxies that constitute the SHINING survey. These galaxies include star-forming, active-galactic nuclei (AGNs), and luminous infrared galaxies (LIRGs). We find an increasing number of galaxies (and kil…
Revisiting the Extended Schmidt Law: The Important Role of Existing Stars in Regulating Star Formation
Fang, Min; Qiu, Keping; Chen, Yanmei +13 more
We revisit the proposed extended Schmidt law, which posits that the star formation efficiency in galaxies depends on the stellar mass surface density, by investigating spatially resolved star formation rates (SFRs), gas masses, and stellar masses of star formation regions in a vast range of galactic environments, from the outer disks of dwarf gala…
The Disk Substructures at High Angular Resolution Program (DSHARP). VIII. The Rich Ringed Substructures in the AS 209 Disk
Wilner, David J.; Andrews, Sean M.; Guzmán, Viviana V. +12 more
We present a detailed analysis of the high angular resolution (0.″037, corresponding to 5 au) observations of the 1.25 mm continuum and 12CO 2 - 1 emission from the disk around the T Tauri star AS 209. AS 209 hosts one of the most unusual disks from the Disk Substructures at High Angular Resolution Project sample, the first high angular…