The polarization properties of Broad Absorption Line QSOs: observational results

Correlations between BAL QSO intrinsic properties and polarization have been searched for. Some results are summarized here, providing possible constraints on BAL outflow models.Comment: 4 pages, 5 figures; to appear in ``Mass Outflow in Active Galactic Nuclei: New Perspectives'' ASP Conference Series, eds. D.M. Crenshaw, S.B. Kraemer, and I.M. Georg

Large-scale coherent orientations of quasar polarisation vectors: interpretation in terms of axion-like particles

The observation of redshift-dependent coherent orientations of quasar polarisation vectors over cosmological distances in some regions of the sky is reviewed. Based on a good-quality sample of 355 measured quasars, this observation seems to infer the existence of a new effect acting on light propagation on such huge distances. A solution in terms of nearly massless axion-like particles has been proposed in the literature and its current status is discussed.Comment: Replaced because of a previously badly displayed caption. Contributed to "Axions 2010", Gainesville (FL), January 15-17 2010. To be published in AIP conference series. 6 page

Sub-arcsecond imaging and spectroscopy of the radio-loud highly polarized quasar PKS 1610-771

We report on imaging and spectroscopic observations of the radio-loud, highly polarized quasar PKS 1610-771 (z = 1.71). Our long-slit spectroscopy of the companion 4.55 arcseconds NW of the quasar confirms the stellar nature of this object, so ruling out the previously suspected gravitationally lensed nature of this system. PKS 1610-771 looks fuzzy on our sub-arcsecond R and I images and appears located in a rich environment of faint galaxies. Possible magnification, without image splitting of the quasar itself, by some of these maybe foreground galaxies cannot be excluded. The continuum fuzz (made of the closest two objects, viz. A and D) is elongated in a direction orthogonal to the E vector of the optical polarization, as in high-redshift radio-galaxies. The spectrum of PKS 1610-771 appears strongly curved, in a convex way, with a maximum of intensity at ~ 7,600 A (2,800 A rest frame), possibly indicating a strong ultraviolet absorption by dust.Comment: 6 pages, uuencoded gziped tar file including TeX file + postscript figures. Accepted for publication in A&A main journa

The atypical emission-line star Hen3-209

We analyse observations, spanning 15 years, dedicated to the extreme emission-line object Hen3-209. Our photometric data indicate that the luminosity of the star undergoes marked variations with a peak-to-peak amplitude of 0.65mag. These variations are recurrent, with a period of 16.093+-0.005d. The spectrum of Hen3-209 is peculiar with many different lines (HI, HeI, FeII,...) showing P Cygni profiles. The line profiles are apparently changing in harmony with the photometry. The spectrum also contains [OIII] lines that display a saddle profile topped by three peaks, with a maximum separation of about 600km/s. Hen3-209 is most likely an evolved luminous object suffering from mass ejection events and maybe belonging to a binary system.Comment: 6p, 5 fig, accepted for publication in MNRAS (www.blackwell-synergy.com

HST Observations of the Gravitationally Lensed Cloverleaf Broad Absorption Line QSO H1413+1143: Modeling the Lens

We investigate gravitational lens models for the quadruply-lensed Cloverleaf BAL QSO H1413+1143 based on the HST WFPC/WFPC2 astrometric and photometric data of the system by Turnshek et al. and the HST NICMOS-2 data by Falco et al. The accurate image positions and the dust-extinction-corrected relative amplifications, along with a possible detection of the lensing galaxy in the infrared, permit more accurate lens models than were previously possible. While more recent models are qualitatively consistent with the HST data, none of the previous models considered the dust-extinction-corrected relative amplifications of the image components. We use the power-law elliptical mass model to fit the HST data. We find that a single elliptical galaxy perturbed by an external shear can fit the image positions within the observational uncertainties; however, the predicted relative magnifications are only roughly consistent with the observational relative amplifications. We find that a primary galaxy combined with a secondary galaxy in the vicinity of the Cloverleaf or a cluster centered (south-)west of the Cloverleaf can fit both the image positions and relative amplifications within the observational uncertainties. We discuss future observations which could be used to test and/or further constrain lens models of the Cloverleaf.Comment: 23 pages (in aaspp.sty) including 5 tables and 3 figures, Accepted for publication in the Astrophysical Journa

Strong Gravitational Lensing and the Structure of Quasar Outflows

We show that by analyzing the spectra of lensed broad absorption line quasars (BALQSOs), it is possible to reveal key properties of the outflowing gas in the inner regions of these objects. This results from the fact that each image of the quasar corresponds to a different line of sight through the outflow. This combined with dynamical estimates for the location of the flow, adds new information concerning the lateral, non line of sight structure of the absorbing gas. Here we consider a sample of lensed BALQSOs and note that the similarity of BAL profiles of different images of the same quasar implies that the flow is relatively isotropic on small scales. We show that its geometry is inconsistent with the ballistically accelerated spherical cloud model, and that wind models provide a better description of the flow structure. Furthermore, observations seem to disagree with naive interpretations of recent time-dependent wind simulations. This may hint on several important physical processes that govern the structure and dynamics of such flows. Future prospects for the study of quasar outflows with the effect of strong gravitational lensing are discussed.Comment: 4 pages, 1 figure, accepted for publication in ApJ

TRAPPIST: a robotic telescope dedicated to the study of planetary systems

We present here a new robotic telescope called TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope). Equipped with a high-quality CCD camera mounted on a 0.6 meter light weight optical tube, TRAPPIST has been installed in April 2010 at the ESO La Silla Observatory (Chile), and is now beginning its scientific program. The science goal of TRAPPIST is the study of planetary systems through two approaches: the detection and study of exoplanets, and the study of comets. We describe here the objectives of the project, the hardware, and we present some of the first results obtained during the commissioning phase.Comment: To appear in Detection and Dynamics of Transiting Exoplanets, Proceedings of Haute Provence Observatory Colloquium (23-27 August 2010), eds. F. Bouchy, R.F. Diaz & C.Moutou, Platypus press 201

Submillimetre observations of a sample of broad absorption line quasars

The broad absorption line (BAL) features seen in a small fraction of quasar optical/UV spectra are attributed to bulk outflows away from the quasar core. Observational evidence suggests that dust plays a key role in these systems, although whether the inferred dust properties are a signature of orientation effects or whether they are indicative of an evolutionary sequence remains an outstanding issue. Submillimetre (submm) detections of BAL quasars (BALQSOs), which would clearly help to resolve this issue, have so far been sparse. This paper reports on new submm observations of seven BALQSOs. The strongest influence on the observed flux is found to be the redshift, with the two highest redshift sources appearing intrinsically more submm-luminous than the lower redshift ones. Since this trend is also seen in other high redshift AGN, including non-BAL quasars it implies that the dust emission properties of these systems are no different from those of the general AGN population, which is difficult to reconcile with the evolutionary interpretation of the BAL phenomenon.Comment: 5 Pages, to appear in ApJ Letter

Herschel imaging and spectroscopy of the nebula around the luminous blue variable star WRAY 15-751

We have obtained far-infrared Herschel PACS imaging and spectroscopic observations of the nebular environment of the luminous blue variable WRAY 15-751. These images clearly show that the main, dusty nebula is a shell of radius 0.5 pc and width 0.35 pc extending outside the H-alpha nebula. They also reveal a second, bigger and fainter dust nebula, observed for the first time. Both nebulae lie in an empty cavity, likely the remnant of the O-star wind bubble formed when the star was on the main sequence. The kinematic ages of the nebulae are about 20000 and 80000 years and each nebula contains about 0.05 Msun of dust. Modeling of the inner nebula indicates a Fe-rich dust. The far-infrared spectrum of the main nebula revealed forbidden emission lines coming from ionized and neutral gas. Our study shows that the main nebula consists of a shell of ionized gas surrounded by a thin photodissociation region illuminated by an "average" early-B star. The derived abundance ratios N/O=1.0+/-0.4 and C/O=0.4+/-0.2 indicate a mild N/O enrichment. We estimate that the inner shell contains 1.7+/-0.6 Msun of gas. Assuming a similar dust-to-gas ratio for the outer nebula, the total mass ejected by WRAY 15-751 amounts to 4+/-2 Msun. The measured abundances, masses and kinematic ages of the nebulae were used to constrain the evolution of the star and the epoch at which the nebulae were ejected. Our results point to an ejection of the nebulae during the RSG evolutionary phase of an ~ 40 Msun star. The presence of multiple shells around the star suggests that the mass-loss was not a continuous ejection but rather a series of episodes of extreme mass-loss. Our measurements are compatible with the recent evolutionary tracks computed for an 40 Msun star with little rotation. They support the O-BSG-RSG-YSG-LBV filiation and the idea that high-luminosity and low-luminosity LBVs follow different evolutionary paths.Comment: 19 pages, 13 figures, accepted for publication in A&