Galliformes science and species extinctions: what we know and what we need to know

Extinciones de especies de Galliformes y conocimientos científicos: lo que sabemos y lo que necesitamos saber A principios de 2010, las 193 partes que habían firmado el Convenio sobre la Diversidad Biológica reconocieron que no habían cumplido el objetivo que ellas mismas habían fijado en 1992 de reducir de forma significativa las extinciones de especies en 2010. Al final del año establecieron un objetivo nuevo y más ambicioso que consistía en evitar las extinciones de especies en 2020. Lograr dicho objetivo requerirá una utilización mucho más eficiente de los recursos y la investigación tiene un papel fundamental en hacer que esto ocurra. Existen 290 especies de Galliformes, de las cuales el 26% se considera en peligro de extinción, en comparación con el 12% del total de las 10.000 especies de aves. Al mismo tiempo, hay numerosos estudios publicados sobre el grupo que abarcan décadas para algunas especies. Por consiguiente, es oportuno analizar si es posible aumentar la eficiencia y las repercusiones a escala mundial de la investigación sobre aves de caza, de forma que, con la planificación meticulosa que conlleva más orientación estratégica e intercambio de experiencias, los biólogos especializados en este tipo de aves puedan desempeñar una función destacada en la consecución del objetivo de 2020 para las especies aprobado por el Convenio sobre la Diversidad Biológica. Los ámbitos específicos que necesitan este planteamiento de intercambio de experiencias son la estimación de la población y la evaluación de las amenazas, el análisis de la explotación y la determinación de la base ecológica de las intervenciones que hayan obtenido buenos resultados

Optical Follow-up of New SMC Wing Be/X-ray Binaries

We investigate the optical counterparts of recently discovered Be/X-ray binaries in the Small Magellanic Cloud. In total four sources, SXP101, SXP700, SXP348 and SXP65.8 were detected during the Chandra Survey of the Wing of the SMC. SXP700 and SXP65.8 were previously unknown. Many optical ground based telescopes have been utilised in the optical follow-up, providing coverage in both the red and blue bands. This has led to the classification of all of the counterparts as Be stars and confirms that three lie within the Galactic spectral distribution of known Be/X-ray binaries. SXP101 lies outside this distribution becoming the latest spectral type known. Monitoring of the Halpha emission line suggests that all the sources bar SXP700 have highly variable circumstellar disks, possibly a result of their comparatively short orbital periods. Phase resolved X-ray spectroscopy has also been performed on SXP65.8, revealing that the emission is indeed harder during the passage of the X-ray beam through the line of sight.Comment: 9 pages, 9 figures, 2 tables, accepted for publication in MNRA

Limits on I-band microvariability of the Galactic Bulge Miras

We search for microvariability in a sample of 485 Mira variables with high quality I-band light curves from the second generation Optical Gravitational Lensing Experiment (OGLE-II). Rapid variations with amplitudes in the ~0.2-1.1 mag range lasting hours to days were discovered in Hipparcos data by de Laverny et al. (1998). Our search is primarily sensitive to events with time-scales of about 1 day, but retains a few percent efficiency (per object) for detecting unresolved microvariability events as short as 2 hours. We do not detect any candidate events. Assuming that the distribution of the event time profiles is identical to that from the Hipparcos light curves we derive the 95% confidence level upper limit of 0.038 per year per star for the rate of such events (1 per 26 years per average object of the ensemble). The high event rates of the order of 1 per year per star implied by the Hipparcos study in the H_P band are excluded with high confidence by the OGLE-II data in the I band. Our non-detection could still be explained by much redder spectral response of the I filter compared to the H_P band or by population differences between the bulge and the solar neighborhood. In any case, the OGLE-II I-band data provide the first limit on the rate of the postulated microvariability events in Mira stars and offer new quantitative constraints on their properties. Similar limits are obtained for other pulse shapes and a range of the assumed time-scales and size-frequency distributions.Comment: Accepted for publication in Ap

Probing the Pulsar Wind Nebula of PSR B0355+54

We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also from a compact diffuse component extending ~50'' in the opposite direction to the pulsar's proper motion. There is also evidence for the presence of fainter diffuse emission extending ~5' from the point source. The compact diffuse feature is well-fitted with a power-law, the index of which is consistent with the values found for other pulsar wind nebulae. The morphology of the diffuse component is similar to the ram-pressure confined pulsar wind nebulae detected for other sources. The X-ray emission from the pulsar itself is described well by a thermal plus power-law fit, with the thermal emission most likely originating in a hot polar cap.Comment: 9 pages (uses emulateapj.cls), 8 figures, 2 tables, accepted for publication in Ap

The early and late-time spectral and temporal evolution of GRB 050716

We report on a comprehensive set of observations of Gamma Ray Burst 050716, detected by the Swift satellite and subsequently followed-up rapidly in X-ray, optical and near infra-red wavebands. The prompt emission is typical of long-duration bursts, with two peaks in a time interval of T90 = 68 seconds (15 - 350 keV). The prompt emission continues at lower flux levels in the X-ray band, where several smaller flares can be seen, on top of a decaying light curve that exhibits an apparent break around 220 seconds post trigger. This temporal break is roughly coincident with a spectral break. The latter can be related to the extrapolated evolution of the break energy in the prompt gamma-ray emission, and is possibly the manifestation of the peak flux break frequency of the internal shock passing through the observing band. A possible 3 sigma change in the X-ray absorption column is also seen during this time. The late-time afterglow behaviour is relatively standard, with an electron distribution power-law index of p = 2 there is no noticable temporal break out to at least 10 days. The broad-band optical/nIR to X-ray spectrum indicates a redshift of z ~> 2 for this burst, with a host-galaxy extinction value of E(B-V) ~ 0.7 that prefers an SMC-like extinction curve.Comment: Accepted to MNRAS. 8 pages, 5 figure

Atom lithography using MRI-type feature placement

We demonstrate the use of frequency-encoded light masks in neutral atom lithography. We demonstrate that multiple features can be patterned across a monotonic potential gradient. Features as narrow as 0.9 microns are fabricated on silicon substrates with a metastable argon beam. Internal state manipulation with such a mask enables continuously adjustable feature positions and feature densities not limited by the optical wavelength, unlike previous light masks.Comment: 4 pages, 4 figure

Searching for periodicities in the MACHO light curve of LMC X-2

Using the exceptional long-term monitoring capabilities of the MACHO project, we present here the optical history of LMC X-2 for a continuous 6-yr period. These data were used to investigate the previously claimed periodicities for this source of 8.15 h and 12.54 d : we find upper amplitude limits of 0.10 mag and 0.09 mag, respectively.Comment: 4 pages, 4 figures. Minor changes, including title. MNRAS, in pres

Prompt optical observations of GRB050319 with the Swift UVOT

The UVOT telescope on the Swift observatory has detected optical afterglow emission from GRB 050319. The flux declines with a power law slope of alpha = -0.57 between the start of observations some 230 seconds after the burst onset (90s after the burst trigger) until it faded below the sensitivity threshold of the instrument after ~5 x 10^4s. There is no evidence for the rapidly declining component in the early light curve that is seen at the same time in the X-ray band. The afterglow is not detected in UVOT shortward of the B-band, suggesting a redshift of about 3.5. The optical V-band emission lies on the extension of the X-ray spectrum, with an optical to X-ray slope of beta = -0.8. The relatively flat decay rate of the burst suggests that the central engine continues to inject energy into the fireball for as long as a few x 10^4s after the burst.Comment: 16 pages, 4 figures, accepted by Ap

Swift-UVOT Observations of the X-Ray Flash 050406

We present Swift-UVOT data on the optical afterglow of the X-ray flash of 2005 April 6 (XRF 050406) from 88s to \sim 10^5s after the initial prompt gamma-ray emission. Our observations in the V, B and U bands are the earliest that have been taken of an XRF optical counterpart. Combining the early -time optical temporal and spectral properties with \gamma- and simultaneous X-ray data taken with the BAT and XRT telescopes on-board Swift, we are able to constrain possible origins of the XRF. The prompt emission had a FRED profile (fast-rise, exponential decay) with a duration of T_90 = 5.7\pm 0.2s, putting it at the short end of the long-burst duration distribution. The absence of photoelectric absorption red-ward of 4000 \AA in the UV/optical spectrum provides a firm upper limit of z\leq 3.1 on the redshift, thus excluding a high redshift as the sole reason for the soft spectrum. The optical light curve is consistent with a power-law decay with slope alpha = -0.75\pm 0.26 (F_{\nu}\propto t^{\alpha}), and a maximum occurring in the first 200s after the initial gamma-ray emission. The softness of the prompt emission is well described by an off-axis structured jet model, which is able to account for the early peak flux and shallow decay observed in the optical and X-ray bands.Comment: 14 pages, 4 figures, accepted for publication in ApJ; typos corrected and upper limits in table 1 changed from background subtracted count rate in extraction region to the error associated with thi