Search Publications
The acoustic low-degree modes of the Sun measured with 14 years of continuous GOLF & VIRGO measurements
García, R. A.; Mathur, S.; Jiménez, A. +3 more
The helioseismic Global Oscillation at Low Frequency (GOLF) and the Variability of solar Irradiance and Gravity Oscillations (VIRGO) instruments onboard SoHO, have been observing the Sun continuously for the last 14 years. In this preliminary work, we characterize the acoustic modes over the entire p-mode range in both, Doppler velocity and lumino…
Hubble Space Telescope study of resolved red giant stars in the outer halos of nearby dwarf starburst galaxies
van der Marel, R. P.; Aloisi, A.; Annibali, F. +2 more
Context. Central starbursts in galaxies are an extreme example of ongoing galaxy evolution. The outer parts of galaxies contain a fossil record of galaxy formation and evolution processes in the more distant past. The characterization of resolved stellar populations allows one a detailed study of these topics.
Aims: We observed the outer part…
Suzaku Measurement of Electron and Magnetic Energy Densities in the East Lobe of the Giant Radio Galaxy DA 240
Isobe, Naoki; Tashiro, Makoto S.; Seta, Hiromi
A careful analysis of the Suzaku data of the giant radio galaxy DA 240, of which the size is 1.48 Mpc, revealed diffuse X-ray emission associated with its east lobe. The diffuse X-ray spectrum was described with a simple power-law model with a photon index of
Distinguishing post-AGB impostors in a sample of pre-main sequence stars
Vieira, R. G.; Szczerba, R.; Stasińska, G. +2 more
Context. A sample of 27 sources, cataloged as pre-main sequence stars by the Pico dos Dias Survey (PDS), is analyzed to investigate a possible contamination by post-AGB stars. The far-infrared excess due to dust present in the circumstellar envelope is typical of both categories: young stars and objects that have already left the main sequence and…
Long-term evolution of the aerosol debris cloud produced by the 2009 impact on Jupiter
Hueso, R.; Sánchez-Lavega, A.; Fletcher, L. N. +43 more
We present a study of the long-term evolution of the cloud of aerosols produced in the atmosphere of Jupiter by the impact of an object on 19 July 2009 (Sánchez-Lavega, A. et al. [2010]. Astrophys. J. 715, L155-L159). The work is based on images obtained during 5 months from the impact to 31 December 2009 taken in visible continuum wavelengths and…
Large-scale Shock-ionized and Photoionized Gas in M83: The Impact of Star Formation
Mutchler, Max; McCarthy, Patrick J.; Blair, William P. +20 more
We investigate the ionization structure of the nebular gas in M83 using the line diagnostic diagram, [O III](5007 Å)/Hβ versus [S II](6716 Å+6731 Å)/Hα, with the newly available narrowband images from the Wide Field Camera 3 (WFC3) of the Hubble Space Telescope (HST). We produce the diagnostic diagram on a pixel-by-pixel (0farcs2 × 0farcs2) basis …
Velocity distributions of superthermal electrons fitted with a power law function in the magnetosheath: Cluster observations
Zhang, Tielong; Wang, Shui; Lu, Quanming +3 more
Satellite observations have revealed that superthermal electrons in space plasma generally possess a power law distribution. In this paper, we utilize a power law function to model the omnidirectional differential fluxes of superthermal electrons observed by Cluster in the magnetosheath. By assuming an isotropic pitch angle distribution and perfor…
Distances and stellar population properties for 12 elliptical galaxies
Cantiello, M.; Capaccioli, M.; Brocato, E.
Aims: We use the surface brightness fluctuation (SBF) technique to derive the distances and analyse the radial behaviour of stellar populations in a sample of 12 elliptical galaxies. The data are I-band images collected with the FORS1 camera at the Very Large Telescope (VLT), drawn from the ESO archive. The main purpose of our analysis is to …
X-ray and optical properties of broad absorption line quasars in the Canada-France-Hawaii Telescope Legacy Survey
Stalin, C. S.; Petitjean, P.; Srianand, R.
We study the X-ray and optical properties of 16 broad absorption line (BAL) quasars detected in a ≈3 deg2 region common to the wide synoptic (W-1) component of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) and the XMM Large Scale Structure Survey (XMM-LSS). The BAL fraction is found to be 10 per cent in the full sample, 7 pe…
An X-Ray Spectroscopic Study of the Hot Interstellar Medium toward the Galactic Bulge
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Wang, Q. Daniel +5 more
We present a detailed spectroscopic study of the hot gas toward the galactic bulge along the 4U 1820