Search Publications
A high fraction of Be stars in young massive clusters: evidence for a large population of near-critically rotating stars
Cabrera-Ziri, I.; Usher, C.; Bastian, N. +6 more
Recent photometric analyses of the colour-magnitude diagrams of young massive clusters (YMCs) have found evidence for splitting in the main sequence and extended main-sequence turn-offs, both of which have been suggested to be caused by stellar rotation. Comparison of the observed main-sequence splitting with models has led various authors to sugg…
The statistical properties of neutral gas at z < 1.65 from UV measurements of Damped Lyman Alpha systems
Turnshek, David A.; Rao, Sandhya M.; Monier, Eric M. +1 more
We derive the statistical properties of neutral gas at redshifts 0.11 < z < 1.65 from ultraviolet (UV) measurements of quasar Ly α absorption lines corresponding to 369 Mg II systems with W^{λ 2796}0 ≥ 0.3 Å. In addition to the 41 damped Lyman alpha (DLA) systems presented in Rao et al. (2006), the current DLA sample includes 29 n…
Calibration of Ultraviolet, Mid-infrared, and Radio Star Formation Rate Indicators
Imanishi, Masatoshi; Peek, J. E. G.; Kennicutt, Robert C. +12 more
We present calibrations for star formation rate (SFR) indicators in the ultraviolet, mid-infrared, and radio-continuum bands, including one of the first direct calibrations of 150 MHz as an SFR indicator. Our calibrations utilize 66 nearby star-forming galaxies with Balmer-decrement-corrected {{H}}α luminosities, which span five orders of magnitud…
Polycyclic Aromatic Hydrocarbons in Protoplanetary Disks around Herbig Ae/Be and T Tauri Stars
Seok, Ji Yeon; Li, Aigen
A distinct set of broad emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 µm, is often detected in protoplanetary disks (PPDs). These features are commonly attributed to polycyclic aromatic hydrocarbons (PAHs). We model these emission features in the infrared spectra of 69 PPDs around 14 T Tauri and 55 Herbig Ae/Be stars in terms of as…
Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE
Enoto, Teruaki; Makishima, Kazuo; Kitaguchi, Takao +7 more
The 1-70 keV persistent spectra of 15 magnetars, observed with Suzaku from 2006 to 2013, were studied as a complete sample. Combined with early NuSTAR observations of four hard X-ray emitters, nine objects showed a hard power-law emission dominating at ≳ 10 keV with the 15-60 keV flux of ∼1-11× {10}-11 erg s-1 cm-2…
Partially acoustic dark matter cosmology and cosmological constraints
Raveri, Marco; Hu, Wayne; Hoffman, Timothy +1 more
Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard Λ CDM cosmological model. On one side CMB observations imply a Hubble constant that is lower than local measurements an…
Planck intermediate results. L. Evidence of spatial variation of the polarized thermal dust spectral energy distribution and implications for CMB B-mode analysis
Miville-Deschênes, M. -A.; Boulanger, F.; Bernard, J. -P. +156 more
The characterization of the Galactic foregrounds has been shown to be the main obstacle in thechallenging quest to detect primordial B-modes in the polarized microwave sky. We make use of the Planck-HFI 2015 data release at high frequencies to place new constraints on the properties of the polarized thermal dust emission at high Galactic latitudes…
X-Ray Counterpart of Gravitational Waves Due to Binary Neutron Star Mergers: Light Curves, Luminosity Function, and Event Rate Density
Sun, Hui; Zhang, Bing; Gao, He
Zhang proposed a type of GRB-less X-ray transient associated with double neutron star (NS-NS) mergers under the conjecture of a rapidly spinning magnetar merger product with the line of sight off the short gamma-ray burst (GRB) jet. We investigate possible light curves of these transients by considering different observers’ viewing angles. We perf…
SAPS/SAID revisited: A causal relation to the substorm current wedge
Mishin, Evgeny; Nishimura, Yukitoshi; Foster, John
We present multispacecraft observations of enhanced flow/electric field channels in the inner magnetosphere and conjugate subauroral ionosphere, i.e., subauroral polarization streams (SAPS) near dusk and subauroral ion drifts (SAID) near midnight. The channels collocate with ring current (RC) injections lagging the onset of substorms by a few to ∼…
Stars caught in the braking stage in young Magellanic Cloud clusters
D'Antona, Francesca; Milone, Antonino P.; Tailo, Marco +3 more
The colour-magnitude diagrams of many Magellanic Cloud clusters (with ages up to 2 billion years) display extended turnoff regions where the stars leave the main sequence, suggesting the presence of multiple stellar populations with ages that may differ even by hundreds of millions of years 1,2,3 . A strongly debated question is whether…