We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. These sources were chosen to have similar optical properties (MB, spectra) as samples of (z ≥ 3.7 QSOs) for which we have comparable (sub)millimeter (250 GHz or 350 GHz) and centimeter observations. Half of the chosen quasars are bright at 250 or 350 GHz while the other half have not been detected at (sub)mm wavelengths. All eight submm-loud sources in our study were detected at 1.4 GHz, the majority of these at high significance (≥0.2±0.02 mJy). Only three of the submm-quiet QSO's were detected at radio frequencies, and these at lower significance (≤0.17 mJy). These results argue for a real physical difference between the submm-luminous and submm-quiet sources, and against a continuum of submm luminosities. Four of these sources have radio spectral indices and radio-to-FIR ratios consistent with star forming galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We discuss the results so far of a program to image in the rest-frame optical and near-UV the host galaxies of a sample of 5 high redshift (z∼2−3) radio-quiet quasars with nuclear luminosities lower than most samples studied at high z. We found that in the rest-frame optical the hosts have luminosities of about L∗, comparable to the Lyman break galaxies at similar redshifts. From the rest-frame UV imaging, we can derive optical–UV colors, and find they show a great deal of variation, but may be somewhat redder and less starforming than the LBGs. We are supplementing this work at high z with study of the hosts of z∼1 radio-quiet quasars with similar low nuclear luminosities.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present VLT–ISAAC spectra of unprecedented S/N and resolution for the Hβ region in a sample of n = 17 quasars in the range z=0.8–2.5. The data represent our first attempt to test source occupation and line properties for the Eigenvector 1 parameter space that was defined using a sample of sources with z<0.8. We find no strong luminosity/redshift dependent effects with the possible exception of an increase in the minimum broad line profile width from 1000 to 3000 km s−1 between MB≈−20 and −28.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Based on our previous work about a co-evolution of massive black holes (MBH) and their host spheroids, we estimate the cosmic star formation history associated with AGN accretion by ROSAT X-ray All sky surveys. We show: 1) the total amount of star formation associated with MBH growth is at least half of the net star formation at high redshift, which probably totally missed by the current UV/optical deep surveys; 2) the FIR emission from the dust heated by star formation on-going during the MBH growth could be a significant energy source for SCUBA populations; 3)the peak redshift of the massive spheroid formation in this case is around 1.5, not necessary to be at much higher redshift.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

In order to analyse the large numbers of Seyfert galaxy spectra available at present, we are testing new techniques to derive their physical parameters fastly and accurately.

We present an experiment on such a new technique to segregate old and young stellar populations in galactic spectra using machine learning methods. We used an ensemble of classifiers, each classifier in the ensemble specializes in young or old populations and was trained with locally weighted regression and tested using ten-fold cross-validation. Since the relevant information concentrates in certain regions of the spectra we used the method of sequential floating backward selection offline for feature selection.

Very interestingly, the application to Seyfert galaxies proved that this technique is very insensitive to the dilution by the Active Galactic Nucleus (AGN) continuum. Comparing with exhaustive search we concluded that both methods are similar in terms of accuracy but the machine learning method is faster by about two orders of magnitude.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Abundances in Galactic globular clusters are important for understanding Galactic chemical evolution and the formation of the Milk Way. 47 Tucanae (NGC 104) is a template metal-rich globular cluster ([Fe/H] ∼–0.7 dex). From the point of view of high resolution spectroscopy, there is still a lack of abundance analyses in the literature. In this work we present a detailed analysis carried out for 5 giants stars (12.10 < V < 14.30) of 47 Tucanae, using high resolution spectra (λ/Δλ∼60,000) with high signal-to-noise ratio (S/N > 200), obtained at the ESO VLT-UT2 8m telescope, equipped with the UVES spectrograph. Abundances of α- (O, Mg, Ca, Si, Ti), s- (Ba, Y, Sr) and r- (Eu) process elements are obtained.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present here the self-similar collapse of a relativistic singular isothermal sphere (SIS) that leads to monolithic black hole formation. The dynamic evolution is triggered by the central portion of the SIS collapsing to for an infinitesimal black hole. This perturbation removes the pressure support for the layer immediately above, which causes it to collapse, and so on. The influence of gravitational collapse propagates out as an expansion wave moving at the speed of sound. Outside of the expansion wave, matter remains in local equilibrium.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The “Herschel Space Observatory” is an ESA mission to perform imaging photometry and spectroscopy in the far-IR & submm 57–670 μm range. It carries a 3.5 m diameter radiatively cooled telescope. The scientific instruments – two cameras/medium resolution spectrometers (PACS and SPIRE) and a very high resolution heterodyne spectrometer (HIFI) – are housed in a superfluid helium cryostat. Herschel will be placed in orbit around the Earth-Sun L2 point in 2007 and will operate for a minimum of 3 years. Roughly 2/3 of the observing time is open to the general astronomical community through a competitive proposal procedure.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We predict the metallicity distribution of stars for 6 Dwarf Spheroidal (dSph) galaxies of the Local Group by means of a chemical evolution model which is able to reproduce several observed abundance ratios and the present day total mass and gas content of these galaxies. The model adopts up to date nucleosynthesis and takes into account the role played by supernovae of different types (II, Ia). Each galaxy model is specified by the prescriptions of the star formation rate and by the galactic wind efficiency chosen to reproduce the main features of these galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

A single web link is provided to a maintained site giving detailed descriptions of telescope and instrumentation combinations available – and planned for the near future – at Gemini South, CTIO, SOAR and SMARTS for observers of AGN.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html