Search Publications
Dust to Dust: Three Years in the Evolution of the Unusual SN 2008S
Garnavich, P. M.; Kochanek, C. S.; Stanek, K. Z. +5 more
We obtained late-time optical and near-IR imaging of SN 2008S with the Large Binocular Telescope, near-IR data with the Hubble Space Telescope, and mid-IR data with the Spitzer Space Telescope. We find that (1) it is again invisible at optical (UBVR) wavelengths to magnitude limits of approximately 25 mag, (2) while detected in the near-IR (H) at …
The hypergiant HR 8752 evolving through the yellow evolutionary void
Meynet, G.; Lobel, A.; Kolka, I. +5 more
Context. We study the time history of the yellow hypergiant HR 8752 based on high-resolution spectra (1973-2005), the observed MK spectral classification data, B - V- and V-observations (1918-1996) and yet earlier V-observations (1840-1918).
Aims: Our local thermal equilibrium analysis of the spectra yields accurate values of the effective te…
Ultraviolet extinction toward a quiescent molecular cloud in the Small Magellanic Cloud
Maíz Apellániz, J.; Rubio, M.
Context. The mean UV extinction law for the Small Magellanic Cloud (SMC) is usually taken as a template for low-metallicity galaxies. However, its current derivation is based on only five stars, which renders its universality questionable. More targets with measured extinction laws in the SMC are necessary to determine its possible dependence on p…
Hundred Thousand Degree Gas in the Virgo Cluster of Galaxies
Manset, N.; Sparks, W. B.; Pringle, J. E. +6 more
The physical relationship between low-excitation gas filaments at ~104 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~107 K in the centers of many galaxy clusters is not understood. It is unclear whether the ~104 K filaments have cooled and condensed from the ambient hot (~107
Formation of unsaturated hydrocarbons in interstellar ice analogues by cosmic rays
Pilling, S.; da Silveira, E. F.; Rothard, H. +3 more
The formation of C=C and C≡C bonds from the processing of pure c-C6H12 (cyclohexane) and mixed H2O:NH3:c-C6H12 (1:0.3:0.7) ices by highly charged and energetic ions (219-MeV 16O7 + and 632-MeV 58Ni24 +) is studied. The experiments simulate…
Constraining the parameters of globular cluster NGC 1904 from its variable star population
Arellano Ferro, A.; Kains, N.; Bramich, D. M. +3 more
Aims: We present the analysis of 11 nights of V and I time-series observations of the globular cluster NGC 1904 (M 79). Using this we searched for variable stars in this cluster and attempted to refine the periods of known variables, making use of a time baseline spanning almost 8 years. We use our data to derive the metallicity and distance …
Physical properties of Herschel selected galaxies in a semi-analytic galaxy formation model
Ferguson, Henry C.; Koekemoer, Anton M.; Somerville, Rachel S. +3 more
We make use of a semi-analytic cosmological model that includes simple prescriptions for dust attenuation and emission to make predictions for the observable and physical properties of galaxies that may be detected by the recently launched HerschelSpace Observatory in deep fields such as Great Observatories Origins Deep Survey-Herschel. We compare…
Magnetic Variances and Pitch-angle Scattering Times Upstream of Interplanetary Shocks
Zimbardo, Gaetano; Perri, Silvia
Recent observations of power-law time profiles of energetic particles accelerated at interplanetary shocks have shown the possibility of anomalous, superdiffusive transport for energetic particles throughout the heliosphere. Those findings call for an accurate investigation of the magnetic field fluctuation properties at the resonance frequencies …
Silica-rich Bright Debris Disk around HD 15407A
Onaka, Takashi; Fukagawa, Misato; Murakami, Hiroshi +5 more
We report an intriguing debris disk toward the F3V star HD 15407A in which an extremely large amount of warm fine dust (~10-7 M ⊕) is detected. The dust temperature is derived as ~500-600 K and the location of the debris dust is estimated as 0.6-1.0 AU from the central star, a terrestrial planet region. The fractional luminos…
The cosmological analysis of X-ray cluster surveys - I. A new method for interpreting number counts
Pierre, M.; Clerc, N.; Pacaud, F. +1 more
We present a new method aimed at simplifying the cosmological analysis of X-ray cluster surveys. It is based on purely instrumental observable quantities considered in a two-dimensional X-ray colour-magnitude diagram (hardness ratio versus count rate). The basic principle is that even in rather shallow surveys, substantial information on cluster r…