Julio R Valdes

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Context. We present results of long-term (1987–2010) optical spectral monitoring of the broad-line radio galaxy Arp 102B, a prototype of an active galactic nucleus with double-peaked broad emission lines that are commonly assumed to be emitted from an accretion disk. Aims. To explore the structure of the broad-line region (BLR), we analyze the light-curves(More)
Aims. Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). Methods. High quality spectra (S/N> 50 in the continuum near Hα and Hβ) were obtained in the spectral range ∼ 4000 to 7500 Å, with a resolution between 5 and 15 Å, using the 6-m and the 1-m SAO’s telescopes (Russia), the(More)
Results of optical and NIR spectral and photometric observations of a sample of candidate doublebarred galaxies are presented. Velocity fields and velocity dispersion maps of stars and ionized gas, continuum and emission-line images were constructed from integral-field spectroscopy observations carried out at the 6m telescope (BTA) of SAO RAS, with the MPFS(More)
Between 1996 and 2002, we have carried out a spectral monitoring program for the Seyfert galaxy NGC 5548 with the 6 m and 1 m telescopes of SAO (Russia) and with the 2.1 m telescope of Guillermo Haro Observatory (GHO) at Cananea, México. High quality spectra with S/N> 50 in the continuum near Hα and Hβ were obtained, covering the spectral range ∼(4000 –(More)
The mid infrared emission of early type galaxies traces the presence of intermediate age stellar populations as well as even tiny amounts of ongoing star formation. Here we discuss high S/N Spitzer IRS spectra of a sample of Virgo early type galaxies, with particular reference to NGC 4435. We show that, by combining mid infrared spectroscopic observations(More)
We have obtained high S/N Spitzer IRS spectra of 17 Virgo earlytype galaxies that lie on the colour-magnitude relation of passively evolving galaxies in the cluster. To flux calibrate these extended sources we have devised a new procedure that allows us to obtain the intrinsic spectral energy distribution and to disentangle resolved and unresolved emission(More)
We present VLT long slit optical spectroscopy of the luminous BL Lacertae object PKS 2005-489. The high signal-to-noise ratio and the good spatial resolution of the data allow us to detect the signatures of ongoing star formation in an extended rotating ring, at ∼ 4 kpc from the nucleus. We find that the ring is almost perpendicular to the radio axis and(More)
The first results of the observational program of the study of 2D-kinematics in double-barred galaxies are presented. We show that, for the main part of the sample, the inner bars do not affect the circumnuclear stellar kinematics. Therefore, they are not dynamically decoupled structures. Various types of non-circular gas motion were found in many galaxies.(More)
Two separate laboratory experiment series, surface runoff and steady-state seepage, were performed to determine if dust suppressant products can be applied to soils with an expected minimal to no negative impact on water quality. The experiments were designed to mimic arid field conditions and used two soils (clayey and sandy) and six different dust(More)