Chemical abundances of damped Lyman alpha systems in the XQ-100 survey

The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyman alpha systems (DLAs) identified in the XQ-100 sample are presented, and an investigation into abundances of a variety of DLA classes is conducted. The XQ-100 DLA sample contains five DLAs within 5000 km/s of their host quasar (proximate DLAs; PDLAs) as well as three sightlines which contain two DLAs within 10,000 km/s of each other along the same line-of-sight (multiple DLAs; MDLAs). Combined with previous observations in the literature, we demonstrate that PDLAs with logN(HI)<21.0 show lower [S/H] and [Fe/H] (relative to intervening systems with similar redshift and N(HI)), whilst higher [S/H] and [Si/H] are seen in PDLAs with logN(HI)>21.0. These abundance discrepancies are independent of their line-of-sight velocity separation from the host quasar, and the velocity width of the metal lines (v90). Contrary to previous studies, MDLAs show no difference in [alpha/Fe] relative to single DLAs matched in metallicity and redshift. In addition, we present follow-up UVES data of J0034+1639, a sightline containing three DLAs, including a metal-poor DLA with [Fe/H]=-2.82 (the third lowest [Fe/H] in DLAs identified to date) at z=4.25. Lastly we study the dust-corrected [Zn/Fe], emphasizing that near-IR coverage of X-Shooter provides unprecedented access to MgII, CaII and TiII lines (at redshifts 3-4) to provide additional evidence for subsolar [Zn/Fe] ratio in DLAs.Comment: Accepted to MNRAS. 19 pages plus Appendix material (102 pages total

Measurement driven quantum evolution

We study the problem of mapping an unknown mixed quantum state onto a known pure state without the use of unitary transformations. This is achieved with the help of sequential measurements of two non-commuting observables only. We show that the overall success probability is maximized in the case of measuring two observables whose eigenstates define mutually unbiased bases. We find that for this optimal case the success probability quickly converges to unity as the number of measurement processes increases and that it is almost independent of the initial state. In particular, we show that to guarantee a success probability close to one the number of consecutive measurements must be larger than the dimension of the Hilbert space. We connect these results to quantum copying, quantum deleting and entanglement generation.Comment: 7 pages, 1 figur

Differential-thermal analysis around and below the critical temperature Tc of various low-Tc superconductors: A comparative study

We present specific-heat data on the type-II superconductors V3Si, LuNi2B2C and NbSe2 which were acquired with a low-temperature thermal analysis (DTA) technique. We compare our data with available literature data on these superconductors. In the first part we show that the DTA technique allows for fast measurements while providing a very high resolution on the temperature scale. Sharp features in the specific heat such as at the one at the transition to superconductivity are resolved virtually without instrumental broadening. In the second part we investigate the magnetic-field dependence of the specific heats of V3Si and LuNi2B2C at a fixed temperature T=7.5K to demonstrate that DTA techniques also allow for sufficiently precise measurements of absolute values of cp even in the absence of a sharp phase transition. The corresponding data for V3Si and LuNi2B2C are briefly discussed

The obscured hyper-energetic GRB 120624B hosted by a luminous compact galaxy at z = 2.20

Gamma-ray bursts are the most luminous explosions that we can witness in the Universe. Studying the most extreme cases of these phenomena allows us to constrain the limits for the progenitor models. In this Letter, we study the prompt emission, afterglow, and host galaxy of GRB 120624B, one of the brightest GRBs detected by Fermi, to derive the energetics of the event and characterise the host galaxy in which it was produced. Following the high-energy detection we conducted a multi-wavelength follow-up campaign, including near-infrared imaging from HAWKI/VLT, optical from OSIRIS/GTC, X-ray observations from the Chandra X-ray Observatory and at sub-millimetre/millimetre wavelengths from SMA. Optical/nIR spectroscopy was performed with X-shooter/VLT. We detect the X-ray and nIR afterglow of the burst and determine a redshift of z = 2.1974 +/- 0.0002 through the identification of emission lines of [OII], [OIII] and H-alpha from the host galaxy of the GRB. This implies an energy release of Eiso = (3.0+/-0.2)x10^54 erg, amongst the most luminous ever detected. The observations of the afterglow indicate high obscuration with AV > 1.5. The host galaxy is compact, with R1/2 < 1.6 kpc, but luminous, at L ~ 1.5 L* and has a star formation rate of 91 +/- 6 Msol/yr as derived from H-alpha. As other highly obscured GRBs, GRB 120624B is hosted by a luminous galaxy, which we also proof to be compact, with a very intense star formation. It is one of the most luminous host galaxies associated with a GRB, showing that the host galaxies of long GRBs are not always blue dwarf galaxies, as previously thought.Comment: 6 pages, 4 figures, 4 tables; accepted for publication in A&

Early Science with the Large Millimetre Telescope: Molecules in the Extreme Outflow of a proto-Planetary Nebula

Extremely high velocity emission likely related to jets is known to occur in some proto-Planetary Nebulae. However, the molecular complexity of this kinematic component is largely unknown. We observed the known extreme outflow from the proto-Planetary Nebula IRAS 16342-3814, a prototype water fountain, in the full frequency range from 73 to 111 GHz with the RSR receiver on the Large Millimetre Telescope. We detected the molecules SiO, HCN, SO, and $^{13}$CO. All molecular transitions, with the exception of the latter are detected for the first time in this source, and all present emission with velocities up to a few hundred km s$^{-1}$. IRAS 16342-3814 is therefore the only source of this kind presenting extreme outflow activity simultaneously in all these molecules, with SO and SiO emission showing the highest velocities found of these species in proto-Planetary Nebulae. To be confirmed is a tentative weak SO component with a FWHM $\sim$ 700 km s$^{-1}$. The extreme outflow gas consists of dense gas (n$_{\rm H_2} >$ 10$^{4.8}$--10$^{5.7}$ cm$^{-3}$), with a mass larger than $\sim$ 0.02--0.15 M$_{\odot}$. The relatively high abundances of SiO and SO may be an indication of an oxygen-rich extreme high velocity gas.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society Letter

Characterization of the cytotoxic effects of the combination of cisplatin and flavanol (-)-epicatechin on human lung cancer cell line A549. An isobolographic approach

Background: Among malignancies, lung cancer is a leading cause of death. Platinum-based therapeutic compounds used to treat lung cancer have not been able to increase the survival of patients and such compounds have a high incidence of adverse and toxic effects. It has been proposed that flavonoids such as catechins may significantly reduce the risk of developing cancer, alongside with other health benefits. The aim of this work was to determine the effect of (-)-epicatechin, the main flavanol found in cocoa, on the proliferation of the lung non-small cell adenocarcinoma cancer cell line A549, and to determine its effects when added simultaneously with cisplatin. Materials and Methods: Concentration-response curves for cisplatin and epicatechin were obtained, inhibitory concentrations calculated and an isobolographic analysis was then performed. Results: We found that epicatechin has a concentration-dependent inhibitory effect on proliferation of tumor cells and the isobolographic analysis reveals that the effect of its combination with cisplatin is synergistic. It was also observed that epicatechin promotes cell death by apoptosis. Conclusions: Epicatechin might be considered for future studies to explore its possible use as coadjuvant in cisplatin-based treatments