376 citations · 9.9k across the 229 of their papers we have counts for
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The isolated neutron star candidate 2XMM J104608.7-594306
A. M. Pires, C. Motch, R. Turolla +2
Over the last decade, X-ray observations unveiled the existence of several classes of isolated neutron stars (INSs) which are radio-quiet or exhibit radio emission with properties…
ESO VLT optical spectroscopy of BL Lacertae objects. III. An extension of the sample
B. Sbarufatti, S. Ciprini, J. Kotilainen +4
We present results of an ongoing program at the ESO VLT for spectroscopy of BL Lac objects lacking a firm redshift estimate and here we report on 15 objects. For 11 sources we conf…
Vrijhk Photometry of PKS 0537-441 and PKS 2155-304 in 2006-2008
Domenico Impiombato, Gino Tosti, Aldo Treves +3
We report the 2006-2008 light curves obtained with the REM telescope in VRIJHK bands for the two BL Lac objects PKS 0537-441 and PKS 2155-304
Observations of Isolated Neutron Stars with the ESO Multi-Conjugate Adaptive Optics Demonstrator
R. P. Mignani, R. Falomo, A. Moretti +10
High-energy observations have unveiled peculiar classes of isolated neutron stars which, at variance with radio pulsars, are mostly radio silent and not powered by the star rotatio…
Infrared to X-ray observations of PKS 2155-304 in a low state
L. Foschini, A. Treves, F. Tavecchio +14
AIMS: Our goal is to understand the nature of blazars and the mechanisms for the generation of high-energy gamma-rays, through the investigation of the prototypical blazar PKS 2155…
On the geometry of broad emission region in quasars
R. Decarli, M. Labita, A. Treves +1
We study the geometry of the Hbeta broad emission region by comparing the M_BH values derived from Hbeta through the virial relation with those obtained from the host galaxy lumino…
The NIR to UV continuum of radio loud vs. radio quiet quasars
Marzia Labita, Aldo Treves, Renato Falomo
Starting from a sample of SDSS quasars appearing also in the 2MASS survey, we study the continuum properties of about 1000 objects observed in 8 bands, from NIR to UV. We construct…
Near-infrared adaptive optics imaging of high redshift quasars
R. Falomo, A. Treves, J. K. Kotilainen +2
The properties of high redshift quasar host galaxies are studied, in order to investigate the connection between galaxy evolution, nuclear activity, and the formation of supermassi…
On the distance of PG 1553+11. A lineless BL Lac object active in the TeV band
Aldo Treves, Renato Falomo, Michela Uslenghi
Context: The redshift of PG 1553+11, a bright BL Lac object (V~14), is still unknown. It has been recently observed in the TeV band, a fact that offers an upper limit for the redsh…
Blazar microvariability at hard X-rays
L. Foschini, M. Gliozzi, E. Pian +10
Blazars are known to display strong and erratic variability at almost all the wavelengths of electromagnetic spectrum. Presently, variability studies at high-energies (hard X-rays,…
Simultaneous Swift and REM monitoring of the blazar PKS0537-441 in 2005
E. Pian, P. Romano, A. Treves +24
The blazar PKS0537-441 has been observed by Swift between the end of 2004 and November 2005. The BAT monitored it recurrently for a total of 2.7 Ms, and the XRT and UVOT pointed it…
Swift follow-up of the gigantic TeV outburst of PKS 2155-304 in 2006
L. Foschini, G. Ghisellini, F. Tavecchio +12
At the end of July 2006, the blazar PKS 2155-304 (z=0.116) underwent a strong outburst observed at TeV energies by HESS (up to 17 Crab flux level at E > 200 GeV). The Swift satelli…
X-ray/UV/Optical follow-up of the blazar PKS 2155-304 after the giant TeV flares of July 2006
L. Foschini, G. Ghisellini, F. Tavecchio +12
We present all the publicly available data, from optical/UV wavelengths (UVOT) to X-rays (XRT, BAT), obtained from Swift observations of the blazar PKS 2155-304, performed in respo…
The nuclear to host galaxy relation of high redshift quasars
J. K. Kotilainen, R. Falomo, M. Labita +2
We present near-infrared imaging with ESO VLT+ISAAC of the host galaxies of low luminosity quasars in the redshift range 1 < z < 2, aimed at investigating the relationship between…
X-ray and optical variability of the ultraluminous X-ray source NGC 1313 X-2
P. Mucciarelli, L. Zampieri, A. Treves +2
We present an analysis of recent XMM-Newton and HST archive data of the ultraluminous X-ray source NGC 1313 X-2. Quasi-simultaneous observations taken with XMM-Newton, HST and VLT…
The BH mass of nearby QSOs: a comparison of the bulge luminosity and virial methods
Marzia Labita, Aldo Treves, Renato Falomo +1
We report on the analysis of the photometric and spectroscopic properties of a sample of 29 low redshift (z<0.6) QSOs for which both HST WFPC2 images and ultraviolet HST FOS spectr…
Multiwavelength Observations of the BL Lacertae Object PKS 2155-304 with XMM-Newton
Y. H. Zhang, J. M. Bai, S. N. Zhang +3
The optical-UV and X-ray instruments on-board XMM-Ndewton provide an excellent opportunity to perform simultaneous observations of violently variable objects over a broad wavelengt…
Optical spectroscopy of BL Lacertae objects. Broad lines, companion galaxies and redshift lower limits
B. Sbarufatti, R. Falomo, A. Treves +2
Aims: We present optical spectroscopy of a sample of BL Lac objects, to determine their redshift, to study their broad emission line properties and to characterize their close envi…
Simultaneous X-ray and optical observations of S5 0716+714 after the outburst of March 2004
L. Foschini, G. Tagliaferri, E. Pian +6
At the end of March 2004, the blazar S5 0716+714 underwent an optical outburst that prompted for quasi-simultaneous target-of-opportunity observations with the INTEGRAL and XMM-New…
ESO-VLT optical spectroscopy of BL Lac objects: II. New redshifts, featureless objects and classification assessments
B. Sbarufatti, A. Treves, R. Falomo +3
We report on ESO Very Large Telescope optical spectroscopy of 42 BL Lacertae objects of unknown redshift. Nuclear emission lines were observed in 12 objects, while for another six…
VLT Observations of the Ultraluminous X-ray Source NGC 1313 X-2
P. Mucciarelli, L. Zampieri, R. Falomo +2
We present archive ESO VLT photometric and spectroscopic data of the Ultraluminous X-ray source NGC 1313 X-2. The superb quality of the VLT images reveals that two distinct objects…
Multiband Photometry of the Blazar PKS 0537-441: A Major Active State in December 2004 - March 2005
A. Dolcini, S. Covino, A. Treves +18
Multiband VRIJHK photometry of the Blazar PKS 0537-441 obtained with the REM telescope from December 2004 to March 2005 is presented. A major period of activity is found with more…
XMM-Newton view of PKS 2155-304: hardness ratio and cross-correlation analysis of EPIC pn observations
Y. H. Zhang, A. Treves, L. Maraschi +2
With currently available XMM-Newton EPIC pn observations spanned over about 3 years, we present a detailed spectral and temporal variability of the 0.2--10 keV X-ray emission from…
Is the Bursting Radio-source GCRT J1745-3009 a Double Neutron Star Binary ?
R. Turolla, A. Possenti, A. Treves
GCRT J1745-3009 is a peculiar transient radio-source in the direction of the Galactic Center. It was observed to emit a series of ~ 1 Jy bursts at 0.33 GHz, with typical duration ~…